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Research ArticleBone Marrow-Derived Mesenchymal Stem Cells RepairNecrotic Pancreatic Tissue and Promote Angiogenesis bySecreting Cellular Growth Factors Involved in theSDF-1120572CXCR4 Axis in Rats
Daohai Qian Jian Gong Zhigang He Jie Hua Shengping Lin Chenglei XuHongbo Meng and Zhenshun Song
Department of General Surgery Shanghai Tenth Peoplersquos Hospital Tongji University of Medicine Shanghai 200072 China
Correspondence should be addressed to Zhenshun Song zs songhotmailcom
Received 25 August 2014 Revised 29 December 2014 Accepted 8 January 2015
Academic Editor Ren-Ke Li
Copyright copy 2015 Daohai Qian et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
Acute pancreatitis (AP) a common acute abdominal disease 10ndash20 of which can evolve into severe acute pancreatitis (SAP)is of significant morbidity and mortality Bone marrow-derived mesenchymal stem cells (BMSCs) have been reported to have apotential therapeutic role on SAP but the specific mechanism is unclear Therefore we conducted this experiment to shed light onthe probable mechanism We validated that SDF-1120572 significantly stimulated the expressions of VEGF ANG-1 HGF TGF-120573 andCXCR4 in BMSCs which were inhibited by its receptor agonist AMD3100The capacities of proliferation migration and repair ofhuman umbilical vein endothelial cells were enhanced by BMSCs supernatant Meanwhile BMSCs supernatant could also promoteangiogenesis especially after the stimulation with SDF-1120572 In vivo the migration of BMSCs was regulated by SDF-1120572CXCR4 axisMoreover transplanted BMSCs could significantly alleviate SAP reduce the systematic inflammation (TNF-120572darr IL-1120573darr IL-6darr IL-4uarr IL-10uarr and TGF-120573uarr) and promote tissue repair and angiogenesis (VEGFuarr ANG-1uarr HGFuarr TGF-120573uarr and CD31uarr) comparedwith the SAP and anti-CXCR4 groups Taken together the results showed that BMSCs ameliorated SAP and the SDF-1120572CXCR4axis was involved in the repair and regeneration process
1 Introduction
Though acute pancreatitis (AP) is considered one of thecommonest acute abdominal diseases no effective treat-ment has yet been available The incidence of AP is ris-ing continually with 10ndash20 of patients progressing tosevere acute pancreatitis (SAP) [1] which is associated withsignificant morbidity and mortality AP can also transforminto chronic pancreatitis and even pancreatic cancer andthe overall mortality rate is reported to be about 15ndash20[2] However the pathogenic mechanisms of AP have stillnot been understood It is well recognized that AP beginswith pancreatic acinar injury attributed to the prematureactivation of trypsin within the pancreatic acinar cells afterwhich exudation edema and a local inflammatory responseare observed [3 4] Further pathological deterioration can
be prevented by the self-regulation of the bodies in mostpatients But some AP patients can still progress to SAPwith hemorrhage necrosis and a systematic inflammatoryresponse further leading to shock multiple organ failureand even death Consequently the treatment of SAP focusespredominantly on inhibiting the synthesis and secretion oftrypsin and averting the systemic inflammatory responseMost patients with SAP require drug treatment whereassome choose to receive surgery However no satisfactorytherapeutic effect has been discovered whichever method isadopted
Mesenchymal stem cells (MSCs) first described byFriedenstein et al in 1976 [5] are multipotent adult stemcells that can be derived from many different organs andtissues MSCs are characterized by the expression of cell-surfacemolecules including CD44 CD73 CD90 and CD105
Hindawi Publishing CorporationStem Cells InternationalVolume 2015 Article ID 306836 20 pageshttpdxdoiorg1011552015306836
2 Stem Cells International
[6] MSCs can differentiate into bone cartilage muscleadipose tissue and so forth in vitro depending on the cultureconditions [7] MSCs also have low or no immunogenicitywhichmake them ideal choices for cell transplantationManystudies have also demonstrated that MSCs have therapeuticeffects on several autoimmune ischemic and inflammatorydiseases [8] Therefore they are widely valued and studiedMSCs have been isolated initially from bone marrow andmuch of the literature uses these cells [9ndash11] though othersources of MSCs have been described [12] Recent researcheshave also shown that bone marrow-derived mesenchymalstem cells MSCs (BMSCs) are involved in the pathogenesisof AP and can relieve the severity and improve the prognosisof SAP [9ndash11]Thus we selected these cells as our therapeutictool for SAP Jung et al [9] found that BMSCs reduced the lev-els of proinflammatory cytokines and increased the numbersof Foxp3+ regulatory T cells to improve SAP repair Tu et al[10] believed that BMSCs attenuated systemic inflammationthrough relieving injury to pancreatic acinar cells and smallintestinal epithelium However the specific mechanism hasbeen a controversy so far In our previous work we havefirstly demonstrated that stromal-cell-derived factor 1120572 (SDF-1120572) and its receptor chemokine receptor 4(CXCR4) playedan important role in the process of BMSCs therapy for SAP[11]
SDF-1120572 is a chemokine that regulates the migration ofBMSCs by interacting with CXCR4 [13 14] However recentstudies have also shown that the SDF-1120572CXCR4 axis notonly regulates themigration of cells but also repairs damagedtissue and promotes angiogenesis [15 16] SDF-1120572CXCR4axis has been reported to induce neovascularization inischemic tumor and wounded tissues [17ndash19] Besides SDF-1120572 combines with vascular endothelial growth factor (VEGF)to enhance angiogenesis [20 21] Therefore we come to theconclusion that the SDF-1120572CXCR4 axis is probably involvedin the repair of acute necrotizing pancreatitis through pro-moting the formation of new vessels
To demonstrate our hypothesis we conducted this exper-iment further investigatingwhether SDF-1120572CXCR4 axis canregulate the migration of BMSCs to injured pancreas andvalidating whether it can also enhance tissue repair andregeneration to recover SAP by inducing angiogenesis in rats
In the current study we used superparamagnetic ironoxide nanoparticles (SPION) to label BMSCs in order to tracktheir distribution as previously described [22 23] SPIONhave frequently been used to trace BMSCs in vivo Recentstudies have also indicated that the proliferation migrationand differentiation capacities of SPION-labeled BMSCs arenot affected by labeling (maintaining their ldquostemnessrdquo) [2425]
2 Materials and Methods
21 Materials and Reagents Sodium taurocholate CXCR4agonist (AMD3100) dimethyl sulfoxide (DMSO) 3-(45-dimethylthiazol-2-yl)-2 S-diphenyltetrazolium bromide(MTT) 410158406-diamidino-2-phenylindole (DAPI) poly-l-lysine and Trypan Blue were purchased from Sigma-Aldrich(Brooklyn NY USA) The amylase activity assay kit was
from Biovision (Palo Alto California USA) SPION (Fe2O3
30 nm) were from Dk Nanotechnology Co Ltd (Beijing CityChina) Lipofectamine 2000 Dulbeccorsquos modified Eaglersquosmediumndashlow glucose (DMEM-LG) penicillin streptomycinfetal bovine serum (FBS) and the Histostain-Plus Kit (DABBroad Spectrum)were from Invitrogen (Carlsbad CaliforniaUSA) 025 trypsin was from Hyclone (Logan Utah USA)Transwell plates were fromCorning (NY USA) BCA proteinconcentration assay kit RIPA lysis buffer TRIzol Reagentphenylmethanesulfonyl fluoride (PMSF 100mM) and thePrussian blue staining kit were fromBeyotime BiotechnologyResearch Institute (Nantong City Jiangsu Province China)recombinant rat SDF-1120572 protein was from Peprotech (RockyHill USA) Matrigel matrix was from Becton Dickinsonand Company (New Jersey USA) Antibodies directedagainst CXCR4 were from Abcam (Cambridge MA USA)and VEGF angiopoietin-1 (ANG-1) and GAPDH and afluorescent secondary antibody were from ProteinTech(Wuhan City Hubei Province China) Enzyme-linkedimmunosorbent assay (ELISA) kits for interleukin 1120573 (IL-1120573) IL-4 IL-6 IL-10 tumor necrosis factor 120572 (TNF-120572) andtransforming growth factor 120573 (TGF-120573) were purchased fromRampD Systems (Minneapolis MN USA)
22 Animal Model Healthy Sprague Dawley rats weighing200ndash250 g (119899 = 99) were purchased from Shanghai Labo-ratory Animal Co Ltd (Shanghai China) All animals weremaintained at about 25∘C with an alternating 12 h dark12 hlight cycle with a free access to standard laboratory water andfood An animal model of SAP was established by retrogradepancreatic duct injection of Na-taurocholate as previouslydescribed [14 26] All animal procedures were conductedaccording to the Shanghai LaboratoryAnimalOrdinance andapproved by the Ethics Committee of Shanghai Tenth PeoplersquosHospital (Tongji University Shanghai China)
23 Cells and Cell Culture BMSCs were isolated culturedand identified as described in our previous study [14]A human umbilical-vein endothelial cell line (EAhy926cells) was purchased from Shanghai Cell Bank of the Chi-nese Academy of Sciences EAhy926 cells were culturedin DMEM-LG complete medium with 10 FBS 100UmLpenicillin and 100 120583gmL streptomycin at 37∘C in 5 CO
2
The cells were digested and passaged by 1 3 when theyreached gt90 confluence
24 Experimental Groups Sixteenth-six rats were randomlydivided into four groups normal control (NC) (119899 = 6) sham(119899 = 6) SAP (119899 = 18) and SAP+BMSCs (119899 = 18) SAP+anti-CXCR4 BMSCs (119899 = 18) We established three subgroupsamong the SAP SAP+BMSCs and SAP+anti-CXCR4BMSCsgroups SAP d1 (119899 = 6) d4 (119899 = 6) and d7 (119899 = 6)SAP+BMSCs d1 (119899 = 6) d4 (119899 = 6) and d7 (119899 = 6) andSAP+anti-CXCR4 BMSCs d1 (119899 = 6) d4 (119899 = 6) and d7(119899 = 6) Another thirty-three rats were randomly dividedinto three groups to assess the distributions of SPION-labeledBMSCs normal control (119899 = 3) BMSCs d1 (119899 = 3) d3(119899 = 3) d5 (119899 = 3) d7 (119899 = 3) and d10 (119899 = 3) andanti-CXCR4 BMSCs d1 (119899 = 3) d3 (119899 = 3) d5 (119899 = 3)
Stem Cells International 3
d7 (119899 = 3) and d10 (119899 = 3) BMSCs or SPION-labeled BMSCs(1 times 107 cellsmLkg) were injected into the rats throughthe tail vein for cell therapy or tracing All animals werekilled with a lethal dose of pentobarbital injected into theabdominal cavity Recombinant SDF-1120572 protein (10 ngmL or100 ngmL)was directly added to theBMSCS culturemediumin vitro Alternatively BMSCs were stimulated with SDF-1120572after culture with AMD3100 (10 120583gmL) for 1 h EAhy926cells in 25 cm2 flasks were first damaged by the additionof 100 120583L of 025 trypsin and then incubated in DMEM-LG complete medium supplemented with or without BMSCssupernatant containing DMEM-LG complete medium andBMSCs secretions To assess the migration capacity of thecells in response to BMSCs EAhy926 cells were culturedin the upper chamber of a Transwell apparatus and lowerchamber was filled with DMEM-LG complete medium withor without BMSCs supernatant
25 Sample Collection Blood samples and pancreatic tis-sues were collected from the normal control sham SAPand SAP+BMSCs SAP+anti-CXCR4 BMSCs groups Theserum was first extracted by centrifugation at 8000timesg at4∘C and then stored at minus80∘C The pancreatic tissues werestored in liquid nitrogen or fixed in 4 paraformaldehydeAfter pretreatment with SDF-1120572 for 48 h the BMSCs super-natants were collected including the normal control SDF-1120572 10 ngmL and SDF-1120572 100 ngmL groups and stored atminus80∘C Meanwhile the normal BMSCs supernatants werealso collected at 24 h after cells were given fresh DMEM-LGcomplete medium
26 Hematoxylin-Eosin (HampE) Staining and the Detectionof Serum Amylase Activity HampE staining and the detectionof serum amylase activity were performed as previouslydescribed [11]
27 ELISAs Theserum levels of IL-1120573 IL-4 IL-6 IL-10 TNF-120572 and TGF-120573 were analyzed with ELISAs Samples of serum(150 120583L) were diluted with standard diluent (1 1) and then40 120583L diluted samples were added to the test sample wellsThe test samples (10 120583L) were added to the wells (a finalfivefold dilution of the samples) without touching the wellwalls as far as possible and gentlymixedThe plate was closedwith the closure plate membrane and incubated for 30minat 37∘C Wash solution was diluted 30-fold (or 20-fold) withdistilled water and reservedThe closure plate membrane wasremoved the liquid in the wells was discarded the wells weredried by swinging the plate and washing buffer was addedto every well The plate was left to stand for 30 s and thendrained this was repeated five times and the plate dried bypatting Horseradish peroxidase- (HRP-) conjugated reagent(Agrisera Sweden) (50 120583L) was added to each well except theblank control well After the plate was closed with the plateclosure membrane it was incubated for 30min at 37∘CWashsolution was diluted 30-fold (or 20-fold) with distilled waterand reserved Chromogen solutionA (50120583L) and chromogensolution B (50 120583L) were added to each well and the platewas incubated for 10min at 37∘C in the dark Stop solution(50120583L) was added to each well to stop the reaction (the
solution changed from blue to yellow) Taking the blank wellas zero the absorbance of eachwell was read at 450 nm 15minafter the stop solution was added The concentrations of therat inflammatory cytokines in the samples were determinedby comparing the absorbance of the samples with standardcurves Each sample included three repeated measurements
28 Immunohistochemistry TheHistostain-Plus kit was usedfor the immunohistochemical analysis Paraffin-embeddedpancreatic tissues were dewaxed and rehydrated Hydrogenperoxide (3) was used to inactivate any endogenous per-oxidase for 20min at room temperature Antigen retrievalwas performed in a high-pressure cooker for 30min Thepancreatic slices were incubated overnight with rabbit anti-rat VEGF (1 50) at 4∘C in a wet box after the endogenousantigens were blocked with 5 bovine serum albumin (BSA)for 30min at room temperature On the second day theslices were incubated with biotin-labeled secondary antibody(goat anti-rabbit Epitomics China) for 30min at 37∘C andthen with HRP-conjugated streptavidin for 20min at 37∘CAfter the slices were stained with diaminobenzidine andhematoxylin they were dehydrated cleared and mountedwith neutral resin CD31 and vWF proteins were detectedwith a similar procedure
29 Immunoblotting Assay Each sample of pancreatic tissue(approximately 100 120583g) was crushed to power and 500120583Lof RIPA lysis buffer containing 5 120583L of PMSF (100 1) wasadded to extract the total proteins The concentration ofthe total proteins was determined with the BCA methodThe proteins (20 120583g) were separated with 12 SDS-PAGEand transferred to 045 120583m nitrocellulose membrane Afterthe membrane was blocked with 5 skim milk for 1 h itwas incubated overnight with anti-VEGF polyclonal antibody(1 1000) at 4∘C On the following day the membrane waswashed three times with phosphate-buffered saline (PBS)containing Tween 20 for 10min each time and then incubatedwith a secondary goat anti-rabbit antibody (1 1000) at 37∘Cfor 1 h and washed again three times The experiment wasrepeated five times Finally the signal was detected with theOdyssey 30 analysis software (LI-CORBiotechnology USA)
210 qRT-PCR Total RNA was extracted from the cells andfrozen pancreatic specimens with TRIzol Reagent First-strand cDNA was synthesized with the PrimeScript ReverseTranscriptase Reagent Kit (Takara Biotechnology Japan)with oligo(dT) and random primer The gene expressionof the BMSCs and EAhy926 cells was quantified with theKAPA Kit (Kapa Biosystems USA) and 50 ng of cDNA wasamplified in a 10120583L reaction using the Applied Biosystems7500 Real-Time PCR system based on SYBR Green dye(Applied Biosystems)The primers were purchased from Bei-jing Genomics Institute (Beijing China) Rat glyceraldehyde-phosphate dehydrogenase (GAPDH)was used as the endoge-nous control The sequences of the primers are listed inTable 1 qRT-PCR was performed with the following cyclingconditions 95∘C for 3min followed by 40 cycles of 95∘Cfor 1 s and 60∘C for 20 s Quadruplicate cycle threshold(CT) values were analyzed with the SDS software (Applied
4 Stem Cells International
Table 1 The primer sequences of genes
RatGene Forward primer Reverse primer PCR amplified products (bp)GAPDH 51015840gtACCACAGTCCATGCCATCAClt31015840 51015840gtTCCACCACCCTGTTGCTGTAlt31015840 452VEGF 51015840gtTGTGAGCCTTGTTCAGAGCGlt31015840 51015840gtGACGGTGACGATGGTGGTGTlt31015840 252CXCR4 51015840gtTGTGAGCCTTGTTCAGAGCGlt31015840 51015840gtTGTGAGCCTTGTTCAGAGCGlt31015840 260ANG-1 51015840gtCAAGGCTTGGTTACTCGTCAGlt31015840 51015840gtCCATGAGCTCCAGTTGTTGClt31015840 109HGF 51015840gtAGTCTATGGACCTGAAGGCTClt31015840 51015840gtCCATCTGCGTTGATCAATCClt31015840 171TGF-120573 51015840gtCTACTGCTTCAGCTCCACAGAGlt31015840 51015840gtCTGTACTGTGTGTCCAGGCTClt31015840 162CD31 51015840gtGAGTGCTTCTTGGTGGGTCClt31015840 51015840gtCCTGAGAAGCACTGTACACClt31015840 150
Biosystems USA) using the comparative CT method Theprocedure was replicated three times Eachmeasurement wasset three repeats
211 Immunofluorescent Staining Immunofluorescent stain-ing was used to assess CXCR4 expression in SPION-labeledBMSCs as previously described [11]
212 Labeling BMSCs BMSCs at gt90 confluence werepretreated with or without AMD3100 (10120583gmL) and thenincubated with labeling medium containing 25120583gmL Fe3+and 075 ngmL poly-l-lysine for 24 h After theywere labeledthe cells were washed three times with PBS and harvestedwith 025 trypsin-EDTA The viability of the cells wasassessed with Trypan Blue exclusion before cell transplanta-tion The functions of the different concentrations of Fe3+-labeled BMSCs were analyzed in the following experiments
213 Cell Migration Assay In this experiment 5 times 104EAhy926 cells were added to the upper chamber of the Tran-swell apparatus and supplemented with 180120583L of DMEMand 20 120583L of 1 BSA and the lower chamber was filled with500120583L of DMEM-LG complete medium with or withoutBMSCS supernatant (100 120583L) After incubation for 12 h theupper chamber was removed and the cells were fixed with 4paraformaldehyde for 30min The lower surface of the filtermembrane was stained with 01 crystal violet for 10minin the dark After the membrane was thoroughly washed itwas observed with a digital camera and light microscopeThe experiment was repeated three times Finally the crystalviolet was dissolved in 300 120583L of 33 acetic acid and theabsorbance of the solution was measured at 573 nm with anELISA plate reader (Gene Company Limited HK China)
214 Cell Proliferation Assay (MTT Test) To investigatewhether BMSCs could repair the injured vascular endothelialcells we designed this experiment First EAhy926 cellswere cultured in 25 cm2 culture flasks and then incubatedwith 100 120583L of 025 trypsin-EDTA for 60min at a con-stant temperature of 37∘C in a humidified atmosphere of95 O
2supplemented with 5 CO
2until their confluence
reached approximately 90 Finally the cells were collectedand seeded into 96-well plates at 2000 cellswell Each wellcontained DMEM-LG complete medium with or without
BMSCs supernatant (DMEM-LG complete medium BMSCssupernatant = 1 1) MTT solution (20120583L of 5mgmL) wasadded daily for seven days (12 h 36 h 68 h 92 h 121 h and145 h) The medium was then removed and 150120583L of DMSOwas added to each well The plates were then shaken slowlyfor 10min Absorbance was measured with an ELISA platereader at 490 nm This experiment was repeated three timesSPION-labeled BMSCs were also assayed withMTT test aftertreatment with different concentrations of Fe3+ (25 120583gmL50 120583gmL 75120583gmL or 100 120583gmL)
215 ANG-1 and VEGF Silencing with Small Interfering RNAsGene silencing technology was used to understand the effectsof the BMSCs supernatant on the angiogenic activity ofEAhy926 cells in vitro Small interfering RNA (siRNA) tar-geting rat ANG-1 (51015840-GGCCCAGAUACAACAGAAUUU-dTdT-31015840) and (51015840-AUUCUGUUGUAUCUGGGCCUUdTd-T-31015840) or VEGF (51015840-GGGATTGCACGGAAACUUUdTdT-31015840) and (51015840-AAAGUUUCCGUGCAAUCCCdTdT-31015840) andcontrol nonsilencing siRNAs (51015840-AUGUGAAUGCACCAA-AGAAdTdT-31015840) and (51015840-UUCUUUGGUCUGCAUUCA-CAUdTdT-31015840) were synthesized by Biomics BiotechnologiesCo Ltd (Nantong City Jiangsu Province China) BMSCswere transfected with the siRNAs using Lipofectamine 2000according to the manufacturerrsquos protocol (Biotend ShanghaiChina) The BMSCs supernatant was collected 48 h aftertransfection and stored at minus80∘C for the tube formation assay
216 Angiogenesis A tube formation assay was performedto investigate the effect of the BMSCs supernatant on theangiogenic activity of EAhy926 cells in vitro Ninety-six-wellculture dishes were coated with 50 120583L of matrigel matrix andincubated for 30min at 37∘C EAhy926 cells were starvedfor 24 h and were then seeded onto the solidified gels ata density of 105 cellswell in 50120583L of culture medium TheBMSCs supernatant (50 120583L) or 1 timesPBS (50 120583L) was added toeach well These cells were divided into the normal controlSDF-1120572 10 ngmL SDF-1120572 100 ngmL ANG-1 siRNA andVEGF siRNA groups After incubation for 6 h the totaltube-like structures were photographed with phase-contrastmicroscopy (100x) and five randomly selected microscopicfields per photograph were quantified using the Image Jsoftware To further detect the angiogenesis in vivo theexpressions of vascular endothelialmarkers (VEGF vWF and
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CD31) were measured by immunohistochemistry or westernblotting in SAP SAP+BMSCs and SAP+anti-CXCR4 BMSCsgroups
217 Magnetic Resonance Imaging (MRI) and Prussian BlueStaining To track the distributions of SPION-labeledBMSCsin vivo MRI and Prussian blue staining were used to detectFe3+The animalswere anesthetized and then put into anMRIcoil (Shanghai Niumag Electronic Science and TechnologyCo Ltd China) The T1-weighted imaging (T1WI) param-eters were as follows FOV read = 100mm FOV phase =100mm TR = 500ms TE = 20ms slice width = 35mm slicegap = 05mm and NS = 12 and the T2-weighted imaging(T2WI) parameters were as follows FOV read = 100mmFOV phase = 100mm TR = 2000ms TE = 80ms slice width= 35mm slice gap = 05mm andNS = 8 Finally the animalswere killed and pancreas lung liver spleen and smallintestine were collected and fixed in 4 paraformaldehydefor Prussian blue staining A Prussian blue staining kit wasused to detect Fe3+ in the SPION-labeled BMSCs and abovetissues according to the manufacturerrsquos instructions Thecells were fixed in 4 glutaraldehyde washed and incubatedfor 30min with 2 potassium ferric-ferrocyanide (Perlrsquosreagent) in 37 hydrochloric acid The cells were washedagain counterstained with Nuclear Fast Red and the ironstaining was evaluated with light microscopy (Carl ZeissOberkochen Germany) with a times40075 objective lens andAxiovision 44 software (Carl Zeiss) The SPION labelingefficiency was determined bymanually counting the Prussianblue stained and unstained cells under a Zeiss microscope(Carl Zeiss) at times100 magnification with a times100130 oil-immersion objective lens The percentage of labeled cells wasdetermined as the average of five high-powered fields Afterthe slices were fixed dehydrated embedded and sectionedthe tissues were stained with Prussian blue as describedabove The blue granules were counted by a person who didnot know the experiment from ten areas of each histologicsection
218 Image Processing and Statistical Analysis Adobe Photo-shop 60 (Adobe Systems Inc San Jose CA) Image-Pro Plusversion 60 (Media Cybernetics USA) and Image J (NationalInstitutes of Health USA) were used for image typesettinganalysis and processing GraphPad Prism 50 (GraphPadCo USA) was used for mapping The SPSS 170 statisticalsoftware (Chicago IL) was used for all statistical analysesExperimental data are shown as means plusmn standard deviations(SD) and compared with Studentrsquos or a paired 119905 test or one-way ANOVA A value of 119875 lt 005 was deemed to indicatesignificant differences
3 Results
31 Recombinant SDF-1120572 Protein Stimulated BMSCs Expres-sions of VEGFANG-1HGF TGF-120573 andCXCR4 Theexpres-sions of VEGF ANG-1 HGF TGF-120573 and CXCR4 weredetected with qRT-PCR or immunoblotting assays at 24 hand 48 h after recombinant SDF-1120572 protein was added tothe BMSCs culturemediumThe recombined SDF-1120572 protein
significantly stimulated the expressions of VEGF ANG-1 andCXCR4 in the BMSCs which was also positively correlatedwith the concentration of SDF-1120572 This effect was blockedby the CXCR4 agonist AMD3100 (Figures 1(a)-1(b) and1(d)ndash1(g)) The mRNA levels of HGF and TGF-120573 were bothupregulated after stimulation with SDF-1120572 but were inhibitedby AMD3100 (Figure 1(c))
32 BMSCs Supernatant Promotes the Proliferation Migra-tion and Repair of EAhy926 Cells The BMSCs supernatantpromoted the growth andmigration of EAhy926 cells signifi-cantlymore thanDMEM-LG completemedium (Figures 2(a)and 2(b))Moreover EAhy926 cells impaired by trypsinweremore effectively repaired by the BMSCs supernatant than byDMEM-LG complete medium (Figure 2(c))
33 SDF-1120572CXCR4 Axis Induces Angiogenesis In Vitro BeingRelated to the Expressions of VEGF and ANG-1 The BMSCssupernatant pretreated with SDF-1120572 significantly promotedangiogenesis compared with the normal BMSCs supernatantin vitro which was also positively related to the concentrationof SDF-1120572 Furthermore the angiogenesis was reduced inbothVEGF siRNA andANG-1 siRNA comparedwith normalBMSCs supernatant (Figure 1(h))
34 No Significant Differences on Biological Functions betweenBMSCs and SPION-Labeled BMSCs ([Fe3+] = 25 120583gmL)More than 95 of BMSCs were successfully labeled withSPION ([Fe3+] = 25 120583gmL) (Figure 3(a))The growth activityof SPION-labeled BMSCs ([Fe3+] = 25120583gmL) was similarto unlabeled BMSCs which was significantly stronger thanthat of other SPION-labeled BMSCs ([Fe3+] = 50 75 or100 120583gmL) (Figure 3(b)) CXCR4 expression was observedwith confocalmicroscopy and similar in both the BMSCs andSPION-labeled BMSCs (Figures 3(c)ndash3(e))
35 SDF-1120572CXCR4 Axis Regulates the Migration of SPION-Labeled BMSCs to Necrotic Pancreatic Tissues and the Migra-tion Increased Gradually Peaking on Days 5ndash7 The resultsof Prussian blue staining showed that the SPION-labeledBMSCs were relatively low in pancreas liver spleen andsmall intestine at the first day of the transplant comparedto lung but gradually increasing in pancreatic tissue atposttransplant days 3 and 7 and relatively high comparedto liver spleen and small intestine when the formation oftubular complexes (TCs) was also maximal (Figures 4(a)ndash4(c)) On the contrary SPION-labeled BMSCs in the lungtissue became less and less (Figure 5(b))Themore importantpoint was that the migrations of SPION-labeled BMSCs toinjured pancreas could be inhibited by anti-CXCR4 treatment(Figures 4(a)ndash4(c)) To further visually investigate whetherthe SPION-labeledBMSCs couldmigrate to injured pancreasthe MRI method was selected for realizing the tracing invivo The magnetic resonance images displayed that SPION-labeled BMSCs ([Fe3+] = 25 gmL) were high signal in T1WI(white) and low signal (dark) in T2WI as shown in Fig-ure 5(a) The high signal intensity (white points) in pancreas(as indicated by red circle) increased gradually in T1WI andpeaked on days 5 and 7 (Figure 5(b)) We also performedT2WI on day 7 in order to exclude the possibility of false
6 Stem Cells International
Relat
ive m
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expr
essio
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CXCR4
NC
SDF-1
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ngm
L)
SDF-1
(100
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1
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(10120583
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Relat
ive m
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(10120583
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Relat
ive m
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essio
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lowast
lowast
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daggerdaggerdagger
NC
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(10
ngm
L)
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(100
ngm
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TGF-120573HGF
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Figure 1 Continued
Stem Cells International 7
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D3100
(10120583
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(g)
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-1siR
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ions
Tube formation assay
lowast
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(100
ngm
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VEGF-A siRNANormal
SDF-1 (10ngmL) Ang-1 siRNA
PBS SDF-1 (100ngmL)
(h)
Figure 1 The SDF-1120572CXCR4 axis could promote the expressions of cellular growth factors in BMSCs and induce angiogenesis in vitro((a) (d) and (e))The CXCR4 expression of BMSCs was significantly unregulated after being stimulated by combined SDF-1120572 protein whichcould be inhibited by the CXCR4 receptor agonist AMD3100 ((b)ndash(d) (f)-(g)) Recombined SDF-1120572 protein could significantly promoteBMSCS expression of VEGF ANG-1 HGF and TGF-120573 and the effect could also blocked by AMD3100 Moreover there was a dose-effectrelationship between combined SDF-1120572 protein and CXCR4 VEGF ANG-1 HGF and TGF-120573 expressions Data are expressed as mean plusmn SD(lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SDF-1120572 (10 ngmL or 100 ngmL) versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSDF-1120572 (10 ngmL or 100 ngmL) versus SDF-1120572 (10 ngmL or 100 ngmL) + AMD3100 10 120583gmL) (h) BMSCs supernatant could significantlypromoted angiogenesis especially after being pretreated with SDF-1120572 and this increase was partly offset by AMD3100 Both VEGF siRNAand Ang-1 siRNA significantly weakened proangiogenic capacity of BMSCs Data are expressed as mean plusmn SD (119875 lt 001 for NC versusPBS lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SDF-1120572 (10 ngmL or 100 ngmL) Ang-1 siRNA or VEGF siRNA versus NC) (NC normalcontrol SDF-1120572 stromal cell derived factor-1a CXCR4 CXC chemokine receptor 4 VEGF vascular endothelial growth factor and ANG-1angiopoietin-1)
positive and the result showed that the high signals (whitepoints) in T1WI became low signals (dark points) in T2WIwhereas the low signals (dark points) in T1WI became highsignals (white points) as shown in Figure 5(c) Furthermorethe high signals in T1WI decreased obviously in anti-CXCR4group compared with BMSCs group on posttransplant day 5(Figure 5(b))
36 Transplanted BMSCs Reduced Pancreatic Edema Hem-orrhage and Necrosis Inhibited Systematic Inflammationand Promoted the Formation of TCs Involved in the SDF-1120572CXCR4 Axis Pancreatic edema hemorrhage and necro-sis were markedly reduced and the levels of serum amylasewere significantly lower in the SAP+BMSCs group than in theSAP and SAP+anti-CXCR4 BMSCs groups (Figures 6(a) and
8 Stem Cells International
DMEM-LG
DMEM-LG
DMEM-LG + BMSCs supernatant
DMEM-LG + BMSCs supernatant
DMEM-LG000
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ues (
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BMSCs supernatant + 025 trypsinDMEM-LG + 025 trypsin
(c)
Figure 2 The BMSCs supernatant could promote the proliferation migration and repair of human umbilical-vein endothelial cell line(EAhy926 cells) (a)Themethylene blue staining (magnification times200) is indicating that the BMSCs supernatant could significantly promotethe migration of EAhy926 cells Data are expressed as mean plusmn SD (lowast119875 lt 005 for DMEM-LG versus DMEM-LG + BMSCs supernatant) (b)The significant increase of the growth of EAhy926 cells was investigated in MTT test after being given BMSCs supernatant (c) ImpairedEAhy926 cells could be repaired by BMSCs supernatant Data are expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005and lowastlowast119875 lt 001 for DMEM-LG versus DMEM-LG + BMSCs supernatant at each corresponding time point) Data analysis was performedby a one-way ANOVA (BMSCs bone marrow-derived mesenchymal stem cells MTT 3-(45-dimethylthiazol-2-yl)-2S-diphenyltetrazoliumbromide)
6(b)) Inflammatory cytokines were detected with ELISAsThe results show that the levels of serum proinflamma-tory cytokines (IL-1120573 IL-6 and TNF-120572) were significantlydownregulated in the SAP+BMSCs group compared with theSAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines (IL-4 IL-10 andTGF-120573) were significantly upregulated in the SAP+BMSCsgroup comparedwith the SAP and SAP+anti-CXCR4BMSCsgroups (Figure 6(c)) We also found that a large number ofTCs appeared in the BMSCs group (as indicated by red arrowand a magnified picture in Figure 6(a))
37 SDF-1120572CXCR4 Axis Enhances the Expressions of VEGFandANG-1 inDamaged Pancreatic Tissues VEGF expressionin injured pancreatic tissues was measured with qRT-PCRand immunoblotting VEGF expression was higher in theSAP+BMSCS group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups on postoperative days 1and 4 but had decreased on postoperative day 7 (Figures 7(b)7(c) and 7(e)) The expression of ANG-1 was detected withqRT-PCR and immunoblotting and its expression was higherin the SAP+BMSCS group than in the normal control SAPand SAP+anti-CXCR4 BMSCs groups (Figures 7(a) 7(c)
Stem Cells International 9
(a)
Control
Days
$$
$$$
ampampamp
$$ $ampampamp
ampamp
amp
dagger
$$ $ampampamp
daggerdagger dagger$$ $
ampampamp
daggerdagger dagger
15
10
05
000 1 2 3 4 5 6 7 8
Fe = 75120583gmLFe = 25120583gmL Fe = 100120583gmLFe = 50120583gmL
OD
val
ues (
OD490
nm)
(b)
SPIO
N-la
bele
d BM
SCs
Unl
abel
ed B
MSC
s
(c)
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BMSCs
36
43
(kD)CXCR4
GAPDH
(d)
BMSCs
BMSCsSPION-labeled BMSCs
SPION-labeledBMSCs
15
10
05
00
Relat
ive m
RNA
expr
essio
ns
P gt 005
(e)
Figure 3There is similarity in the proliferation andCXCR4 expression between unlabeled and SPION-labeled BMSCs ([Fe3+] = 25 gmL) (a)The Prussian blue staining shows that BMSCs were labeled by SPION successfully (b) TheMTT tests are showing that the growth activity ofSPION-labeled BMSCs ([Fe3+] = 25 gmL) slowed slightly compared with that of the unlabeled BMSCs which was also significantly strongerthan that of other SPION-labeled BMSCs ([Fe3+] = 50 75 or 100 gmL) Data are expressed as mean plusmn SD (ampamp119875 lt 001 and ampampamp
119875 lt 0001
for normal control versus SPION-labeled BMSCS ([Fe3+] = 100 gmL) $$119875 lt 001 and $$$119875 lt 0001 for normal control versus SPION-labeled
BMSCS ([Fe3+] = 75 gmL) and dagger119875 lt 005 and daggerdaggerdagger119875 lt 0001 for normal control versus SPION-labeled BMSCS ([Fe3+] = 50 gmL) at eachcorresponding time point) ((c)-(d)) CXCR4 expression was detected by immunofluorescence and western blotting and similar betweenunlabeled and SPION-labeled BMSCs (119875 gt 005) (SPION superparamagnetic iron oxide nanoparticles BMSCs bone marrow-derivedmesenchymal stem cells)
10 Stem Cells International
Ant
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SCs
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Figure 4 Continued
Stem Cells International 11
100
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The n
umbe
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10d
BMSCsAnti-CXCR4 BMSCs
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
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(c)
Figure 4 Prussian blue staining was performed for detecting the SPION-labeled BMSCs in pancreatic and lung tissues (a) The Prussianblue staining of pancreatic tissue indicates that the cells were stained blue (as indicated by black arrows) gradually increased and peaked onpostoperative days 5ndash7 when the formation of tubular complexes was also maximal (as indicated by red arrows) However the migration waspartly inhibited and the trend was not obviously investigated in anti-CXCR4 group (b) The lung tissues were stained by Prussian blue andthe blue particles (as indicated by black arrows) were gradually decreasing in both BMSCs and anti-CXCR4 groups (c) The blue particles inlung pancreas liver spleen and small intestine were counted and analyzed between BMSCs and anti-CXCR4 groupsThe result showed thatthe number of blue particles of pancreas in BMSCs group was significantly more than in anti-CXCR4 group at postoperative days 1 3 5 and7 Data are expressed as mean plusmn SD (lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for BMSCs versus anti-CXCR4 at each corresponding time point)
and 7(d)) The mRNA levels of HGF and TGF-120573 were alsodetected with qRT-PCR and were significantly higher in theSAP+BMSCs group than in the normal SAP and SAP+anti-CXCR4 BMSCs groups (Figures 7(f) and 7(g))
38 SDF-1120572CXCR4 Axis Induces the Neovascularization InVivo To assess the neovascularization we conducted qRT-PCR or immunohistochemistry for detecting these angiogen-esis markers (CD31 VEGF and vWF) The results indicatedthat the expressions of CD31 VEGF and vWF in necroticpancreatic tissue were higher in the SAP+BMSCs group thanin the normal control SAP and SAP+anti-CXCR4 BMSCsgroups especially in early phase (Figures 7(h) and 8(a)ndash8(d))
4 Discussion
Several studies have shown that MSCs from the bone orumbilical cord can attenuate acute necrotic pancreatitis byinhibiting systematic inflammation regulating the immuneresponses reducing the apoptosis of pancreatic acinar cellsand repairing damaged the small intestinal epithelium [9ndash12]However these functions do not account for how to repairand regenerate the necrotic pancreatic tissues In the studywe found that BMSCs can reduce severe acute pancreatitisby alleviating the systematic inflammation promoting theformation of tubular complexes (TCs) and inducing angio-genesis involving the SDF-1120572CXCR4 axis by enhancing the
expression of cell growth factors in a rat model of SAP Largeprevious studies have found that MSCs can not only differ-entiate into different kinds of functional adult cells but alsosecrete various soluble factors including VEGF HGF andTGF-120573 [27] These factors which promote angiogenesis andmitosis and reduce apoptosis can explain tissue repair andregeneration after MSCs transplanted [28 29] Moreover theregeneration of the pancreas begins with the TCs that consistof a cluster of epithelia surrounded by the mesenchymalcells [30 31] Thus we inferred that SDF-1120572CXCR4 axis wasinvolved in the repair and regeneration of SAP
SDF-1120572 and its receptor CXCR4 have been studiedextensively together with their roles in migration homingproliferation angiogenesis and so forth [11 13ndash15 18 3233] Many researches have shown that BMSCs can migrateto injured tissues via the SDF-1120572CXCR4 axis and relievemyocardial infraction [13 14] promote wound healing [19]heal bone fracture [34] reduce cerebral ischemia [35] andameliorate acute necrotizing pancreatitis [11] SDF-1120572 expres-sion is upregulated by hypoxia-inducible factor-1 (HIF-1)[36] In the study we successfully established a rat model ofacute necrotizing pancreatitis with the retrograde injectionof Na-taurocholate which causes acinar cell injurynecrosisby triggering transient pathological intra-acinar-cell cal-cium ions and activating digestive zymogens [37ndash39] Theinjurednecrotic pancreatic tissue causes HIF-1 expressionand thus induces SDF-1120572 expression which attracts BMSCsto injured pancreas through the interaction with CXCR4
12 Stem Cells International
T1WI
SPIO
N-la
bele
d BM
SCs
T2WI
5 10 15 20 25 30[Fe] (120583gmL)
(a)
Normal (T1WI)
BMSCs BMSCs BMSCs
Anti-CXCR4 BMSCsBMSCsBMSCs
BMSCs
5d (T1WI)7d (T1WI)
1d (T1WI) 3d (T1WI) 5d (T1WI)
10d (T1WI)
(b)
BMSCs
7d (T1WI)
BMSCs
7d (T2WI)
(c)
Figure 5 The transplanted SPION-labeled BMSCs were tracked by MRI in vivo (a) [Fe3+] was detected by MRI and the result showed thatthe SPION-labeled BMSCs ([Fe3+] = 25 gmL) appeared high signals (white spots) on T1WI and low signals (dark spots) on T2WI (b) TheSPION-BMSCs ([Fe3+] = 25 gmL) was tracked by MRI in vivo and the photos show that the white spots (inside of red circle) were increasinggradually and peaked on postoperative days 5ndash7 Instead the white spots decreased on postoperative day 5 in anti-CXCR4 group comparedwith BMSCs group (c) The SPION-BMSCs ([Fe3+] = 25 gmL) were detected in SAP rats at postoperative day 7 by T1WI and T2WI andthe result was showing that the high signals (white spots) which appeared in T1WI became low signals (dark spots) in T2WI (SPIONsuperparamagnetic iron oxide nanoparticles T1WI T1-weighted imaging and T2WI T2-weighted imaging)
For further investigating whether BMSCs could migrateto injured pancreas and the migration was regulated by SDF-1120572CXCR4 axis in a SAP rat model SPION was used tolabel BMSCs SPION were initially used as a unique MRcontrast agent in the clinical context Recently their two useshave been discoveredmdashthe labeling of live cells and tissuesdisease diagnosis and therapy [22 23 40ndash42] Studies havedemonstrated that SPION-labeling does not deleteriouslyaffect the functions of the target cells [25] In our study wealso demonstrated that there was no difference in the pro-liferation capacities between SPION-labeled (Fe = 25 120583gmLlabeling efficiency gt 95) and unlabeled BMSCs Moreover
the expression of CXCR4was also similar between the labeledand unlabeled cells SPION-labeled BMSCs could be detectedby both MRI and Prussian blue staining because SPIONis the nanometer particles of ferric oxide The dynamicmovement of labeling cells could be observed at the photosof MRI so that we can intuitively assess the proportions ofSPION-labeled BMSCs in vivo The result showed that thesecells could migrate to the damaged pancreatic tissues andthere was also a gradual increase in migration peaking onpostoperative days 5ndash7 with the formation of large numbersof TCs SDF-1120572CXCR4 axis could regulate the migrationof BMSCs as our previously described [11] Meanwhile the
Stem Cells International 13
SAP
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P+
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CXCR
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1d 4d 7d
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Scor
e $
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SAP + BMSCsSAP + anti-CXCR4
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Normal
0
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e
$
lowastdagger
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BMSCsShamSAP
Normal
SAP + BMSCs
BMSCsShamSAP
Normal
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1000
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$$$
$$$
1d 4d 7d
1d 4d 7d 1d 4d 7d
1d 4d 7dInfiltration
Necrosis
Am
ylas
e act
ivity
(b)
Figure 6 Continued
14 Stem Cells International
130
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80The c
once
ntra
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of se
rum
IL-1
(pg
mL)
daggerdaggerlowast
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Control Day 1 Day 4 Day 7
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
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SAP
Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham
$
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The c
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rum
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The c
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260
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220
200
180
160
140
120The c
once
ntra
tion
of se
rum
TG
F-120573
(pg
mL)
(c)
Figure 6 Transplanted BMSCs could reduce severe acute pancreatitis (SAP) promoting the formation of tubular complexes and inhibitingsystematic inflammatory response being involved in the SDF-1120572CXCR4 axis ((a) (b))TheHampE staining of pancreatic tissues (magnificationtimes100) is showing that the edema infiltration and necrosis were significantly reduced in the SAP+BMSCs group compared with SAP andSAP+anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively A large number of tubular complexes were also investigatedin SAP+BMSCs group (as indicated by red arrow in a 400x magnified picture) Serum amylase activity was also significantly reduced inSAP+BMSCs group than in normal SAP and anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively (c) The levels ofserum proinflammatory cytokines are significantly lower in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines are significantly higher in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups Dataare expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SAP versus Normal dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP versus SAP+BMSCs $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4BMSCs) Data analysis was performed by Studentrsquos test (BMSCs bone marrow-derived mesenchymal stem cells HampE hematoxylin-eosin)
number of cells whichmigrated to the necrotic pancreas waspositively related to the therapeutic effect However SPION-labeled BMSCs could be rarely seen on postoperative day 10perhaps because the SPIONwere degraded or the BMSCs haddifferentiated into other cells including pancreatic exocrinecells
To validate whether the SDF-1120572CXCR4 axis also playsan important role in the repair and regeneration of SAPwe conducted the study in vitro and vivo We found thatthe secretions of BMSCs could promote the proliferationmigration and restoration of EAhy926 cells The BMSCssupernatant induced angiogenesis and the SDF-1120572CXCR4axis stimulated BMSCs to express VEGF ANG-1 HGFand TGF-120573 promoting further angiogenesis in vitro Both
VEGF and ANG-1 play important roles in angiogenesisMoreover the expressions of VEGFANG-1HGF andTGF-120573in the damaged pancreatic tissues were higher in the BMSCstransplantation group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups Taken all together theresult showed that transplantedBMSCs repaired the damagedpancreas through secreting large cellular growth factors andthe effect was regulated by SDF-1120572CXCR4 axis
As we all know VEGF a potent inducer of angiogenesispromotes the repair of injured vascular endothelial cellsand neovascularization Studies have shown that the SDF-1120572CXCR4 axis promotes the synthesis and secretion ofVEGF [17 43] and SDF-1120572 combined with VEGF enhancesischemic angiogenesis [20] In our study we confirmed that
Stem Cells International 15
15
10
5
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SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
expr
essio
nslowastlowastlowastdagger
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$
1d 4d 7dVEGF
(a)
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atio
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Relat
ive r
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Relat
ive m
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NCShamSAP
(f)
Figure 7 Continued
16 Stem Cells International
dagger
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Relat
ive m
RNA
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essio
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GA
PDH
HGF
lowastlowast
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(g)
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Relat
ive m
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daggerlowast
lowast
lowast
daggerlowastlowast
dagger daggerlowast
lowast
lowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
2 Stem Cells International
[6] MSCs can differentiate into bone cartilage muscleadipose tissue and so forth in vitro depending on the cultureconditions [7] MSCs also have low or no immunogenicitywhichmake them ideal choices for cell transplantationManystudies have also demonstrated that MSCs have therapeuticeffects on several autoimmune ischemic and inflammatorydiseases [8] Therefore they are widely valued and studiedMSCs have been isolated initially from bone marrow andmuch of the literature uses these cells [9ndash11] though othersources of MSCs have been described [12] Recent researcheshave also shown that bone marrow-derived mesenchymalstem cells MSCs (BMSCs) are involved in the pathogenesisof AP and can relieve the severity and improve the prognosisof SAP [9ndash11]Thus we selected these cells as our therapeutictool for SAP Jung et al [9] found that BMSCs reduced the lev-els of proinflammatory cytokines and increased the numbersof Foxp3+ regulatory T cells to improve SAP repair Tu et al[10] believed that BMSCs attenuated systemic inflammationthrough relieving injury to pancreatic acinar cells and smallintestinal epithelium However the specific mechanism hasbeen a controversy so far In our previous work we havefirstly demonstrated that stromal-cell-derived factor 1120572 (SDF-1120572) and its receptor chemokine receptor 4(CXCR4) playedan important role in the process of BMSCs therapy for SAP[11]
SDF-1120572 is a chemokine that regulates the migration ofBMSCs by interacting with CXCR4 [13 14] However recentstudies have also shown that the SDF-1120572CXCR4 axis notonly regulates themigration of cells but also repairs damagedtissue and promotes angiogenesis [15 16] SDF-1120572CXCR4axis has been reported to induce neovascularization inischemic tumor and wounded tissues [17ndash19] Besides SDF-1120572 combines with vascular endothelial growth factor (VEGF)to enhance angiogenesis [20 21] Therefore we come to theconclusion that the SDF-1120572CXCR4 axis is probably involvedin the repair of acute necrotizing pancreatitis through pro-moting the formation of new vessels
To demonstrate our hypothesis we conducted this exper-iment further investigatingwhether SDF-1120572CXCR4 axis canregulate the migration of BMSCs to injured pancreas andvalidating whether it can also enhance tissue repair andregeneration to recover SAP by inducing angiogenesis in rats
In the current study we used superparamagnetic ironoxide nanoparticles (SPION) to label BMSCs in order to tracktheir distribution as previously described [22 23] SPIONhave frequently been used to trace BMSCs in vivo Recentstudies have also indicated that the proliferation migrationand differentiation capacities of SPION-labeled BMSCs arenot affected by labeling (maintaining their ldquostemnessrdquo) [2425]
2 Materials and Methods
21 Materials and Reagents Sodium taurocholate CXCR4agonist (AMD3100) dimethyl sulfoxide (DMSO) 3-(45-dimethylthiazol-2-yl)-2 S-diphenyltetrazolium bromide(MTT) 410158406-diamidino-2-phenylindole (DAPI) poly-l-lysine and Trypan Blue were purchased from Sigma-Aldrich(Brooklyn NY USA) The amylase activity assay kit was
from Biovision (Palo Alto California USA) SPION (Fe2O3
30 nm) were from Dk Nanotechnology Co Ltd (Beijing CityChina) Lipofectamine 2000 Dulbeccorsquos modified Eaglersquosmediumndashlow glucose (DMEM-LG) penicillin streptomycinfetal bovine serum (FBS) and the Histostain-Plus Kit (DABBroad Spectrum)were from Invitrogen (Carlsbad CaliforniaUSA) 025 trypsin was from Hyclone (Logan Utah USA)Transwell plates were fromCorning (NY USA) BCA proteinconcentration assay kit RIPA lysis buffer TRIzol Reagentphenylmethanesulfonyl fluoride (PMSF 100mM) and thePrussian blue staining kit were fromBeyotime BiotechnologyResearch Institute (Nantong City Jiangsu Province China)recombinant rat SDF-1120572 protein was from Peprotech (RockyHill USA) Matrigel matrix was from Becton Dickinsonand Company (New Jersey USA) Antibodies directedagainst CXCR4 were from Abcam (Cambridge MA USA)and VEGF angiopoietin-1 (ANG-1) and GAPDH and afluorescent secondary antibody were from ProteinTech(Wuhan City Hubei Province China) Enzyme-linkedimmunosorbent assay (ELISA) kits for interleukin 1120573 (IL-1120573) IL-4 IL-6 IL-10 tumor necrosis factor 120572 (TNF-120572) andtransforming growth factor 120573 (TGF-120573) were purchased fromRampD Systems (Minneapolis MN USA)
22 Animal Model Healthy Sprague Dawley rats weighing200ndash250 g (119899 = 99) were purchased from Shanghai Labo-ratory Animal Co Ltd (Shanghai China) All animals weremaintained at about 25∘C with an alternating 12 h dark12 hlight cycle with a free access to standard laboratory water andfood An animal model of SAP was established by retrogradepancreatic duct injection of Na-taurocholate as previouslydescribed [14 26] All animal procedures were conductedaccording to the Shanghai LaboratoryAnimalOrdinance andapproved by the Ethics Committee of Shanghai Tenth PeoplersquosHospital (Tongji University Shanghai China)
23 Cells and Cell Culture BMSCs were isolated culturedand identified as described in our previous study [14]A human umbilical-vein endothelial cell line (EAhy926cells) was purchased from Shanghai Cell Bank of the Chi-nese Academy of Sciences EAhy926 cells were culturedin DMEM-LG complete medium with 10 FBS 100UmLpenicillin and 100 120583gmL streptomycin at 37∘C in 5 CO
2
The cells were digested and passaged by 1 3 when theyreached gt90 confluence
24 Experimental Groups Sixteenth-six rats were randomlydivided into four groups normal control (NC) (119899 = 6) sham(119899 = 6) SAP (119899 = 18) and SAP+BMSCs (119899 = 18) SAP+anti-CXCR4 BMSCs (119899 = 18) We established three subgroupsamong the SAP SAP+BMSCs and SAP+anti-CXCR4BMSCsgroups SAP d1 (119899 = 6) d4 (119899 = 6) and d7 (119899 = 6)SAP+BMSCs d1 (119899 = 6) d4 (119899 = 6) and d7 (119899 = 6) andSAP+anti-CXCR4 BMSCs d1 (119899 = 6) d4 (119899 = 6) and d7(119899 = 6) Another thirty-three rats were randomly dividedinto three groups to assess the distributions of SPION-labeledBMSCs normal control (119899 = 3) BMSCs d1 (119899 = 3) d3(119899 = 3) d5 (119899 = 3) d7 (119899 = 3) and d10 (119899 = 3) andanti-CXCR4 BMSCs d1 (119899 = 3) d3 (119899 = 3) d5 (119899 = 3)
Stem Cells International 3
d7 (119899 = 3) and d10 (119899 = 3) BMSCs or SPION-labeled BMSCs(1 times 107 cellsmLkg) were injected into the rats throughthe tail vein for cell therapy or tracing All animals werekilled with a lethal dose of pentobarbital injected into theabdominal cavity Recombinant SDF-1120572 protein (10 ngmL or100 ngmL)was directly added to theBMSCS culturemediumin vitro Alternatively BMSCs were stimulated with SDF-1120572after culture with AMD3100 (10 120583gmL) for 1 h EAhy926cells in 25 cm2 flasks were first damaged by the additionof 100 120583L of 025 trypsin and then incubated in DMEM-LG complete medium supplemented with or without BMSCssupernatant containing DMEM-LG complete medium andBMSCs secretions To assess the migration capacity of thecells in response to BMSCs EAhy926 cells were culturedin the upper chamber of a Transwell apparatus and lowerchamber was filled with DMEM-LG complete medium withor without BMSCs supernatant
25 Sample Collection Blood samples and pancreatic tis-sues were collected from the normal control sham SAPand SAP+BMSCs SAP+anti-CXCR4 BMSCs groups Theserum was first extracted by centrifugation at 8000timesg at4∘C and then stored at minus80∘C The pancreatic tissues werestored in liquid nitrogen or fixed in 4 paraformaldehydeAfter pretreatment with SDF-1120572 for 48 h the BMSCs super-natants were collected including the normal control SDF-1120572 10 ngmL and SDF-1120572 100 ngmL groups and stored atminus80∘C Meanwhile the normal BMSCs supernatants werealso collected at 24 h after cells were given fresh DMEM-LGcomplete medium
26 Hematoxylin-Eosin (HampE) Staining and the Detectionof Serum Amylase Activity HampE staining and the detectionof serum amylase activity were performed as previouslydescribed [11]
27 ELISAs Theserum levels of IL-1120573 IL-4 IL-6 IL-10 TNF-120572 and TGF-120573 were analyzed with ELISAs Samples of serum(150 120583L) were diluted with standard diluent (1 1) and then40 120583L diluted samples were added to the test sample wellsThe test samples (10 120583L) were added to the wells (a finalfivefold dilution of the samples) without touching the wellwalls as far as possible and gentlymixedThe plate was closedwith the closure plate membrane and incubated for 30minat 37∘C Wash solution was diluted 30-fold (or 20-fold) withdistilled water and reservedThe closure plate membrane wasremoved the liquid in the wells was discarded the wells weredried by swinging the plate and washing buffer was addedto every well The plate was left to stand for 30 s and thendrained this was repeated five times and the plate dried bypatting Horseradish peroxidase- (HRP-) conjugated reagent(Agrisera Sweden) (50 120583L) was added to each well except theblank control well After the plate was closed with the plateclosure membrane it was incubated for 30min at 37∘CWashsolution was diluted 30-fold (or 20-fold) with distilled waterand reserved Chromogen solutionA (50120583L) and chromogensolution B (50 120583L) were added to each well and the platewas incubated for 10min at 37∘C in the dark Stop solution(50120583L) was added to each well to stop the reaction (the
solution changed from blue to yellow) Taking the blank wellas zero the absorbance of eachwell was read at 450 nm 15minafter the stop solution was added The concentrations of therat inflammatory cytokines in the samples were determinedby comparing the absorbance of the samples with standardcurves Each sample included three repeated measurements
28 Immunohistochemistry TheHistostain-Plus kit was usedfor the immunohistochemical analysis Paraffin-embeddedpancreatic tissues were dewaxed and rehydrated Hydrogenperoxide (3) was used to inactivate any endogenous per-oxidase for 20min at room temperature Antigen retrievalwas performed in a high-pressure cooker for 30min Thepancreatic slices were incubated overnight with rabbit anti-rat VEGF (1 50) at 4∘C in a wet box after the endogenousantigens were blocked with 5 bovine serum albumin (BSA)for 30min at room temperature On the second day theslices were incubated with biotin-labeled secondary antibody(goat anti-rabbit Epitomics China) for 30min at 37∘C andthen with HRP-conjugated streptavidin for 20min at 37∘CAfter the slices were stained with diaminobenzidine andhematoxylin they were dehydrated cleared and mountedwith neutral resin CD31 and vWF proteins were detectedwith a similar procedure
29 Immunoblotting Assay Each sample of pancreatic tissue(approximately 100 120583g) was crushed to power and 500120583Lof RIPA lysis buffer containing 5 120583L of PMSF (100 1) wasadded to extract the total proteins The concentration ofthe total proteins was determined with the BCA methodThe proteins (20 120583g) were separated with 12 SDS-PAGEand transferred to 045 120583m nitrocellulose membrane Afterthe membrane was blocked with 5 skim milk for 1 h itwas incubated overnight with anti-VEGF polyclonal antibody(1 1000) at 4∘C On the following day the membrane waswashed three times with phosphate-buffered saline (PBS)containing Tween 20 for 10min each time and then incubatedwith a secondary goat anti-rabbit antibody (1 1000) at 37∘Cfor 1 h and washed again three times The experiment wasrepeated five times Finally the signal was detected with theOdyssey 30 analysis software (LI-CORBiotechnology USA)
210 qRT-PCR Total RNA was extracted from the cells andfrozen pancreatic specimens with TRIzol Reagent First-strand cDNA was synthesized with the PrimeScript ReverseTranscriptase Reagent Kit (Takara Biotechnology Japan)with oligo(dT) and random primer The gene expressionof the BMSCs and EAhy926 cells was quantified with theKAPA Kit (Kapa Biosystems USA) and 50 ng of cDNA wasamplified in a 10120583L reaction using the Applied Biosystems7500 Real-Time PCR system based on SYBR Green dye(Applied Biosystems)The primers were purchased from Bei-jing Genomics Institute (Beijing China) Rat glyceraldehyde-phosphate dehydrogenase (GAPDH)was used as the endoge-nous control The sequences of the primers are listed inTable 1 qRT-PCR was performed with the following cyclingconditions 95∘C for 3min followed by 40 cycles of 95∘Cfor 1 s and 60∘C for 20 s Quadruplicate cycle threshold(CT) values were analyzed with the SDS software (Applied
4 Stem Cells International
Table 1 The primer sequences of genes
RatGene Forward primer Reverse primer PCR amplified products (bp)GAPDH 51015840gtACCACAGTCCATGCCATCAClt31015840 51015840gtTCCACCACCCTGTTGCTGTAlt31015840 452VEGF 51015840gtTGTGAGCCTTGTTCAGAGCGlt31015840 51015840gtGACGGTGACGATGGTGGTGTlt31015840 252CXCR4 51015840gtTGTGAGCCTTGTTCAGAGCGlt31015840 51015840gtTGTGAGCCTTGTTCAGAGCGlt31015840 260ANG-1 51015840gtCAAGGCTTGGTTACTCGTCAGlt31015840 51015840gtCCATGAGCTCCAGTTGTTGClt31015840 109HGF 51015840gtAGTCTATGGACCTGAAGGCTClt31015840 51015840gtCCATCTGCGTTGATCAATCClt31015840 171TGF-120573 51015840gtCTACTGCTTCAGCTCCACAGAGlt31015840 51015840gtCTGTACTGTGTGTCCAGGCTClt31015840 162CD31 51015840gtGAGTGCTTCTTGGTGGGTCClt31015840 51015840gtCCTGAGAAGCACTGTACACClt31015840 150
Biosystems USA) using the comparative CT method Theprocedure was replicated three times Eachmeasurement wasset three repeats
211 Immunofluorescent Staining Immunofluorescent stain-ing was used to assess CXCR4 expression in SPION-labeledBMSCs as previously described [11]
212 Labeling BMSCs BMSCs at gt90 confluence werepretreated with or without AMD3100 (10120583gmL) and thenincubated with labeling medium containing 25120583gmL Fe3+and 075 ngmL poly-l-lysine for 24 h After theywere labeledthe cells were washed three times with PBS and harvestedwith 025 trypsin-EDTA The viability of the cells wasassessed with Trypan Blue exclusion before cell transplanta-tion The functions of the different concentrations of Fe3+-labeled BMSCs were analyzed in the following experiments
213 Cell Migration Assay In this experiment 5 times 104EAhy926 cells were added to the upper chamber of the Tran-swell apparatus and supplemented with 180120583L of DMEMand 20 120583L of 1 BSA and the lower chamber was filled with500120583L of DMEM-LG complete medium with or withoutBMSCS supernatant (100 120583L) After incubation for 12 h theupper chamber was removed and the cells were fixed with 4paraformaldehyde for 30min The lower surface of the filtermembrane was stained with 01 crystal violet for 10minin the dark After the membrane was thoroughly washed itwas observed with a digital camera and light microscopeThe experiment was repeated three times Finally the crystalviolet was dissolved in 300 120583L of 33 acetic acid and theabsorbance of the solution was measured at 573 nm with anELISA plate reader (Gene Company Limited HK China)
214 Cell Proliferation Assay (MTT Test) To investigatewhether BMSCs could repair the injured vascular endothelialcells we designed this experiment First EAhy926 cellswere cultured in 25 cm2 culture flasks and then incubatedwith 100 120583L of 025 trypsin-EDTA for 60min at a con-stant temperature of 37∘C in a humidified atmosphere of95 O
2supplemented with 5 CO
2until their confluence
reached approximately 90 Finally the cells were collectedand seeded into 96-well plates at 2000 cellswell Each wellcontained DMEM-LG complete medium with or without
BMSCs supernatant (DMEM-LG complete medium BMSCssupernatant = 1 1) MTT solution (20120583L of 5mgmL) wasadded daily for seven days (12 h 36 h 68 h 92 h 121 h and145 h) The medium was then removed and 150120583L of DMSOwas added to each well The plates were then shaken slowlyfor 10min Absorbance was measured with an ELISA platereader at 490 nm This experiment was repeated three timesSPION-labeled BMSCs were also assayed withMTT test aftertreatment with different concentrations of Fe3+ (25 120583gmL50 120583gmL 75120583gmL or 100 120583gmL)
215 ANG-1 and VEGF Silencing with Small Interfering RNAsGene silencing technology was used to understand the effectsof the BMSCs supernatant on the angiogenic activity ofEAhy926 cells in vitro Small interfering RNA (siRNA) tar-geting rat ANG-1 (51015840-GGCCCAGAUACAACAGAAUUU-dTdT-31015840) and (51015840-AUUCUGUUGUAUCUGGGCCUUdTd-T-31015840) or VEGF (51015840-GGGATTGCACGGAAACUUUdTdT-31015840) and (51015840-AAAGUUUCCGUGCAAUCCCdTdT-31015840) andcontrol nonsilencing siRNAs (51015840-AUGUGAAUGCACCAA-AGAAdTdT-31015840) and (51015840-UUCUUUGGUCUGCAUUCA-CAUdTdT-31015840) were synthesized by Biomics BiotechnologiesCo Ltd (Nantong City Jiangsu Province China) BMSCswere transfected with the siRNAs using Lipofectamine 2000according to the manufacturerrsquos protocol (Biotend ShanghaiChina) The BMSCs supernatant was collected 48 h aftertransfection and stored at minus80∘C for the tube formation assay
216 Angiogenesis A tube formation assay was performedto investigate the effect of the BMSCs supernatant on theangiogenic activity of EAhy926 cells in vitro Ninety-six-wellculture dishes were coated with 50 120583L of matrigel matrix andincubated for 30min at 37∘C EAhy926 cells were starvedfor 24 h and were then seeded onto the solidified gels ata density of 105 cellswell in 50120583L of culture medium TheBMSCs supernatant (50 120583L) or 1 timesPBS (50 120583L) was added toeach well These cells were divided into the normal controlSDF-1120572 10 ngmL SDF-1120572 100 ngmL ANG-1 siRNA andVEGF siRNA groups After incubation for 6 h the totaltube-like structures were photographed with phase-contrastmicroscopy (100x) and five randomly selected microscopicfields per photograph were quantified using the Image Jsoftware To further detect the angiogenesis in vivo theexpressions of vascular endothelialmarkers (VEGF vWF and
Stem Cells International 5
CD31) were measured by immunohistochemistry or westernblotting in SAP SAP+BMSCs and SAP+anti-CXCR4 BMSCsgroups
217 Magnetic Resonance Imaging (MRI) and Prussian BlueStaining To track the distributions of SPION-labeledBMSCsin vivo MRI and Prussian blue staining were used to detectFe3+The animalswere anesthetized and then put into anMRIcoil (Shanghai Niumag Electronic Science and TechnologyCo Ltd China) The T1-weighted imaging (T1WI) param-eters were as follows FOV read = 100mm FOV phase =100mm TR = 500ms TE = 20ms slice width = 35mm slicegap = 05mm and NS = 12 and the T2-weighted imaging(T2WI) parameters were as follows FOV read = 100mmFOV phase = 100mm TR = 2000ms TE = 80ms slice width= 35mm slice gap = 05mm andNS = 8 Finally the animalswere killed and pancreas lung liver spleen and smallintestine were collected and fixed in 4 paraformaldehydefor Prussian blue staining A Prussian blue staining kit wasused to detect Fe3+ in the SPION-labeled BMSCs and abovetissues according to the manufacturerrsquos instructions Thecells were fixed in 4 glutaraldehyde washed and incubatedfor 30min with 2 potassium ferric-ferrocyanide (Perlrsquosreagent) in 37 hydrochloric acid The cells were washedagain counterstained with Nuclear Fast Red and the ironstaining was evaluated with light microscopy (Carl ZeissOberkochen Germany) with a times40075 objective lens andAxiovision 44 software (Carl Zeiss) The SPION labelingefficiency was determined bymanually counting the Prussianblue stained and unstained cells under a Zeiss microscope(Carl Zeiss) at times100 magnification with a times100130 oil-immersion objective lens The percentage of labeled cells wasdetermined as the average of five high-powered fields Afterthe slices were fixed dehydrated embedded and sectionedthe tissues were stained with Prussian blue as describedabove The blue granules were counted by a person who didnot know the experiment from ten areas of each histologicsection
218 Image Processing and Statistical Analysis Adobe Photo-shop 60 (Adobe Systems Inc San Jose CA) Image-Pro Plusversion 60 (Media Cybernetics USA) and Image J (NationalInstitutes of Health USA) were used for image typesettinganalysis and processing GraphPad Prism 50 (GraphPadCo USA) was used for mapping The SPSS 170 statisticalsoftware (Chicago IL) was used for all statistical analysesExperimental data are shown as means plusmn standard deviations(SD) and compared with Studentrsquos or a paired 119905 test or one-way ANOVA A value of 119875 lt 005 was deemed to indicatesignificant differences
3 Results
31 Recombinant SDF-1120572 Protein Stimulated BMSCs Expres-sions of VEGFANG-1HGF TGF-120573 andCXCR4 Theexpres-sions of VEGF ANG-1 HGF TGF-120573 and CXCR4 weredetected with qRT-PCR or immunoblotting assays at 24 hand 48 h after recombinant SDF-1120572 protein was added tothe BMSCs culturemediumThe recombined SDF-1120572 protein
significantly stimulated the expressions of VEGF ANG-1 andCXCR4 in the BMSCs which was also positively correlatedwith the concentration of SDF-1120572 This effect was blockedby the CXCR4 agonist AMD3100 (Figures 1(a)-1(b) and1(d)ndash1(g)) The mRNA levels of HGF and TGF-120573 were bothupregulated after stimulation with SDF-1120572 but were inhibitedby AMD3100 (Figure 1(c))
32 BMSCs Supernatant Promotes the Proliferation Migra-tion and Repair of EAhy926 Cells The BMSCs supernatantpromoted the growth andmigration of EAhy926 cells signifi-cantlymore thanDMEM-LG completemedium (Figures 2(a)and 2(b))Moreover EAhy926 cells impaired by trypsinweremore effectively repaired by the BMSCs supernatant than byDMEM-LG complete medium (Figure 2(c))
33 SDF-1120572CXCR4 Axis Induces Angiogenesis In Vitro BeingRelated to the Expressions of VEGF and ANG-1 The BMSCssupernatant pretreated with SDF-1120572 significantly promotedangiogenesis compared with the normal BMSCs supernatantin vitro which was also positively related to the concentrationof SDF-1120572 Furthermore the angiogenesis was reduced inbothVEGF siRNA andANG-1 siRNA comparedwith normalBMSCs supernatant (Figure 1(h))
34 No Significant Differences on Biological Functions betweenBMSCs and SPION-Labeled BMSCs ([Fe3+] = 25 120583gmL)More than 95 of BMSCs were successfully labeled withSPION ([Fe3+] = 25 120583gmL) (Figure 3(a))The growth activityof SPION-labeled BMSCs ([Fe3+] = 25120583gmL) was similarto unlabeled BMSCs which was significantly stronger thanthat of other SPION-labeled BMSCs ([Fe3+] = 50 75 or100 120583gmL) (Figure 3(b)) CXCR4 expression was observedwith confocalmicroscopy and similar in both the BMSCs andSPION-labeled BMSCs (Figures 3(c)ndash3(e))
35 SDF-1120572CXCR4 Axis Regulates the Migration of SPION-Labeled BMSCs to Necrotic Pancreatic Tissues and the Migra-tion Increased Gradually Peaking on Days 5ndash7 The resultsof Prussian blue staining showed that the SPION-labeledBMSCs were relatively low in pancreas liver spleen andsmall intestine at the first day of the transplant comparedto lung but gradually increasing in pancreatic tissue atposttransplant days 3 and 7 and relatively high comparedto liver spleen and small intestine when the formation oftubular complexes (TCs) was also maximal (Figures 4(a)ndash4(c)) On the contrary SPION-labeled BMSCs in the lungtissue became less and less (Figure 5(b))Themore importantpoint was that the migrations of SPION-labeled BMSCs toinjured pancreas could be inhibited by anti-CXCR4 treatment(Figures 4(a)ndash4(c)) To further visually investigate whetherthe SPION-labeledBMSCs couldmigrate to injured pancreasthe MRI method was selected for realizing the tracing invivo The magnetic resonance images displayed that SPION-labeled BMSCs ([Fe3+] = 25 gmL) were high signal in T1WI(white) and low signal (dark) in T2WI as shown in Fig-ure 5(a) The high signal intensity (white points) in pancreas(as indicated by red circle) increased gradually in T1WI andpeaked on days 5 and 7 (Figure 5(b)) We also performedT2WI on day 7 in order to exclude the possibility of false
6 Stem Cells International
Relat
ive m
RNA
expr
essio
ns
CXCR4
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
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lowastdagger
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(10120583
gm
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ngm
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D3100
(10120583
gm
L)(a)
Relat
ive m
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essio
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lowast
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(10
ngm
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ngm
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Ang-1VEGF
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(10120583
gm
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(b)
Relat
ive m
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essio
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lowast
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+ +
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43
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36GAPDH
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XCR4
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lowastdaggerlowastdagger
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SDF-1
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ngm
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(10120583
gm
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(10
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(10120583
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SDF-1
(100
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(f)
Figure 1 Continued
Stem Cells International 7
NC
SDF-1
(10
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(100
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lowastdagger
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of A
ng-1
to G
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NC
Ang
-1siR
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Num
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f tub
e for
mat
ions
Tube formation assay
lowast
lowastlowast
lowastlowast
lowastdaggerdagger
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
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VEGF-A siRNANormal
SDF-1 (10ngmL) Ang-1 siRNA
PBS SDF-1 (100ngmL)
(h)
Figure 1 The SDF-1120572CXCR4 axis could promote the expressions of cellular growth factors in BMSCs and induce angiogenesis in vitro((a) (d) and (e))The CXCR4 expression of BMSCs was significantly unregulated after being stimulated by combined SDF-1120572 protein whichcould be inhibited by the CXCR4 receptor agonist AMD3100 ((b)ndash(d) (f)-(g)) Recombined SDF-1120572 protein could significantly promoteBMSCS expression of VEGF ANG-1 HGF and TGF-120573 and the effect could also blocked by AMD3100 Moreover there was a dose-effectrelationship between combined SDF-1120572 protein and CXCR4 VEGF ANG-1 HGF and TGF-120573 expressions Data are expressed as mean plusmn SD(lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SDF-1120572 (10 ngmL or 100 ngmL) versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSDF-1120572 (10 ngmL or 100 ngmL) versus SDF-1120572 (10 ngmL or 100 ngmL) + AMD3100 10 120583gmL) (h) BMSCs supernatant could significantlypromoted angiogenesis especially after being pretreated with SDF-1120572 and this increase was partly offset by AMD3100 Both VEGF siRNAand Ang-1 siRNA significantly weakened proangiogenic capacity of BMSCs Data are expressed as mean plusmn SD (119875 lt 001 for NC versusPBS lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SDF-1120572 (10 ngmL or 100 ngmL) Ang-1 siRNA or VEGF siRNA versus NC) (NC normalcontrol SDF-1120572 stromal cell derived factor-1a CXCR4 CXC chemokine receptor 4 VEGF vascular endothelial growth factor and ANG-1angiopoietin-1)
positive and the result showed that the high signals (whitepoints) in T1WI became low signals (dark points) in T2WIwhereas the low signals (dark points) in T1WI became highsignals (white points) as shown in Figure 5(c) Furthermorethe high signals in T1WI decreased obviously in anti-CXCR4group compared with BMSCs group on posttransplant day 5(Figure 5(b))
36 Transplanted BMSCs Reduced Pancreatic Edema Hem-orrhage and Necrosis Inhibited Systematic Inflammationand Promoted the Formation of TCs Involved in the SDF-1120572CXCR4 Axis Pancreatic edema hemorrhage and necro-sis were markedly reduced and the levels of serum amylasewere significantly lower in the SAP+BMSCs group than in theSAP and SAP+anti-CXCR4 BMSCs groups (Figures 6(a) and
8 Stem Cells International
DMEM-LG
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BMSCs supernatant + 025 trypsinDMEM-LG + 025 trypsin
(c)
Figure 2 The BMSCs supernatant could promote the proliferation migration and repair of human umbilical-vein endothelial cell line(EAhy926 cells) (a)Themethylene blue staining (magnification times200) is indicating that the BMSCs supernatant could significantly promotethe migration of EAhy926 cells Data are expressed as mean plusmn SD (lowast119875 lt 005 for DMEM-LG versus DMEM-LG + BMSCs supernatant) (b)The significant increase of the growth of EAhy926 cells was investigated in MTT test after being given BMSCs supernatant (c) ImpairedEAhy926 cells could be repaired by BMSCs supernatant Data are expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005and lowastlowast119875 lt 001 for DMEM-LG versus DMEM-LG + BMSCs supernatant at each corresponding time point) Data analysis was performedby a one-way ANOVA (BMSCs bone marrow-derived mesenchymal stem cells MTT 3-(45-dimethylthiazol-2-yl)-2S-diphenyltetrazoliumbromide)
6(b)) Inflammatory cytokines were detected with ELISAsThe results show that the levels of serum proinflamma-tory cytokines (IL-1120573 IL-6 and TNF-120572) were significantlydownregulated in the SAP+BMSCs group compared with theSAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines (IL-4 IL-10 andTGF-120573) were significantly upregulated in the SAP+BMSCsgroup comparedwith the SAP and SAP+anti-CXCR4BMSCsgroups (Figure 6(c)) We also found that a large number ofTCs appeared in the BMSCs group (as indicated by red arrowand a magnified picture in Figure 6(a))
37 SDF-1120572CXCR4 Axis Enhances the Expressions of VEGFandANG-1 inDamaged Pancreatic Tissues VEGF expressionin injured pancreatic tissues was measured with qRT-PCRand immunoblotting VEGF expression was higher in theSAP+BMSCS group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups on postoperative days 1and 4 but had decreased on postoperative day 7 (Figures 7(b)7(c) and 7(e)) The expression of ANG-1 was detected withqRT-PCR and immunoblotting and its expression was higherin the SAP+BMSCS group than in the normal control SAPand SAP+anti-CXCR4 BMSCs groups (Figures 7(a) 7(c)
Stem Cells International 9
(a)
Control
Days
$$
$$$
ampampamp
$$ $ampampamp
ampamp
amp
dagger
$$ $ampampamp
daggerdagger dagger$$ $
ampampamp
daggerdagger dagger
15
10
05
000 1 2 3 4 5 6 7 8
Fe = 75120583gmLFe = 25120583gmL Fe = 100120583gmLFe = 50120583gmL
OD
val
ues (
OD490
nm)
(b)
SPIO
N-la
bele
d BM
SCs
Unl
abel
ed B
MSC
s
(c)
BMSCsSPION-labeled
BMSCs
36
43
(kD)CXCR4
GAPDH
(d)
BMSCs
BMSCsSPION-labeled BMSCs
SPION-labeledBMSCs
15
10
05
00
Relat
ive m
RNA
expr
essio
ns
P gt 005
(e)
Figure 3There is similarity in the proliferation andCXCR4 expression between unlabeled and SPION-labeled BMSCs ([Fe3+] = 25 gmL) (a)The Prussian blue staining shows that BMSCs were labeled by SPION successfully (b) TheMTT tests are showing that the growth activity ofSPION-labeled BMSCs ([Fe3+] = 25 gmL) slowed slightly compared with that of the unlabeled BMSCs which was also significantly strongerthan that of other SPION-labeled BMSCs ([Fe3+] = 50 75 or 100 gmL) Data are expressed as mean plusmn SD (ampamp119875 lt 001 and ampampamp
119875 lt 0001
for normal control versus SPION-labeled BMSCS ([Fe3+] = 100 gmL) $$119875 lt 001 and $$$119875 lt 0001 for normal control versus SPION-labeled
BMSCS ([Fe3+] = 75 gmL) and dagger119875 lt 005 and daggerdaggerdagger119875 lt 0001 for normal control versus SPION-labeled BMSCS ([Fe3+] = 50 gmL) at eachcorresponding time point) ((c)-(d)) CXCR4 expression was detected by immunofluorescence and western blotting and similar betweenunlabeled and SPION-labeled BMSCs (119875 gt 005) (SPION superparamagnetic iron oxide nanoparticles BMSCs bone marrow-derivedmesenchymal stem cells)
10 Stem Cells International
Ant
i-CXC
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SCs
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s
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mal
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Lung
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Figure 4 Continued
Stem Cells International 11
100
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The n
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10d
BMSCsAnti-CXCR4 BMSCs
Lung
Live
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Smal
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(c)
Figure 4 Prussian blue staining was performed for detecting the SPION-labeled BMSCs in pancreatic and lung tissues (a) The Prussianblue staining of pancreatic tissue indicates that the cells were stained blue (as indicated by black arrows) gradually increased and peaked onpostoperative days 5ndash7 when the formation of tubular complexes was also maximal (as indicated by red arrows) However the migration waspartly inhibited and the trend was not obviously investigated in anti-CXCR4 group (b) The lung tissues were stained by Prussian blue andthe blue particles (as indicated by black arrows) were gradually decreasing in both BMSCs and anti-CXCR4 groups (c) The blue particles inlung pancreas liver spleen and small intestine were counted and analyzed between BMSCs and anti-CXCR4 groupsThe result showed thatthe number of blue particles of pancreas in BMSCs group was significantly more than in anti-CXCR4 group at postoperative days 1 3 5 and7 Data are expressed as mean plusmn SD (lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for BMSCs versus anti-CXCR4 at each corresponding time point)
and 7(d)) The mRNA levels of HGF and TGF-120573 were alsodetected with qRT-PCR and were significantly higher in theSAP+BMSCs group than in the normal SAP and SAP+anti-CXCR4 BMSCs groups (Figures 7(f) and 7(g))
38 SDF-1120572CXCR4 Axis Induces the Neovascularization InVivo To assess the neovascularization we conducted qRT-PCR or immunohistochemistry for detecting these angiogen-esis markers (CD31 VEGF and vWF) The results indicatedthat the expressions of CD31 VEGF and vWF in necroticpancreatic tissue were higher in the SAP+BMSCs group thanin the normal control SAP and SAP+anti-CXCR4 BMSCsgroups especially in early phase (Figures 7(h) and 8(a)ndash8(d))
4 Discussion
Several studies have shown that MSCs from the bone orumbilical cord can attenuate acute necrotic pancreatitis byinhibiting systematic inflammation regulating the immuneresponses reducing the apoptosis of pancreatic acinar cellsand repairing damaged the small intestinal epithelium [9ndash12]However these functions do not account for how to repairand regenerate the necrotic pancreatic tissues In the studywe found that BMSCs can reduce severe acute pancreatitisby alleviating the systematic inflammation promoting theformation of tubular complexes (TCs) and inducing angio-genesis involving the SDF-1120572CXCR4 axis by enhancing the
expression of cell growth factors in a rat model of SAP Largeprevious studies have found that MSCs can not only differ-entiate into different kinds of functional adult cells but alsosecrete various soluble factors including VEGF HGF andTGF-120573 [27] These factors which promote angiogenesis andmitosis and reduce apoptosis can explain tissue repair andregeneration after MSCs transplanted [28 29] Moreover theregeneration of the pancreas begins with the TCs that consistof a cluster of epithelia surrounded by the mesenchymalcells [30 31] Thus we inferred that SDF-1120572CXCR4 axis wasinvolved in the repair and regeneration of SAP
SDF-1120572 and its receptor CXCR4 have been studiedextensively together with their roles in migration homingproliferation angiogenesis and so forth [11 13ndash15 18 3233] Many researches have shown that BMSCs can migrateto injured tissues via the SDF-1120572CXCR4 axis and relievemyocardial infraction [13 14] promote wound healing [19]heal bone fracture [34] reduce cerebral ischemia [35] andameliorate acute necrotizing pancreatitis [11] SDF-1120572 expres-sion is upregulated by hypoxia-inducible factor-1 (HIF-1)[36] In the study we successfully established a rat model ofacute necrotizing pancreatitis with the retrograde injectionof Na-taurocholate which causes acinar cell injurynecrosisby triggering transient pathological intra-acinar-cell cal-cium ions and activating digestive zymogens [37ndash39] Theinjurednecrotic pancreatic tissue causes HIF-1 expressionand thus induces SDF-1120572 expression which attracts BMSCsto injured pancreas through the interaction with CXCR4
12 Stem Cells International
T1WI
SPIO
N-la
bele
d BM
SCs
T2WI
5 10 15 20 25 30[Fe] (120583gmL)
(a)
Normal (T1WI)
BMSCs BMSCs BMSCs
Anti-CXCR4 BMSCsBMSCsBMSCs
BMSCs
5d (T1WI)7d (T1WI)
1d (T1WI) 3d (T1WI) 5d (T1WI)
10d (T1WI)
(b)
BMSCs
7d (T1WI)
BMSCs
7d (T2WI)
(c)
Figure 5 The transplanted SPION-labeled BMSCs were tracked by MRI in vivo (a) [Fe3+] was detected by MRI and the result showed thatthe SPION-labeled BMSCs ([Fe3+] = 25 gmL) appeared high signals (white spots) on T1WI and low signals (dark spots) on T2WI (b) TheSPION-BMSCs ([Fe3+] = 25 gmL) was tracked by MRI in vivo and the photos show that the white spots (inside of red circle) were increasinggradually and peaked on postoperative days 5ndash7 Instead the white spots decreased on postoperative day 5 in anti-CXCR4 group comparedwith BMSCs group (c) The SPION-BMSCs ([Fe3+] = 25 gmL) were detected in SAP rats at postoperative day 7 by T1WI and T2WI andthe result was showing that the high signals (white spots) which appeared in T1WI became low signals (dark spots) in T2WI (SPIONsuperparamagnetic iron oxide nanoparticles T1WI T1-weighted imaging and T2WI T2-weighted imaging)
For further investigating whether BMSCs could migrateto injured pancreas and the migration was regulated by SDF-1120572CXCR4 axis in a SAP rat model SPION was used tolabel BMSCs SPION were initially used as a unique MRcontrast agent in the clinical context Recently their two useshave been discoveredmdashthe labeling of live cells and tissuesdisease diagnosis and therapy [22 23 40ndash42] Studies havedemonstrated that SPION-labeling does not deleteriouslyaffect the functions of the target cells [25] In our study wealso demonstrated that there was no difference in the pro-liferation capacities between SPION-labeled (Fe = 25 120583gmLlabeling efficiency gt 95) and unlabeled BMSCs Moreover
the expression of CXCR4was also similar between the labeledand unlabeled cells SPION-labeled BMSCs could be detectedby both MRI and Prussian blue staining because SPIONis the nanometer particles of ferric oxide The dynamicmovement of labeling cells could be observed at the photosof MRI so that we can intuitively assess the proportions ofSPION-labeled BMSCs in vivo The result showed that thesecells could migrate to the damaged pancreatic tissues andthere was also a gradual increase in migration peaking onpostoperative days 5ndash7 with the formation of large numbersof TCs SDF-1120572CXCR4 axis could regulate the migrationof BMSCs as our previously described [11] Meanwhile the
Stem Cells International 13
SAP
NC Sham Tubular complex
SAP+
BMSC
sSA
P+
anti-
CXCR
4BM
SCs
1d 4d 7d
(a)
0
1
2
3
4
Edema
Scor
e $
$$$
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
SAP + BMSCsSAP + anti-CXCR4
SAP + anti-CXCR4SAP + anti-CXCR4
SAP + anti-CXCR4 BMSCs
ShamSAP
Normal
0
1
2
3
4
Scor
e
$
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
SAP + BMSCs
BMSCsShamSAP
Normal
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1000
800
600
400
200
0
0
1
2
3
4
Scor
e
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1d 4d 7d
1d 4d 7d 1d 4d 7d
1d 4d 7dInfiltration
Necrosis
Am
ylas
e act
ivity
(b)
Figure 6 Continued
14 Stem Cells International
130
120
110
100
90
80The c
once
ntra
tion
of se
rum
IL-1
(pg
mL)
daggerdaggerlowast
daggerlowast
daggerdaggerdagger
daggerdaggerdagger
lowast
lowastlowastlowastlowast
daggerlowast
lowastlowastlowast
daggerdaggerdaggerlowastlowast
daggerdaggerdaggerlowast
Control Day 1 Day 4 Day 7
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham
$
daggerdaggerlowast
$ daggerdagger daggerlowastlowast
$daggerdagger dagger
daggerlowastlowastlowastlowastlowast
daggerlowastlowast
$$$daggerdagger daggerlowastlowast
$daggerdagger daggerlowastlowast
$
daggerlowast dagger
lowast
$
$
$$
$$$$$$
The c
once
ntra
tion
of se
rum
IL-4
(pg
mL)
80
70
60
50
40
The c
once
ntra
tion
of se
rum
IL-6
(pg
mL)
90
80
70
60
The c
once
ntra
tion
of se
rum
IL-10
(pg
mL)
60
55
50
45
40
35
The c
once
ntra
tion
of se
rum
TN
F-120572
(pg
mL)
260
240
220
200
180
160
220
200
180
160
140
120The c
once
ntra
tion
of se
rum
TG
F-120573
(pg
mL)
(c)
Figure 6 Transplanted BMSCs could reduce severe acute pancreatitis (SAP) promoting the formation of tubular complexes and inhibitingsystematic inflammatory response being involved in the SDF-1120572CXCR4 axis ((a) (b))TheHampE staining of pancreatic tissues (magnificationtimes100) is showing that the edema infiltration and necrosis were significantly reduced in the SAP+BMSCs group compared with SAP andSAP+anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively A large number of tubular complexes were also investigatedin SAP+BMSCs group (as indicated by red arrow in a 400x magnified picture) Serum amylase activity was also significantly reduced inSAP+BMSCs group than in normal SAP and anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively (c) The levels ofserum proinflammatory cytokines are significantly lower in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines are significantly higher in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups Dataare expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SAP versus Normal dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP versus SAP+BMSCs $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4BMSCs) Data analysis was performed by Studentrsquos test (BMSCs bone marrow-derived mesenchymal stem cells HampE hematoxylin-eosin)
number of cells whichmigrated to the necrotic pancreas waspositively related to the therapeutic effect However SPION-labeled BMSCs could be rarely seen on postoperative day 10perhaps because the SPIONwere degraded or the BMSCs haddifferentiated into other cells including pancreatic exocrinecells
To validate whether the SDF-1120572CXCR4 axis also playsan important role in the repair and regeneration of SAPwe conducted the study in vitro and vivo We found thatthe secretions of BMSCs could promote the proliferationmigration and restoration of EAhy926 cells The BMSCssupernatant induced angiogenesis and the SDF-1120572CXCR4axis stimulated BMSCs to express VEGF ANG-1 HGFand TGF-120573 promoting further angiogenesis in vitro Both
VEGF and ANG-1 play important roles in angiogenesisMoreover the expressions of VEGFANG-1HGF andTGF-120573in the damaged pancreatic tissues were higher in the BMSCstransplantation group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups Taken all together theresult showed that transplantedBMSCs repaired the damagedpancreas through secreting large cellular growth factors andthe effect was regulated by SDF-1120572CXCR4 axis
As we all know VEGF a potent inducer of angiogenesispromotes the repair of injured vascular endothelial cellsand neovascularization Studies have shown that the SDF-1120572CXCR4 axis promotes the synthesis and secretion ofVEGF [17 43] and SDF-1120572 combined with VEGF enhancesischemic angiogenesis [20] In our study we confirmed that
Stem Cells International 15
15
10
5
0
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
expr
essio
nslowastlowastlowastdagger
lowastlowastlowastdagger
daggerdaggerdagger
$
1d 4d 7dVEGF
(a)
daggerdaggerdaggerdagger
dagger
$
$
lowast
lowast
lowast
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
0
5
10
15
Relat
ive m
RNA
expr
essio
ns
Ang-11d 4d 7d
(b)NC Sham
ANG-1
VEGF
GAPDH
Ant
i-CXC
R4SA
PA
nti-C
XCR4
SAP
SAP
+BM
SCs
SAP
+BM
SCs
36
1d 4d 7d
45
70
(kD)
(c)
dagger
daggerdaggerdagger
$
10
00
02
04
06
08
lowastlowastlowast
dagger$lowastlowastlowast
lowastlowastlowast
SAP + BMSCsNCShamSAP
1d 4d 7d
Relat
ive r
atio
of V
EGF
to G
APD
H
SAP + anti-CXCR4 BMSCs
(d)
dagger
daggerdaggerdagger
$$
lowastlowastlowastlowastlowastlowast
lowastlowastlowast
$$$daggerdaggerdagger
0020
0015
0010
0005
0000
Relat
ive r
atio
of A
ng-1
to G
APD
H
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(e)
daggerdagger
dagger$
lowast
lowastlowast
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
TGF-1205731d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(f)
Figure 7 Continued
16 Stem Cells International
dagger
dagger$
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
HGF
lowastlowast
lowastlowastlowastlowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(g)
$
$
0
2
4
6
8
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
CD31
daggerlowast
lowast
lowast
daggerlowastlowast
dagger daggerlowast
lowast
lowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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International Journal of
Volume 2014
Zoology
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International Journal of
Microbiology
Stem Cells International 3
d7 (119899 = 3) and d10 (119899 = 3) BMSCs or SPION-labeled BMSCs(1 times 107 cellsmLkg) were injected into the rats throughthe tail vein for cell therapy or tracing All animals werekilled with a lethal dose of pentobarbital injected into theabdominal cavity Recombinant SDF-1120572 protein (10 ngmL or100 ngmL)was directly added to theBMSCS culturemediumin vitro Alternatively BMSCs were stimulated with SDF-1120572after culture with AMD3100 (10 120583gmL) for 1 h EAhy926cells in 25 cm2 flasks were first damaged by the additionof 100 120583L of 025 trypsin and then incubated in DMEM-LG complete medium supplemented with or without BMSCssupernatant containing DMEM-LG complete medium andBMSCs secretions To assess the migration capacity of thecells in response to BMSCs EAhy926 cells were culturedin the upper chamber of a Transwell apparatus and lowerchamber was filled with DMEM-LG complete medium withor without BMSCs supernatant
25 Sample Collection Blood samples and pancreatic tis-sues were collected from the normal control sham SAPand SAP+BMSCs SAP+anti-CXCR4 BMSCs groups Theserum was first extracted by centrifugation at 8000timesg at4∘C and then stored at minus80∘C The pancreatic tissues werestored in liquid nitrogen or fixed in 4 paraformaldehydeAfter pretreatment with SDF-1120572 for 48 h the BMSCs super-natants were collected including the normal control SDF-1120572 10 ngmL and SDF-1120572 100 ngmL groups and stored atminus80∘C Meanwhile the normal BMSCs supernatants werealso collected at 24 h after cells were given fresh DMEM-LGcomplete medium
26 Hematoxylin-Eosin (HampE) Staining and the Detectionof Serum Amylase Activity HampE staining and the detectionof serum amylase activity were performed as previouslydescribed [11]
27 ELISAs Theserum levels of IL-1120573 IL-4 IL-6 IL-10 TNF-120572 and TGF-120573 were analyzed with ELISAs Samples of serum(150 120583L) were diluted with standard diluent (1 1) and then40 120583L diluted samples were added to the test sample wellsThe test samples (10 120583L) were added to the wells (a finalfivefold dilution of the samples) without touching the wellwalls as far as possible and gentlymixedThe plate was closedwith the closure plate membrane and incubated for 30minat 37∘C Wash solution was diluted 30-fold (or 20-fold) withdistilled water and reservedThe closure plate membrane wasremoved the liquid in the wells was discarded the wells weredried by swinging the plate and washing buffer was addedto every well The plate was left to stand for 30 s and thendrained this was repeated five times and the plate dried bypatting Horseradish peroxidase- (HRP-) conjugated reagent(Agrisera Sweden) (50 120583L) was added to each well except theblank control well After the plate was closed with the plateclosure membrane it was incubated for 30min at 37∘CWashsolution was diluted 30-fold (or 20-fold) with distilled waterand reserved Chromogen solutionA (50120583L) and chromogensolution B (50 120583L) were added to each well and the platewas incubated for 10min at 37∘C in the dark Stop solution(50120583L) was added to each well to stop the reaction (the
solution changed from blue to yellow) Taking the blank wellas zero the absorbance of eachwell was read at 450 nm 15minafter the stop solution was added The concentrations of therat inflammatory cytokines in the samples were determinedby comparing the absorbance of the samples with standardcurves Each sample included three repeated measurements
28 Immunohistochemistry TheHistostain-Plus kit was usedfor the immunohistochemical analysis Paraffin-embeddedpancreatic tissues were dewaxed and rehydrated Hydrogenperoxide (3) was used to inactivate any endogenous per-oxidase for 20min at room temperature Antigen retrievalwas performed in a high-pressure cooker for 30min Thepancreatic slices were incubated overnight with rabbit anti-rat VEGF (1 50) at 4∘C in a wet box after the endogenousantigens were blocked with 5 bovine serum albumin (BSA)for 30min at room temperature On the second day theslices were incubated with biotin-labeled secondary antibody(goat anti-rabbit Epitomics China) for 30min at 37∘C andthen with HRP-conjugated streptavidin for 20min at 37∘CAfter the slices were stained with diaminobenzidine andhematoxylin they were dehydrated cleared and mountedwith neutral resin CD31 and vWF proteins were detectedwith a similar procedure
29 Immunoblotting Assay Each sample of pancreatic tissue(approximately 100 120583g) was crushed to power and 500120583Lof RIPA lysis buffer containing 5 120583L of PMSF (100 1) wasadded to extract the total proteins The concentration ofthe total proteins was determined with the BCA methodThe proteins (20 120583g) were separated with 12 SDS-PAGEand transferred to 045 120583m nitrocellulose membrane Afterthe membrane was blocked with 5 skim milk for 1 h itwas incubated overnight with anti-VEGF polyclonal antibody(1 1000) at 4∘C On the following day the membrane waswashed three times with phosphate-buffered saline (PBS)containing Tween 20 for 10min each time and then incubatedwith a secondary goat anti-rabbit antibody (1 1000) at 37∘Cfor 1 h and washed again three times The experiment wasrepeated five times Finally the signal was detected with theOdyssey 30 analysis software (LI-CORBiotechnology USA)
210 qRT-PCR Total RNA was extracted from the cells andfrozen pancreatic specimens with TRIzol Reagent First-strand cDNA was synthesized with the PrimeScript ReverseTranscriptase Reagent Kit (Takara Biotechnology Japan)with oligo(dT) and random primer The gene expressionof the BMSCs and EAhy926 cells was quantified with theKAPA Kit (Kapa Biosystems USA) and 50 ng of cDNA wasamplified in a 10120583L reaction using the Applied Biosystems7500 Real-Time PCR system based on SYBR Green dye(Applied Biosystems)The primers were purchased from Bei-jing Genomics Institute (Beijing China) Rat glyceraldehyde-phosphate dehydrogenase (GAPDH)was used as the endoge-nous control The sequences of the primers are listed inTable 1 qRT-PCR was performed with the following cyclingconditions 95∘C for 3min followed by 40 cycles of 95∘Cfor 1 s and 60∘C for 20 s Quadruplicate cycle threshold(CT) values were analyzed with the SDS software (Applied
4 Stem Cells International
Table 1 The primer sequences of genes
RatGene Forward primer Reverse primer PCR amplified products (bp)GAPDH 51015840gtACCACAGTCCATGCCATCAClt31015840 51015840gtTCCACCACCCTGTTGCTGTAlt31015840 452VEGF 51015840gtTGTGAGCCTTGTTCAGAGCGlt31015840 51015840gtGACGGTGACGATGGTGGTGTlt31015840 252CXCR4 51015840gtTGTGAGCCTTGTTCAGAGCGlt31015840 51015840gtTGTGAGCCTTGTTCAGAGCGlt31015840 260ANG-1 51015840gtCAAGGCTTGGTTACTCGTCAGlt31015840 51015840gtCCATGAGCTCCAGTTGTTGClt31015840 109HGF 51015840gtAGTCTATGGACCTGAAGGCTClt31015840 51015840gtCCATCTGCGTTGATCAATCClt31015840 171TGF-120573 51015840gtCTACTGCTTCAGCTCCACAGAGlt31015840 51015840gtCTGTACTGTGTGTCCAGGCTClt31015840 162CD31 51015840gtGAGTGCTTCTTGGTGGGTCClt31015840 51015840gtCCTGAGAAGCACTGTACACClt31015840 150
Biosystems USA) using the comparative CT method Theprocedure was replicated three times Eachmeasurement wasset three repeats
211 Immunofluorescent Staining Immunofluorescent stain-ing was used to assess CXCR4 expression in SPION-labeledBMSCs as previously described [11]
212 Labeling BMSCs BMSCs at gt90 confluence werepretreated with or without AMD3100 (10120583gmL) and thenincubated with labeling medium containing 25120583gmL Fe3+and 075 ngmL poly-l-lysine for 24 h After theywere labeledthe cells were washed three times with PBS and harvestedwith 025 trypsin-EDTA The viability of the cells wasassessed with Trypan Blue exclusion before cell transplanta-tion The functions of the different concentrations of Fe3+-labeled BMSCs were analyzed in the following experiments
213 Cell Migration Assay In this experiment 5 times 104EAhy926 cells were added to the upper chamber of the Tran-swell apparatus and supplemented with 180120583L of DMEMand 20 120583L of 1 BSA and the lower chamber was filled with500120583L of DMEM-LG complete medium with or withoutBMSCS supernatant (100 120583L) After incubation for 12 h theupper chamber was removed and the cells were fixed with 4paraformaldehyde for 30min The lower surface of the filtermembrane was stained with 01 crystal violet for 10minin the dark After the membrane was thoroughly washed itwas observed with a digital camera and light microscopeThe experiment was repeated three times Finally the crystalviolet was dissolved in 300 120583L of 33 acetic acid and theabsorbance of the solution was measured at 573 nm with anELISA plate reader (Gene Company Limited HK China)
214 Cell Proliferation Assay (MTT Test) To investigatewhether BMSCs could repair the injured vascular endothelialcells we designed this experiment First EAhy926 cellswere cultured in 25 cm2 culture flasks and then incubatedwith 100 120583L of 025 trypsin-EDTA for 60min at a con-stant temperature of 37∘C in a humidified atmosphere of95 O
2supplemented with 5 CO
2until their confluence
reached approximately 90 Finally the cells were collectedand seeded into 96-well plates at 2000 cellswell Each wellcontained DMEM-LG complete medium with or without
BMSCs supernatant (DMEM-LG complete medium BMSCssupernatant = 1 1) MTT solution (20120583L of 5mgmL) wasadded daily for seven days (12 h 36 h 68 h 92 h 121 h and145 h) The medium was then removed and 150120583L of DMSOwas added to each well The plates were then shaken slowlyfor 10min Absorbance was measured with an ELISA platereader at 490 nm This experiment was repeated three timesSPION-labeled BMSCs were also assayed withMTT test aftertreatment with different concentrations of Fe3+ (25 120583gmL50 120583gmL 75120583gmL or 100 120583gmL)
215 ANG-1 and VEGF Silencing with Small Interfering RNAsGene silencing technology was used to understand the effectsof the BMSCs supernatant on the angiogenic activity ofEAhy926 cells in vitro Small interfering RNA (siRNA) tar-geting rat ANG-1 (51015840-GGCCCAGAUACAACAGAAUUU-dTdT-31015840) and (51015840-AUUCUGUUGUAUCUGGGCCUUdTd-T-31015840) or VEGF (51015840-GGGATTGCACGGAAACUUUdTdT-31015840) and (51015840-AAAGUUUCCGUGCAAUCCCdTdT-31015840) andcontrol nonsilencing siRNAs (51015840-AUGUGAAUGCACCAA-AGAAdTdT-31015840) and (51015840-UUCUUUGGUCUGCAUUCA-CAUdTdT-31015840) were synthesized by Biomics BiotechnologiesCo Ltd (Nantong City Jiangsu Province China) BMSCswere transfected with the siRNAs using Lipofectamine 2000according to the manufacturerrsquos protocol (Biotend ShanghaiChina) The BMSCs supernatant was collected 48 h aftertransfection and stored at minus80∘C for the tube formation assay
216 Angiogenesis A tube formation assay was performedto investigate the effect of the BMSCs supernatant on theangiogenic activity of EAhy926 cells in vitro Ninety-six-wellculture dishes were coated with 50 120583L of matrigel matrix andincubated for 30min at 37∘C EAhy926 cells were starvedfor 24 h and were then seeded onto the solidified gels ata density of 105 cellswell in 50120583L of culture medium TheBMSCs supernatant (50 120583L) or 1 timesPBS (50 120583L) was added toeach well These cells were divided into the normal controlSDF-1120572 10 ngmL SDF-1120572 100 ngmL ANG-1 siRNA andVEGF siRNA groups After incubation for 6 h the totaltube-like structures were photographed with phase-contrastmicroscopy (100x) and five randomly selected microscopicfields per photograph were quantified using the Image Jsoftware To further detect the angiogenesis in vivo theexpressions of vascular endothelialmarkers (VEGF vWF and
Stem Cells International 5
CD31) were measured by immunohistochemistry or westernblotting in SAP SAP+BMSCs and SAP+anti-CXCR4 BMSCsgroups
217 Magnetic Resonance Imaging (MRI) and Prussian BlueStaining To track the distributions of SPION-labeledBMSCsin vivo MRI and Prussian blue staining were used to detectFe3+The animalswere anesthetized and then put into anMRIcoil (Shanghai Niumag Electronic Science and TechnologyCo Ltd China) The T1-weighted imaging (T1WI) param-eters were as follows FOV read = 100mm FOV phase =100mm TR = 500ms TE = 20ms slice width = 35mm slicegap = 05mm and NS = 12 and the T2-weighted imaging(T2WI) parameters were as follows FOV read = 100mmFOV phase = 100mm TR = 2000ms TE = 80ms slice width= 35mm slice gap = 05mm andNS = 8 Finally the animalswere killed and pancreas lung liver spleen and smallintestine were collected and fixed in 4 paraformaldehydefor Prussian blue staining A Prussian blue staining kit wasused to detect Fe3+ in the SPION-labeled BMSCs and abovetissues according to the manufacturerrsquos instructions Thecells were fixed in 4 glutaraldehyde washed and incubatedfor 30min with 2 potassium ferric-ferrocyanide (Perlrsquosreagent) in 37 hydrochloric acid The cells were washedagain counterstained with Nuclear Fast Red and the ironstaining was evaluated with light microscopy (Carl ZeissOberkochen Germany) with a times40075 objective lens andAxiovision 44 software (Carl Zeiss) The SPION labelingefficiency was determined bymanually counting the Prussianblue stained and unstained cells under a Zeiss microscope(Carl Zeiss) at times100 magnification with a times100130 oil-immersion objective lens The percentage of labeled cells wasdetermined as the average of five high-powered fields Afterthe slices were fixed dehydrated embedded and sectionedthe tissues were stained with Prussian blue as describedabove The blue granules were counted by a person who didnot know the experiment from ten areas of each histologicsection
218 Image Processing and Statistical Analysis Adobe Photo-shop 60 (Adobe Systems Inc San Jose CA) Image-Pro Plusversion 60 (Media Cybernetics USA) and Image J (NationalInstitutes of Health USA) were used for image typesettinganalysis and processing GraphPad Prism 50 (GraphPadCo USA) was used for mapping The SPSS 170 statisticalsoftware (Chicago IL) was used for all statistical analysesExperimental data are shown as means plusmn standard deviations(SD) and compared with Studentrsquos or a paired 119905 test or one-way ANOVA A value of 119875 lt 005 was deemed to indicatesignificant differences
3 Results
31 Recombinant SDF-1120572 Protein Stimulated BMSCs Expres-sions of VEGFANG-1HGF TGF-120573 andCXCR4 Theexpres-sions of VEGF ANG-1 HGF TGF-120573 and CXCR4 weredetected with qRT-PCR or immunoblotting assays at 24 hand 48 h after recombinant SDF-1120572 protein was added tothe BMSCs culturemediumThe recombined SDF-1120572 protein
significantly stimulated the expressions of VEGF ANG-1 andCXCR4 in the BMSCs which was also positively correlatedwith the concentration of SDF-1120572 This effect was blockedby the CXCR4 agonist AMD3100 (Figures 1(a)-1(b) and1(d)ndash1(g)) The mRNA levels of HGF and TGF-120573 were bothupregulated after stimulation with SDF-1120572 but were inhibitedby AMD3100 (Figure 1(c))
32 BMSCs Supernatant Promotes the Proliferation Migra-tion and Repair of EAhy926 Cells The BMSCs supernatantpromoted the growth andmigration of EAhy926 cells signifi-cantlymore thanDMEM-LG completemedium (Figures 2(a)and 2(b))Moreover EAhy926 cells impaired by trypsinweremore effectively repaired by the BMSCs supernatant than byDMEM-LG complete medium (Figure 2(c))
33 SDF-1120572CXCR4 Axis Induces Angiogenesis In Vitro BeingRelated to the Expressions of VEGF and ANG-1 The BMSCssupernatant pretreated with SDF-1120572 significantly promotedangiogenesis compared with the normal BMSCs supernatantin vitro which was also positively related to the concentrationof SDF-1120572 Furthermore the angiogenesis was reduced inbothVEGF siRNA andANG-1 siRNA comparedwith normalBMSCs supernatant (Figure 1(h))
34 No Significant Differences on Biological Functions betweenBMSCs and SPION-Labeled BMSCs ([Fe3+] = 25 120583gmL)More than 95 of BMSCs were successfully labeled withSPION ([Fe3+] = 25 120583gmL) (Figure 3(a))The growth activityof SPION-labeled BMSCs ([Fe3+] = 25120583gmL) was similarto unlabeled BMSCs which was significantly stronger thanthat of other SPION-labeled BMSCs ([Fe3+] = 50 75 or100 120583gmL) (Figure 3(b)) CXCR4 expression was observedwith confocalmicroscopy and similar in both the BMSCs andSPION-labeled BMSCs (Figures 3(c)ndash3(e))
35 SDF-1120572CXCR4 Axis Regulates the Migration of SPION-Labeled BMSCs to Necrotic Pancreatic Tissues and the Migra-tion Increased Gradually Peaking on Days 5ndash7 The resultsof Prussian blue staining showed that the SPION-labeledBMSCs were relatively low in pancreas liver spleen andsmall intestine at the first day of the transplant comparedto lung but gradually increasing in pancreatic tissue atposttransplant days 3 and 7 and relatively high comparedto liver spleen and small intestine when the formation oftubular complexes (TCs) was also maximal (Figures 4(a)ndash4(c)) On the contrary SPION-labeled BMSCs in the lungtissue became less and less (Figure 5(b))Themore importantpoint was that the migrations of SPION-labeled BMSCs toinjured pancreas could be inhibited by anti-CXCR4 treatment(Figures 4(a)ndash4(c)) To further visually investigate whetherthe SPION-labeledBMSCs couldmigrate to injured pancreasthe MRI method was selected for realizing the tracing invivo The magnetic resonance images displayed that SPION-labeled BMSCs ([Fe3+] = 25 gmL) were high signal in T1WI(white) and low signal (dark) in T2WI as shown in Fig-ure 5(a) The high signal intensity (white points) in pancreas(as indicated by red circle) increased gradually in T1WI andpeaked on days 5 and 7 (Figure 5(b)) We also performedT2WI on day 7 in order to exclude the possibility of false
6 Stem Cells International
Relat
ive m
RNA
expr
essio
ns
CXCR4
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
lowastdagger
lowastdagger
0
1
2
3
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)(a)
Relat
ive m
RNA
expr
essio
ns
lowast
lowastdagger
lowastdaggerlowastdagger
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
Ang-1VEGF
0
1
2
3
4
5
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(b)
Relat
ive m
RNA
expr
essio
ns
lowast
lowast
daggerdaggerdaggerdaggerdaggerdagger
daggerdaggerdagger
daggerdaggerdagger
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
0
2
4
6
8
10
TGF-120573HGF
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(c)
+ +
+
+ +
+
43
45
36GAPDH
VEGF
CXCR4
ANG-1 70
(kD)
minus
minus
minus
minus minus
minus minus
minus minus
SDF-1
SDF-1(10ngmL)
(100ngmL)AMD3100(10120583gmL)
(d)
000
005
010
015
Ratio
of C
XCR4
to G
APD
H
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
lowastdaggerlowastdagger
dagger
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(e)
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
10
08
06
04
02
00
Ratio
of V
EGF
to G
APD
H
lowastdagger
lowastlowast lowastdagger
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(f)
Figure 1 Continued
Stem Cells International 7
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
lowastdagger
lowastdagger
000
001
002
003
004
005
Ratio
of A
ng-1
to G
APD
H
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(g)
0
20
40
60
80
100
PBS
NC
Ang
-1siR
NA
VEG
F siR
NA
Num
ber o
f tub
e for
mat
ions
Tube formation assay
lowast
lowastlowast
lowastlowast
lowastdaggerdagger
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
VEGF-A siRNANormal
SDF-1 (10ngmL) Ang-1 siRNA
PBS SDF-1 (100ngmL)
(h)
Figure 1 The SDF-1120572CXCR4 axis could promote the expressions of cellular growth factors in BMSCs and induce angiogenesis in vitro((a) (d) and (e))The CXCR4 expression of BMSCs was significantly unregulated after being stimulated by combined SDF-1120572 protein whichcould be inhibited by the CXCR4 receptor agonist AMD3100 ((b)ndash(d) (f)-(g)) Recombined SDF-1120572 protein could significantly promoteBMSCS expression of VEGF ANG-1 HGF and TGF-120573 and the effect could also blocked by AMD3100 Moreover there was a dose-effectrelationship between combined SDF-1120572 protein and CXCR4 VEGF ANG-1 HGF and TGF-120573 expressions Data are expressed as mean plusmn SD(lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SDF-1120572 (10 ngmL or 100 ngmL) versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSDF-1120572 (10 ngmL or 100 ngmL) versus SDF-1120572 (10 ngmL or 100 ngmL) + AMD3100 10 120583gmL) (h) BMSCs supernatant could significantlypromoted angiogenesis especially after being pretreated with SDF-1120572 and this increase was partly offset by AMD3100 Both VEGF siRNAand Ang-1 siRNA significantly weakened proangiogenic capacity of BMSCs Data are expressed as mean plusmn SD (119875 lt 001 for NC versusPBS lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SDF-1120572 (10 ngmL or 100 ngmL) Ang-1 siRNA or VEGF siRNA versus NC) (NC normalcontrol SDF-1120572 stromal cell derived factor-1a CXCR4 CXC chemokine receptor 4 VEGF vascular endothelial growth factor and ANG-1angiopoietin-1)
positive and the result showed that the high signals (whitepoints) in T1WI became low signals (dark points) in T2WIwhereas the low signals (dark points) in T1WI became highsignals (white points) as shown in Figure 5(c) Furthermorethe high signals in T1WI decreased obviously in anti-CXCR4group compared with BMSCs group on posttransplant day 5(Figure 5(b))
36 Transplanted BMSCs Reduced Pancreatic Edema Hem-orrhage and Necrosis Inhibited Systematic Inflammationand Promoted the Formation of TCs Involved in the SDF-1120572CXCR4 Axis Pancreatic edema hemorrhage and necro-sis were markedly reduced and the levels of serum amylasewere significantly lower in the SAP+BMSCs group than in theSAP and SAP+anti-CXCR4 BMSCs groups (Figures 6(a) and
8 Stem Cells International
DMEM-LG
DMEM-LG
DMEM-LG + BMSCs supernatant
DMEM-LG + BMSCs supernatant
DMEM-LG000
005
010
015
020
OD
val
ues (
OD573
nm)
DMEM-LG+ BMSCs supernatant
lowast
(a)
00
07
14
OD490
nm
0 50 100 150
BMSCs supernatantDMEM-LG
Incubation time (h)
lowast
lowastlowast
lowastlowast
lowastlowast
lowastlowast
(b)
10
08
06
04
02
00
OD490
nm
0 50 100 150
Incubation time (h)
lowast
lowast
lowast
lowast
lowastlowast
BMSCs supernatant + 025 trypsinDMEM-LG + 025 trypsin
(c)
Figure 2 The BMSCs supernatant could promote the proliferation migration and repair of human umbilical-vein endothelial cell line(EAhy926 cells) (a)Themethylene blue staining (magnification times200) is indicating that the BMSCs supernatant could significantly promotethe migration of EAhy926 cells Data are expressed as mean plusmn SD (lowast119875 lt 005 for DMEM-LG versus DMEM-LG + BMSCs supernatant) (b)The significant increase of the growth of EAhy926 cells was investigated in MTT test after being given BMSCs supernatant (c) ImpairedEAhy926 cells could be repaired by BMSCs supernatant Data are expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005and lowastlowast119875 lt 001 for DMEM-LG versus DMEM-LG + BMSCs supernatant at each corresponding time point) Data analysis was performedby a one-way ANOVA (BMSCs bone marrow-derived mesenchymal stem cells MTT 3-(45-dimethylthiazol-2-yl)-2S-diphenyltetrazoliumbromide)
6(b)) Inflammatory cytokines were detected with ELISAsThe results show that the levels of serum proinflamma-tory cytokines (IL-1120573 IL-6 and TNF-120572) were significantlydownregulated in the SAP+BMSCs group compared with theSAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines (IL-4 IL-10 andTGF-120573) were significantly upregulated in the SAP+BMSCsgroup comparedwith the SAP and SAP+anti-CXCR4BMSCsgroups (Figure 6(c)) We also found that a large number ofTCs appeared in the BMSCs group (as indicated by red arrowand a magnified picture in Figure 6(a))
37 SDF-1120572CXCR4 Axis Enhances the Expressions of VEGFandANG-1 inDamaged Pancreatic Tissues VEGF expressionin injured pancreatic tissues was measured with qRT-PCRand immunoblotting VEGF expression was higher in theSAP+BMSCS group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups on postoperative days 1and 4 but had decreased on postoperative day 7 (Figures 7(b)7(c) and 7(e)) The expression of ANG-1 was detected withqRT-PCR and immunoblotting and its expression was higherin the SAP+BMSCS group than in the normal control SAPand SAP+anti-CXCR4 BMSCs groups (Figures 7(a) 7(c)
Stem Cells International 9
(a)
Control
Days
$$
$$$
ampampamp
$$ $ampampamp
ampamp
amp
dagger
$$ $ampampamp
daggerdagger dagger$$ $
ampampamp
daggerdagger dagger
15
10
05
000 1 2 3 4 5 6 7 8
Fe = 75120583gmLFe = 25120583gmL Fe = 100120583gmLFe = 50120583gmL
OD
val
ues (
OD490
nm)
(b)
SPIO
N-la
bele
d BM
SCs
Unl
abel
ed B
MSC
s
(c)
BMSCsSPION-labeled
BMSCs
36
43
(kD)CXCR4
GAPDH
(d)
BMSCs
BMSCsSPION-labeled BMSCs
SPION-labeledBMSCs
15
10
05
00
Relat
ive m
RNA
expr
essio
ns
P gt 005
(e)
Figure 3There is similarity in the proliferation andCXCR4 expression between unlabeled and SPION-labeled BMSCs ([Fe3+] = 25 gmL) (a)The Prussian blue staining shows that BMSCs were labeled by SPION successfully (b) TheMTT tests are showing that the growth activity ofSPION-labeled BMSCs ([Fe3+] = 25 gmL) slowed slightly compared with that of the unlabeled BMSCs which was also significantly strongerthan that of other SPION-labeled BMSCs ([Fe3+] = 50 75 or 100 gmL) Data are expressed as mean plusmn SD (ampamp119875 lt 001 and ampampamp
119875 lt 0001
for normal control versus SPION-labeled BMSCS ([Fe3+] = 100 gmL) $$119875 lt 001 and $$$119875 lt 0001 for normal control versus SPION-labeled
BMSCS ([Fe3+] = 75 gmL) and dagger119875 lt 005 and daggerdaggerdagger119875 lt 0001 for normal control versus SPION-labeled BMSCS ([Fe3+] = 50 gmL) at eachcorresponding time point) ((c)-(d)) CXCR4 expression was detected by immunofluorescence and western blotting and similar betweenunlabeled and SPION-labeled BMSCs (119875 gt 005) (SPION superparamagnetic iron oxide nanoparticles BMSCs bone marrow-derivedmesenchymal stem cells)
10 Stem Cells International
Ant
i-CXC
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reas
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reas
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Figure 4 Continued
Stem Cells International 11
100
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The n
umbe
r of b
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10d
BMSCsAnti-CXCR4 BMSCs
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
(c)
Figure 4 Prussian blue staining was performed for detecting the SPION-labeled BMSCs in pancreatic and lung tissues (a) The Prussianblue staining of pancreatic tissue indicates that the cells were stained blue (as indicated by black arrows) gradually increased and peaked onpostoperative days 5ndash7 when the formation of tubular complexes was also maximal (as indicated by red arrows) However the migration waspartly inhibited and the trend was not obviously investigated in anti-CXCR4 group (b) The lung tissues were stained by Prussian blue andthe blue particles (as indicated by black arrows) were gradually decreasing in both BMSCs and anti-CXCR4 groups (c) The blue particles inlung pancreas liver spleen and small intestine were counted and analyzed between BMSCs and anti-CXCR4 groupsThe result showed thatthe number of blue particles of pancreas in BMSCs group was significantly more than in anti-CXCR4 group at postoperative days 1 3 5 and7 Data are expressed as mean plusmn SD (lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for BMSCs versus anti-CXCR4 at each corresponding time point)
and 7(d)) The mRNA levels of HGF and TGF-120573 were alsodetected with qRT-PCR and were significantly higher in theSAP+BMSCs group than in the normal SAP and SAP+anti-CXCR4 BMSCs groups (Figures 7(f) and 7(g))
38 SDF-1120572CXCR4 Axis Induces the Neovascularization InVivo To assess the neovascularization we conducted qRT-PCR or immunohistochemistry for detecting these angiogen-esis markers (CD31 VEGF and vWF) The results indicatedthat the expressions of CD31 VEGF and vWF in necroticpancreatic tissue were higher in the SAP+BMSCs group thanin the normal control SAP and SAP+anti-CXCR4 BMSCsgroups especially in early phase (Figures 7(h) and 8(a)ndash8(d))
4 Discussion
Several studies have shown that MSCs from the bone orumbilical cord can attenuate acute necrotic pancreatitis byinhibiting systematic inflammation regulating the immuneresponses reducing the apoptosis of pancreatic acinar cellsand repairing damaged the small intestinal epithelium [9ndash12]However these functions do not account for how to repairand regenerate the necrotic pancreatic tissues In the studywe found that BMSCs can reduce severe acute pancreatitisby alleviating the systematic inflammation promoting theformation of tubular complexes (TCs) and inducing angio-genesis involving the SDF-1120572CXCR4 axis by enhancing the
expression of cell growth factors in a rat model of SAP Largeprevious studies have found that MSCs can not only differ-entiate into different kinds of functional adult cells but alsosecrete various soluble factors including VEGF HGF andTGF-120573 [27] These factors which promote angiogenesis andmitosis and reduce apoptosis can explain tissue repair andregeneration after MSCs transplanted [28 29] Moreover theregeneration of the pancreas begins with the TCs that consistof a cluster of epithelia surrounded by the mesenchymalcells [30 31] Thus we inferred that SDF-1120572CXCR4 axis wasinvolved in the repair and regeneration of SAP
SDF-1120572 and its receptor CXCR4 have been studiedextensively together with their roles in migration homingproliferation angiogenesis and so forth [11 13ndash15 18 3233] Many researches have shown that BMSCs can migrateto injured tissues via the SDF-1120572CXCR4 axis and relievemyocardial infraction [13 14] promote wound healing [19]heal bone fracture [34] reduce cerebral ischemia [35] andameliorate acute necrotizing pancreatitis [11] SDF-1120572 expres-sion is upregulated by hypoxia-inducible factor-1 (HIF-1)[36] In the study we successfully established a rat model ofacute necrotizing pancreatitis with the retrograde injectionof Na-taurocholate which causes acinar cell injurynecrosisby triggering transient pathological intra-acinar-cell cal-cium ions and activating digestive zymogens [37ndash39] Theinjurednecrotic pancreatic tissue causes HIF-1 expressionand thus induces SDF-1120572 expression which attracts BMSCsto injured pancreas through the interaction with CXCR4
12 Stem Cells International
T1WI
SPIO
N-la
bele
d BM
SCs
T2WI
5 10 15 20 25 30[Fe] (120583gmL)
(a)
Normal (T1WI)
BMSCs BMSCs BMSCs
Anti-CXCR4 BMSCsBMSCsBMSCs
BMSCs
5d (T1WI)7d (T1WI)
1d (T1WI) 3d (T1WI) 5d (T1WI)
10d (T1WI)
(b)
BMSCs
7d (T1WI)
BMSCs
7d (T2WI)
(c)
Figure 5 The transplanted SPION-labeled BMSCs were tracked by MRI in vivo (a) [Fe3+] was detected by MRI and the result showed thatthe SPION-labeled BMSCs ([Fe3+] = 25 gmL) appeared high signals (white spots) on T1WI and low signals (dark spots) on T2WI (b) TheSPION-BMSCs ([Fe3+] = 25 gmL) was tracked by MRI in vivo and the photos show that the white spots (inside of red circle) were increasinggradually and peaked on postoperative days 5ndash7 Instead the white spots decreased on postoperative day 5 in anti-CXCR4 group comparedwith BMSCs group (c) The SPION-BMSCs ([Fe3+] = 25 gmL) were detected in SAP rats at postoperative day 7 by T1WI and T2WI andthe result was showing that the high signals (white spots) which appeared in T1WI became low signals (dark spots) in T2WI (SPIONsuperparamagnetic iron oxide nanoparticles T1WI T1-weighted imaging and T2WI T2-weighted imaging)
For further investigating whether BMSCs could migrateto injured pancreas and the migration was regulated by SDF-1120572CXCR4 axis in a SAP rat model SPION was used tolabel BMSCs SPION were initially used as a unique MRcontrast agent in the clinical context Recently their two useshave been discoveredmdashthe labeling of live cells and tissuesdisease diagnosis and therapy [22 23 40ndash42] Studies havedemonstrated that SPION-labeling does not deleteriouslyaffect the functions of the target cells [25] In our study wealso demonstrated that there was no difference in the pro-liferation capacities between SPION-labeled (Fe = 25 120583gmLlabeling efficiency gt 95) and unlabeled BMSCs Moreover
the expression of CXCR4was also similar between the labeledand unlabeled cells SPION-labeled BMSCs could be detectedby both MRI and Prussian blue staining because SPIONis the nanometer particles of ferric oxide The dynamicmovement of labeling cells could be observed at the photosof MRI so that we can intuitively assess the proportions ofSPION-labeled BMSCs in vivo The result showed that thesecells could migrate to the damaged pancreatic tissues andthere was also a gradual increase in migration peaking onpostoperative days 5ndash7 with the formation of large numbersof TCs SDF-1120572CXCR4 axis could regulate the migrationof BMSCs as our previously described [11] Meanwhile the
Stem Cells International 13
SAP
NC Sham Tubular complex
SAP+
BMSC
sSA
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anti-
CXCR
4BM
SCs
1d 4d 7d
(a)
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e $
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Normal
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e
$
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Normal
SAP + BMSCs
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Normal
$$$
$$$
1000
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$$$
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1d 4d 7d
1d 4d 7d 1d 4d 7d
1d 4d 7dInfiltration
Necrosis
Am
ylas
e act
ivity
(b)
Figure 6 Continued
14 Stem Cells International
130
120
110
100
90
80The c
once
ntra
tion
of se
rum
IL-1
(pg
mL)
daggerdaggerlowast
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Control Day 1 Day 4 Day 7
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The c
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rum
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rum
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(pg
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rum
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(pg
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The c
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rum
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(pg
mL)
260
240
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180
160
220
200
180
160
140
120The c
once
ntra
tion
of se
rum
TG
F-120573
(pg
mL)
(c)
Figure 6 Transplanted BMSCs could reduce severe acute pancreatitis (SAP) promoting the formation of tubular complexes and inhibitingsystematic inflammatory response being involved in the SDF-1120572CXCR4 axis ((a) (b))TheHampE staining of pancreatic tissues (magnificationtimes100) is showing that the edema infiltration and necrosis were significantly reduced in the SAP+BMSCs group compared with SAP andSAP+anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively A large number of tubular complexes were also investigatedin SAP+BMSCs group (as indicated by red arrow in a 400x magnified picture) Serum amylase activity was also significantly reduced inSAP+BMSCs group than in normal SAP and anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively (c) The levels ofserum proinflammatory cytokines are significantly lower in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines are significantly higher in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups Dataare expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SAP versus Normal dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP versus SAP+BMSCs $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4BMSCs) Data analysis was performed by Studentrsquos test (BMSCs bone marrow-derived mesenchymal stem cells HampE hematoxylin-eosin)
number of cells whichmigrated to the necrotic pancreas waspositively related to the therapeutic effect However SPION-labeled BMSCs could be rarely seen on postoperative day 10perhaps because the SPIONwere degraded or the BMSCs haddifferentiated into other cells including pancreatic exocrinecells
To validate whether the SDF-1120572CXCR4 axis also playsan important role in the repair and regeneration of SAPwe conducted the study in vitro and vivo We found thatthe secretions of BMSCs could promote the proliferationmigration and restoration of EAhy926 cells The BMSCssupernatant induced angiogenesis and the SDF-1120572CXCR4axis stimulated BMSCs to express VEGF ANG-1 HGFand TGF-120573 promoting further angiogenesis in vitro Both
VEGF and ANG-1 play important roles in angiogenesisMoreover the expressions of VEGFANG-1HGF andTGF-120573in the damaged pancreatic tissues were higher in the BMSCstransplantation group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups Taken all together theresult showed that transplantedBMSCs repaired the damagedpancreas through secreting large cellular growth factors andthe effect was regulated by SDF-1120572CXCR4 axis
As we all know VEGF a potent inducer of angiogenesispromotes the repair of injured vascular endothelial cellsand neovascularization Studies have shown that the SDF-1120572CXCR4 axis promotes the synthesis and secretion ofVEGF [17 43] and SDF-1120572 combined with VEGF enhancesischemic angiogenesis [20] In our study we confirmed that
Stem Cells International 15
15
10
5
0
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
expr
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16 Stem Cells International
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ive m
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NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
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1d 4d 7d
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orm
alSA
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Relat
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NCShamSAP BMSCs
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NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
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ositi
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0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
4 Stem Cells International
Table 1 The primer sequences of genes
RatGene Forward primer Reverse primer PCR amplified products (bp)GAPDH 51015840gtACCACAGTCCATGCCATCAClt31015840 51015840gtTCCACCACCCTGTTGCTGTAlt31015840 452VEGF 51015840gtTGTGAGCCTTGTTCAGAGCGlt31015840 51015840gtGACGGTGACGATGGTGGTGTlt31015840 252CXCR4 51015840gtTGTGAGCCTTGTTCAGAGCGlt31015840 51015840gtTGTGAGCCTTGTTCAGAGCGlt31015840 260ANG-1 51015840gtCAAGGCTTGGTTACTCGTCAGlt31015840 51015840gtCCATGAGCTCCAGTTGTTGClt31015840 109HGF 51015840gtAGTCTATGGACCTGAAGGCTClt31015840 51015840gtCCATCTGCGTTGATCAATCClt31015840 171TGF-120573 51015840gtCTACTGCTTCAGCTCCACAGAGlt31015840 51015840gtCTGTACTGTGTGTCCAGGCTClt31015840 162CD31 51015840gtGAGTGCTTCTTGGTGGGTCClt31015840 51015840gtCCTGAGAAGCACTGTACACClt31015840 150
Biosystems USA) using the comparative CT method Theprocedure was replicated three times Eachmeasurement wasset three repeats
211 Immunofluorescent Staining Immunofluorescent stain-ing was used to assess CXCR4 expression in SPION-labeledBMSCs as previously described [11]
212 Labeling BMSCs BMSCs at gt90 confluence werepretreated with or without AMD3100 (10120583gmL) and thenincubated with labeling medium containing 25120583gmL Fe3+and 075 ngmL poly-l-lysine for 24 h After theywere labeledthe cells were washed three times with PBS and harvestedwith 025 trypsin-EDTA The viability of the cells wasassessed with Trypan Blue exclusion before cell transplanta-tion The functions of the different concentrations of Fe3+-labeled BMSCs were analyzed in the following experiments
213 Cell Migration Assay In this experiment 5 times 104EAhy926 cells were added to the upper chamber of the Tran-swell apparatus and supplemented with 180120583L of DMEMand 20 120583L of 1 BSA and the lower chamber was filled with500120583L of DMEM-LG complete medium with or withoutBMSCS supernatant (100 120583L) After incubation for 12 h theupper chamber was removed and the cells were fixed with 4paraformaldehyde for 30min The lower surface of the filtermembrane was stained with 01 crystal violet for 10minin the dark After the membrane was thoroughly washed itwas observed with a digital camera and light microscopeThe experiment was repeated three times Finally the crystalviolet was dissolved in 300 120583L of 33 acetic acid and theabsorbance of the solution was measured at 573 nm with anELISA plate reader (Gene Company Limited HK China)
214 Cell Proliferation Assay (MTT Test) To investigatewhether BMSCs could repair the injured vascular endothelialcells we designed this experiment First EAhy926 cellswere cultured in 25 cm2 culture flasks and then incubatedwith 100 120583L of 025 trypsin-EDTA for 60min at a con-stant temperature of 37∘C in a humidified atmosphere of95 O
2supplemented with 5 CO
2until their confluence
reached approximately 90 Finally the cells were collectedand seeded into 96-well plates at 2000 cellswell Each wellcontained DMEM-LG complete medium with or without
BMSCs supernatant (DMEM-LG complete medium BMSCssupernatant = 1 1) MTT solution (20120583L of 5mgmL) wasadded daily for seven days (12 h 36 h 68 h 92 h 121 h and145 h) The medium was then removed and 150120583L of DMSOwas added to each well The plates were then shaken slowlyfor 10min Absorbance was measured with an ELISA platereader at 490 nm This experiment was repeated three timesSPION-labeled BMSCs were also assayed withMTT test aftertreatment with different concentrations of Fe3+ (25 120583gmL50 120583gmL 75120583gmL or 100 120583gmL)
215 ANG-1 and VEGF Silencing with Small Interfering RNAsGene silencing technology was used to understand the effectsof the BMSCs supernatant on the angiogenic activity ofEAhy926 cells in vitro Small interfering RNA (siRNA) tar-geting rat ANG-1 (51015840-GGCCCAGAUACAACAGAAUUU-dTdT-31015840) and (51015840-AUUCUGUUGUAUCUGGGCCUUdTd-T-31015840) or VEGF (51015840-GGGATTGCACGGAAACUUUdTdT-31015840) and (51015840-AAAGUUUCCGUGCAAUCCCdTdT-31015840) andcontrol nonsilencing siRNAs (51015840-AUGUGAAUGCACCAA-AGAAdTdT-31015840) and (51015840-UUCUUUGGUCUGCAUUCA-CAUdTdT-31015840) were synthesized by Biomics BiotechnologiesCo Ltd (Nantong City Jiangsu Province China) BMSCswere transfected with the siRNAs using Lipofectamine 2000according to the manufacturerrsquos protocol (Biotend ShanghaiChina) The BMSCs supernatant was collected 48 h aftertransfection and stored at minus80∘C for the tube formation assay
216 Angiogenesis A tube formation assay was performedto investigate the effect of the BMSCs supernatant on theangiogenic activity of EAhy926 cells in vitro Ninety-six-wellculture dishes were coated with 50 120583L of matrigel matrix andincubated for 30min at 37∘C EAhy926 cells were starvedfor 24 h and were then seeded onto the solidified gels ata density of 105 cellswell in 50120583L of culture medium TheBMSCs supernatant (50 120583L) or 1 timesPBS (50 120583L) was added toeach well These cells were divided into the normal controlSDF-1120572 10 ngmL SDF-1120572 100 ngmL ANG-1 siRNA andVEGF siRNA groups After incubation for 6 h the totaltube-like structures were photographed with phase-contrastmicroscopy (100x) and five randomly selected microscopicfields per photograph were quantified using the Image Jsoftware To further detect the angiogenesis in vivo theexpressions of vascular endothelialmarkers (VEGF vWF and
Stem Cells International 5
CD31) were measured by immunohistochemistry or westernblotting in SAP SAP+BMSCs and SAP+anti-CXCR4 BMSCsgroups
217 Magnetic Resonance Imaging (MRI) and Prussian BlueStaining To track the distributions of SPION-labeledBMSCsin vivo MRI and Prussian blue staining were used to detectFe3+The animalswere anesthetized and then put into anMRIcoil (Shanghai Niumag Electronic Science and TechnologyCo Ltd China) The T1-weighted imaging (T1WI) param-eters were as follows FOV read = 100mm FOV phase =100mm TR = 500ms TE = 20ms slice width = 35mm slicegap = 05mm and NS = 12 and the T2-weighted imaging(T2WI) parameters were as follows FOV read = 100mmFOV phase = 100mm TR = 2000ms TE = 80ms slice width= 35mm slice gap = 05mm andNS = 8 Finally the animalswere killed and pancreas lung liver spleen and smallintestine were collected and fixed in 4 paraformaldehydefor Prussian blue staining A Prussian blue staining kit wasused to detect Fe3+ in the SPION-labeled BMSCs and abovetissues according to the manufacturerrsquos instructions Thecells were fixed in 4 glutaraldehyde washed and incubatedfor 30min with 2 potassium ferric-ferrocyanide (Perlrsquosreagent) in 37 hydrochloric acid The cells were washedagain counterstained with Nuclear Fast Red and the ironstaining was evaluated with light microscopy (Carl ZeissOberkochen Germany) with a times40075 objective lens andAxiovision 44 software (Carl Zeiss) The SPION labelingefficiency was determined bymanually counting the Prussianblue stained and unstained cells under a Zeiss microscope(Carl Zeiss) at times100 magnification with a times100130 oil-immersion objective lens The percentage of labeled cells wasdetermined as the average of five high-powered fields Afterthe slices were fixed dehydrated embedded and sectionedthe tissues were stained with Prussian blue as describedabove The blue granules were counted by a person who didnot know the experiment from ten areas of each histologicsection
218 Image Processing and Statistical Analysis Adobe Photo-shop 60 (Adobe Systems Inc San Jose CA) Image-Pro Plusversion 60 (Media Cybernetics USA) and Image J (NationalInstitutes of Health USA) were used for image typesettinganalysis and processing GraphPad Prism 50 (GraphPadCo USA) was used for mapping The SPSS 170 statisticalsoftware (Chicago IL) was used for all statistical analysesExperimental data are shown as means plusmn standard deviations(SD) and compared with Studentrsquos or a paired 119905 test or one-way ANOVA A value of 119875 lt 005 was deemed to indicatesignificant differences
3 Results
31 Recombinant SDF-1120572 Protein Stimulated BMSCs Expres-sions of VEGFANG-1HGF TGF-120573 andCXCR4 Theexpres-sions of VEGF ANG-1 HGF TGF-120573 and CXCR4 weredetected with qRT-PCR or immunoblotting assays at 24 hand 48 h after recombinant SDF-1120572 protein was added tothe BMSCs culturemediumThe recombined SDF-1120572 protein
significantly stimulated the expressions of VEGF ANG-1 andCXCR4 in the BMSCs which was also positively correlatedwith the concentration of SDF-1120572 This effect was blockedby the CXCR4 agonist AMD3100 (Figures 1(a)-1(b) and1(d)ndash1(g)) The mRNA levels of HGF and TGF-120573 were bothupregulated after stimulation with SDF-1120572 but were inhibitedby AMD3100 (Figure 1(c))
32 BMSCs Supernatant Promotes the Proliferation Migra-tion and Repair of EAhy926 Cells The BMSCs supernatantpromoted the growth andmigration of EAhy926 cells signifi-cantlymore thanDMEM-LG completemedium (Figures 2(a)and 2(b))Moreover EAhy926 cells impaired by trypsinweremore effectively repaired by the BMSCs supernatant than byDMEM-LG complete medium (Figure 2(c))
33 SDF-1120572CXCR4 Axis Induces Angiogenesis In Vitro BeingRelated to the Expressions of VEGF and ANG-1 The BMSCssupernatant pretreated with SDF-1120572 significantly promotedangiogenesis compared with the normal BMSCs supernatantin vitro which was also positively related to the concentrationof SDF-1120572 Furthermore the angiogenesis was reduced inbothVEGF siRNA andANG-1 siRNA comparedwith normalBMSCs supernatant (Figure 1(h))
34 No Significant Differences on Biological Functions betweenBMSCs and SPION-Labeled BMSCs ([Fe3+] = 25 120583gmL)More than 95 of BMSCs were successfully labeled withSPION ([Fe3+] = 25 120583gmL) (Figure 3(a))The growth activityof SPION-labeled BMSCs ([Fe3+] = 25120583gmL) was similarto unlabeled BMSCs which was significantly stronger thanthat of other SPION-labeled BMSCs ([Fe3+] = 50 75 or100 120583gmL) (Figure 3(b)) CXCR4 expression was observedwith confocalmicroscopy and similar in both the BMSCs andSPION-labeled BMSCs (Figures 3(c)ndash3(e))
35 SDF-1120572CXCR4 Axis Regulates the Migration of SPION-Labeled BMSCs to Necrotic Pancreatic Tissues and the Migra-tion Increased Gradually Peaking on Days 5ndash7 The resultsof Prussian blue staining showed that the SPION-labeledBMSCs were relatively low in pancreas liver spleen andsmall intestine at the first day of the transplant comparedto lung but gradually increasing in pancreatic tissue atposttransplant days 3 and 7 and relatively high comparedto liver spleen and small intestine when the formation oftubular complexes (TCs) was also maximal (Figures 4(a)ndash4(c)) On the contrary SPION-labeled BMSCs in the lungtissue became less and less (Figure 5(b))Themore importantpoint was that the migrations of SPION-labeled BMSCs toinjured pancreas could be inhibited by anti-CXCR4 treatment(Figures 4(a)ndash4(c)) To further visually investigate whetherthe SPION-labeledBMSCs couldmigrate to injured pancreasthe MRI method was selected for realizing the tracing invivo The magnetic resonance images displayed that SPION-labeled BMSCs ([Fe3+] = 25 gmL) were high signal in T1WI(white) and low signal (dark) in T2WI as shown in Fig-ure 5(a) The high signal intensity (white points) in pancreas(as indicated by red circle) increased gradually in T1WI andpeaked on days 5 and 7 (Figure 5(b)) We also performedT2WI on day 7 in order to exclude the possibility of false
6 Stem Cells International
Relat
ive m
RNA
expr
essio
ns
CXCR4
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
lowastdagger
lowastdagger
0
1
2
3
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)(a)
Relat
ive m
RNA
expr
essio
ns
lowast
lowastdagger
lowastdaggerlowastdagger
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
Ang-1VEGF
0
1
2
3
4
5
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(b)
Relat
ive m
RNA
expr
essio
ns
lowast
lowast
daggerdaggerdaggerdaggerdaggerdagger
daggerdaggerdagger
daggerdaggerdagger
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
0
2
4
6
8
10
TGF-120573HGF
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(c)
+ +
+
+ +
+
43
45
36GAPDH
VEGF
CXCR4
ANG-1 70
(kD)
minus
minus
minus
minus minus
minus minus
minus minus
SDF-1
SDF-1(10ngmL)
(100ngmL)AMD3100(10120583gmL)
(d)
000
005
010
015
Ratio
of C
XCR4
to G
APD
H
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
lowastdaggerlowastdagger
dagger
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(e)
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
10
08
06
04
02
00
Ratio
of V
EGF
to G
APD
H
lowastdagger
lowastlowast lowastdagger
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(f)
Figure 1 Continued
Stem Cells International 7
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SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
lowastdagger
lowastdagger
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005
Ratio
of A
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APD
H
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gm
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(100
ngm
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-1siR
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F siR
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Num
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f tub
e for
mat
ions
Tube formation assay
lowast
lowastlowast
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lowastdaggerdagger
SDF-1
(10
ngm
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SDF-1
(100
ngm
L)
VEGF-A siRNANormal
SDF-1 (10ngmL) Ang-1 siRNA
PBS SDF-1 (100ngmL)
(h)
Figure 1 The SDF-1120572CXCR4 axis could promote the expressions of cellular growth factors in BMSCs and induce angiogenesis in vitro((a) (d) and (e))The CXCR4 expression of BMSCs was significantly unregulated after being stimulated by combined SDF-1120572 protein whichcould be inhibited by the CXCR4 receptor agonist AMD3100 ((b)ndash(d) (f)-(g)) Recombined SDF-1120572 protein could significantly promoteBMSCS expression of VEGF ANG-1 HGF and TGF-120573 and the effect could also blocked by AMD3100 Moreover there was a dose-effectrelationship between combined SDF-1120572 protein and CXCR4 VEGF ANG-1 HGF and TGF-120573 expressions Data are expressed as mean plusmn SD(lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SDF-1120572 (10 ngmL or 100 ngmL) versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSDF-1120572 (10 ngmL or 100 ngmL) versus SDF-1120572 (10 ngmL or 100 ngmL) + AMD3100 10 120583gmL) (h) BMSCs supernatant could significantlypromoted angiogenesis especially after being pretreated with SDF-1120572 and this increase was partly offset by AMD3100 Both VEGF siRNAand Ang-1 siRNA significantly weakened proangiogenic capacity of BMSCs Data are expressed as mean plusmn SD (119875 lt 001 for NC versusPBS lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SDF-1120572 (10 ngmL or 100 ngmL) Ang-1 siRNA or VEGF siRNA versus NC) (NC normalcontrol SDF-1120572 stromal cell derived factor-1a CXCR4 CXC chemokine receptor 4 VEGF vascular endothelial growth factor and ANG-1angiopoietin-1)
positive and the result showed that the high signals (whitepoints) in T1WI became low signals (dark points) in T2WIwhereas the low signals (dark points) in T1WI became highsignals (white points) as shown in Figure 5(c) Furthermorethe high signals in T1WI decreased obviously in anti-CXCR4group compared with BMSCs group on posttransplant day 5(Figure 5(b))
36 Transplanted BMSCs Reduced Pancreatic Edema Hem-orrhage and Necrosis Inhibited Systematic Inflammationand Promoted the Formation of TCs Involved in the SDF-1120572CXCR4 Axis Pancreatic edema hemorrhage and necro-sis were markedly reduced and the levels of serum amylasewere significantly lower in the SAP+BMSCs group than in theSAP and SAP+anti-CXCR4 BMSCs groups (Figures 6(a) and
8 Stem Cells International
DMEM-LG
DMEM-LG
DMEM-LG + BMSCs supernatant
DMEM-LG + BMSCs supernatant
DMEM-LG000
005
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015
020
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val
ues (
OD573
nm)
DMEM-LG+ BMSCs supernatant
lowast
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nm
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Incubation time (h)
lowast
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nm
0 50 100 150
Incubation time (h)
lowast
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BMSCs supernatant + 025 trypsinDMEM-LG + 025 trypsin
(c)
Figure 2 The BMSCs supernatant could promote the proliferation migration and repair of human umbilical-vein endothelial cell line(EAhy926 cells) (a)Themethylene blue staining (magnification times200) is indicating that the BMSCs supernatant could significantly promotethe migration of EAhy926 cells Data are expressed as mean plusmn SD (lowast119875 lt 005 for DMEM-LG versus DMEM-LG + BMSCs supernatant) (b)The significant increase of the growth of EAhy926 cells was investigated in MTT test after being given BMSCs supernatant (c) ImpairedEAhy926 cells could be repaired by BMSCs supernatant Data are expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005and lowastlowast119875 lt 001 for DMEM-LG versus DMEM-LG + BMSCs supernatant at each corresponding time point) Data analysis was performedby a one-way ANOVA (BMSCs bone marrow-derived mesenchymal stem cells MTT 3-(45-dimethylthiazol-2-yl)-2S-diphenyltetrazoliumbromide)
6(b)) Inflammatory cytokines were detected with ELISAsThe results show that the levels of serum proinflamma-tory cytokines (IL-1120573 IL-6 and TNF-120572) were significantlydownregulated in the SAP+BMSCs group compared with theSAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines (IL-4 IL-10 andTGF-120573) were significantly upregulated in the SAP+BMSCsgroup comparedwith the SAP and SAP+anti-CXCR4BMSCsgroups (Figure 6(c)) We also found that a large number ofTCs appeared in the BMSCs group (as indicated by red arrowand a magnified picture in Figure 6(a))
37 SDF-1120572CXCR4 Axis Enhances the Expressions of VEGFandANG-1 inDamaged Pancreatic Tissues VEGF expressionin injured pancreatic tissues was measured with qRT-PCRand immunoblotting VEGF expression was higher in theSAP+BMSCS group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups on postoperative days 1and 4 but had decreased on postoperative day 7 (Figures 7(b)7(c) and 7(e)) The expression of ANG-1 was detected withqRT-PCR and immunoblotting and its expression was higherin the SAP+BMSCS group than in the normal control SAPand SAP+anti-CXCR4 BMSCs groups (Figures 7(a) 7(c)
Stem Cells International 9
(a)
Control
Days
$$
$$$
ampampamp
$$ $ampampamp
ampamp
amp
dagger
$$ $ampampamp
daggerdagger dagger$$ $
ampampamp
daggerdagger dagger
15
10
05
000 1 2 3 4 5 6 7 8
Fe = 75120583gmLFe = 25120583gmL Fe = 100120583gmLFe = 50120583gmL
OD
val
ues (
OD490
nm)
(b)
SPIO
N-la
bele
d BM
SCs
Unl
abel
ed B
MSC
s
(c)
BMSCsSPION-labeled
BMSCs
36
43
(kD)CXCR4
GAPDH
(d)
BMSCs
BMSCsSPION-labeled BMSCs
SPION-labeledBMSCs
15
10
05
00
Relat
ive m
RNA
expr
essio
ns
P gt 005
(e)
Figure 3There is similarity in the proliferation andCXCR4 expression between unlabeled and SPION-labeled BMSCs ([Fe3+] = 25 gmL) (a)The Prussian blue staining shows that BMSCs were labeled by SPION successfully (b) TheMTT tests are showing that the growth activity ofSPION-labeled BMSCs ([Fe3+] = 25 gmL) slowed slightly compared with that of the unlabeled BMSCs which was also significantly strongerthan that of other SPION-labeled BMSCs ([Fe3+] = 50 75 or 100 gmL) Data are expressed as mean plusmn SD (ampamp119875 lt 001 and ampampamp
119875 lt 0001
for normal control versus SPION-labeled BMSCS ([Fe3+] = 100 gmL) $$119875 lt 001 and $$$119875 lt 0001 for normal control versus SPION-labeled
BMSCS ([Fe3+] = 75 gmL) and dagger119875 lt 005 and daggerdaggerdagger119875 lt 0001 for normal control versus SPION-labeled BMSCS ([Fe3+] = 50 gmL) at eachcorresponding time point) ((c)-(d)) CXCR4 expression was detected by immunofluorescence and western blotting and similar betweenunlabeled and SPION-labeled BMSCs (119875 gt 005) (SPION superparamagnetic iron oxide nanoparticles BMSCs bone marrow-derivedmesenchymal stem cells)
10 Stem Cells International
Ant
i-CXC
R4BM
SCs
BMSC
s
Nor
mal
1d 3d 7d5d 10d
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Lung
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reas
Smal
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Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
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Figure 4 Continued
Stem Cells International 11
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
10d
BMSCsAnti-CXCR4 BMSCs
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
(c)
Figure 4 Prussian blue staining was performed for detecting the SPION-labeled BMSCs in pancreatic and lung tissues (a) The Prussianblue staining of pancreatic tissue indicates that the cells were stained blue (as indicated by black arrows) gradually increased and peaked onpostoperative days 5ndash7 when the formation of tubular complexes was also maximal (as indicated by red arrows) However the migration waspartly inhibited and the trend was not obviously investigated in anti-CXCR4 group (b) The lung tissues were stained by Prussian blue andthe blue particles (as indicated by black arrows) were gradually decreasing in both BMSCs and anti-CXCR4 groups (c) The blue particles inlung pancreas liver spleen and small intestine were counted and analyzed between BMSCs and anti-CXCR4 groupsThe result showed thatthe number of blue particles of pancreas in BMSCs group was significantly more than in anti-CXCR4 group at postoperative days 1 3 5 and7 Data are expressed as mean plusmn SD (lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for BMSCs versus anti-CXCR4 at each corresponding time point)
and 7(d)) The mRNA levels of HGF and TGF-120573 were alsodetected with qRT-PCR and were significantly higher in theSAP+BMSCs group than in the normal SAP and SAP+anti-CXCR4 BMSCs groups (Figures 7(f) and 7(g))
38 SDF-1120572CXCR4 Axis Induces the Neovascularization InVivo To assess the neovascularization we conducted qRT-PCR or immunohistochemistry for detecting these angiogen-esis markers (CD31 VEGF and vWF) The results indicatedthat the expressions of CD31 VEGF and vWF in necroticpancreatic tissue were higher in the SAP+BMSCs group thanin the normal control SAP and SAP+anti-CXCR4 BMSCsgroups especially in early phase (Figures 7(h) and 8(a)ndash8(d))
4 Discussion
Several studies have shown that MSCs from the bone orumbilical cord can attenuate acute necrotic pancreatitis byinhibiting systematic inflammation regulating the immuneresponses reducing the apoptosis of pancreatic acinar cellsand repairing damaged the small intestinal epithelium [9ndash12]However these functions do not account for how to repairand regenerate the necrotic pancreatic tissues In the studywe found that BMSCs can reduce severe acute pancreatitisby alleviating the systematic inflammation promoting theformation of tubular complexes (TCs) and inducing angio-genesis involving the SDF-1120572CXCR4 axis by enhancing the
expression of cell growth factors in a rat model of SAP Largeprevious studies have found that MSCs can not only differ-entiate into different kinds of functional adult cells but alsosecrete various soluble factors including VEGF HGF andTGF-120573 [27] These factors which promote angiogenesis andmitosis and reduce apoptosis can explain tissue repair andregeneration after MSCs transplanted [28 29] Moreover theregeneration of the pancreas begins with the TCs that consistof a cluster of epithelia surrounded by the mesenchymalcells [30 31] Thus we inferred that SDF-1120572CXCR4 axis wasinvolved in the repair and regeneration of SAP
SDF-1120572 and its receptor CXCR4 have been studiedextensively together with their roles in migration homingproliferation angiogenesis and so forth [11 13ndash15 18 3233] Many researches have shown that BMSCs can migrateto injured tissues via the SDF-1120572CXCR4 axis and relievemyocardial infraction [13 14] promote wound healing [19]heal bone fracture [34] reduce cerebral ischemia [35] andameliorate acute necrotizing pancreatitis [11] SDF-1120572 expres-sion is upregulated by hypoxia-inducible factor-1 (HIF-1)[36] In the study we successfully established a rat model ofacute necrotizing pancreatitis with the retrograde injectionof Na-taurocholate which causes acinar cell injurynecrosisby triggering transient pathological intra-acinar-cell cal-cium ions and activating digestive zymogens [37ndash39] Theinjurednecrotic pancreatic tissue causes HIF-1 expressionand thus induces SDF-1120572 expression which attracts BMSCsto injured pancreas through the interaction with CXCR4
12 Stem Cells International
T1WI
SPIO
N-la
bele
d BM
SCs
T2WI
5 10 15 20 25 30[Fe] (120583gmL)
(a)
Normal (T1WI)
BMSCs BMSCs BMSCs
Anti-CXCR4 BMSCsBMSCsBMSCs
BMSCs
5d (T1WI)7d (T1WI)
1d (T1WI) 3d (T1WI) 5d (T1WI)
10d (T1WI)
(b)
BMSCs
7d (T1WI)
BMSCs
7d (T2WI)
(c)
Figure 5 The transplanted SPION-labeled BMSCs were tracked by MRI in vivo (a) [Fe3+] was detected by MRI and the result showed thatthe SPION-labeled BMSCs ([Fe3+] = 25 gmL) appeared high signals (white spots) on T1WI and low signals (dark spots) on T2WI (b) TheSPION-BMSCs ([Fe3+] = 25 gmL) was tracked by MRI in vivo and the photos show that the white spots (inside of red circle) were increasinggradually and peaked on postoperative days 5ndash7 Instead the white spots decreased on postoperative day 5 in anti-CXCR4 group comparedwith BMSCs group (c) The SPION-BMSCs ([Fe3+] = 25 gmL) were detected in SAP rats at postoperative day 7 by T1WI and T2WI andthe result was showing that the high signals (white spots) which appeared in T1WI became low signals (dark spots) in T2WI (SPIONsuperparamagnetic iron oxide nanoparticles T1WI T1-weighted imaging and T2WI T2-weighted imaging)
For further investigating whether BMSCs could migrateto injured pancreas and the migration was regulated by SDF-1120572CXCR4 axis in a SAP rat model SPION was used tolabel BMSCs SPION were initially used as a unique MRcontrast agent in the clinical context Recently their two useshave been discoveredmdashthe labeling of live cells and tissuesdisease diagnosis and therapy [22 23 40ndash42] Studies havedemonstrated that SPION-labeling does not deleteriouslyaffect the functions of the target cells [25] In our study wealso demonstrated that there was no difference in the pro-liferation capacities between SPION-labeled (Fe = 25 120583gmLlabeling efficiency gt 95) and unlabeled BMSCs Moreover
the expression of CXCR4was also similar between the labeledand unlabeled cells SPION-labeled BMSCs could be detectedby both MRI and Prussian blue staining because SPIONis the nanometer particles of ferric oxide The dynamicmovement of labeling cells could be observed at the photosof MRI so that we can intuitively assess the proportions ofSPION-labeled BMSCs in vivo The result showed that thesecells could migrate to the damaged pancreatic tissues andthere was also a gradual increase in migration peaking onpostoperative days 5ndash7 with the formation of large numbersof TCs SDF-1120572CXCR4 axis could regulate the migrationof BMSCs as our previously described [11] Meanwhile the
Stem Cells International 13
SAP
NC Sham Tubular complex
SAP+
BMSC
sSA
P+
anti-
CXCR
4BM
SCs
1d 4d 7d
(a)
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Edema
Scor
e $
$$$
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
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daggerlowastdaggerlowastdagger
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lowastdaggerlowastdaggerlowastdagger
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SAP + BMSCsSAP + anti-CXCR4
SAP + anti-CXCR4SAP + anti-CXCR4
SAP + anti-CXCR4 BMSCs
ShamSAP
Normal
0
1
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Scor
e
$
lowastdagger
lowastdaggerlowastdagger
lowastdagger
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SAP + BMSCs
BMSCsShamSAP
Normal
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1000
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BMSCsShamSAP
Normal
$$$
$$$
1d 4d 7d
1d 4d 7d 1d 4d 7d
1d 4d 7dInfiltration
Necrosis
Am
ylas
e act
ivity
(b)
Figure 6 Continued
14 Stem Cells International
130
120
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100
90
80The c
once
ntra
tion
of se
rum
IL-1
(pg
mL)
daggerdaggerlowast
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Control Day 1 Day 4 Day 7
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham
$
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The c
once
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of se
rum
IL-4
(pg
mL)
80
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The c
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The c
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F-120572
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mL)
260
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160
220
200
180
160
140
120The c
once
ntra
tion
of se
rum
TG
F-120573
(pg
mL)
(c)
Figure 6 Transplanted BMSCs could reduce severe acute pancreatitis (SAP) promoting the formation of tubular complexes and inhibitingsystematic inflammatory response being involved in the SDF-1120572CXCR4 axis ((a) (b))TheHampE staining of pancreatic tissues (magnificationtimes100) is showing that the edema infiltration and necrosis were significantly reduced in the SAP+BMSCs group compared with SAP andSAP+anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively A large number of tubular complexes were also investigatedin SAP+BMSCs group (as indicated by red arrow in a 400x magnified picture) Serum amylase activity was also significantly reduced inSAP+BMSCs group than in normal SAP and anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively (c) The levels ofserum proinflammatory cytokines are significantly lower in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines are significantly higher in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups Dataare expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SAP versus Normal dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP versus SAP+BMSCs $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4BMSCs) Data analysis was performed by Studentrsquos test (BMSCs bone marrow-derived mesenchymal stem cells HampE hematoxylin-eosin)
number of cells whichmigrated to the necrotic pancreas waspositively related to the therapeutic effect However SPION-labeled BMSCs could be rarely seen on postoperative day 10perhaps because the SPIONwere degraded or the BMSCs haddifferentiated into other cells including pancreatic exocrinecells
To validate whether the SDF-1120572CXCR4 axis also playsan important role in the repair and regeneration of SAPwe conducted the study in vitro and vivo We found thatthe secretions of BMSCs could promote the proliferationmigration and restoration of EAhy926 cells The BMSCssupernatant induced angiogenesis and the SDF-1120572CXCR4axis stimulated BMSCs to express VEGF ANG-1 HGFand TGF-120573 promoting further angiogenesis in vitro Both
VEGF and ANG-1 play important roles in angiogenesisMoreover the expressions of VEGFANG-1HGF andTGF-120573in the damaged pancreatic tissues were higher in the BMSCstransplantation group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups Taken all together theresult showed that transplantedBMSCs repaired the damagedpancreas through secreting large cellular growth factors andthe effect was regulated by SDF-1120572CXCR4 axis
As we all know VEGF a potent inducer of angiogenesispromotes the repair of injured vascular endothelial cellsand neovascularization Studies have shown that the SDF-1120572CXCR4 axis promotes the synthesis and secretion ofVEGF [17 43] and SDF-1120572 combined with VEGF enhancesischemic angiogenesis [20] In our study we confirmed that
Stem Cells International 15
15
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5
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SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
expr
essio
nslowastlowastlowastdagger
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$
1d 4d 7dVEGF
(a)
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0
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Relat
ive m
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Ang-11d 4d 7d
(b)NC Sham
ANG-1
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i-CXC
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Relat
ive r
atio
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0020
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Relat
ive r
atio
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(e)
daggerdagger
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Relat
ive m
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PDH
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NCShamSAP
(f)
Figure 7 Continued
16 Stem Cells International
dagger
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Relat
ive m
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essio
ns to
GA
PDH
HGF
lowastlowast
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NCShamSAP
(g)
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Relat
ive m
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daggerlowast
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lowast
daggerlowastlowast
dagger daggerlowast
lowast
lowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
Stem Cells International 5
CD31) were measured by immunohistochemistry or westernblotting in SAP SAP+BMSCs and SAP+anti-CXCR4 BMSCsgroups
217 Magnetic Resonance Imaging (MRI) and Prussian BlueStaining To track the distributions of SPION-labeledBMSCsin vivo MRI and Prussian blue staining were used to detectFe3+The animalswere anesthetized and then put into anMRIcoil (Shanghai Niumag Electronic Science and TechnologyCo Ltd China) The T1-weighted imaging (T1WI) param-eters were as follows FOV read = 100mm FOV phase =100mm TR = 500ms TE = 20ms slice width = 35mm slicegap = 05mm and NS = 12 and the T2-weighted imaging(T2WI) parameters were as follows FOV read = 100mmFOV phase = 100mm TR = 2000ms TE = 80ms slice width= 35mm slice gap = 05mm andNS = 8 Finally the animalswere killed and pancreas lung liver spleen and smallintestine were collected and fixed in 4 paraformaldehydefor Prussian blue staining A Prussian blue staining kit wasused to detect Fe3+ in the SPION-labeled BMSCs and abovetissues according to the manufacturerrsquos instructions Thecells were fixed in 4 glutaraldehyde washed and incubatedfor 30min with 2 potassium ferric-ferrocyanide (Perlrsquosreagent) in 37 hydrochloric acid The cells were washedagain counterstained with Nuclear Fast Red and the ironstaining was evaluated with light microscopy (Carl ZeissOberkochen Germany) with a times40075 objective lens andAxiovision 44 software (Carl Zeiss) The SPION labelingefficiency was determined bymanually counting the Prussianblue stained and unstained cells under a Zeiss microscope(Carl Zeiss) at times100 magnification with a times100130 oil-immersion objective lens The percentage of labeled cells wasdetermined as the average of five high-powered fields Afterthe slices were fixed dehydrated embedded and sectionedthe tissues were stained with Prussian blue as describedabove The blue granules were counted by a person who didnot know the experiment from ten areas of each histologicsection
218 Image Processing and Statistical Analysis Adobe Photo-shop 60 (Adobe Systems Inc San Jose CA) Image-Pro Plusversion 60 (Media Cybernetics USA) and Image J (NationalInstitutes of Health USA) were used for image typesettinganalysis and processing GraphPad Prism 50 (GraphPadCo USA) was used for mapping The SPSS 170 statisticalsoftware (Chicago IL) was used for all statistical analysesExperimental data are shown as means plusmn standard deviations(SD) and compared with Studentrsquos or a paired 119905 test or one-way ANOVA A value of 119875 lt 005 was deemed to indicatesignificant differences
3 Results
31 Recombinant SDF-1120572 Protein Stimulated BMSCs Expres-sions of VEGFANG-1HGF TGF-120573 andCXCR4 Theexpres-sions of VEGF ANG-1 HGF TGF-120573 and CXCR4 weredetected with qRT-PCR or immunoblotting assays at 24 hand 48 h after recombinant SDF-1120572 protein was added tothe BMSCs culturemediumThe recombined SDF-1120572 protein
significantly stimulated the expressions of VEGF ANG-1 andCXCR4 in the BMSCs which was also positively correlatedwith the concentration of SDF-1120572 This effect was blockedby the CXCR4 agonist AMD3100 (Figures 1(a)-1(b) and1(d)ndash1(g)) The mRNA levels of HGF and TGF-120573 were bothupregulated after stimulation with SDF-1120572 but were inhibitedby AMD3100 (Figure 1(c))
32 BMSCs Supernatant Promotes the Proliferation Migra-tion and Repair of EAhy926 Cells The BMSCs supernatantpromoted the growth andmigration of EAhy926 cells signifi-cantlymore thanDMEM-LG completemedium (Figures 2(a)and 2(b))Moreover EAhy926 cells impaired by trypsinweremore effectively repaired by the BMSCs supernatant than byDMEM-LG complete medium (Figure 2(c))
33 SDF-1120572CXCR4 Axis Induces Angiogenesis In Vitro BeingRelated to the Expressions of VEGF and ANG-1 The BMSCssupernatant pretreated with SDF-1120572 significantly promotedangiogenesis compared with the normal BMSCs supernatantin vitro which was also positively related to the concentrationof SDF-1120572 Furthermore the angiogenesis was reduced inbothVEGF siRNA andANG-1 siRNA comparedwith normalBMSCs supernatant (Figure 1(h))
34 No Significant Differences on Biological Functions betweenBMSCs and SPION-Labeled BMSCs ([Fe3+] = 25 120583gmL)More than 95 of BMSCs were successfully labeled withSPION ([Fe3+] = 25 120583gmL) (Figure 3(a))The growth activityof SPION-labeled BMSCs ([Fe3+] = 25120583gmL) was similarto unlabeled BMSCs which was significantly stronger thanthat of other SPION-labeled BMSCs ([Fe3+] = 50 75 or100 120583gmL) (Figure 3(b)) CXCR4 expression was observedwith confocalmicroscopy and similar in both the BMSCs andSPION-labeled BMSCs (Figures 3(c)ndash3(e))
35 SDF-1120572CXCR4 Axis Regulates the Migration of SPION-Labeled BMSCs to Necrotic Pancreatic Tissues and the Migra-tion Increased Gradually Peaking on Days 5ndash7 The resultsof Prussian blue staining showed that the SPION-labeledBMSCs were relatively low in pancreas liver spleen andsmall intestine at the first day of the transplant comparedto lung but gradually increasing in pancreatic tissue atposttransplant days 3 and 7 and relatively high comparedto liver spleen and small intestine when the formation oftubular complexes (TCs) was also maximal (Figures 4(a)ndash4(c)) On the contrary SPION-labeled BMSCs in the lungtissue became less and less (Figure 5(b))Themore importantpoint was that the migrations of SPION-labeled BMSCs toinjured pancreas could be inhibited by anti-CXCR4 treatment(Figures 4(a)ndash4(c)) To further visually investigate whetherthe SPION-labeledBMSCs couldmigrate to injured pancreasthe MRI method was selected for realizing the tracing invivo The magnetic resonance images displayed that SPION-labeled BMSCs ([Fe3+] = 25 gmL) were high signal in T1WI(white) and low signal (dark) in T2WI as shown in Fig-ure 5(a) The high signal intensity (white points) in pancreas(as indicated by red circle) increased gradually in T1WI andpeaked on days 5 and 7 (Figure 5(b)) We also performedT2WI on day 7 in order to exclude the possibility of false
6 Stem Cells International
Relat
ive m
RNA
expr
essio
ns
CXCR4
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
lowastdagger
lowastdagger
0
1
2
3
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)(a)
Relat
ive m
RNA
expr
essio
ns
lowast
lowastdagger
lowastdaggerlowastdagger
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
Ang-1VEGF
0
1
2
3
4
5
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(b)
Relat
ive m
RNA
expr
essio
ns
lowast
lowast
daggerdaggerdaggerdaggerdaggerdagger
daggerdaggerdagger
daggerdaggerdagger
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
0
2
4
6
8
10
TGF-120573HGF
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(c)
+ +
+
+ +
+
43
45
36GAPDH
VEGF
CXCR4
ANG-1 70
(kD)
minus
minus
minus
minus minus
minus minus
minus minus
SDF-1
SDF-1(10ngmL)
(100ngmL)AMD3100(10120583gmL)
(d)
000
005
010
015
Ratio
of C
XCR4
to G
APD
H
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
lowastdaggerlowastdagger
dagger
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(e)
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
10
08
06
04
02
00
Ratio
of V
EGF
to G
APD
H
lowastdagger
lowastlowast lowastdagger
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(f)
Figure 1 Continued
Stem Cells International 7
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SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
lowastdagger
lowastdagger
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005
Ratio
of A
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APD
H
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gm
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(100
ngm
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-1siR
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F siR
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Num
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f tub
e for
mat
ions
Tube formation assay
lowast
lowastlowast
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lowastdaggerdagger
SDF-1
(10
ngm
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SDF-1
(100
ngm
L)
VEGF-A siRNANormal
SDF-1 (10ngmL) Ang-1 siRNA
PBS SDF-1 (100ngmL)
(h)
Figure 1 The SDF-1120572CXCR4 axis could promote the expressions of cellular growth factors in BMSCs and induce angiogenesis in vitro((a) (d) and (e))The CXCR4 expression of BMSCs was significantly unregulated after being stimulated by combined SDF-1120572 protein whichcould be inhibited by the CXCR4 receptor agonist AMD3100 ((b)ndash(d) (f)-(g)) Recombined SDF-1120572 protein could significantly promoteBMSCS expression of VEGF ANG-1 HGF and TGF-120573 and the effect could also blocked by AMD3100 Moreover there was a dose-effectrelationship between combined SDF-1120572 protein and CXCR4 VEGF ANG-1 HGF and TGF-120573 expressions Data are expressed as mean plusmn SD(lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SDF-1120572 (10 ngmL or 100 ngmL) versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSDF-1120572 (10 ngmL or 100 ngmL) versus SDF-1120572 (10 ngmL or 100 ngmL) + AMD3100 10 120583gmL) (h) BMSCs supernatant could significantlypromoted angiogenesis especially after being pretreated with SDF-1120572 and this increase was partly offset by AMD3100 Both VEGF siRNAand Ang-1 siRNA significantly weakened proangiogenic capacity of BMSCs Data are expressed as mean plusmn SD (119875 lt 001 for NC versusPBS lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SDF-1120572 (10 ngmL or 100 ngmL) Ang-1 siRNA or VEGF siRNA versus NC) (NC normalcontrol SDF-1120572 stromal cell derived factor-1a CXCR4 CXC chemokine receptor 4 VEGF vascular endothelial growth factor and ANG-1angiopoietin-1)
positive and the result showed that the high signals (whitepoints) in T1WI became low signals (dark points) in T2WIwhereas the low signals (dark points) in T1WI became highsignals (white points) as shown in Figure 5(c) Furthermorethe high signals in T1WI decreased obviously in anti-CXCR4group compared with BMSCs group on posttransplant day 5(Figure 5(b))
36 Transplanted BMSCs Reduced Pancreatic Edema Hem-orrhage and Necrosis Inhibited Systematic Inflammationand Promoted the Formation of TCs Involved in the SDF-1120572CXCR4 Axis Pancreatic edema hemorrhage and necro-sis were markedly reduced and the levels of serum amylasewere significantly lower in the SAP+BMSCs group than in theSAP and SAP+anti-CXCR4 BMSCs groups (Figures 6(a) and
8 Stem Cells International
DMEM-LG
DMEM-LG
DMEM-LG + BMSCs supernatant
DMEM-LG + BMSCs supernatant
DMEM-LG000
005
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015
020
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val
ues (
OD573
nm)
DMEM-LG+ BMSCs supernatant
lowast
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nm
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Incubation time (h)
lowast
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nm
0 50 100 150
Incubation time (h)
lowast
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BMSCs supernatant + 025 trypsinDMEM-LG + 025 trypsin
(c)
Figure 2 The BMSCs supernatant could promote the proliferation migration and repair of human umbilical-vein endothelial cell line(EAhy926 cells) (a)Themethylene blue staining (magnification times200) is indicating that the BMSCs supernatant could significantly promotethe migration of EAhy926 cells Data are expressed as mean plusmn SD (lowast119875 lt 005 for DMEM-LG versus DMEM-LG + BMSCs supernatant) (b)The significant increase of the growth of EAhy926 cells was investigated in MTT test after being given BMSCs supernatant (c) ImpairedEAhy926 cells could be repaired by BMSCs supernatant Data are expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005and lowastlowast119875 lt 001 for DMEM-LG versus DMEM-LG + BMSCs supernatant at each corresponding time point) Data analysis was performedby a one-way ANOVA (BMSCs bone marrow-derived mesenchymal stem cells MTT 3-(45-dimethylthiazol-2-yl)-2S-diphenyltetrazoliumbromide)
6(b)) Inflammatory cytokines were detected with ELISAsThe results show that the levels of serum proinflamma-tory cytokines (IL-1120573 IL-6 and TNF-120572) were significantlydownregulated in the SAP+BMSCs group compared with theSAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines (IL-4 IL-10 andTGF-120573) were significantly upregulated in the SAP+BMSCsgroup comparedwith the SAP and SAP+anti-CXCR4BMSCsgroups (Figure 6(c)) We also found that a large number ofTCs appeared in the BMSCs group (as indicated by red arrowand a magnified picture in Figure 6(a))
37 SDF-1120572CXCR4 Axis Enhances the Expressions of VEGFandANG-1 inDamaged Pancreatic Tissues VEGF expressionin injured pancreatic tissues was measured with qRT-PCRand immunoblotting VEGF expression was higher in theSAP+BMSCS group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups on postoperative days 1and 4 but had decreased on postoperative day 7 (Figures 7(b)7(c) and 7(e)) The expression of ANG-1 was detected withqRT-PCR and immunoblotting and its expression was higherin the SAP+BMSCS group than in the normal control SAPand SAP+anti-CXCR4 BMSCs groups (Figures 7(a) 7(c)
Stem Cells International 9
(a)
Control
Days
$$
$$$
ampampamp
$$ $ampampamp
ampamp
amp
dagger
$$ $ampampamp
daggerdagger dagger$$ $
ampampamp
daggerdagger dagger
15
10
05
000 1 2 3 4 5 6 7 8
Fe = 75120583gmLFe = 25120583gmL Fe = 100120583gmLFe = 50120583gmL
OD
val
ues (
OD490
nm)
(b)
SPIO
N-la
bele
d BM
SCs
Unl
abel
ed B
MSC
s
(c)
BMSCsSPION-labeled
BMSCs
36
43
(kD)CXCR4
GAPDH
(d)
BMSCs
BMSCsSPION-labeled BMSCs
SPION-labeledBMSCs
15
10
05
00
Relat
ive m
RNA
expr
essio
ns
P gt 005
(e)
Figure 3There is similarity in the proliferation andCXCR4 expression between unlabeled and SPION-labeled BMSCs ([Fe3+] = 25 gmL) (a)The Prussian blue staining shows that BMSCs were labeled by SPION successfully (b) TheMTT tests are showing that the growth activity ofSPION-labeled BMSCs ([Fe3+] = 25 gmL) slowed slightly compared with that of the unlabeled BMSCs which was also significantly strongerthan that of other SPION-labeled BMSCs ([Fe3+] = 50 75 or 100 gmL) Data are expressed as mean plusmn SD (ampamp119875 lt 001 and ampampamp
119875 lt 0001
for normal control versus SPION-labeled BMSCS ([Fe3+] = 100 gmL) $$119875 lt 001 and $$$119875 lt 0001 for normal control versus SPION-labeled
BMSCS ([Fe3+] = 75 gmL) and dagger119875 lt 005 and daggerdaggerdagger119875 lt 0001 for normal control versus SPION-labeled BMSCS ([Fe3+] = 50 gmL) at eachcorresponding time point) ((c)-(d)) CXCR4 expression was detected by immunofluorescence and western blotting and similar betweenunlabeled and SPION-labeled BMSCs (119875 gt 005) (SPION superparamagnetic iron oxide nanoparticles BMSCs bone marrow-derivedmesenchymal stem cells)
10 Stem Cells International
Ant
i-CXC
R4BM
SCs
BMSC
s
Nor
mal
1d 3d 7d5d 10d
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Lung
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reas
Smal
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Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
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Figure 4 Continued
Stem Cells International 11
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
10d
BMSCsAnti-CXCR4 BMSCs
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
(c)
Figure 4 Prussian blue staining was performed for detecting the SPION-labeled BMSCs in pancreatic and lung tissues (a) The Prussianblue staining of pancreatic tissue indicates that the cells were stained blue (as indicated by black arrows) gradually increased and peaked onpostoperative days 5ndash7 when the formation of tubular complexes was also maximal (as indicated by red arrows) However the migration waspartly inhibited and the trend was not obviously investigated in anti-CXCR4 group (b) The lung tissues were stained by Prussian blue andthe blue particles (as indicated by black arrows) were gradually decreasing in both BMSCs and anti-CXCR4 groups (c) The blue particles inlung pancreas liver spleen and small intestine were counted and analyzed between BMSCs and anti-CXCR4 groupsThe result showed thatthe number of blue particles of pancreas in BMSCs group was significantly more than in anti-CXCR4 group at postoperative days 1 3 5 and7 Data are expressed as mean plusmn SD (lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for BMSCs versus anti-CXCR4 at each corresponding time point)
and 7(d)) The mRNA levels of HGF and TGF-120573 were alsodetected with qRT-PCR and were significantly higher in theSAP+BMSCs group than in the normal SAP and SAP+anti-CXCR4 BMSCs groups (Figures 7(f) and 7(g))
38 SDF-1120572CXCR4 Axis Induces the Neovascularization InVivo To assess the neovascularization we conducted qRT-PCR or immunohistochemistry for detecting these angiogen-esis markers (CD31 VEGF and vWF) The results indicatedthat the expressions of CD31 VEGF and vWF in necroticpancreatic tissue were higher in the SAP+BMSCs group thanin the normal control SAP and SAP+anti-CXCR4 BMSCsgroups especially in early phase (Figures 7(h) and 8(a)ndash8(d))
4 Discussion
Several studies have shown that MSCs from the bone orumbilical cord can attenuate acute necrotic pancreatitis byinhibiting systematic inflammation regulating the immuneresponses reducing the apoptosis of pancreatic acinar cellsand repairing damaged the small intestinal epithelium [9ndash12]However these functions do not account for how to repairand regenerate the necrotic pancreatic tissues In the studywe found that BMSCs can reduce severe acute pancreatitisby alleviating the systematic inflammation promoting theformation of tubular complexes (TCs) and inducing angio-genesis involving the SDF-1120572CXCR4 axis by enhancing the
expression of cell growth factors in a rat model of SAP Largeprevious studies have found that MSCs can not only differ-entiate into different kinds of functional adult cells but alsosecrete various soluble factors including VEGF HGF andTGF-120573 [27] These factors which promote angiogenesis andmitosis and reduce apoptosis can explain tissue repair andregeneration after MSCs transplanted [28 29] Moreover theregeneration of the pancreas begins with the TCs that consistof a cluster of epithelia surrounded by the mesenchymalcells [30 31] Thus we inferred that SDF-1120572CXCR4 axis wasinvolved in the repair and regeneration of SAP
SDF-1120572 and its receptor CXCR4 have been studiedextensively together with their roles in migration homingproliferation angiogenesis and so forth [11 13ndash15 18 3233] Many researches have shown that BMSCs can migrateto injured tissues via the SDF-1120572CXCR4 axis and relievemyocardial infraction [13 14] promote wound healing [19]heal bone fracture [34] reduce cerebral ischemia [35] andameliorate acute necrotizing pancreatitis [11] SDF-1120572 expres-sion is upregulated by hypoxia-inducible factor-1 (HIF-1)[36] In the study we successfully established a rat model ofacute necrotizing pancreatitis with the retrograde injectionof Na-taurocholate which causes acinar cell injurynecrosisby triggering transient pathological intra-acinar-cell cal-cium ions and activating digestive zymogens [37ndash39] Theinjurednecrotic pancreatic tissue causes HIF-1 expressionand thus induces SDF-1120572 expression which attracts BMSCsto injured pancreas through the interaction with CXCR4
12 Stem Cells International
T1WI
SPIO
N-la
bele
d BM
SCs
T2WI
5 10 15 20 25 30[Fe] (120583gmL)
(a)
Normal (T1WI)
BMSCs BMSCs BMSCs
Anti-CXCR4 BMSCsBMSCsBMSCs
BMSCs
5d (T1WI)7d (T1WI)
1d (T1WI) 3d (T1WI) 5d (T1WI)
10d (T1WI)
(b)
BMSCs
7d (T1WI)
BMSCs
7d (T2WI)
(c)
Figure 5 The transplanted SPION-labeled BMSCs were tracked by MRI in vivo (a) [Fe3+] was detected by MRI and the result showed thatthe SPION-labeled BMSCs ([Fe3+] = 25 gmL) appeared high signals (white spots) on T1WI and low signals (dark spots) on T2WI (b) TheSPION-BMSCs ([Fe3+] = 25 gmL) was tracked by MRI in vivo and the photos show that the white spots (inside of red circle) were increasinggradually and peaked on postoperative days 5ndash7 Instead the white spots decreased on postoperative day 5 in anti-CXCR4 group comparedwith BMSCs group (c) The SPION-BMSCs ([Fe3+] = 25 gmL) were detected in SAP rats at postoperative day 7 by T1WI and T2WI andthe result was showing that the high signals (white spots) which appeared in T1WI became low signals (dark spots) in T2WI (SPIONsuperparamagnetic iron oxide nanoparticles T1WI T1-weighted imaging and T2WI T2-weighted imaging)
For further investigating whether BMSCs could migrateto injured pancreas and the migration was regulated by SDF-1120572CXCR4 axis in a SAP rat model SPION was used tolabel BMSCs SPION were initially used as a unique MRcontrast agent in the clinical context Recently their two useshave been discoveredmdashthe labeling of live cells and tissuesdisease diagnosis and therapy [22 23 40ndash42] Studies havedemonstrated that SPION-labeling does not deleteriouslyaffect the functions of the target cells [25] In our study wealso demonstrated that there was no difference in the pro-liferation capacities between SPION-labeled (Fe = 25 120583gmLlabeling efficiency gt 95) and unlabeled BMSCs Moreover
the expression of CXCR4was also similar between the labeledand unlabeled cells SPION-labeled BMSCs could be detectedby both MRI and Prussian blue staining because SPIONis the nanometer particles of ferric oxide The dynamicmovement of labeling cells could be observed at the photosof MRI so that we can intuitively assess the proportions ofSPION-labeled BMSCs in vivo The result showed that thesecells could migrate to the damaged pancreatic tissues andthere was also a gradual increase in migration peaking onpostoperative days 5ndash7 with the formation of large numbersof TCs SDF-1120572CXCR4 axis could regulate the migrationof BMSCs as our previously described [11] Meanwhile the
Stem Cells International 13
SAP
NC Sham Tubular complex
SAP+
BMSC
sSA
P+
anti-
CXCR
4BM
SCs
1d 4d 7d
(a)
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Edema
Scor
e $
$$$
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
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daggerlowastdaggerlowastdagger
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lowastdaggerlowastdaggerlowastdagger
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SAP + BMSCsSAP + anti-CXCR4
SAP + anti-CXCR4SAP + anti-CXCR4
SAP + anti-CXCR4 BMSCs
ShamSAP
Normal
0
1
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Scor
e
$
lowastdagger
lowastdaggerlowastdagger
lowastdagger
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SAP + BMSCs
BMSCsShamSAP
Normal
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1000
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BMSCsShamSAP
Normal
$$$
$$$
1d 4d 7d
1d 4d 7d 1d 4d 7d
1d 4d 7dInfiltration
Necrosis
Am
ylas
e act
ivity
(b)
Figure 6 Continued
14 Stem Cells International
130
120
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100
90
80The c
once
ntra
tion
of se
rum
IL-1
(pg
mL)
daggerdaggerlowast
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Control Day 1 Day 4 Day 7
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham
$
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The c
once
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of se
rum
IL-4
(pg
mL)
80
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The c
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The c
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F-120572
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mL)
260
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160
220
200
180
160
140
120The c
once
ntra
tion
of se
rum
TG
F-120573
(pg
mL)
(c)
Figure 6 Transplanted BMSCs could reduce severe acute pancreatitis (SAP) promoting the formation of tubular complexes and inhibitingsystematic inflammatory response being involved in the SDF-1120572CXCR4 axis ((a) (b))TheHampE staining of pancreatic tissues (magnificationtimes100) is showing that the edema infiltration and necrosis were significantly reduced in the SAP+BMSCs group compared with SAP andSAP+anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively A large number of tubular complexes were also investigatedin SAP+BMSCs group (as indicated by red arrow in a 400x magnified picture) Serum amylase activity was also significantly reduced inSAP+BMSCs group than in normal SAP and anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively (c) The levels ofserum proinflammatory cytokines are significantly lower in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines are significantly higher in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups Dataare expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SAP versus Normal dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP versus SAP+BMSCs $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4BMSCs) Data analysis was performed by Studentrsquos test (BMSCs bone marrow-derived mesenchymal stem cells HampE hematoxylin-eosin)
number of cells whichmigrated to the necrotic pancreas waspositively related to the therapeutic effect However SPION-labeled BMSCs could be rarely seen on postoperative day 10perhaps because the SPIONwere degraded or the BMSCs haddifferentiated into other cells including pancreatic exocrinecells
To validate whether the SDF-1120572CXCR4 axis also playsan important role in the repair and regeneration of SAPwe conducted the study in vitro and vivo We found thatthe secretions of BMSCs could promote the proliferationmigration and restoration of EAhy926 cells The BMSCssupernatant induced angiogenesis and the SDF-1120572CXCR4axis stimulated BMSCs to express VEGF ANG-1 HGFand TGF-120573 promoting further angiogenesis in vitro Both
VEGF and ANG-1 play important roles in angiogenesisMoreover the expressions of VEGFANG-1HGF andTGF-120573in the damaged pancreatic tissues were higher in the BMSCstransplantation group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups Taken all together theresult showed that transplantedBMSCs repaired the damagedpancreas through secreting large cellular growth factors andthe effect was regulated by SDF-1120572CXCR4 axis
As we all know VEGF a potent inducer of angiogenesispromotes the repair of injured vascular endothelial cellsand neovascularization Studies have shown that the SDF-1120572CXCR4 axis promotes the synthesis and secretion ofVEGF [17 43] and SDF-1120572 combined with VEGF enhancesischemic angiogenesis [20] In our study we confirmed that
Stem Cells International 15
15
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5
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SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
expr
essio
nslowastlowastlowastdagger
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$
1d 4d 7dVEGF
(a)
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0
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Relat
ive m
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Ang-11d 4d 7d
(b)NC Sham
ANG-1
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i-CXC
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Relat
ive r
atio
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0020
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Relat
ive r
atio
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(e)
daggerdagger
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Relat
ive m
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PDH
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NCShamSAP
(f)
Figure 7 Continued
16 Stem Cells International
dagger
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Relat
ive m
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essio
ns to
GA
PDH
HGF
lowastlowast
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NCShamSAP
(g)
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Relat
ive m
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daggerlowast
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lowast
daggerlowastlowast
dagger daggerlowast
lowast
lowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
6 Stem Cells International
Relat
ive m
RNA
expr
essio
ns
CXCR4
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
lowastdagger
lowastdagger
0
1
2
3
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)(a)
Relat
ive m
RNA
expr
essio
ns
lowast
lowastdagger
lowastdaggerlowastdagger
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
Ang-1VEGF
0
1
2
3
4
5
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(b)
Relat
ive m
RNA
expr
essio
ns
lowast
lowast
daggerdaggerdaggerdaggerdaggerdagger
daggerdaggerdagger
daggerdaggerdagger
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
0
2
4
6
8
10
TGF-120573HGF
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(c)
+ +
+
+ +
+
43
45
36GAPDH
VEGF
CXCR4
ANG-1 70
(kD)
minus
minus
minus
minus minus
minus minus
minus minus
SDF-1
SDF-1(10ngmL)
(100ngmL)AMD3100(10120583gmL)
(d)
000
005
010
015
Ratio
of C
XCR4
to G
APD
H
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
lowastdaggerlowastdagger
dagger
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(e)
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
10
08
06
04
02
00
Ratio
of V
EGF
to G
APD
H
lowastdagger
lowastlowast lowastdagger
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(f)
Figure 1 Continued
Stem Cells International 7
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
lowastdagger
lowastdagger
000
001
002
003
004
005
Ratio
of A
ng-1
to G
APD
H
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(g)
0
20
40
60
80
100
PBS
NC
Ang
-1siR
NA
VEG
F siR
NA
Num
ber o
f tub
e for
mat
ions
Tube formation assay
lowast
lowastlowast
lowastlowast
lowastdaggerdagger
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
VEGF-A siRNANormal
SDF-1 (10ngmL) Ang-1 siRNA
PBS SDF-1 (100ngmL)
(h)
Figure 1 The SDF-1120572CXCR4 axis could promote the expressions of cellular growth factors in BMSCs and induce angiogenesis in vitro((a) (d) and (e))The CXCR4 expression of BMSCs was significantly unregulated after being stimulated by combined SDF-1120572 protein whichcould be inhibited by the CXCR4 receptor agonist AMD3100 ((b)ndash(d) (f)-(g)) Recombined SDF-1120572 protein could significantly promoteBMSCS expression of VEGF ANG-1 HGF and TGF-120573 and the effect could also blocked by AMD3100 Moreover there was a dose-effectrelationship between combined SDF-1120572 protein and CXCR4 VEGF ANG-1 HGF and TGF-120573 expressions Data are expressed as mean plusmn SD(lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SDF-1120572 (10 ngmL or 100 ngmL) versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSDF-1120572 (10 ngmL or 100 ngmL) versus SDF-1120572 (10 ngmL or 100 ngmL) + AMD3100 10 120583gmL) (h) BMSCs supernatant could significantlypromoted angiogenesis especially after being pretreated with SDF-1120572 and this increase was partly offset by AMD3100 Both VEGF siRNAand Ang-1 siRNA significantly weakened proangiogenic capacity of BMSCs Data are expressed as mean plusmn SD (119875 lt 001 for NC versusPBS lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SDF-1120572 (10 ngmL or 100 ngmL) Ang-1 siRNA or VEGF siRNA versus NC) (NC normalcontrol SDF-1120572 stromal cell derived factor-1a CXCR4 CXC chemokine receptor 4 VEGF vascular endothelial growth factor and ANG-1angiopoietin-1)
positive and the result showed that the high signals (whitepoints) in T1WI became low signals (dark points) in T2WIwhereas the low signals (dark points) in T1WI became highsignals (white points) as shown in Figure 5(c) Furthermorethe high signals in T1WI decreased obviously in anti-CXCR4group compared with BMSCs group on posttransplant day 5(Figure 5(b))
36 Transplanted BMSCs Reduced Pancreatic Edema Hem-orrhage and Necrosis Inhibited Systematic Inflammationand Promoted the Formation of TCs Involved in the SDF-1120572CXCR4 Axis Pancreatic edema hemorrhage and necro-sis were markedly reduced and the levels of serum amylasewere significantly lower in the SAP+BMSCs group than in theSAP and SAP+anti-CXCR4 BMSCs groups (Figures 6(a) and
8 Stem Cells International
DMEM-LG
DMEM-LG
DMEM-LG + BMSCs supernatant
DMEM-LG + BMSCs supernatant
DMEM-LG000
005
010
015
020
OD
val
ues (
OD573
nm)
DMEM-LG+ BMSCs supernatant
lowast
(a)
00
07
14
OD490
nm
0 50 100 150
BMSCs supernatantDMEM-LG
Incubation time (h)
lowast
lowastlowast
lowastlowast
lowastlowast
lowastlowast
(b)
10
08
06
04
02
00
OD490
nm
0 50 100 150
Incubation time (h)
lowast
lowast
lowast
lowast
lowastlowast
BMSCs supernatant + 025 trypsinDMEM-LG + 025 trypsin
(c)
Figure 2 The BMSCs supernatant could promote the proliferation migration and repair of human umbilical-vein endothelial cell line(EAhy926 cells) (a)Themethylene blue staining (magnification times200) is indicating that the BMSCs supernatant could significantly promotethe migration of EAhy926 cells Data are expressed as mean plusmn SD (lowast119875 lt 005 for DMEM-LG versus DMEM-LG + BMSCs supernatant) (b)The significant increase of the growth of EAhy926 cells was investigated in MTT test after being given BMSCs supernatant (c) ImpairedEAhy926 cells could be repaired by BMSCs supernatant Data are expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005and lowastlowast119875 lt 001 for DMEM-LG versus DMEM-LG + BMSCs supernatant at each corresponding time point) Data analysis was performedby a one-way ANOVA (BMSCs bone marrow-derived mesenchymal stem cells MTT 3-(45-dimethylthiazol-2-yl)-2S-diphenyltetrazoliumbromide)
6(b)) Inflammatory cytokines were detected with ELISAsThe results show that the levels of serum proinflamma-tory cytokines (IL-1120573 IL-6 and TNF-120572) were significantlydownregulated in the SAP+BMSCs group compared with theSAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines (IL-4 IL-10 andTGF-120573) were significantly upregulated in the SAP+BMSCsgroup comparedwith the SAP and SAP+anti-CXCR4BMSCsgroups (Figure 6(c)) We also found that a large number ofTCs appeared in the BMSCs group (as indicated by red arrowand a magnified picture in Figure 6(a))
37 SDF-1120572CXCR4 Axis Enhances the Expressions of VEGFandANG-1 inDamaged Pancreatic Tissues VEGF expressionin injured pancreatic tissues was measured with qRT-PCRand immunoblotting VEGF expression was higher in theSAP+BMSCS group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups on postoperative days 1and 4 but had decreased on postoperative day 7 (Figures 7(b)7(c) and 7(e)) The expression of ANG-1 was detected withqRT-PCR and immunoblotting and its expression was higherin the SAP+BMSCS group than in the normal control SAPand SAP+anti-CXCR4 BMSCs groups (Figures 7(a) 7(c)
Stem Cells International 9
(a)
Control
Days
$$
$$$
ampampamp
$$ $ampampamp
ampamp
amp
dagger
$$ $ampampamp
daggerdagger dagger$$ $
ampampamp
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15
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000 1 2 3 4 5 6 7 8
Fe = 75120583gmLFe = 25120583gmL Fe = 100120583gmLFe = 50120583gmL
OD
val
ues (
OD490
nm)
(b)
SPIO
N-la
bele
d BM
SCs
Unl
abel
ed B
MSC
s
(c)
BMSCsSPION-labeled
BMSCs
36
43
(kD)CXCR4
GAPDH
(d)
BMSCs
BMSCsSPION-labeled BMSCs
SPION-labeledBMSCs
15
10
05
00
Relat
ive m
RNA
expr
essio
ns
P gt 005
(e)
Figure 3There is similarity in the proliferation andCXCR4 expression between unlabeled and SPION-labeled BMSCs ([Fe3+] = 25 gmL) (a)The Prussian blue staining shows that BMSCs were labeled by SPION successfully (b) TheMTT tests are showing that the growth activity ofSPION-labeled BMSCs ([Fe3+] = 25 gmL) slowed slightly compared with that of the unlabeled BMSCs which was also significantly strongerthan that of other SPION-labeled BMSCs ([Fe3+] = 50 75 or 100 gmL) Data are expressed as mean plusmn SD (ampamp119875 lt 001 and ampampamp
119875 lt 0001
for normal control versus SPION-labeled BMSCS ([Fe3+] = 100 gmL) $$119875 lt 001 and $$$119875 lt 0001 for normal control versus SPION-labeled
BMSCS ([Fe3+] = 75 gmL) and dagger119875 lt 005 and daggerdaggerdagger119875 lt 0001 for normal control versus SPION-labeled BMSCS ([Fe3+] = 50 gmL) at eachcorresponding time point) ((c)-(d)) CXCR4 expression was detected by immunofluorescence and western blotting and similar betweenunlabeled and SPION-labeled BMSCs (119875 gt 005) (SPION superparamagnetic iron oxide nanoparticles BMSCs bone marrow-derivedmesenchymal stem cells)
10 Stem Cells International
Ant
i-CXC
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reas
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Figure 4 Continued
Stem Cells International 11
100
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The n
umbe
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10d
BMSCsAnti-CXCR4 BMSCs
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
(c)
Figure 4 Prussian blue staining was performed for detecting the SPION-labeled BMSCs in pancreatic and lung tissues (a) The Prussianblue staining of pancreatic tissue indicates that the cells were stained blue (as indicated by black arrows) gradually increased and peaked onpostoperative days 5ndash7 when the formation of tubular complexes was also maximal (as indicated by red arrows) However the migration waspartly inhibited and the trend was not obviously investigated in anti-CXCR4 group (b) The lung tissues were stained by Prussian blue andthe blue particles (as indicated by black arrows) were gradually decreasing in both BMSCs and anti-CXCR4 groups (c) The blue particles inlung pancreas liver spleen and small intestine were counted and analyzed between BMSCs and anti-CXCR4 groupsThe result showed thatthe number of blue particles of pancreas in BMSCs group was significantly more than in anti-CXCR4 group at postoperative days 1 3 5 and7 Data are expressed as mean plusmn SD (lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for BMSCs versus anti-CXCR4 at each corresponding time point)
and 7(d)) The mRNA levels of HGF and TGF-120573 were alsodetected with qRT-PCR and were significantly higher in theSAP+BMSCs group than in the normal SAP and SAP+anti-CXCR4 BMSCs groups (Figures 7(f) and 7(g))
38 SDF-1120572CXCR4 Axis Induces the Neovascularization InVivo To assess the neovascularization we conducted qRT-PCR or immunohistochemistry for detecting these angiogen-esis markers (CD31 VEGF and vWF) The results indicatedthat the expressions of CD31 VEGF and vWF in necroticpancreatic tissue were higher in the SAP+BMSCs group thanin the normal control SAP and SAP+anti-CXCR4 BMSCsgroups especially in early phase (Figures 7(h) and 8(a)ndash8(d))
4 Discussion
Several studies have shown that MSCs from the bone orumbilical cord can attenuate acute necrotic pancreatitis byinhibiting systematic inflammation regulating the immuneresponses reducing the apoptosis of pancreatic acinar cellsand repairing damaged the small intestinal epithelium [9ndash12]However these functions do not account for how to repairand regenerate the necrotic pancreatic tissues In the studywe found that BMSCs can reduce severe acute pancreatitisby alleviating the systematic inflammation promoting theformation of tubular complexes (TCs) and inducing angio-genesis involving the SDF-1120572CXCR4 axis by enhancing the
expression of cell growth factors in a rat model of SAP Largeprevious studies have found that MSCs can not only differ-entiate into different kinds of functional adult cells but alsosecrete various soluble factors including VEGF HGF andTGF-120573 [27] These factors which promote angiogenesis andmitosis and reduce apoptosis can explain tissue repair andregeneration after MSCs transplanted [28 29] Moreover theregeneration of the pancreas begins with the TCs that consistof a cluster of epithelia surrounded by the mesenchymalcells [30 31] Thus we inferred that SDF-1120572CXCR4 axis wasinvolved in the repair and regeneration of SAP
SDF-1120572 and its receptor CXCR4 have been studiedextensively together with their roles in migration homingproliferation angiogenesis and so forth [11 13ndash15 18 3233] Many researches have shown that BMSCs can migrateto injured tissues via the SDF-1120572CXCR4 axis and relievemyocardial infraction [13 14] promote wound healing [19]heal bone fracture [34] reduce cerebral ischemia [35] andameliorate acute necrotizing pancreatitis [11] SDF-1120572 expres-sion is upregulated by hypoxia-inducible factor-1 (HIF-1)[36] In the study we successfully established a rat model ofacute necrotizing pancreatitis with the retrograde injectionof Na-taurocholate which causes acinar cell injurynecrosisby triggering transient pathological intra-acinar-cell cal-cium ions and activating digestive zymogens [37ndash39] Theinjurednecrotic pancreatic tissue causes HIF-1 expressionand thus induces SDF-1120572 expression which attracts BMSCsto injured pancreas through the interaction with CXCR4
12 Stem Cells International
T1WI
SPIO
N-la
bele
d BM
SCs
T2WI
5 10 15 20 25 30[Fe] (120583gmL)
(a)
Normal (T1WI)
BMSCs BMSCs BMSCs
Anti-CXCR4 BMSCsBMSCsBMSCs
BMSCs
5d (T1WI)7d (T1WI)
1d (T1WI) 3d (T1WI) 5d (T1WI)
10d (T1WI)
(b)
BMSCs
7d (T1WI)
BMSCs
7d (T2WI)
(c)
Figure 5 The transplanted SPION-labeled BMSCs were tracked by MRI in vivo (a) [Fe3+] was detected by MRI and the result showed thatthe SPION-labeled BMSCs ([Fe3+] = 25 gmL) appeared high signals (white spots) on T1WI and low signals (dark spots) on T2WI (b) TheSPION-BMSCs ([Fe3+] = 25 gmL) was tracked by MRI in vivo and the photos show that the white spots (inside of red circle) were increasinggradually and peaked on postoperative days 5ndash7 Instead the white spots decreased on postoperative day 5 in anti-CXCR4 group comparedwith BMSCs group (c) The SPION-BMSCs ([Fe3+] = 25 gmL) were detected in SAP rats at postoperative day 7 by T1WI and T2WI andthe result was showing that the high signals (white spots) which appeared in T1WI became low signals (dark spots) in T2WI (SPIONsuperparamagnetic iron oxide nanoparticles T1WI T1-weighted imaging and T2WI T2-weighted imaging)
For further investigating whether BMSCs could migrateto injured pancreas and the migration was regulated by SDF-1120572CXCR4 axis in a SAP rat model SPION was used tolabel BMSCs SPION were initially used as a unique MRcontrast agent in the clinical context Recently their two useshave been discoveredmdashthe labeling of live cells and tissuesdisease diagnosis and therapy [22 23 40ndash42] Studies havedemonstrated that SPION-labeling does not deleteriouslyaffect the functions of the target cells [25] In our study wealso demonstrated that there was no difference in the pro-liferation capacities between SPION-labeled (Fe = 25 120583gmLlabeling efficiency gt 95) and unlabeled BMSCs Moreover
the expression of CXCR4was also similar between the labeledand unlabeled cells SPION-labeled BMSCs could be detectedby both MRI and Prussian blue staining because SPIONis the nanometer particles of ferric oxide The dynamicmovement of labeling cells could be observed at the photosof MRI so that we can intuitively assess the proportions ofSPION-labeled BMSCs in vivo The result showed that thesecells could migrate to the damaged pancreatic tissues andthere was also a gradual increase in migration peaking onpostoperative days 5ndash7 with the formation of large numbersof TCs SDF-1120572CXCR4 axis could regulate the migrationof BMSCs as our previously described [11] Meanwhile the
Stem Cells International 13
SAP
NC Sham Tubular complex
SAP+
BMSC
sSA
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CXCR
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1d 4d 7d
(a)
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e $
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Normal
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Normal
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Normal
$$$
$$$
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1d 4d 7d
1d 4d 7d 1d 4d 7d
1d 4d 7dInfiltration
Necrosis
Am
ylas
e act
ivity
(b)
Figure 6 Continued
14 Stem Cells International
130
120
110
100
90
80The c
once
ntra
tion
of se
rum
IL-1
(pg
mL)
daggerdaggerlowast
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Control Day 1 Day 4 Day 7
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The c
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rum
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(pg
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rum
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(pg
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260
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180
160
220
200
180
160
140
120The c
once
ntra
tion
of se
rum
TG
F-120573
(pg
mL)
(c)
Figure 6 Transplanted BMSCs could reduce severe acute pancreatitis (SAP) promoting the formation of tubular complexes and inhibitingsystematic inflammatory response being involved in the SDF-1120572CXCR4 axis ((a) (b))TheHampE staining of pancreatic tissues (magnificationtimes100) is showing that the edema infiltration and necrosis were significantly reduced in the SAP+BMSCs group compared with SAP andSAP+anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively A large number of tubular complexes were also investigatedin SAP+BMSCs group (as indicated by red arrow in a 400x magnified picture) Serum amylase activity was also significantly reduced inSAP+BMSCs group than in normal SAP and anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively (c) The levels ofserum proinflammatory cytokines are significantly lower in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines are significantly higher in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups Dataare expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SAP versus Normal dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP versus SAP+BMSCs $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4BMSCs) Data analysis was performed by Studentrsquos test (BMSCs bone marrow-derived mesenchymal stem cells HampE hematoxylin-eosin)
number of cells whichmigrated to the necrotic pancreas waspositively related to the therapeutic effect However SPION-labeled BMSCs could be rarely seen on postoperative day 10perhaps because the SPIONwere degraded or the BMSCs haddifferentiated into other cells including pancreatic exocrinecells
To validate whether the SDF-1120572CXCR4 axis also playsan important role in the repair and regeneration of SAPwe conducted the study in vitro and vivo We found thatthe secretions of BMSCs could promote the proliferationmigration and restoration of EAhy926 cells The BMSCssupernatant induced angiogenesis and the SDF-1120572CXCR4axis stimulated BMSCs to express VEGF ANG-1 HGFand TGF-120573 promoting further angiogenesis in vitro Both
VEGF and ANG-1 play important roles in angiogenesisMoreover the expressions of VEGFANG-1HGF andTGF-120573in the damaged pancreatic tissues were higher in the BMSCstransplantation group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups Taken all together theresult showed that transplantedBMSCs repaired the damagedpancreas through secreting large cellular growth factors andthe effect was regulated by SDF-1120572CXCR4 axis
As we all know VEGF a potent inducer of angiogenesispromotes the repair of injured vascular endothelial cellsand neovascularization Studies have shown that the SDF-1120572CXCR4 axis promotes the synthesis and secretion ofVEGF [17 43] and SDF-1120572 combined with VEGF enhancesischemic angiogenesis [20] In our study we confirmed that
Stem Cells International 15
15
10
5
0
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
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16 Stem Cells International
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(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
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1d 4d 7d
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orm
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NCShamSAP BMSCs
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1d 4d 7d 1d 4d 7d
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Relat
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0004
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0000
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1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
Stem Cells International 7
NC
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
lowastdagger
lowastdagger
000
001
002
003
004
005
Ratio
of A
ng-1
to G
APD
H
SDF-1
(10
ngm
L)+
AM
D3100
(10120583
gm
L)
SDF-1
(100
ngm
L)+
AM
D3100
(10120583
gm
L)
(g)
0
20
40
60
80
100
PBS
NC
Ang
-1siR
NA
VEG
F siR
NA
Num
ber o
f tub
e for
mat
ions
Tube formation assay
lowast
lowastlowast
lowastlowast
lowastdaggerdagger
SDF-1
(10
ngm
L)
SDF-1
(100
ngm
L)
VEGF-A siRNANormal
SDF-1 (10ngmL) Ang-1 siRNA
PBS SDF-1 (100ngmL)
(h)
Figure 1 The SDF-1120572CXCR4 axis could promote the expressions of cellular growth factors in BMSCs and induce angiogenesis in vitro((a) (d) and (e))The CXCR4 expression of BMSCs was significantly unregulated after being stimulated by combined SDF-1120572 protein whichcould be inhibited by the CXCR4 receptor agonist AMD3100 ((b)ndash(d) (f)-(g)) Recombined SDF-1120572 protein could significantly promoteBMSCS expression of VEGF ANG-1 HGF and TGF-120573 and the effect could also blocked by AMD3100 Moreover there was a dose-effectrelationship between combined SDF-1120572 protein and CXCR4 VEGF ANG-1 HGF and TGF-120573 expressions Data are expressed as mean plusmn SD(lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SDF-1120572 (10 ngmL or 100 ngmL) versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSDF-1120572 (10 ngmL or 100 ngmL) versus SDF-1120572 (10 ngmL or 100 ngmL) + AMD3100 10 120583gmL) (h) BMSCs supernatant could significantlypromoted angiogenesis especially after being pretreated with SDF-1120572 and this increase was partly offset by AMD3100 Both VEGF siRNAand Ang-1 siRNA significantly weakened proangiogenic capacity of BMSCs Data are expressed as mean plusmn SD (119875 lt 001 for NC versusPBS lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SDF-1120572 (10 ngmL or 100 ngmL) Ang-1 siRNA or VEGF siRNA versus NC) (NC normalcontrol SDF-1120572 stromal cell derived factor-1a CXCR4 CXC chemokine receptor 4 VEGF vascular endothelial growth factor and ANG-1angiopoietin-1)
positive and the result showed that the high signals (whitepoints) in T1WI became low signals (dark points) in T2WIwhereas the low signals (dark points) in T1WI became highsignals (white points) as shown in Figure 5(c) Furthermorethe high signals in T1WI decreased obviously in anti-CXCR4group compared with BMSCs group on posttransplant day 5(Figure 5(b))
36 Transplanted BMSCs Reduced Pancreatic Edema Hem-orrhage and Necrosis Inhibited Systematic Inflammationand Promoted the Formation of TCs Involved in the SDF-1120572CXCR4 Axis Pancreatic edema hemorrhage and necro-sis were markedly reduced and the levels of serum amylasewere significantly lower in the SAP+BMSCs group than in theSAP and SAP+anti-CXCR4 BMSCs groups (Figures 6(a) and
8 Stem Cells International
DMEM-LG
DMEM-LG
DMEM-LG + BMSCs supernatant
DMEM-LG + BMSCs supernatant
DMEM-LG000
005
010
015
020
OD
val
ues (
OD573
nm)
DMEM-LG+ BMSCs supernatant
lowast
(a)
00
07
14
OD490
nm
0 50 100 150
BMSCs supernatantDMEM-LG
Incubation time (h)
lowast
lowastlowast
lowastlowast
lowastlowast
lowastlowast
(b)
10
08
06
04
02
00
OD490
nm
0 50 100 150
Incubation time (h)
lowast
lowast
lowast
lowast
lowastlowast
BMSCs supernatant + 025 trypsinDMEM-LG + 025 trypsin
(c)
Figure 2 The BMSCs supernatant could promote the proliferation migration and repair of human umbilical-vein endothelial cell line(EAhy926 cells) (a)Themethylene blue staining (magnification times200) is indicating that the BMSCs supernatant could significantly promotethe migration of EAhy926 cells Data are expressed as mean plusmn SD (lowast119875 lt 005 for DMEM-LG versus DMEM-LG + BMSCs supernatant) (b)The significant increase of the growth of EAhy926 cells was investigated in MTT test after being given BMSCs supernatant (c) ImpairedEAhy926 cells could be repaired by BMSCs supernatant Data are expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005and lowastlowast119875 lt 001 for DMEM-LG versus DMEM-LG + BMSCs supernatant at each corresponding time point) Data analysis was performedby a one-way ANOVA (BMSCs bone marrow-derived mesenchymal stem cells MTT 3-(45-dimethylthiazol-2-yl)-2S-diphenyltetrazoliumbromide)
6(b)) Inflammatory cytokines were detected with ELISAsThe results show that the levels of serum proinflamma-tory cytokines (IL-1120573 IL-6 and TNF-120572) were significantlydownregulated in the SAP+BMSCs group compared with theSAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines (IL-4 IL-10 andTGF-120573) were significantly upregulated in the SAP+BMSCsgroup comparedwith the SAP and SAP+anti-CXCR4BMSCsgroups (Figure 6(c)) We also found that a large number ofTCs appeared in the BMSCs group (as indicated by red arrowand a magnified picture in Figure 6(a))
37 SDF-1120572CXCR4 Axis Enhances the Expressions of VEGFandANG-1 inDamaged Pancreatic Tissues VEGF expressionin injured pancreatic tissues was measured with qRT-PCRand immunoblotting VEGF expression was higher in theSAP+BMSCS group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups on postoperative days 1and 4 but had decreased on postoperative day 7 (Figures 7(b)7(c) and 7(e)) The expression of ANG-1 was detected withqRT-PCR and immunoblotting and its expression was higherin the SAP+BMSCS group than in the normal control SAPand SAP+anti-CXCR4 BMSCs groups (Figures 7(a) 7(c)
Stem Cells International 9
(a)
Control
Days
$$
$$$
ampampamp
$$ $ampampamp
ampamp
amp
dagger
$$ $ampampamp
daggerdagger dagger$$ $
ampampamp
daggerdagger dagger
15
10
05
000 1 2 3 4 5 6 7 8
Fe = 75120583gmLFe = 25120583gmL Fe = 100120583gmLFe = 50120583gmL
OD
val
ues (
OD490
nm)
(b)
SPIO
N-la
bele
d BM
SCs
Unl
abel
ed B
MSC
s
(c)
BMSCsSPION-labeled
BMSCs
36
43
(kD)CXCR4
GAPDH
(d)
BMSCs
BMSCsSPION-labeled BMSCs
SPION-labeledBMSCs
15
10
05
00
Relat
ive m
RNA
expr
essio
ns
P gt 005
(e)
Figure 3There is similarity in the proliferation andCXCR4 expression between unlabeled and SPION-labeled BMSCs ([Fe3+] = 25 gmL) (a)The Prussian blue staining shows that BMSCs were labeled by SPION successfully (b) TheMTT tests are showing that the growth activity ofSPION-labeled BMSCs ([Fe3+] = 25 gmL) slowed slightly compared with that of the unlabeled BMSCs which was also significantly strongerthan that of other SPION-labeled BMSCs ([Fe3+] = 50 75 or 100 gmL) Data are expressed as mean plusmn SD (ampamp119875 lt 001 and ampampamp
119875 lt 0001
for normal control versus SPION-labeled BMSCS ([Fe3+] = 100 gmL) $$119875 lt 001 and $$$119875 lt 0001 for normal control versus SPION-labeled
BMSCS ([Fe3+] = 75 gmL) and dagger119875 lt 005 and daggerdaggerdagger119875 lt 0001 for normal control versus SPION-labeled BMSCS ([Fe3+] = 50 gmL) at eachcorresponding time point) ((c)-(d)) CXCR4 expression was detected by immunofluorescence and western blotting and similar betweenunlabeled and SPION-labeled BMSCs (119875 gt 005) (SPION superparamagnetic iron oxide nanoparticles BMSCs bone marrow-derivedmesenchymal stem cells)
10 Stem Cells International
Ant
i-CXC
R4BM
SCs
BMSC
s
Nor
mal
1d 3d 7d5d 10d
Nor
mal
BMSC
sA
nti-C
XCR4
BM
SCs
1d 3d 7d5d 10d(a)
(b)100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
lowastlowastlowast
1d 100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
lowastlowast
3d
(c)
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
lowastlowastlowast
lowastlowast
7d5d
BMSCsAnti-CXCR4 BMSCs
BMSCsAnti-CXCR4 BMSCs
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
Figure 4 Continued
Stem Cells International 11
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
10d
BMSCsAnti-CXCR4 BMSCs
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
(c)
Figure 4 Prussian blue staining was performed for detecting the SPION-labeled BMSCs in pancreatic and lung tissues (a) The Prussianblue staining of pancreatic tissue indicates that the cells were stained blue (as indicated by black arrows) gradually increased and peaked onpostoperative days 5ndash7 when the formation of tubular complexes was also maximal (as indicated by red arrows) However the migration waspartly inhibited and the trend was not obviously investigated in anti-CXCR4 group (b) The lung tissues were stained by Prussian blue andthe blue particles (as indicated by black arrows) were gradually decreasing in both BMSCs and anti-CXCR4 groups (c) The blue particles inlung pancreas liver spleen and small intestine were counted and analyzed between BMSCs and anti-CXCR4 groupsThe result showed thatthe number of blue particles of pancreas in BMSCs group was significantly more than in anti-CXCR4 group at postoperative days 1 3 5 and7 Data are expressed as mean plusmn SD (lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for BMSCs versus anti-CXCR4 at each corresponding time point)
and 7(d)) The mRNA levels of HGF and TGF-120573 were alsodetected with qRT-PCR and were significantly higher in theSAP+BMSCs group than in the normal SAP and SAP+anti-CXCR4 BMSCs groups (Figures 7(f) and 7(g))
38 SDF-1120572CXCR4 Axis Induces the Neovascularization InVivo To assess the neovascularization we conducted qRT-PCR or immunohistochemistry for detecting these angiogen-esis markers (CD31 VEGF and vWF) The results indicatedthat the expressions of CD31 VEGF and vWF in necroticpancreatic tissue were higher in the SAP+BMSCs group thanin the normal control SAP and SAP+anti-CXCR4 BMSCsgroups especially in early phase (Figures 7(h) and 8(a)ndash8(d))
4 Discussion
Several studies have shown that MSCs from the bone orumbilical cord can attenuate acute necrotic pancreatitis byinhibiting systematic inflammation regulating the immuneresponses reducing the apoptosis of pancreatic acinar cellsand repairing damaged the small intestinal epithelium [9ndash12]However these functions do not account for how to repairand regenerate the necrotic pancreatic tissues In the studywe found that BMSCs can reduce severe acute pancreatitisby alleviating the systematic inflammation promoting theformation of tubular complexes (TCs) and inducing angio-genesis involving the SDF-1120572CXCR4 axis by enhancing the
expression of cell growth factors in a rat model of SAP Largeprevious studies have found that MSCs can not only differ-entiate into different kinds of functional adult cells but alsosecrete various soluble factors including VEGF HGF andTGF-120573 [27] These factors which promote angiogenesis andmitosis and reduce apoptosis can explain tissue repair andregeneration after MSCs transplanted [28 29] Moreover theregeneration of the pancreas begins with the TCs that consistof a cluster of epithelia surrounded by the mesenchymalcells [30 31] Thus we inferred that SDF-1120572CXCR4 axis wasinvolved in the repair and regeneration of SAP
SDF-1120572 and its receptor CXCR4 have been studiedextensively together with their roles in migration homingproliferation angiogenesis and so forth [11 13ndash15 18 3233] Many researches have shown that BMSCs can migrateto injured tissues via the SDF-1120572CXCR4 axis and relievemyocardial infraction [13 14] promote wound healing [19]heal bone fracture [34] reduce cerebral ischemia [35] andameliorate acute necrotizing pancreatitis [11] SDF-1120572 expres-sion is upregulated by hypoxia-inducible factor-1 (HIF-1)[36] In the study we successfully established a rat model ofacute necrotizing pancreatitis with the retrograde injectionof Na-taurocholate which causes acinar cell injurynecrosisby triggering transient pathological intra-acinar-cell cal-cium ions and activating digestive zymogens [37ndash39] Theinjurednecrotic pancreatic tissue causes HIF-1 expressionand thus induces SDF-1120572 expression which attracts BMSCsto injured pancreas through the interaction with CXCR4
12 Stem Cells International
T1WI
SPIO
N-la
bele
d BM
SCs
T2WI
5 10 15 20 25 30[Fe] (120583gmL)
(a)
Normal (T1WI)
BMSCs BMSCs BMSCs
Anti-CXCR4 BMSCsBMSCsBMSCs
BMSCs
5d (T1WI)7d (T1WI)
1d (T1WI) 3d (T1WI) 5d (T1WI)
10d (T1WI)
(b)
BMSCs
7d (T1WI)
BMSCs
7d (T2WI)
(c)
Figure 5 The transplanted SPION-labeled BMSCs were tracked by MRI in vivo (a) [Fe3+] was detected by MRI and the result showed thatthe SPION-labeled BMSCs ([Fe3+] = 25 gmL) appeared high signals (white spots) on T1WI and low signals (dark spots) on T2WI (b) TheSPION-BMSCs ([Fe3+] = 25 gmL) was tracked by MRI in vivo and the photos show that the white spots (inside of red circle) were increasinggradually and peaked on postoperative days 5ndash7 Instead the white spots decreased on postoperative day 5 in anti-CXCR4 group comparedwith BMSCs group (c) The SPION-BMSCs ([Fe3+] = 25 gmL) were detected in SAP rats at postoperative day 7 by T1WI and T2WI andthe result was showing that the high signals (white spots) which appeared in T1WI became low signals (dark spots) in T2WI (SPIONsuperparamagnetic iron oxide nanoparticles T1WI T1-weighted imaging and T2WI T2-weighted imaging)
For further investigating whether BMSCs could migrateto injured pancreas and the migration was regulated by SDF-1120572CXCR4 axis in a SAP rat model SPION was used tolabel BMSCs SPION were initially used as a unique MRcontrast agent in the clinical context Recently their two useshave been discoveredmdashthe labeling of live cells and tissuesdisease diagnosis and therapy [22 23 40ndash42] Studies havedemonstrated that SPION-labeling does not deleteriouslyaffect the functions of the target cells [25] In our study wealso demonstrated that there was no difference in the pro-liferation capacities between SPION-labeled (Fe = 25 120583gmLlabeling efficiency gt 95) and unlabeled BMSCs Moreover
the expression of CXCR4was also similar between the labeledand unlabeled cells SPION-labeled BMSCs could be detectedby both MRI and Prussian blue staining because SPIONis the nanometer particles of ferric oxide The dynamicmovement of labeling cells could be observed at the photosof MRI so that we can intuitively assess the proportions ofSPION-labeled BMSCs in vivo The result showed that thesecells could migrate to the damaged pancreatic tissues andthere was also a gradual increase in migration peaking onpostoperative days 5ndash7 with the formation of large numbersof TCs SDF-1120572CXCR4 axis could regulate the migrationof BMSCs as our previously described [11] Meanwhile the
Stem Cells International 13
SAP
NC Sham Tubular complex
SAP+
BMSC
sSA
P+
anti-
CXCR
4BM
SCs
1d 4d 7d
(a)
0
1
2
3
4
Edema
Scor
e $
$$$
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
SAP + BMSCsSAP + anti-CXCR4
SAP + anti-CXCR4SAP + anti-CXCR4
SAP + anti-CXCR4 BMSCs
ShamSAP
Normal
0
1
2
3
4
Scor
e
$
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
SAP + BMSCs
BMSCsShamSAP
Normal
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1000
800
600
400
200
0
0
1
2
3
4
Scor
e
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1d 4d 7d
1d 4d 7d 1d 4d 7d
1d 4d 7dInfiltration
Necrosis
Am
ylas
e act
ivity
(b)
Figure 6 Continued
14 Stem Cells International
130
120
110
100
90
80The c
once
ntra
tion
of se
rum
IL-1
(pg
mL)
daggerdaggerlowast
daggerlowast
daggerdaggerdagger
daggerdaggerdagger
lowast
lowastlowastlowastlowast
daggerlowast
lowastlowastlowast
daggerdaggerdaggerlowastlowast
daggerdaggerdaggerlowast
Control Day 1 Day 4 Day 7
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham
$
daggerdaggerlowast
$ daggerdagger daggerlowastlowast
$daggerdagger dagger
daggerlowastlowastlowastlowastlowast
daggerlowastlowast
$$$daggerdagger daggerlowastlowast
$daggerdagger daggerlowastlowast
$
daggerlowast dagger
lowast
$
$
$$
$$$$$$
The c
once
ntra
tion
of se
rum
IL-4
(pg
mL)
80
70
60
50
40
The c
once
ntra
tion
of se
rum
IL-6
(pg
mL)
90
80
70
60
The c
once
ntra
tion
of se
rum
IL-10
(pg
mL)
60
55
50
45
40
35
The c
once
ntra
tion
of se
rum
TN
F-120572
(pg
mL)
260
240
220
200
180
160
220
200
180
160
140
120The c
once
ntra
tion
of se
rum
TG
F-120573
(pg
mL)
(c)
Figure 6 Transplanted BMSCs could reduce severe acute pancreatitis (SAP) promoting the formation of tubular complexes and inhibitingsystematic inflammatory response being involved in the SDF-1120572CXCR4 axis ((a) (b))TheHampE staining of pancreatic tissues (magnificationtimes100) is showing that the edema infiltration and necrosis were significantly reduced in the SAP+BMSCs group compared with SAP andSAP+anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively A large number of tubular complexes were also investigatedin SAP+BMSCs group (as indicated by red arrow in a 400x magnified picture) Serum amylase activity was also significantly reduced inSAP+BMSCs group than in normal SAP and anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively (c) The levels ofserum proinflammatory cytokines are significantly lower in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines are significantly higher in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups Dataare expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SAP versus Normal dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP versus SAP+BMSCs $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4BMSCs) Data analysis was performed by Studentrsquos test (BMSCs bone marrow-derived mesenchymal stem cells HampE hematoxylin-eosin)
number of cells whichmigrated to the necrotic pancreas waspositively related to the therapeutic effect However SPION-labeled BMSCs could be rarely seen on postoperative day 10perhaps because the SPIONwere degraded or the BMSCs haddifferentiated into other cells including pancreatic exocrinecells
To validate whether the SDF-1120572CXCR4 axis also playsan important role in the repair and regeneration of SAPwe conducted the study in vitro and vivo We found thatthe secretions of BMSCs could promote the proliferationmigration and restoration of EAhy926 cells The BMSCssupernatant induced angiogenesis and the SDF-1120572CXCR4axis stimulated BMSCs to express VEGF ANG-1 HGFand TGF-120573 promoting further angiogenesis in vitro Both
VEGF and ANG-1 play important roles in angiogenesisMoreover the expressions of VEGFANG-1HGF andTGF-120573in the damaged pancreatic tissues were higher in the BMSCstransplantation group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups Taken all together theresult showed that transplantedBMSCs repaired the damagedpancreas through secreting large cellular growth factors andthe effect was regulated by SDF-1120572CXCR4 axis
As we all know VEGF a potent inducer of angiogenesispromotes the repair of injured vascular endothelial cellsand neovascularization Studies have shown that the SDF-1120572CXCR4 axis promotes the synthesis and secretion ofVEGF [17 43] and SDF-1120572 combined with VEGF enhancesischemic angiogenesis [20] In our study we confirmed that
Stem Cells International 15
15
10
5
0
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
expr
essio
nslowastlowastlowastdagger
lowastlowastlowastdagger
daggerdaggerdagger
$
1d 4d 7dVEGF
(a)
daggerdaggerdaggerdagger
dagger
$
$
lowast
lowast
lowast
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
0
5
10
15
Relat
ive m
RNA
expr
essio
ns
Ang-11d 4d 7d
(b)NC Sham
ANG-1
VEGF
GAPDH
Ant
i-CXC
R4SA
PA
nti-C
XCR4
SAP
SAP
+BM
SCs
SAP
+BM
SCs
36
1d 4d 7d
45
70
(kD)
(c)
dagger
daggerdaggerdagger
$
10
00
02
04
06
08
lowastlowastlowast
dagger$lowastlowastlowast
lowastlowastlowast
SAP + BMSCsNCShamSAP
1d 4d 7d
Relat
ive r
atio
of V
EGF
to G
APD
H
SAP + anti-CXCR4 BMSCs
(d)
dagger
daggerdaggerdagger
$$
lowastlowastlowastlowastlowastlowast
lowastlowastlowast
$$$daggerdaggerdagger
0020
0015
0010
0005
0000
Relat
ive r
atio
of A
ng-1
to G
APD
H
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(e)
daggerdagger
dagger$
lowast
lowastlowast
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
TGF-1205731d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(f)
Figure 7 Continued
16 Stem Cells International
dagger
dagger$
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
HGF
lowastlowast
lowastlowastlowastlowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(g)
$
$
0
2
4
6
8
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
CD31
daggerlowast
lowast
lowast
daggerlowastlowast
dagger daggerlowast
lowast
lowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
8 Stem Cells International
DMEM-LG
DMEM-LG
DMEM-LG + BMSCs supernatant
DMEM-LG + BMSCs supernatant
DMEM-LG000
005
010
015
020
OD
val
ues (
OD573
nm)
DMEM-LG+ BMSCs supernatant
lowast
(a)
00
07
14
OD490
nm
0 50 100 150
BMSCs supernatantDMEM-LG
Incubation time (h)
lowast
lowastlowast
lowastlowast
lowastlowast
lowastlowast
(b)
10
08
06
04
02
00
OD490
nm
0 50 100 150
Incubation time (h)
lowast
lowast
lowast
lowast
lowastlowast
BMSCs supernatant + 025 trypsinDMEM-LG + 025 trypsin
(c)
Figure 2 The BMSCs supernatant could promote the proliferation migration and repair of human umbilical-vein endothelial cell line(EAhy926 cells) (a)Themethylene blue staining (magnification times200) is indicating that the BMSCs supernatant could significantly promotethe migration of EAhy926 cells Data are expressed as mean plusmn SD (lowast119875 lt 005 for DMEM-LG versus DMEM-LG + BMSCs supernatant) (b)The significant increase of the growth of EAhy926 cells was investigated in MTT test after being given BMSCs supernatant (c) ImpairedEAhy926 cells could be repaired by BMSCs supernatant Data are expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005and lowastlowast119875 lt 001 for DMEM-LG versus DMEM-LG + BMSCs supernatant at each corresponding time point) Data analysis was performedby a one-way ANOVA (BMSCs bone marrow-derived mesenchymal stem cells MTT 3-(45-dimethylthiazol-2-yl)-2S-diphenyltetrazoliumbromide)
6(b)) Inflammatory cytokines were detected with ELISAsThe results show that the levels of serum proinflamma-tory cytokines (IL-1120573 IL-6 and TNF-120572) were significantlydownregulated in the SAP+BMSCs group compared with theSAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines (IL-4 IL-10 andTGF-120573) were significantly upregulated in the SAP+BMSCsgroup comparedwith the SAP and SAP+anti-CXCR4BMSCsgroups (Figure 6(c)) We also found that a large number ofTCs appeared in the BMSCs group (as indicated by red arrowand a magnified picture in Figure 6(a))
37 SDF-1120572CXCR4 Axis Enhances the Expressions of VEGFandANG-1 inDamaged Pancreatic Tissues VEGF expressionin injured pancreatic tissues was measured with qRT-PCRand immunoblotting VEGF expression was higher in theSAP+BMSCS group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups on postoperative days 1and 4 but had decreased on postoperative day 7 (Figures 7(b)7(c) and 7(e)) The expression of ANG-1 was detected withqRT-PCR and immunoblotting and its expression was higherin the SAP+BMSCS group than in the normal control SAPand SAP+anti-CXCR4 BMSCs groups (Figures 7(a) 7(c)
Stem Cells International 9
(a)
Control
Days
$$
$$$
ampampamp
$$ $ampampamp
ampamp
amp
dagger
$$ $ampampamp
daggerdagger dagger$$ $
ampampamp
daggerdagger dagger
15
10
05
000 1 2 3 4 5 6 7 8
Fe = 75120583gmLFe = 25120583gmL Fe = 100120583gmLFe = 50120583gmL
OD
val
ues (
OD490
nm)
(b)
SPIO
N-la
bele
d BM
SCs
Unl
abel
ed B
MSC
s
(c)
BMSCsSPION-labeled
BMSCs
36
43
(kD)CXCR4
GAPDH
(d)
BMSCs
BMSCsSPION-labeled BMSCs
SPION-labeledBMSCs
15
10
05
00
Relat
ive m
RNA
expr
essio
ns
P gt 005
(e)
Figure 3There is similarity in the proliferation andCXCR4 expression between unlabeled and SPION-labeled BMSCs ([Fe3+] = 25 gmL) (a)The Prussian blue staining shows that BMSCs were labeled by SPION successfully (b) TheMTT tests are showing that the growth activity ofSPION-labeled BMSCs ([Fe3+] = 25 gmL) slowed slightly compared with that of the unlabeled BMSCs which was also significantly strongerthan that of other SPION-labeled BMSCs ([Fe3+] = 50 75 or 100 gmL) Data are expressed as mean plusmn SD (ampamp119875 lt 001 and ampampamp
119875 lt 0001
for normal control versus SPION-labeled BMSCS ([Fe3+] = 100 gmL) $$119875 lt 001 and $$$119875 lt 0001 for normal control versus SPION-labeled
BMSCS ([Fe3+] = 75 gmL) and dagger119875 lt 005 and daggerdaggerdagger119875 lt 0001 for normal control versus SPION-labeled BMSCS ([Fe3+] = 50 gmL) at eachcorresponding time point) ((c)-(d)) CXCR4 expression was detected by immunofluorescence and western blotting and similar betweenunlabeled and SPION-labeled BMSCs (119875 gt 005) (SPION superparamagnetic iron oxide nanoparticles BMSCs bone marrow-derivedmesenchymal stem cells)
10 Stem Cells International
Ant
i-CXC
R4BM
SCs
BMSC
s
Nor
mal
1d 3d 7d5d 10d
Nor
mal
BMSC
sA
nti-C
XCR4
BM
SCs
1d 3d 7d5d 10d(a)
(b)100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
lowastlowastlowast
1d 100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
lowastlowast
3d
(c)
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
lowastlowastlowast
lowastlowast
7d5d
BMSCsAnti-CXCR4 BMSCs
BMSCsAnti-CXCR4 BMSCs
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
Figure 4 Continued
Stem Cells International 11
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
10d
BMSCsAnti-CXCR4 BMSCs
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
(c)
Figure 4 Prussian blue staining was performed for detecting the SPION-labeled BMSCs in pancreatic and lung tissues (a) The Prussianblue staining of pancreatic tissue indicates that the cells were stained blue (as indicated by black arrows) gradually increased and peaked onpostoperative days 5ndash7 when the formation of tubular complexes was also maximal (as indicated by red arrows) However the migration waspartly inhibited and the trend was not obviously investigated in anti-CXCR4 group (b) The lung tissues were stained by Prussian blue andthe blue particles (as indicated by black arrows) were gradually decreasing in both BMSCs and anti-CXCR4 groups (c) The blue particles inlung pancreas liver spleen and small intestine were counted and analyzed between BMSCs and anti-CXCR4 groupsThe result showed thatthe number of blue particles of pancreas in BMSCs group was significantly more than in anti-CXCR4 group at postoperative days 1 3 5 and7 Data are expressed as mean plusmn SD (lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for BMSCs versus anti-CXCR4 at each corresponding time point)
and 7(d)) The mRNA levels of HGF and TGF-120573 were alsodetected with qRT-PCR and were significantly higher in theSAP+BMSCs group than in the normal SAP and SAP+anti-CXCR4 BMSCs groups (Figures 7(f) and 7(g))
38 SDF-1120572CXCR4 Axis Induces the Neovascularization InVivo To assess the neovascularization we conducted qRT-PCR or immunohistochemistry for detecting these angiogen-esis markers (CD31 VEGF and vWF) The results indicatedthat the expressions of CD31 VEGF and vWF in necroticpancreatic tissue were higher in the SAP+BMSCs group thanin the normal control SAP and SAP+anti-CXCR4 BMSCsgroups especially in early phase (Figures 7(h) and 8(a)ndash8(d))
4 Discussion
Several studies have shown that MSCs from the bone orumbilical cord can attenuate acute necrotic pancreatitis byinhibiting systematic inflammation regulating the immuneresponses reducing the apoptosis of pancreatic acinar cellsand repairing damaged the small intestinal epithelium [9ndash12]However these functions do not account for how to repairand regenerate the necrotic pancreatic tissues In the studywe found that BMSCs can reduce severe acute pancreatitisby alleviating the systematic inflammation promoting theformation of tubular complexes (TCs) and inducing angio-genesis involving the SDF-1120572CXCR4 axis by enhancing the
expression of cell growth factors in a rat model of SAP Largeprevious studies have found that MSCs can not only differ-entiate into different kinds of functional adult cells but alsosecrete various soluble factors including VEGF HGF andTGF-120573 [27] These factors which promote angiogenesis andmitosis and reduce apoptosis can explain tissue repair andregeneration after MSCs transplanted [28 29] Moreover theregeneration of the pancreas begins with the TCs that consistof a cluster of epithelia surrounded by the mesenchymalcells [30 31] Thus we inferred that SDF-1120572CXCR4 axis wasinvolved in the repair and regeneration of SAP
SDF-1120572 and its receptor CXCR4 have been studiedextensively together with their roles in migration homingproliferation angiogenesis and so forth [11 13ndash15 18 3233] Many researches have shown that BMSCs can migrateto injured tissues via the SDF-1120572CXCR4 axis and relievemyocardial infraction [13 14] promote wound healing [19]heal bone fracture [34] reduce cerebral ischemia [35] andameliorate acute necrotizing pancreatitis [11] SDF-1120572 expres-sion is upregulated by hypoxia-inducible factor-1 (HIF-1)[36] In the study we successfully established a rat model ofacute necrotizing pancreatitis with the retrograde injectionof Na-taurocholate which causes acinar cell injurynecrosisby triggering transient pathological intra-acinar-cell cal-cium ions and activating digestive zymogens [37ndash39] Theinjurednecrotic pancreatic tissue causes HIF-1 expressionand thus induces SDF-1120572 expression which attracts BMSCsto injured pancreas through the interaction with CXCR4
12 Stem Cells International
T1WI
SPIO
N-la
bele
d BM
SCs
T2WI
5 10 15 20 25 30[Fe] (120583gmL)
(a)
Normal (T1WI)
BMSCs BMSCs BMSCs
Anti-CXCR4 BMSCsBMSCsBMSCs
BMSCs
5d (T1WI)7d (T1WI)
1d (T1WI) 3d (T1WI) 5d (T1WI)
10d (T1WI)
(b)
BMSCs
7d (T1WI)
BMSCs
7d (T2WI)
(c)
Figure 5 The transplanted SPION-labeled BMSCs were tracked by MRI in vivo (a) [Fe3+] was detected by MRI and the result showed thatthe SPION-labeled BMSCs ([Fe3+] = 25 gmL) appeared high signals (white spots) on T1WI and low signals (dark spots) on T2WI (b) TheSPION-BMSCs ([Fe3+] = 25 gmL) was tracked by MRI in vivo and the photos show that the white spots (inside of red circle) were increasinggradually and peaked on postoperative days 5ndash7 Instead the white spots decreased on postoperative day 5 in anti-CXCR4 group comparedwith BMSCs group (c) The SPION-BMSCs ([Fe3+] = 25 gmL) were detected in SAP rats at postoperative day 7 by T1WI and T2WI andthe result was showing that the high signals (white spots) which appeared in T1WI became low signals (dark spots) in T2WI (SPIONsuperparamagnetic iron oxide nanoparticles T1WI T1-weighted imaging and T2WI T2-weighted imaging)
For further investigating whether BMSCs could migrateto injured pancreas and the migration was regulated by SDF-1120572CXCR4 axis in a SAP rat model SPION was used tolabel BMSCs SPION were initially used as a unique MRcontrast agent in the clinical context Recently their two useshave been discoveredmdashthe labeling of live cells and tissuesdisease diagnosis and therapy [22 23 40ndash42] Studies havedemonstrated that SPION-labeling does not deleteriouslyaffect the functions of the target cells [25] In our study wealso demonstrated that there was no difference in the pro-liferation capacities between SPION-labeled (Fe = 25 120583gmLlabeling efficiency gt 95) and unlabeled BMSCs Moreover
the expression of CXCR4was also similar between the labeledand unlabeled cells SPION-labeled BMSCs could be detectedby both MRI and Prussian blue staining because SPIONis the nanometer particles of ferric oxide The dynamicmovement of labeling cells could be observed at the photosof MRI so that we can intuitively assess the proportions ofSPION-labeled BMSCs in vivo The result showed that thesecells could migrate to the damaged pancreatic tissues andthere was also a gradual increase in migration peaking onpostoperative days 5ndash7 with the formation of large numbersof TCs SDF-1120572CXCR4 axis could regulate the migrationof BMSCs as our previously described [11] Meanwhile the
Stem Cells International 13
SAP
NC Sham Tubular complex
SAP+
BMSC
sSA
P+
anti-
CXCR
4BM
SCs
1d 4d 7d
(a)
0
1
2
3
4
Edema
Scor
e $
$$$
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
SAP + BMSCsSAP + anti-CXCR4
SAP + anti-CXCR4SAP + anti-CXCR4
SAP + anti-CXCR4 BMSCs
ShamSAP
Normal
0
1
2
3
4
Scor
e
$
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
SAP + BMSCs
BMSCsShamSAP
Normal
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1000
800
600
400
200
0
0
1
2
3
4
Scor
e
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1d 4d 7d
1d 4d 7d 1d 4d 7d
1d 4d 7dInfiltration
Necrosis
Am
ylas
e act
ivity
(b)
Figure 6 Continued
14 Stem Cells International
130
120
110
100
90
80The c
once
ntra
tion
of se
rum
IL-1
(pg
mL)
daggerdaggerlowast
daggerlowast
daggerdaggerdagger
daggerdaggerdagger
lowast
lowastlowastlowastlowast
daggerlowast
lowastlowastlowast
daggerdaggerdaggerlowastlowast
daggerdaggerdaggerlowast
Control Day 1 Day 4 Day 7
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham
$
daggerdaggerlowast
$ daggerdagger daggerlowastlowast
$daggerdagger dagger
daggerlowastlowastlowastlowastlowast
daggerlowastlowast
$$$daggerdagger daggerlowastlowast
$daggerdagger daggerlowastlowast
$
daggerlowast dagger
lowast
$
$
$$
$$$$$$
The c
once
ntra
tion
of se
rum
IL-4
(pg
mL)
80
70
60
50
40
The c
once
ntra
tion
of se
rum
IL-6
(pg
mL)
90
80
70
60
The c
once
ntra
tion
of se
rum
IL-10
(pg
mL)
60
55
50
45
40
35
The c
once
ntra
tion
of se
rum
TN
F-120572
(pg
mL)
260
240
220
200
180
160
220
200
180
160
140
120The c
once
ntra
tion
of se
rum
TG
F-120573
(pg
mL)
(c)
Figure 6 Transplanted BMSCs could reduce severe acute pancreatitis (SAP) promoting the formation of tubular complexes and inhibitingsystematic inflammatory response being involved in the SDF-1120572CXCR4 axis ((a) (b))TheHampE staining of pancreatic tissues (magnificationtimes100) is showing that the edema infiltration and necrosis were significantly reduced in the SAP+BMSCs group compared with SAP andSAP+anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively A large number of tubular complexes were also investigatedin SAP+BMSCs group (as indicated by red arrow in a 400x magnified picture) Serum amylase activity was also significantly reduced inSAP+BMSCs group than in normal SAP and anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively (c) The levels ofserum proinflammatory cytokines are significantly lower in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines are significantly higher in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups Dataare expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SAP versus Normal dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP versus SAP+BMSCs $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4BMSCs) Data analysis was performed by Studentrsquos test (BMSCs bone marrow-derived mesenchymal stem cells HampE hematoxylin-eosin)
number of cells whichmigrated to the necrotic pancreas waspositively related to the therapeutic effect However SPION-labeled BMSCs could be rarely seen on postoperative day 10perhaps because the SPIONwere degraded or the BMSCs haddifferentiated into other cells including pancreatic exocrinecells
To validate whether the SDF-1120572CXCR4 axis also playsan important role in the repair and regeneration of SAPwe conducted the study in vitro and vivo We found thatthe secretions of BMSCs could promote the proliferationmigration and restoration of EAhy926 cells The BMSCssupernatant induced angiogenesis and the SDF-1120572CXCR4axis stimulated BMSCs to express VEGF ANG-1 HGFand TGF-120573 promoting further angiogenesis in vitro Both
VEGF and ANG-1 play important roles in angiogenesisMoreover the expressions of VEGFANG-1HGF andTGF-120573in the damaged pancreatic tissues were higher in the BMSCstransplantation group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups Taken all together theresult showed that transplantedBMSCs repaired the damagedpancreas through secreting large cellular growth factors andthe effect was regulated by SDF-1120572CXCR4 axis
As we all know VEGF a potent inducer of angiogenesispromotes the repair of injured vascular endothelial cellsand neovascularization Studies have shown that the SDF-1120572CXCR4 axis promotes the synthesis and secretion ofVEGF [17 43] and SDF-1120572 combined with VEGF enhancesischemic angiogenesis [20] In our study we confirmed that
Stem Cells International 15
15
10
5
0
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
expr
essio
nslowastlowastlowastdagger
lowastlowastlowastdagger
daggerdaggerdagger
$
1d 4d 7dVEGF
(a)
daggerdaggerdaggerdagger
dagger
$
$
lowast
lowast
lowast
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
0
5
10
15
Relat
ive m
RNA
expr
essio
ns
Ang-11d 4d 7d
(b)NC Sham
ANG-1
VEGF
GAPDH
Ant
i-CXC
R4SA
PA
nti-C
XCR4
SAP
SAP
+BM
SCs
SAP
+BM
SCs
36
1d 4d 7d
45
70
(kD)
(c)
dagger
daggerdaggerdagger
$
10
00
02
04
06
08
lowastlowastlowast
dagger$lowastlowastlowast
lowastlowastlowast
SAP + BMSCsNCShamSAP
1d 4d 7d
Relat
ive r
atio
of V
EGF
to G
APD
H
SAP + anti-CXCR4 BMSCs
(d)
dagger
daggerdaggerdagger
$$
lowastlowastlowastlowastlowastlowast
lowastlowastlowast
$$$daggerdaggerdagger
0020
0015
0010
0005
0000
Relat
ive r
atio
of A
ng-1
to G
APD
H
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(e)
daggerdagger
dagger$
lowast
lowastlowast
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
TGF-1205731d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(f)
Figure 7 Continued
16 Stem Cells International
dagger
dagger$
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
HGF
lowastlowast
lowastlowastlowastlowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(g)
$
$
0
2
4
6
8
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
CD31
daggerlowast
lowast
lowast
daggerlowastlowast
dagger daggerlowast
lowast
lowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
Stem Cells International 9
(a)
Control
Days
$$
$$$
ampampamp
$$ $ampampamp
ampamp
amp
dagger
$$ $ampampamp
daggerdagger dagger$$ $
ampampamp
daggerdagger dagger
15
10
05
000 1 2 3 4 5 6 7 8
Fe = 75120583gmLFe = 25120583gmL Fe = 100120583gmLFe = 50120583gmL
OD
val
ues (
OD490
nm)
(b)
SPIO
N-la
bele
d BM
SCs
Unl
abel
ed B
MSC
s
(c)
BMSCsSPION-labeled
BMSCs
36
43
(kD)CXCR4
GAPDH
(d)
BMSCs
BMSCsSPION-labeled BMSCs
SPION-labeledBMSCs
15
10
05
00
Relat
ive m
RNA
expr
essio
ns
P gt 005
(e)
Figure 3There is similarity in the proliferation andCXCR4 expression between unlabeled and SPION-labeled BMSCs ([Fe3+] = 25 gmL) (a)The Prussian blue staining shows that BMSCs were labeled by SPION successfully (b) TheMTT tests are showing that the growth activity ofSPION-labeled BMSCs ([Fe3+] = 25 gmL) slowed slightly compared with that of the unlabeled BMSCs which was also significantly strongerthan that of other SPION-labeled BMSCs ([Fe3+] = 50 75 or 100 gmL) Data are expressed as mean plusmn SD (ampamp119875 lt 001 and ampampamp
119875 lt 0001
for normal control versus SPION-labeled BMSCS ([Fe3+] = 100 gmL) $$119875 lt 001 and $$$119875 lt 0001 for normal control versus SPION-labeled
BMSCS ([Fe3+] = 75 gmL) and dagger119875 lt 005 and daggerdaggerdagger119875 lt 0001 for normal control versus SPION-labeled BMSCS ([Fe3+] = 50 gmL) at eachcorresponding time point) ((c)-(d)) CXCR4 expression was detected by immunofluorescence and western blotting and similar betweenunlabeled and SPION-labeled BMSCs (119875 gt 005) (SPION superparamagnetic iron oxide nanoparticles BMSCs bone marrow-derivedmesenchymal stem cells)
10 Stem Cells International
Ant
i-CXC
R4BM
SCs
BMSC
s
Nor
mal
1d 3d 7d5d 10d
Nor
mal
BMSC
sA
nti-C
XCR4
BM
SCs
1d 3d 7d5d 10d(a)
(b)100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
lowastlowastlowast
1d 100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
lowastlowast
3d
(c)
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
lowastlowastlowast
lowastlowast
7d5d
BMSCsAnti-CXCR4 BMSCs
BMSCsAnti-CXCR4 BMSCs
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
Figure 4 Continued
Stem Cells International 11
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
10d
BMSCsAnti-CXCR4 BMSCs
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
(c)
Figure 4 Prussian blue staining was performed for detecting the SPION-labeled BMSCs in pancreatic and lung tissues (a) The Prussianblue staining of pancreatic tissue indicates that the cells were stained blue (as indicated by black arrows) gradually increased and peaked onpostoperative days 5ndash7 when the formation of tubular complexes was also maximal (as indicated by red arrows) However the migration waspartly inhibited and the trend was not obviously investigated in anti-CXCR4 group (b) The lung tissues were stained by Prussian blue andthe blue particles (as indicated by black arrows) were gradually decreasing in both BMSCs and anti-CXCR4 groups (c) The blue particles inlung pancreas liver spleen and small intestine were counted and analyzed between BMSCs and anti-CXCR4 groupsThe result showed thatthe number of blue particles of pancreas in BMSCs group was significantly more than in anti-CXCR4 group at postoperative days 1 3 5 and7 Data are expressed as mean plusmn SD (lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for BMSCs versus anti-CXCR4 at each corresponding time point)
and 7(d)) The mRNA levels of HGF and TGF-120573 were alsodetected with qRT-PCR and were significantly higher in theSAP+BMSCs group than in the normal SAP and SAP+anti-CXCR4 BMSCs groups (Figures 7(f) and 7(g))
38 SDF-1120572CXCR4 Axis Induces the Neovascularization InVivo To assess the neovascularization we conducted qRT-PCR or immunohistochemistry for detecting these angiogen-esis markers (CD31 VEGF and vWF) The results indicatedthat the expressions of CD31 VEGF and vWF in necroticpancreatic tissue were higher in the SAP+BMSCs group thanin the normal control SAP and SAP+anti-CXCR4 BMSCsgroups especially in early phase (Figures 7(h) and 8(a)ndash8(d))
4 Discussion
Several studies have shown that MSCs from the bone orumbilical cord can attenuate acute necrotic pancreatitis byinhibiting systematic inflammation regulating the immuneresponses reducing the apoptosis of pancreatic acinar cellsand repairing damaged the small intestinal epithelium [9ndash12]However these functions do not account for how to repairand regenerate the necrotic pancreatic tissues In the studywe found that BMSCs can reduce severe acute pancreatitisby alleviating the systematic inflammation promoting theformation of tubular complexes (TCs) and inducing angio-genesis involving the SDF-1120572CXCR4 axis by enhancing the
expression of cell growth factors in a rat model of SAP Largeprevious studies have found that MSCs can not only differ-entiate into different kinds of functional adult cells but alsosecrete various soluble factors including VEGF HGF andTGF-120573 [27] These factors which promote angiogenesis andmitosis and reduce apoptosis can explain tissue repair andregeneration after MSCs transplanted [28 29] Moreover theregeneration of the pancreas begins with the TCs that consistof a cluster of epithelia surrounded by the mesenchymalcells [30 31] Thus we inferred that SDF-1120572CXCR4 axis wasinvolved in the repair and regeneration of SAP
SDF-1120572 and its receptor CXCR4 have been studiedextensively together with their roles in migration homingproliferation angiogenesis and so forth [11 13ndash15 18 3233] Many researches have shown that BMSCs can migrateto injured tissues via the SDF-1120572CXCR4 axis and relievemyocardial infraction [13 14] promote wound healing [19]heal bone fracture [34] reduce cerebral ischemia [35] andameliorate acute necrotizing pancreatitis [11] SDF-1120572 expres-sion is upregulated by hypoxia-inducible factor-1 (HIF-1)[36] In the study we successfully established a rat model ofacute necrotizing pancreatitis with the retrograde injectionof Na-taurocholate which causes acinar cell injurynecrosisby triggering transient pathological intra-acinar-cell cal-cium ions and activating digestive zymogens [37ndash39] Theinjurednecrotic pancreatic tissue causes HIF-1 expressionand thus induces SDF-1120572 expression which attracts BMSCsto injured pancreas through the interaction with CXCR4
12 Stem Cells International
T1WI
SPIO
N-la
bele
d BM
SCs
T2WI
5 10 15 20 25 30[Fe] (120583gmL)
(a)
Normal (T1WI)
BMSCs BMSCs BMSCs
Anti-CXCR4 BMSCsBMSCsBMSCs
BMSCs
5d (T1WI)7d (T1WI)
1d (T1WI) 3d (T1WI) 5d (T1WI)
10d (T1WI)
(b)
BMSCs
7d (T1WI)
BMSCs
7d (T2WI)
(c)
Figure 5 The transplanted SPION-labeled BMSCs were tracked by MRI in vivo (a) [Fe3+] was detected by MRI and the result showed thatthe SPION-labeled BMSCs ([Fe3+] = 25 gmL) appeared high signals (white spots) on T1WI and low signals (dark spots) on T2WI (b) TheSPION-BMSCs ([Fe3+] = 25 gmL) was tracked by MRI in vivo and the photos show that the white spots (inside of red circle) were increasinggradually and peaked on postoperative days 5ndash7 Instead the white spots decreased on postoperative day 5 in anti-CXCR4 group comparedwith BMSCs group (c) The SPION-BMSCs ([Fe3+] = 25 gmL) were detected in SAP rats at postoperative day 7 by T1WI and T2WI andthe result was showing that the high signals (white spots) which appeared in T1WI became low signals (dark spots) in T2WI (SPIONsuperparamagnetic iron oxide nanoparticles T1WI T1-weighted imaging and T2WI T2-weighted imaging)
For further investigating whether BMSCs could migrateto injured pancreas and the migration was regulated by SDF-1120572CXCR4 axis in a SAP rat model SPION was used tolabel BMSCs SPION were initially used as a unique MRcontrast agent in the clinical context Recently their two useshave been discoveredmdashthe labeling of live cells and tissuesdisease diagnosis and therapy [22 23 40ndash42] Studies havedemonstrated that SPION-labeling does not deleteriouslyaffect the functions of the target cells [25] In our study wealso demonstrated that there was no difference in the pro-liferation capacities between SPION-labeled (Fe = 25 120583gmLlabeling efficiency gt 95) and unlabeled BMSCs Moreover
the expression of CXCR4was also similar between the labeledand unlabeled cells SPION-labeled BMSCs could be detectedby both MRI and Prussian blue staining because SPIONis the nanometer particles of ferric oxide The dynamicmovement of labeling cells could be observed at the photosof MRI so that we can intuitively assess the proportions ofSPION-labeled BMSCs in vivo The result showed that thesecells could migrate to the damaged pancreatic tissues andthere was also a gradual increase in migration peaking onpostoperative days 5ndash7 with the formation of large numbersof TCs SDF-1120572CXCR4 axis could regulate the migrationof BMSCs as our previously described [11] Meanwhile the
Stem Cells International 13
SAP
NC Sham Tubular complex
SAP+
BMSC
sSA
P+
anti-
CXCR
4BM
SCs
1d 4d 7d
(a)
0
1
2
3
4
Edema
Scor
e $
$$$
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
SAP + BMSCsSAP + anti-CXCR4
SAP + anti-CXCR4SAP + anti-CXCR4
SAP + anti-CXCR4 BMSCs
ShamSAP
Normal
0
1
2
3
4
Scor
e
$
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
SAP + BMSCs
BMSCsShamSAP
Normal
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1000
800
600
400
200
0
0
1
2
3
4
Scor
e
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1d 4d 7d
1d 4d 7d 1d 4d 7d
1d 4d 7dInfiltration
Necrosis
Am
ylas
e act
ivity
(b)
Figure 6 Continued
14 Stem Cells International
130
120
110
100
90
80The c
once
ntra
tion
of se
rum
IL-1
(pg
mL)
daggerdaggerlowast
daggerlowast
daggerdaggerdagger
daggerdaggerdagger
lowast
lowastlowastlowastlowast
daggerlowast
lowastlowastlowast
daggerdaggerdaggerlowastlowast
daggerdaggerdaggerlowast
Control Day 1 Day 4 Day 7
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham
$
daggerdaggerlowast
$ daggerdagger daggerlowastlowast
$daggerdagger dagger
daggerlowastlowastlowastlowastlowast
daggerlowastlowast
$$$daggerdagger daggerlowastlowast
$daggerdagger daggerlowastlowast
$
daggerlowast dagger
lowast
$
$
$$
$$$$$$
The c
once
ntra
tion
of se
rum
IL-4
(pg
mL)
80
70
60
50
40
The c
once
ntra
tion
of se
rum
IL-6
(pg
mL)
90
80
70
60
The c
once
ntra
tion
of se
rum
IL-10
(pg
mL)
60
55
50
45
40
35
The c
once
ntra
tion
of se
rum
TN
F-120572
(pg
mL)
260
240
220
200
180
160
220
200
180
160
140
120The c
once
ntra
tion
of se
rum
TG
F-120573
(pg
mL)
(c)
Figure 6 Transplanted BMSCs could reduce severe acute pancreatitis (SAP) promoting the formation of tubular complexes and inhibitingsystematic inflammatory response being involved in the SDF-1120572CXCR4 axis ((a) (b))TheHampE staining of pancreatic tissues (magnificationtimes100) is showing that the edema infiltration and necrosis were significantly reduced in the SAP+BMSCs group compared with SAP andSAP+anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively A large number of tubular complexes were also investigatedin SAP+BMSCs group (as indicated by red arrow in a 400x magnified picture) Serum amylase activity was also significantly reduced inSAP+BMSCs group than in normal SAP and anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively (c) The levels ofserum proinflammatory cytokines are significantly lower in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines are significantly higher in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups Dataare expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SAP versus Normal dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP versus SAP+BMSCs $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4BMSCs) Data analysis was performed by Studentrsquos test (BMSCs bone marrow-derived mesenchymal stem cells HampE hematoxylin-eosin)
number of cells whichmigrated to the necrotic pancreas waspositively related to the therapeutic effect However SPION-labeled BMSCs could be rarely seen on postoperative day 10perhaps because the SPIONwere degraded or the BMSCs haddifferentiated into other cells including pancreatic exocrinecells
To validate whether the SDF-1120572CXCR4 axis also playsan important role in the repair and regeneration of SAPwe conducted the study in vitro and vivo We found thatthe secretions of BMSCs could promote the proliferationmigration and restoration of EAhy926 cells The BMSCssupernatant induced angiogenesis and the SDF-1120572CXCR4axis stimulated BMSCs to express VEGF ANG-1 HGFand TGF-120573 promoting further angiogenesis in vitro Both
VEGF and ANG-1 play important roles in angiogenesisMoreover the expressions of VEGFANG-1HGF andTGF-120573in the damaged pancreatic tissues were higher in the BMSCstransplantation group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups Taken all together theresult showed that transplantedBMSCs repaired the damagedpancreas through secreting large cellular growth factors andthe effect was regulated by SDF-1120572CXCR4 axis
As we all know VEGF a potent inducer of angiogenesispromotes the repair of injured vascular endothelial cellsand neovascularization Studies have shown that the SDF-1120572CXCR4 axis promotes the synthesis and secretion ofVEGF [17 43] and SDF-1120572 combined with VEGF enhancesischemic angiogenesis [20] In our study we confirmed that
Stem Cells International 15
15
10
5
0
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
expr
essio
nslowastlowastlowastdagger
lowastlowastlowastdagger
daggerdaggerdagger
$
1d 4d 7dVEGF
(a)
daggerdaggerdaggerdagger
dagger
$
$
lowast
lowast
lowast
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
0
5
10
15
Relat
ive m
RNA
expr
essio
ns
Ang-11d 4d 7d
(b)NC Sham
ANG-1
VEGF
GAPDH
Ant
i-CXC
R4SA
PA
nti-C
XCR4
SAP
SAP
+BM
SCs
SAP
+BM
SCs
36
1d 4d 7d
45
70
(kD)
(c)
dagger
daggerdaggerdagger
$
10
00
02
04
06
08
lowastlowastlowast
dagger$lowastlowastlowast
lowastlowastlowast
SAP + BMSCsNCShamSAP
1d 4d 7d
Relat
ive r
atio
of V
EGF
to G
APD
H
SAP + anti-CXCR4 BMSCs
(d)
dagger
daggerdaggerdagger
$$
lowastlowastlowastlowastlowastlowast
lowastlowastlowast
$$$daggerdaggerdagger
0020
0015
0010
0005
0000
Relat
ive r
atio
of A
ng-1
to G
APD
H
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(e)
daggerdagger
dagger$
lowast
lowastlowast
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
TGF-1205731d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(f)
Figure 7 Continued
16 Stem Cells International
dagger
dagger$
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
HGF
lowastlowast
lowastlowastlowastlowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(g)
$
$
0
2
4
6
8
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
CD31
daggerlowast
lowast
lowast
daggerlowastlowast
dagger daggerlowast
lowast
lowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
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Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
10 Stem Cells International
Ant
i-CXC
R4BM
SCs
BMSC
s
Nor
mal
1d 3d 7d5d 10d
Nor
mal
BMSC
sA
nti-C
XCR4
BM
SCs
1d 3d 7d5d 10d(a)
(b)100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
lowastlowastlowast
1d 100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
lowastlowast
3d
(c)
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
lowastlowastlowast
lowastlowast
7d5d
BMSCsAnti-CXCR4 BMSCs
BMSCsAnti-CXCR4 BMSCs
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
Figure 4 Continued
Stem Cells International 11
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
10d
BMSCsAnti-CXCR4 BMSCs
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
(c)
Figure 4 Prussian blue staining was performed for detecting the SPION-labeled BMSCs in pancreatic and lung tissues (a) The Prussianblue staining of pancreatic tissue indicates that the cells were stained blue (as indicated by black arrows) gradually increased and peaked onpostoperative days 5ndash7 when the formation of tubular complexes was also maximal (as indicated by red arrows) However the migration waspartly inhibited and the trend was not obviously investigated in anti-CXCR4 group (b) The lung tissues were stained by Prussian blue andthe blue particles (as indicated by black arrows) were gradually decreasing in both BMSCs and anti-CXCR4 groups (c) The blue particles inlung pancreas liver spleen and small intestine were counted and analyzed between BMSCs and anti-CXCR4 groupsThe result showed thatthe number of blue particles of pancreas in BMSCs group was significantly more than in anti-CXCR4 group at postoperative days 1 3 5 and7 Data are expressed as mean plusmn SD (lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for BMSCs versus anti-CXCR4 at each corresponding time point)
and 7(d)) The mRNA levels of HGF and TGF-120573 were alsodetected with qRT-PCR and were significantly higher in theSAP+BMSCs group than in the normal SAP and SAP+anti-CXCR4 BMSCs groups (Figures 7(f) and 7(g))
38 SDF-1120572CXCR4 Axis Induces the Neovascularization InVivo To assess the neovascularization we conducted qRT-PCR or immunohistochemistry for detecting these angiogen-esis markers (CD31 VEGF and vWF) The results indicatedthat the expressions of CD31 VEGF and vWF in necroticpancreatic tissue were higher in the SAP+BMSCs group thanin the normal control SAP and SAP+anti-CXCR4 BMSCsgroups especially in early phase (Figures 7(h) and 8(a)ndash8(d))
4 Discussion
Several studies have shown that MSCs from the bone orumbilical cord can attenuate acute necrotic pancreatitis byinhibiting systematic inflammation regulating the immuneresponses reducing the apoptosis of pancreatic acinar cellsand repairing damaged the small intestinal epithelium [9ndash12]However these functions do not account for how to repairand regenerate the necrotic pancreatic tissues In the studywe found that BMSCs can reduce severe acute pancreatitisby alleviating the systematic inflammation promoting theformation of tubular complexes (TCs) and inducing angio-genesis involving the SDF-1120572CXCR4 axis by enhancing the
expression of cell growth factors in a rat model of SAP Largeprevious studies have found that MSCs can not only differ-entiate into different kinds of functional adult cells but alsosecrete various soluble factors including VEGF HGF andTGF-120573 [27] These factors which promote angiogenesis andmitosis and reduce apoptosis can explain tissue repair andregeneration after MSCs transplanted [28 29] Moreover theregeneration of the pancreas begins with the TCs that consistof a cluster of epithelia surrounded by the mesenchymalcells [30 31] Thus we inferred that SDF-1120572CXCR4 axis wasinvolved in the repair and regeneration of SAP
SDF-1120572 and its receptor CXCR4 have been studiedextensively together with their roles in migration homingproliferation angiogenesis and so forth [11 13ndash15 18 3233] Many researches have shown that BMSCs can migrateto injured tissues via the SDF-1120572CXCR4 axis and relievemyocardial infraction [13 14] promote wound healing [19]heal bone fracture [34] reduce cerebral ischemia [35] andameliorate acute necrotizing pancreatitis [11] SDF-1120572 expres-sion is upregulated by hypoxia-inducible factor-1 (HIF-1)[36] In the study we successfully established a rat model ofacute necrotizing pancreatitis with the retrograde injectionof Na-taurocholate which causes acinar cell injurynecrosisby triggering transient pathological intra-acinar-cell cal-cium ions and activating digestive zymogens [37ndash39] Theinjurednecrotic pancreatic tissue causes HIF-1 expressionand thus induces SDF-1120572 expression which attracts BMSCsto injured pancreas through the interaction with CXCR4
12 Stem Cells International
T1WI
SPIO
N-la
bele
d BM
SCs
T2WI
5 10 15 20 25 30[Fe] (120583gmL)
(a)
Normal (T1WI)
BMSCs BMSCs BMSCs
Anti-CXCR4 BMSCsBMSCsBMSCs
BMSCs
5d (T1WI)7d (T1WI)
1d (T1WI) 3d (T1WI) 5d (T1WI)
10d (T1WI)
(b)
BMSCs
7d (T1WI)
BMSCs
7d (T2WI)
(c)
Figure 5 The transplanted SPION-labeled BMSCs were tracked by MRI in vivo (a) [Fe3+] was detected by MRI and the result showed thatthe SPION-labeled BMSCs ([Fe3+] = 25 gmL) appeared high signals (white spots) on T1WI and low signals (dark spots) on T2WI (b) TheSPION-BMSCs ([Fe3+] = 25 gmL) was tracked by MRI in vivo and the photos show that the white spots (inside of red circle) were increasinggradually and peaked on postoperative days 5ndash7 Instead the white spots decreased on postoperative day 5 in anti-CXCR4 group comparedwith BMSCs group (c) The SPION-BMSCs ([Fe3+] = 25 gmL) were detected in SAP rats at postoperative day 7 by T1WI and T2WI andthe result was showing that the high signals (white spots) which appeared in T1WI became low signals (dark spots) in T2WI (SPIONsuperparamagnetic iron oxide nanoparticles T1WI T1-weighted imaging and T2WI T2-weighted imaging)
For further investigating whether BMSCs could migrateto injured pancreas and the migration was regulated by SDF-1120572CXCR4 axis in a SAP rat model SPION was used tolabel BMSCs SPION were initially used as a unique MRcontrast agent in the clinical context Recently their two useshave been discoveredmdashthe labeling of live cells and tissuesdisease diagnosis and therapy [22 23 40ndash42] Studies havedemonstrated that SPION-labeling does not deleteriouslyaffect the functions of the target cells [25] In our study wealso demonstrated that there was no difference in the pro-liferation capacities between SPION-labeled (Fe = 25 120583gmLlabeling efficiency gt 95) and unlabeled BMSCs Moreover
the expression of CXCR4was also similar between the labeledand unlabeled cells SPION-labeled BMSCs could be detectedby both MRI and Prussian blue staining because SPIONis the nanometer particles of ferric oxide The dynamicmovement of labeling cells could be observed at the photosof MRI so that we can intuitively assess the proportions ofSPION-labeled BMSCs in vivo The result showed that thesecells could migrate to the damaged pancreatic tissues andthere was also a gradual increase in migration peaking onpostoperative days 5ndash7 with the formation of large numbersof TCs SDF-1120572CXCR4 axis could regulate the migrationof BMSCs as our previously described [11] Meanwhile the
Stem Cells International 13
SAP
NC Sham Tubular complex
SAP+
BMSC
sSA
P+
anti-
CXCR
4BM
SCs
1d 4d 7d
(a)
0
1
2
3
4
Edema
Scor
e $
$$$
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
SAP + BMSCsSAP + anti-CXCR4
SAP + anti-CXCR4SAP + anti-CXCR4
SAP + anti-CXCR4 BMSCs
ShamSAP
Normal
0
1
2
3
4
Scor
e
$
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
SAP + BMSCs
BMSCsShamSAP
Normal
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1000
800
600
400
200
0
0
1
2
3
4
Scor
e
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1d 4d 7d
1d 4d 7d 1d 4d 7d
1d 4d 7dInfiltration
Necrosis
Am
ylas
e act
ivity
(b)
Figure 6 Continued
14 Stem Cells International
130
120
110
100
90
80The c
once
ntra
tion
of se
rum
IL-1
(pg
mL)
daggerdaggerlowast
daggerlowast
daggerdaggerdagger
daggerdaggerdagger
lowast
lowastlowastlowastlowast
daggerlowast
lowastlowastlowast
daggerdaggerdaggerlowastlowast
daggerdaggerdaggerlowast
Control Day 1 Day 4 Day 7
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham
$
daggerdaggerlowast
$ daggerdagger daggerlowastlowast
$daggerdagger dagger
daggerlowastlowastlowastlowastlowast
daggerlowastlowast
$$$daggerdagger daggerlowastlowast
$daggerdagger daggerlowastlowast
$
daggerlowast dagger
lowast
$
$
$$
$$$$$$
The c
once
ntra
tion
of se
rum
IL-4
(pg
mL)
80
70
60
50
40
The c
once
ntra
tion
of se
rum
IL-6
(pg
mL)
90
80
70
60
The c
once
ntra
tion
of se
rum
IL-10
(pg
mL)
60
55
50
45
40
35
The c
once
ntra
tion
of se
rum
TN
F-120572
(pg
mL)
260
240
220
200
180
160
220
200
180
160
140
120The c
once
ntra
tion
of se
rum
TG
F-120573
(pg
mL)
(c)
Figure 6 Transplanted BMSCs could reduce severe acute pancreatitis (SAP) promoting the formation of tubular complexes and inhibitingsystematic inflammatory response being involved in the SDF-1120572CXCR4 axis ((a) (b))TheHampE staining of pancreatic tissues (magnificationtimes100) is showing that the edema infiltration and necrosis were significantly reduced in the SAP+BMSCs group compared with SAP andSAP+anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively A large number of tubular complexes were also investigatedin SAP+BMSCs group (as indicated by red arrow in a 400x magnified picture) Serum amylase activity was also significantly reduced inSAP+BMSCs group than in normal SAP and anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively (c) The levels ofserum proinflammatory cytokines are significantly lower in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines are significantly higher in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups Dataare expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SAP versus Normal dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP versus SAP+BMSCs $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4BMSCs) Data analysis was performed by Studentrsquos test (BMSCs bone marrow-derived mesenchymal stem cells HampE hematoxylin-eosin)
number of cells whichmigrated to the necrotic pancreas waspositively related to the therapeutic effect However SPION-labeled BMSCs could be rarely seen on postoperative day 10perhaps because the SPIONwere degraded or the BMSCs haddifferentiated into other cells including pancreatic exocrinecells
To validate whether the SDF-1120572CXCR4 axis also playsan important role in the repair and regeneration of SAPwe conducted the study in vitro and vivo We found thatthe secretions of BMSCs could promote the proliferationmigration and restoration of EAhy926 cells The BMSCssupernatant induced angiogenesis and the SDF-1120572CXCR4axis stimulated BMSCs to express VEGF ANG-1 HGFand TGF-120573 promoting further angiogenesis in vitro Both
VEGF and ANG-1 play important roles in angiogenesisMoreover the expressions of VEGFANG-1HGF andTGF-120573in the damaged pancreatic tissues were higher in the BMSCstransplantation group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups Taken all together theresult showed that transplantedBMSCs repaired the damagedpancreas through secreting large cellular growth factors andthe effect was regulated by SDF-1120572CXCR4 axis
As we all know VEGF a potent inducer of angiogenesispromotes the repair of injured vascular endothelial cellsand neovascularization Studies have shown that the SDF-1120572CXCR4 axis promotes the synthesis and secretion ofVEGF [17 43] and SDF-1120572 combined with VEGF enhancesischemic angiogenesis [20] In our study we confirmed that
Stem Cells International 15
15
10
5
0
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
expr
essio
nslowastlowastlowastdagger
lowastlowastlowastdagger
daggerdaggerdagger
$
1d 4d 7dVEGF
(a)
daggerdaggerdaggerdagger
dagger
$
$
lowast
lowast
lowast
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
0
5
10
15
Relat
ive m
RNA
expr
essio
ns
Ang-11d 4d 7d
(b)NC Sham
ANG-1
VEGF
GAPDH
Ant
i-CXC
R4SA
PA
nti-C
XCR4
SAP
SAP
+BM
SCs
SAP
+BM
SCs
36
1d 4d 7d
45
70
(kD)
(c)
dagger
daggerdaggerdagger
$
10
00
02
04
06
08
lowastlowastlowast
dagger$lowastlowastlowast
lowastlowastlowast
SAP + BMSCsNCShamSAP
1d 4d 7d
Relat
ive r
atio
of V
EGF
to G
APD
H
SAP + anti-CXCR4 BMSCs
(d)
dagger
daggerdaggerdagger
$$
lowastlowastlowastlowastlowastlowast
lowastlowastlowast
$$$daggerdaggerdagger
0020
0015
0010
0005
0000
Relat
ive r
atio
of A
ng-1
to G
APD
H
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(e)
daggerdagger
dagger$
lowast
lowastlowast
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
TGF-1205731d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(f)
Figure 7 Continued
16 Stem Cells International
dagger
dagger$
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
HGF
lowastlowast
lowastlowastlowastlowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(g)
$
$
0
2
4
6
8
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
CD31
daggerlowast
lowast
lowast
daggerlowastlowast
dagger daggerlowast
lowast
lowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
Stem Cells International 11
100
80
60
40
20
0
The n
umbe
r of b
lue p
artic
les
10d
BMSCsAnti-CXCR4 BMSCs
Lung
Live
r
Sple
en
Panc
reas
Smal
lin
testi
ne
(c)
Figure 4 Prussian blue staining was performed for detecting the SPION-labeled BMSCs in pancreatic and lung tissues (a) The Prussianblue staining of pancreatic tissue indicates that the cells were stained blue (as indicated by black arrows) gradually increased and peaked onpostoperative days 5ndash7 when the formation of tubular complexes was also maximal (as indicated by red arrows) However the migration waspartly inhibited and the trend was not obviously investigated in anti-CXCR4 group (b) The lung tissues were stained by Prussian blue andthe blue particles (as indicated by black arrows) were gradually decreasing in both BMSCs and anti-CXCR4 groups (c) The blue particles inlung pancreas liver spleen and small intestine were counted and analyzed between BMSCs and anti-CXCR4 groupsThe result showed thatthe number of blue particles of pancreas in BMSCs group was significantly more than in anti-CXCR4 group at postoperative days 1 3 5 and7 Data are expressed as mean plusmn SD (lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for BMSCs versus anti-CXCR4 at each corresponding time point)
and 7(d)) The mRNA levels of HGF and TGF-120573 were alsodetected with qRT-PCR and were significantly higher in theSAP+BMSCs group than in the normal SAP and SAP+anti-CXCR4 BMSCs groups (Figures 7(f) and 7(g))
38 SDF-1120572CXCR4 Axis Induces the Neovascularization InVivo To assess the neovascularization we conducted qRT-PCR or immunohistochemistry for detecting these angiogen-esis markers (CD31 VEGF and vWF) The results indicatedthat the expressions of CD31 VEGF and vWF in necroticpancreatic tissue were higher in the SAP+BMSCs group thanin the normal control SAP and SAP+anti-CXCR4 BMSCsgroups especially in early phase (Figures 7(h) and 8(a)ndash8(d))
4 Discussion
Several studies have shown that MSCs from the bone orumbilical cord can attenuate acute necrotic pancreatitis byinhibiting systematic inflammation regulating the immuneresponses reducing the apoptosis of pancreatic acinar cellsand repairing damaged the small intestinal epithelium [9ndash12]However these functions do not account for how to repairand regenerate the necrotic pancreatic tissues In the studywe found that BMSCs can reduce severe acute pancreatitisby alleviating the systematic inflammation promoting theformation of tubular complexes (TCs) and inducing angio-genesis involving the SDF-1120572CXCR4 axis by enhancing the
expression of cell growth factors in a rat model of SAP Largeprevious studies have found that MSCs can not only differ-entiate into different kinds of functional adult cells but alsosecrete various soluble factors including VEGF HGF andTGF-120573 [27] These factors which promote angiogenesis andmitosis and reduce apoptosis can explain tissue repair andregeneration after MSCs transplanted [28 29] Moreover theregeneration of the pancreas begins with the TCs that consistof a cluster of epithelia surrounded by the mesenchymalcells [30 31] Thus we inferred that SDF-1120572CXCR4 axis wasinvolved in the repair and regeneration of SAP
SDF-1120572 and its receptor CXCR4 have been studiedextensively together with their roles in migration homingproliferation angiogenesis and so forth [11 13ndash15 18 3233] Many researches have shown that BMSCs can migrateto injured tissues via the SDF-1120572CXCR4 axis and relievemyocardial infraction [13 14] promote wound healing [19]heal bone fracture [34] reduce cerebral ischemia [35] andameliorate acute necrotizing pancreatitis [11] SDF-1120572 expres-sion is upregulated by hypoxia-inducible factor-1 (HIF-1)[36] In the study we successfully established a rat model ofacute necrotizing pancreatitis with the retrograde injectionof Na-taurocholate which causes acinar cell injurynecrosisby triggering transient pathological intra-acinar-cell cal-cium ions and activating digestive zymogens [37ndash39] Theinjurednecrotic pancreatic tissue causes HIF-1 expressionand thus induces SDF-1120572 expression which attracts BMSCsto injured pancreas through the interaction with CXCR4
12 Stem Cells International
T1WI
SPIO
N-la
bele
d BM
SCs
T2WI
5 10 15 20 25 30[Fe] (120583gmL)
(a)
Normal (T1WI)
BMSCs BMSCs BMSCs
Anti-CXCR4 BMSCsBMSCsBMSCs
BMSCs
5d (T1WI)7d (T1WI)
1d (T1WI) 3d (T1WI) 5d (T1WI)
10d (T1WI)
(b)
BMSCs
7d (T1WI)
BMSCs
7d (T2WI)
(c)
Figure 5 The transplanted SPION-labeled BMSCs were tracked by MRI in vivo (a) [Fe3+] was detected by MRI and the result showed thatthe SPION-labeled BMSCs ([Fe3+] = 25 gmL) appeared high signals (white spots) on T1WI and low signals (dark spots) on T2WI (b) TheSPION-BMSCs ([Fe3+] = 25 gmL) was tracked by MRI in vivo and the photos show that the white spots (inside of red circle) were increasinggradually and peaked on postoperative days 5ndash7 Instead the white spots decreased on postoperative day 5 in anti-CXCR4 group comparedwith BMSCs group (c) The SPION-BMSCs ([Fe3+] = 25 gmL) were detected in SAP rats at postoperative day 7 by T1WI and T2WI andthe result was showing that the high signals (white spots) which appeared in T1WI became low signals (dark spots) in T2WI (SPIONsuperparamagnetic iron oxide nanoparticles T1WI T1-weighted imaging and T2WI T2-weighted imaging)
For further investigating whether BMSCs could migrateto injured pancreas and the migration was regulated by SDF-1120572CXCR4 axis in a SAP rat model SPION was used tolabel BMSCs SPION were initially used as a unique MRcontrast agent in the clinical context Recently their two useshave been discoveredmdashthe labeling of live cells and tissuesdisease diagnosis and therapy [22 23 40ndash42] Studies havedemonstrated that SPION-labeling does not deleteriouslyaffect the functions of the target cells [25] In our study wealso demonstrated that there was no difference in the pro-liferation capacities between SPION-labeled (Fe = 25 120583gmLlabeling efficiency gt 95) and unlabeled BMSCs Moreover
the expression of CXCR4was also similar between the labeledand unlabeled cells SPION-labeled BMSCs could be detectedby both MRI and Prussian blue staining because SPIONis the nanometer particles of ferric oxide The dynamicmovement of labeling cells could be observed at the photosof MRI so that we can intuitively assess the proportions ofSPION-labeled BMSCs in vivo The result showed that thesecells could migrate to the damaged pancreatic tissues andthere was also a gradual increase in migration peaking onpostoperative days 5ndash7 with the formation of large numbersof TCs SDF-1120572CXCR4 axis could regulate the migrationof BMSCs as our previously described [11] Meanwhile the
Stem Cells International 13
SAP
NC Sham Tubular complex
SAP+
BMSC
sSA
P+
anti-
CXCR
4BM
SCs
1d 4d 7d
(a)
0
1
2
3
4
Edema
Scor
e $
$$$
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
SAP + BMSCsSAP + anti-CXCR4
SAP + anti-CXCR4SAP + anti-CXCR4
SAP + anti-CXCR4 BMSCs
ShamSAP
Normal
0
1
2
3
4
Scor
e
$
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
SAP + BMSCs
BMSCsShamSAP
Normal
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1000
800
600
400
200
0
0
1
2
3
4
Scor
e
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1d 4d 7d
1d 4d 7d 1d 4d 7d
1d 4d 7dInfiltration
Necrosis
Am
ylas
e act
ivity
(b)
Figure 6 Continued
14 Stem Cells International
130
120
110
100
90
80The c
once
ntra
tion
of se
rum
IL-1
(pg
mL)
daggerdaggerlowast
daggerlowast
daggerdaggerdagger
daggerdaggerdagger
lowast
lowastlowastlowastlowast
daggerlowast
lowastlowastlowast
daggerdaggerdaggerlowastlowast
daggerdaggerdaggerlowast
Control Day 1 Day 4 Day 7
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham
$
daggerdaggerlowast
$ daggerdagger daggerlowastlowast
$daggerdagger dagger
daggerlowastlowastlowastlowastlowast
daggerlowastlowast
$$$daggerdagger daggerlowastlowast
$daggerdagger daggerlowastlowast
$
daggerlowast dagger
lowast
$
$
$$
$$$$$$
The c
once
ntra
tion
of se
rum
IL-4
(pg
mL)
80
70
60
50
40
The c
once
ntra
tion
of se
rum
IL-6
(pg
mL)
90
80
70
60
The c
once
ntra
tion
of se
rum
IL-10
(pg
mL)
60
55
50
45
40
35
The c
once
ntra
tion
of se
rum
TN
F-120572
(pg
mL)
260
240
220
200
180
160
220
200
180
160
140
120The c
once
ntra
tion
of se
rum
TG
F-120573
(pg
mL)
(c)
Figure 6 Transplanted BMSCs could reduce severe acute pancreatitis (SAP) promoting the formation of tubular complexes and inhibitingsystematic inflammatory response being involved in the SDF-1120572CXCR4 axis ((a) (b))TheHampE staining of pancreatic tissues (magnificationtimes100) is showing that the edema infiltration and necrosis were significantly reduced in the SAP+BMSCs group compared with SAP andSAP+anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively A large number of tubular complexes were also investigatedin SAP+BMSCs group (as indicated by red arrow in a 400x magnified picture) Serum amylase activity was also significantly reduced inSAP+BMSCs group than in normal SAP and anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively (c) The levels ofserum proinflammatory cytokines are significantly lower in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines are significantly higher in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups Dataare expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SAP versus Normal dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP versus SAP+BMSCs $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4BMSCs) Data analysis was performed by Studentrsquos test (BMSCs bone marrow-derived mesenchymal stem cells HampE hematoxylin-eosin)
number of cells whichmigrated to the necrotic pancreas waspositively related to the therapeutic effect However SPION-labeled BMSCs could be rarely seen on postoperative day 10perhaps because the SPIONwere degraded or the BMSCs haddifferentiated into other cells including pancreatic exocrinecells
To validate whether the SDF-1120572CXCR4 axis also playsan important role in the repair and regeneration of SAPwe conducted the study in vitro and vivo We found thatthe secretions of BMSCs could promote the proliferationmigration and restoration of EAhy926 cells The BMSCssupernatant induced angiogenesis and the SDF-1120572CXCR4axis stimulated BMSCs to express VEGF ANG-1 HGFand TGF-120573 promoting further angiogenesis in vitro Both
VEGF and ANG-1 play important roles in angiogenesisMoreover the expressions of VEGFANG-1HGF andTGF-120573in the damaged pancreatic tissues were higher in the BMSCstransplantation group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups Taken all together theresult showed that transplantedBMSCs repaired the damagedpancreas through secreting large cellular growth factors andthe effect was regulated by SDF-1120572CXCR4 axis
As we all know VEGF a potent inducer of angiogenesispromotes the repair of injured vascular endothelial cellsand neovascularization Studies have shown that the SDF-1120572CXCR4 axis promotes the synthesis and secretion ofVEGF [17 43] and SDF-1120572 combined with VEGF enhancesischemic angiogenesis [20] In our study we confirmed that
Stem Cells International 15
15
10
5
0
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
expr
essio
nslowastlowastlowastdagger
lowastlowastlowastdagger
daggerdaggerdagger
$
1d 4d 7dVEGF
(a)
daggerdaggerdaggerdagger
dagger
$
$
lowast
lowast
lowast
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
0
5
10
15
Relat
ive m
RNA
expr
essio
ns
Ang-11d 4d 7d
(b)NC Sham
ANG-1
VEGF
GAPDH
Ant
i-CXC
R4SA
PA
nti-C
XCR4
SAP
SAP
+BM
SCs
SAP
+BM
SCs
36
1d 4d 7d
45
70
(kD)
(c)
dagger
daggerdaggerdagger
$
10
00
02
04
06
08
lowastlowastlowast
dagger$lowastlowastlowast
lowastlowastlowast
SAP + BMSCsNCShamSAP
1d 4d 7d
Relat
ive r
atio
of V
EGF
to G
APD
H
SAP + anti-CXCR4 BMSCs
(d)
dagger
daggerdaggerdagger
$$
lowastlowastlowastlowastlowastlowast
lowastlowastlowast
$$$daggerdaggerdagger
0020
0015
0010
0005
0000
Relat
ive r
atio
of A
ng-1
to G
APD
H
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(e)
daggerdagger
dagger$
lowast
lowastlowast
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
TGF-1205731d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(f)
Figure 7 Continued
16 Stem Cells International
dagger
dagger$
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
HGF
lowastlowast
lowastlowastlowastlowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(g)
$
$
0
2
4
6
8
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
CD31
daggerlowast
lowast
lowast
daggerlowastlowast
dagger daggerlowast
lowast
lowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
12 Stem Cells International
T1WI
SPIO
N-la
bele
d BM
SCs
T2WI
5 10 15 20 25 30[Fe] (120583gmL)
(a)
Normal (T1WI)
BMSCs BMSCs BMSCs
Anti-CXCR4 BMSCsBMSCsBMSCs
BMSCs
5d (T1WI)7d (T1WI)
1d (T1WI) 3d (T1WI) 5d (T1WI)
10d (T1WI)
(b)
BMSCs
7d (T1WI)
BMSCs
7d (T2WI)
(c)
Figure 5 The transplanted SPION-labeled BMSCs were tracked by MRI in vivo (a) [Fe3+] was detected by MRI and the result showed thatthe SPION-labeled BMSCs ([Fe3+] = 25 gmL) appeared high signals (white spots) on T1WI and low signals (dark spots) on T2WI (b) TheSPION-BMSCs ([Fe3+] = 25 gmL) was tracked by MRI in vivo and the photos show that the white spots (inside of red circle) were increasinggradually and peaked on postoperative days 5ndash7 Instead the white spots decreased on postoperative day 5 in anti-CXCR4 group comparedwith BMSCs group (c) The SPION-BMSCs ([Fe3+] = 25 gmL) were detected in SAP rats at postoperative day 7 by T1WI and T2WI andthe result was showing that the high signals (white spots) which appeared in T1WI became low signals (dark spots) in T2WI (SPIONsuperparamagnetic iron oxide nanoparticles T1WI T1-weighted imaging and T2WI T2-weighted imaging)
For further investigating whether BMSCs could migrateto injured pancreas and the migration was regulated by SDF-1120572CXCR4 axis in a SAP rat model SPION was used tolabel BMSCs SPION were initially used as a unique MRcontrast agent in the clinical context Recently their two useshave been discoveredmdashthe labeling of live cells and tissuesdisease diagnosis and therapy [22 23 40ndash42] Studies havedemonstrated that SPION-labeling does not deleteriouslyaffect the functions of the target cells [25] In our study wealso demonstrated that there was no difference in the pro-liferation capacities between SPION-labeled (Fe = 25 120583gmLlabeling efficiency gt 95) and unlabeled BMSCs Moreover
the expression of CXCR4was also similar between the labeledand unlabeled cells SPION-labeled BMSCs could be detectedby both MRI and Prussian blue staining because SPIONis the nanometer particles of ferric oxide The dynamicmovement of labeling cells could be observed at the photosof MRI so that we can intuitively assess the proportions ofSPION-labeled BMSCs in vivo The result showed that thesecells could migrate to the damaged pancreatic tissues andthere was also a gradual increase in migration peaking onpostoperative days 5ndash7 with the formation of large numbersof TCs SDF-1120572CXCR4 axis could regulate the migrationof BMSCs as our previously described [11] Meanwhile the
Stem Cells International 13
SAP
NC Sham Tubular complex
SAP+
BMSC
sSA
P+
anti-
CXCR
4BM
SCs
1d 4d 7d
(a)
0
1
2
3
4
Edema
Scor
e $
$$$
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
SAP + BMSCsSAP + anti-CXCR4
SAP + anti-CXCR4SAP + anti-CXCR4
SAP + anti-CXCR4 BMSCs
ShamSAP
Normal
0
1
2
3
4
Scor
e
$
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
SAP + BMSCs
BMSCsShamSAP
Normal
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1000
800
600
400
200
0
0
1
2
3
4
Scor
e
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1d 4d 7d
1d 4d 7d 1d 4d 7d
1d 4d 7dInfiltration
Necrosis
Am
ylas
e act
ivity
(b)
Figure 6 Continued
14 Stem Cells International
130
120
110
100
90
80The c
once
ntra
tion
of se
rum
IL-1
(pg
mL)
daggerdaggerlowast
daggerlowast
daggerdaggerdagger
daggerdaggerdagger
lowast
lowastlowastlowastlowast
daggerlowast
lowastlowastlowast
daggerdaggerdaggerlowastlowast
daggerdaggerdaggerlowast
Control Day 1 Day 4 Day 7
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham
$
daggerdaggerlowast
$ daggerdagger daggerlowastlowast
$daggerdagger dagger
daggerlowastlowastlowastlowastlowast
daggerlowastlowast
$$$daggerdagger daggerlowastlowast
$daggerdagger daggerlowastlowast
$
daggerlowast dagger
lowast
$
$
$$
$$$$$$
The c
once
ntra
tion
of se
rum
IL-4
(pg
mL)
80
70
60
50
40
The c
once
ntra
tion
of se
rum
IL-6
(pg
mL)
90
80
70
60
The c
once
ntra
tion
of se
rum
IL-10
(pg
mL)
60
55
50
45
40
35
The c
once
ntra
tion
of se
rum
TN
F-120572
(pg
mL)
260
240
220
200
180
160
220
200
180
160
140
120The c
once
ntra
tion
of se
rum
TG
F-120573
(pg
mL)
(c)
Figure 6 Transplanted BMSCs could reduce severe acute pancreatitis (SAP) promoting the formation of tubular complexes and inhibitingsystematic inflammatory response being involved in the SDF-1120572CXCR4 axis ((a) (b))TheHampE staining of pancreatic tissues (magnificationtimes100) is showing that the edema infiltration and necrosis were significantly reduced in the SAP+BMSCs group compared with SAP andSAP+anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively A large number of tubular complexes were also investigatedin SAP+BMSCs group (as indicated by red arrow in a 400x magnified picture) Serum amylase activity was also significantly reduced inSAP+BMSCs group than in normal SAP and anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively (c) The levels ofserum proinflammatory cytokines are significantly lower in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines are significantly higher in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups Dataare expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SAP versus Normal dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP versus SAP+BMSCs $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4BMSCs) Data analysis was performed by Studentrsquos test (BMSCs bone marrow-derived mesenchymal stem cells HampE hematoxylin-eosin)
number of cells whichmigrated to the necrotic pancreas waspositively related to the therapeutic effect However SPION-labeled BMSCs could be rarely seen on postoperative day 10perhaps because the SPIONwere degraded or the BMSCs haddifferentiated into other cells including pancreatic exocrinecells
To validate whether the SDF-1120572CXCR4 axis also playsan important role in the repair and regeneration of SAPwe conducted the study in vitro and vivo We found thatthe secretions of BMSCs could promote the proliferationmigration and restoration of EAhy926 cells The BMSCssupernatant induced angiogenesis and the SDF-1120572CXCR4axis stimulated BMSCs to express VEGF ANG-1 HGFand TGF-120573 promoting further angiogenesis in vitro Both
VEGF and ANG-1 play important roles in angiogenesisMoreover the expressions of VEGFANG-1HGF andTGF-120573in the damaged pancreatic tissues were higher in the BMSCstransplantation group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups Taken all together theresult showed that transplantedBMSCs repaired the damagedpancreas through secreting large cellular growth factors andthe effect was regulated by SDF-1120572CXCR4 axis
As we all know VEGF a potent inducer of angiogenesispromotes the repair of injured vascular endothelial cellsand neovascularization Studies have shown that the SDF-1120572CXCR4 axis promotes the synthesis and secretion ofVEGF [17 43] and SDF-1120572 combined with VEGF enhancesischemic angiogenesis [20] In our study we confirmed that
Stem Cells International 15
15
10
5
0
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
expr
essio
nslowastlowastlowastdagger
lowastlowastlowastdagger
daggerdaggerdagger
$
1d 4d 7dVEGF
(a)
daggerdaggerdaggerdagger
dagger
$
$
lowast
lowast
lowast
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
0
5
10
15
Relat
ive m
RNA
expr
essio
ns
Ang-11d 4d 7d
(b)NC Sham
ANG-1
VEGF
GAPDH
Ant
i-CXC
R4SA
PA
nti-C
XCR4
SAP
SAP
+BM
SCs
SAP
+BM
SCs
36
1d 4d 7d
45
70
(kD)
(c)
dagger
daggerdaggerdagger
$
10
00
02
04
06
08
lowastlowastlowast
dagger$lowastlowastlowast
lowastlowastlowast
SAP + BMSCsNCShamSAP
1d 4d 7d
Relat
ive r
atio
of V
EGF
to G
APD
H
SAP + anti-CXCR4 BMSCs
(d)
dagger
daggerdaggerdagger
$$
lowastlowastlowastlowastlowastlowast
lowastlowastlowast
$$$daggerdaggerdagger
0020
0015
0010
0005
0000
Relat
ive r
atio
of A
ng-1
to G
APD
H
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(e)
daggerdagger
dagger$
lowast
lowastlowast
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
TGF-1205731d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(f)
Figure 7 Continued
16 Stem Cells International
dagger
dagger$
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
HGF
lowastlowast
lowastlowastlowastlowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(g)
$
$
0
2
4
6
8
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
CD31
daggerlowast
lowast
lowast
daggerlowastlowast
dagger daggerlowast
lowast
lowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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PeptidesInternational Journal of
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International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
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Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
Stem Cells International 13
SAP
NC Sham Tubular complex
SAP+
BMSC
sSA
P+
anti-
CXCR
4BM
SCs
1d 4d 7d
(a)
0
1
2
3
4
Edema
Scor
e $
$$$
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger lowast
daggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
lowastdaggerlowastdaggerlowastdagger
SAP + BMSCsSAP + anti-CXCR4
SAP + anti-CXCR4SAP + anti-CXCR4
SAP + anti-CXCR4 BMSCs
ShamSAP
Normal
0
1
2
3
4
Scor
e
$
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
lowastdagger
lowastdaggerlowastdagger
SAP + BMSCs
BMSCsShamSAP
Normal
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1000
800
600
400
200
0
0
1
2
3
4
Scor
e
SAP + BMSCs
BMSCsShamSAP
Normal
$$$
$$$
1d 4d 7d
1d 4d 7d 1d 4d 7d
1d 4d 7dInfiltration
Necrosis
Am
ylas
e act
ivity
(b)
Figure 6 Continued
14 Stem Cells International
130
120
110
100
90
80The c
once
ntra
tion
of se
rum
IL-1
(pg
mL)
daggerdaggerlowast
daggerlowast
daggerdaggerdagger
daggerdaggerdagger
lowast
lowastlowastlowastlowast
daggerlowast
lowastlowastlowast
daggerdaggerdaggerlowastlowast
daggerdaggerdaggerlowast
Control Day 1 Day 4 Day 7
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham
$
daggerdaggerlowast
$ daggerdagger daggerlowastlowast
$daggerdagger dagger
daggerlowastlowastlowastlowastlowast
daggerlowastlowast
$$$daggerdagger daggerlowastlowast
$daggerdagger daggerlowastlowast
$
daggerlowast dagger
lowast
$
$
$$
$$$$$$
The c
once
ntra
tion
of se
rum
IL-4
(pg
mL)
80
70
60
50
40
The c
once
ntra
tion
of se
rum
IL-6
(pg
mL)
90
80
70
60
The c
once
ntra
tion
of se
rum
IL-10
(pg
mL)
60
55
50
45
40
35
The c
once
ntra
tion
of se
rum
TN
F-120572
(pg
mL)
260
240
220
200
180
160
220
200
180
160
140
120The c
once
ntra
tion
of se
rum
TG
F-120573
(pg
mL)
(c)
Figure 6 Transplanted BMSCs could reduce severe acute pancreatitis (SAP) promoting the formation of tubular complexes and inhibitingsystematic inflammatory response being involved in the SDF-1120572CXCR4 axis ((a) (b))TheHampE staining of pancreatic tissues (magnificationtimes100) is showing that the edema infiltration and necrosis were significantly reduced in the SAP+BMSCs group compared with SAP andSAP+anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively A large number of tubular complexes were also investigatedin SAP+BMSCs group (as indicated by red arrow in a 400x magnified picture) Serum amylase activity was also significantly reduced inSAP+BMSCs group than in normal SAP and anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively (c) The levels ofserum proinflammatory cytokines are significantly lower in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines are significantly higher in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups Dataare expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SAP versus Normal dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP versus SAP+BMSCs $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4BMSCs) Data analysis was performed by Studentrsquos test (BMSCs bone marrow-derived mesenchymal stem cells HampE hematoxylin-eosin)
number of cells whichmigrated to the necrotic pancreas waspositively related to the therapeutic effect However SPION-labeled BMSCs could be rarely seen on postoperative day 10perhaps because the SPIONwere degraded or the BMSCs haddifferentiated into other cells including pancreatic exocrinecells
To validate whether the SDF-1120572CXCR4 axis also playsan important role in the repair and regeneration of SAPwe conducted the study in vitro and vivo We found thatthe secretions of BMSCs could promote the proliferationmigration and restoration of EAhy926 cells The BMSCssupernatant induced angiogenesis and the SDF-1120572CXCR4axis stimulated BMSCs to express VEGF ANG-1 HGFand TGF-120573 promoting further angiogenesis in vitro Both
VEGF and ANG-1 play important roles in angiogenesisMoreover the expressions of VEGFANG-1HGF andTGF-120573in the damaged pancreatic tissues were higher in the BMSCstransplantation group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups Taken all together theresult showed that transplantedBMSCs repaired the damagedpancreas through secreting large cellular growth factors andthe effect was regulated by SDF-1120572CXCR4 axis
As we all know VEGF a potent inducer of angiogenesispromotes the repair of injured vascular endothelial cellsand neovascularization Studies have shown that the SDF-1120572CXCR4 axis promotes the synthesis and secretion ofVEGF [17 43] and SDF-1120572 combined with VEGF enhancesischemic angiogenesis [20] In our study we confirmed that
Stem Cells International 15
15
10
5
0
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
expr
essio
nslowastlowastlowastdagger
lowastlowastlowastdagger
daggerdaggerdagger
$
1d 4d 7dVEGF
(a)
daggerdaggerdaggerdagger
dagger
$
$
lowast
lowast
lowast
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
0
5
10
15
Relat
ive m
RNA
expr
essio
ns
Ang-11d 4d 7d
(b)NC Sham
ANG-1
VEGF
GAPDH
Ant
i-CXC
R4SA
PA
nti-C
XCR4
SAP
SAP
+BM
SCs
SAP
+BM
SCs
36
1d 4d 7d
45
70
(kD)
(c)
dagger
daggerdaggerdagger
$
10
00
02
04
06
08
lowastlowastlowast
dagger$lowastlowastlowast
lowastlowastlowast
SAP + BMSCsNCShamSAP
1d 4d 7d
Relat
ive r
atio
of V
EGF
to G
APD
H
SAP + anti-CXCR4 BMSCs
(d)
dagger
daggerdaggerdagger
$$
lowastlowastlowastlowastlowastlowast
lowastlowastlowast
$$$daggerdaggerdagger
0020
0015
0010
0005
0000
Relat
ive r
atio
of A
ng-1
to G
APD
H
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(e)
daggerdagger
dagger$
lowast
lowastlowast
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
TGF-1205731d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(f)
Figure 7 Continued
16 Stem Cells International
dagger
dagger$
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
HGF
lowastlowast
lowastlowastlowastlowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(g)
$
$
0
2
4
6
8
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
CD31
daggerlowast
lowast
lowast
daggerlowastlowast
dagger daggerlowast
lowast
lowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
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BioinformaticsAdvances in
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Signal TransductionJournal of
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Evolutionary BiologyInternational Journal of
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Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
14 Stem Cells International
130
120
110
100
90
80The c
once
ntra
tion
of se
rum
IL-1
(pg
mL)
daggerdaggerlowast
daggerlowast
daggerdaggerdagger
daggerdaggerdagger
lowast
lowastlowastlowastlowast
daggerlowast
lowastlowastlowast
daggerdaggerdaggerlowastlowast
daggerdaggerdaggerlowast
Control Day 1 Day 4 Day 7
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
SAP + BMSCsSAP + anti-CXCR4 BMSCs
SAPSAP + BMSCsSAP + anti-CXCR4 BMSCs
SAP
Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham Control Day 1 Day 4 Day 7Sham
Control Day 1 Day 4 Day 7Sham
$
daggerdaggerlowast
$ daggerdagger daggerlowastlowast
$daggerdagger dagger
daggerlowastlowastlowastlowastlowast
daggerlowastlowast
$$$daggerdagger daggerlowastlowast
$daggerdagger daggerlowastlowast
$
daggerlowast dagger
lowast
$
$
$$
$$$$$$
The c
once
ntra
tion
of se
rum
IL-4
(pg
mL)
80
70
60
50
40
The c
once
ntra
tion
of se
rum
IL-6
(pg
mL)
90
80
70
60
The c
once
ntra
tion
of se
rum
IL-10
(pg
mL)
60
55
50
45
40
35
The c
once
ntra
tion
of se
rum
TN
F-120572
(pg
mL)
260
240
220
200
180
160
220
200
180
160
140
120The c
once
ntra
tion
of se
rum
TG
F-120573
(pg
mL)
(c)
Figure 6 Transplanted BMSCs could reduce severe acute pancreatitis (SAP) promoting the formation of tubular complexes and inhibitingsystematic inflammatory response being involved in the SDF-1120572CXCR4 axis ((a) (b))TheHampE staining of pancreatic tissues (magnificationtimes100) is showing that the edema infiltration and necrosis were significantly reduced in the SAP+BMSCs group compared with SAP andSAP+anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively A large number of tubular complexes were also investigatedin SAP+BMSCs group (as indicated by red arrow in a 400x magnified picture) Serum amylase activity was also significantly reduced inSAP+BMSCs group than in normal SAP and anti-CXCR4 BMSCs groups at postoperative days 1 4 and 7 respectively (c) The levels ofserum proinflammatory cytokines are significantly lower in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups In contrast thelevels of serum anti-inflammatory cytokines are significantly higher in SAP+BMSCs than in SAP and SAP+anti-CXCR4 BMSCs groups Dataare expressed as mean plusmn SD (119875 gt 005 for sham versus normal lowast119875 lt 005 lowastlowast119875 lt 001 and lowastlowastlowast119875 lt 0001 for SAP versus Normal dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP versus SAP+BMSCs $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4BMSCs) Data analysis was performed by Studentrsquos test (BMSCs bone marrow-derived mesenchymal stem cells HampE hematoxylin-eosin)
number of cells whichmigrated to the necrotic pancreas waspositively related to the therapeutic effect However SPION-labeled BMSCs could be rarely seen on postoperative day 10perhaps because the SPIONwere degraded or the BMSCs haddifferentiated into other cells including pancreatic exocrinecells
To validate whether the SDF-1120572CXCR4 axis also playsan important role in the repair and regeneration of SAPwe conducted the study in vitro and vivo We found thatthe secretions of BMSCs could promote the proliferationmigration and restoration of EAhy926 cells The BMSCssupernatant induced angiogenesis and the SDF-1120572CXCR4axis stimulated BMSCs to express VEGF ANG-1 HGFand TGF-120573 promoting further angiogenesis in vitro Both
VEGF and ANG-1 play important roles in angiogenesisMoreover the expressions of VEGFANG-1HGF andTGF-120573in the damaged pancreatic tissues were higher in the BMSCstransplantation group than in the normal control SAP andSAP+anti-CXCR4 BMSCs groups Taken all together theresult showed that transplantedBMSCs repaired the damagedpancreas through secreting large cellular growth factors andthe effect was regulated by SDF-1120572CXCR4 axis
As we all know VEGF a potent inducer of angiogenesispromotes the repair of injured vascular endothelial cellsand neovascularization Studies have shown that the SDF-1120572CXCR4 axis promotes the synthesis and secretion ofVEGF [17 43] and SDF-1120572 combined with VEGF enhancesischemic angiogenesis [20] In our study we confirmed that
Stem Cells International 15
15
10
5
0
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
expr
essio
nslowastlowastlowastdagger
lowastlowastlowastdagger
daggerdaggerdagger
$
1d 4d 7dVEGF
(a)
daggerdaggerdaggerdagger
dagger
$
$
lowast
lowast
lowast
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
0
5
10
15
Relat
ive m
RNA
expr
essio
ns
Ang-11d 4d 7d
(b)NC Sham
ANG-1
VEGF
GAPDH
Ant
i-CXC
R4SA
PA
nti-C
XCR4
SAP
SAP
+BM
SCs
SAP
+BM
SCs
36
1d 4d 7d
45
70
(kD)
(c)
dagger
daggerdaggerdagger
$
10
00
02
04
06
08
lowastlowastlowast
dagger$lowastlowastlowast
lowastlowastlowast
SAP + BMSCsNCShamSAP
1d 4d 7d
Relat
ive r
atio
of V
EGF
to G
APD
H
SAP + anti-CXCR4 BMSCs
(d)
dagger
daggerdaggerdagger
$$
lowastlowastlowastlowastlowastlowast
lowastlowastlowast
$$$daggerdaggerdagger
0020
0015
0010
0005
0000
Relat
ive r
atio
of A
ng-1
to G
APD
H
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(e)
daggerdagger
dagger$
lowast
lowastlowast
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
TGF-1205731d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(f)
Figure 7 Continued
16 Stem Cells International
dagger
dagger$
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
HGF
lowastlowast
lowastlowastlowastlowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(g)
$
$
0
2
4
6
8
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
CD31
daggerlowast
lowast
lowast
daggerlowastlowast
dagger daggerlowast
lowast
lowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
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The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
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Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
Stem Cells International 15
15
10
5
0
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
Relat
ive m
RNA
expr
essio
nslowastlowastlowastdagger
lowastlowastlowastdagger
daggerdaggerdagger
$
1d 4d 7dVEGF
(a)
daggerdaggerdaggerdagger
dagger
$
$
lowast
lowast
lowast
SAP + BMSCsNCShamSAP
SAP + anti-CXCR4 BMSCs
0
5
10
15
Relat
ive m
RNA
expr
essio
ns
Ang-11d 4d 7d
(b)NC Sham
ANG-1
VEGF
GAPDH
Ant
i-CXC
R4SA
PA
nti-C
XCR4
SAP
SAP
+BM
SCs
SAP
+BM
SCs
36
1d 4d 7d
45
70
(kD)
(c)
dagger
daggerdaggerdagger
$
10
00
02
04
06
08
lowastlowastlowast
dagger$lowastlowastlowast
lowastlowastlowast
SAP + BMSCsNCShamSAP
1d 4d 7d
Relat
ive r
atio
of V
EGF
to G
APD
H
SAP + anti-CXCR4 BMSCs
(d)
dagger
daggerdaggerdagger
$$
lowastlowastlowastlowastlowastlowast
lowastlowastlowast
$$$daggerdaggerdagger
0020
0015
0010
0005
0000
Relat
ive r
atio
of A
ng-1
to G
APD
H
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(e)
daggerdagger
dagger$
lowast
lowastlowast
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
TGF-1205731d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(f)
Figure 7 Continued
16 Stem Cells International
dagger
dagger$
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
HGF
lowastlowast
lowastlowastlowastlowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(g)
$
$
0
2
4
6
8
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
CD31
daggerlowast
lowast
lowast
daggerlowastlowast
dagger daggerlowast
lowast
lowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
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PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
16 Stem Cells International
dagger
dagger$
0
2
4
6
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
HGF
lowastlowast
lowastlowastlowastlowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(g)
$
$
0
2
4
6
8
Relat
ive m
RNA
expr
essio
ns to
GA
PDH
CD31
daggerlowast
lowast
lowast
daggerlowastlowast
dagger daggerlowast
lowast
lowast
1d 4d 7d
SAP + BMSCsSAP + anti-CXCR4 BMSCs
NCShamSAP
(h)
Figure 7 qRT-PCRorwestern-blot assays are showing that the expressions ofANG-1 VEGFHGF TGF-120573 andCD31 in pancreatic tissueweresignificantly higher in SAP+BMSCs group ((a) (c) and (d)) The expression of ANG-1 was investigated higher in SAP+BMSCs group thanin normal SAP and SAP+anti-CXCR4 BMSCs groups ((b) (c) and (e)) There was a significant higher expression of VEGF in SAP+BMSCsgroup than in normal SAP and SAP+anti-CXCR4 BMSCs groups at posttransplant days 1 and 4 with a subsequent decrease at day 7 ((f)ndash(h))ThemRNA level ofHGFTGF-120573 andCD31was significantly higher in SAP+BMSCs group than innormal SAP and SAP+anti-CXCR4BMSCsgroups Data are expressed as mean plusmn SD (119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 for SAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each corresponding time point) (NC normal control ANG-1 angiopoietin-1 VEGF vascular endothelial growth factorSAP severe acute pancreatitis and BMSCs bone marrow-derived mesenchymal stem cells)
the SDF-1120572CXCR4 axis correlates positively with VEGFexpression in BMSCs In vivo VEGF expression in pan-creatic tissues in the early phase of BMSCS transplantationwas significantly higher than that in the normal SAP andSAP+anti-CXCR4 BMSCs groups Therefore we confirmedthat the SDF-1120572CXCR4 axis is involved in the upregulationof VEGF expression in pancreatitis tissues On the one handthe upregulation of SDF-1120572 attracted BMSCs to damagedpancreatic tissues On the other hand the interaction of SDF-1120572 with CXCR4 increased the expression of VEGF whichrepaired the damaged vascular endothelial cells and furtherenhanced angiogenesis SDF-1120572 also increased the expressionof the CXCR4 receptor as shown in our experiment and fur-ther promoted the migration of BMSCs to injured pancreatictissues Meanwhile VEGF can also enhance the expressionof CXCR4 [15] Thus the SDF-1120572CXCR4 axis and VEGFform a virtuous circle producing a cascade effect As a resultthe association between the SDF-1120572CXCR4 axis and VEGFcould account for the migration of BMSCs the restoration ofdamaged vascular endothelial cells neovascularization andthe ultimate repair and regeneration of necrotic pancreatictissues However we also found that the expression of VEGFhad decreased at posttransplant day 7 because the ischemiaand hypoxia in the pancreatic tissues were significantlyreduced after cell transplantation
ANG-1 also involved in the process of angiogenesiswas upregulated by the SDF-1120572CXCR4 axis and that ANG-1 expression was higher in the SAP+BMSCS group thanin the normal SAP and SAP+anti-CXCR4 BMSCs groupsLarge studies have also demonstrated that VEGF combinedwith ANG-1 promotes angiogenesis more effectively [44]Thus the SDF-1120572CXCR4 axis VEGF and ANG-1 are jointlyinvolved in the process of neovascularization of necrotic pan-creatic tissues In addition HGF was significantly expressedafter BMSCs were stimulated by the SDF-1120572CXCR4 axisHGF expression was also elevated in damaged pancreatictissues after BMSCS transplantation HGF can stimulateepithelial cell proliferation motility morphogenesis andangiogenesis in various organs via the tyrosine phospho-rylation of its receptor c-MET [45] Bai et al [46] foundthat HGF mediated MSC-induced recovery in a model ofmultiple sclerosis Wang et al [31] found that HGFc-Metare expressed inside pancreatic tubular complexes and arepossibly involved in the regeneration of islet cells In ourstudy we have also confirmed that HGF participates in theprocess of repairing and regenerating necrotic pancreatictissue
As for TGF-120573 it is a cytokine with a wide range of diver-sity and often has contradictory functions Recent studieslay emphasis on its anti-inflammatory and antiatherogenic
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
Stem Cells International 17
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(a)N
orm
alSA
PBM
SCs+
SAP
Sham
Ant
i-CXC
R4
1d 4d 7d
(b)
Nor
mal
SAP
BMSC
s+SA
P
Sham
Ant
i-CXC
R4
1d 4d 7d
(c)
VEGF
daggerdagger
dagger
dagger
$
$
$
008
006
004
002
000
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
lowastlowastlowast
lowastlowast
lowastlowast
lowast
dagger
daggerdagger
$
$Re
lativ
e rat
io o
f ave
rage
pos
itive
stai
ned
area
lowast
lowastlowastlowast
lowast
015
010
005
000
vWF
0010
SAP + BMSCsSAP + anti-CXCR4
NCShamSAP BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
NC SAP + BMSCs
SAP + anti-CXCR4ShamSAP BMSCs
1d 4d 7d 1d 4d 7d
$
Relat
ive r
atio
of a
vera
ge p
ositi
ve st
aine
d ar
ea
daggerlowastlowastlowast
daggerlowastlowastlowast
$daggerlowastlowastlowast
0008
0006
0004
0002
0000
CD31
NC SAP + BMSCs
1d 4d 7d
(d)
Figure 8 Transplantation BMSCs could promote angiogenesis in damaged pancreatic tissue which was inhibited by anti-CXCR4 treatment((a) (d)) VEGF expression was assayed in pancreatic tissue by immunohistochemistry and the result showed that VEGF expression washigher in SAP+BMSCs group than in normal SAP and anti-CXCR4 groups at postoperative days 1 and 4 On the contrary it was lower inSAP+BMSCs group than in SAP group at postoperative day 7 ((b)ndash(d)) vWf and CD31 expressions in pancreatic tissue were showed to besignificantly higher in SAP+BMSCs group than in normal SAP and SAP+anti-CXCR4 BMSCs groups Data are expressed as mean plusmn SD(119875 gt 005 for sham versus NC lowast119875 lt 005 and lowastlowast119875 lt 001 for SAP+BMSCs versus NC dagger119875 lt 005 daggerdagger119875 lt 001 and daggerdaggerdagger119875 lt 0001 forSAP+BMSCs versus SAP $119875 lt 005 $$119875 lt 001 and $$$
119875 lt 0001 for SAP+BMSCs versus SAP+anti-CXCR4 BMSCs at each correspondingtime point) (NC normal control VEGF vascular endothelial growth factor SAP severe acute pancreatitis BMSCs bone marrow-derivedmesenchymal stem cells vWF von Willebrand factor and CD31 platelet endothelial cell adhesion molecule-1)
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
18 Stem Cells International
roles TGF-120573 influences the activation of macrophages and Tcells as well as the proliferation of smooth muscle cells in thevessel wall [47 48] A reduction in the production or activityof this cytokine is believed to destabilize plaque These andnumerous other experimental data constitute the basis ofDavid Graingerrsquos TGF-120573 protective cytokine hypothesis [4950] In our study we found that the SDF-1120572CXCR4 axisalso promotes the expression of TGF-120573 in vitro and thatthe TGF-120573 in both serum and pancreatic tissue was higherin the BMSCs+SAP group than in the normal SAP andSAP+Anti-CXCR4 groups in vivo Therefore TGF-120573 couldalso be involved in inhibiting inflammation and promotingthe regeneration of damaged pancreas
Many studies have shown that the systematic inflam-matory response plays a key role in the deterioration ofSAP However the inflammatory response is essential as avascular reaction and could be relieved if the injured vesselscould be repaired Conversely the repair and regenerationof injured vessels are helpful to promote tissue repair andregeneration In the study we found that damaged vascularendothelial cells were repaired and regenerated after BMSCstransplantation which may be one of the reasons for thedecrease of proinflammatory factors
In conclusion our results demonstrate that transplantedBMSCs reduce the systematic inflammatory responsesrepair and regenerate necrotic pancreatic tissues by secretingcytokines and promoting angiogenesis with the involvementof the SDF-1120572CXCR4 axis in a rat model of SAP SPION isa good option for labeling BMSCs and the SPION labelingmethod could be applied to live traces in vivo
Of course some problems have not yet been overcomein this study There is still a certain distance from the animalresearch to the clinical application Firstly the necrotizedpancreas was not fully repaired especially in early phaseSecondly the safety of BMSCs transplantation still needsto be tested The occurrences of pulmonary embolism andvenous thrombosis need to be further evaluated Third invivo the cell survival rate and time still need to be improvedafter BMSCs transplanted Thus the future research shouldbe focused on how to lengthen cell survival time enhancethe functions of BMSCs and improve the safety of BMSCstransplantation
Abbreviation
SDF-1120572 Stromal-cell-derived factor-1120572VEGF Vascular endothelial growth factorANG-1 Angiopoietin-1HGF Hepatocyte growth factorTGF-120573 Transforming growth factor-120573CXCR4 CXC chemokine receptor 4TNF-120572 Tumor necrosis factor-120572IL-1120573 Interleukin-1120573CD31 Platelet endothelial cell adhesion molecule-1vWF von Willebrand factorSPION Superparamagnetic iron oxide nanoparticlesFOV Field of visionTR Repetition time
TE Echo timeNS Number of scans
Disclaimer
The authors are solely responsible for the content of thispaper
Conflict of Interests
All authors declare that they have no conflict of interests
Acknowledgments
This project was supported by the Shanghai Committee ofScience and Technology (Grant no 114119a4500) and theNational Natural Science Fund (Grant no 08QA1406900)
References
[1] J Granger andD Remick ldquoAcute pancreatitis models markersand mediatorsrdquo Shock vol 24 supplement 1 pp 45ndash51 2005
[2] T L Berezina S B Zaets D J Mole Z Spolarics E A DeitchandGWMachiedo ldquoMesenteric lymph duct ligation decreasesred blood cell alterations caused by acute pancreatitisrdquo TheAmerican Journal of Surgery vol 190 no 5 pp 800ndash804 2005
[3] R P Sah P Garg and A K Saluja ldquoPathogenic mechanisms ofacute pancreatitisrdquoCurrent Opinion in Gastroenterology vol 28no 5 pp 507ndash515 2012
[4] T Hirano and T Manabe ldquoA possible mechanism for gall-stone pancreatitis repeated short-term pancreaticobiliary ductobstructionwith exocrine stimulation in ratsrdquoProceedings of theSociety for Experimental Biology and Medicine vol 202 no 2pp 246ndash252 1993
[5] A J Friedenstein J F Gorskaja andN N Kulagina ldquoFibroblastprecursors in normal and irradiated mouse hematopoieticorgansrdquo Experimental Hematology vol 4 no 5 pp 267ndash2741976
[6] I Pountos D Corscadden P Emery and P V GiannoudisldquoMesenchymal stem cell tissue engineering techniques for iso-lation expansion and applicationrdquo Injury vol 38 supplement4 pp S23ndashS33 2007
[7] E L Herzog L Chai and D S Krause ldquoPlasticity of marrow-derived stem cellsrdquo Blood vol 102 no 10 pp 3483ndash3493 2003
[8] G Brooke M Cook C Blair et al ldquoTherapeutic applications ofmesenchymal stromal cellsrdquo Seminars in Cell and Developmen-tal Biology vol 18 no 6 pp 846ndash858 2007
[9] K H Jung S U Song T Yi et al ldquoHuman bone marrow-derived clonal mesenchymal stem cells inhibit inflammationand reduce acute pancreatitis in ratsrdquoGastroenterology vol 140no 3 pp 998ndash1008 2011
[10] X-H Tu J-X Song X-J Xue et al ldquoRole of bone marrow-derived mesenchymal stem cells in a rat model of severe acutepancreatitisrdquo World Journal of Gastroenterology vol 18 no 18pp 2270ndash2279 2012
[11] J Gong H-B Meng J Hua et al ldquoThe SDF-1CXCR4 axis reg-ulates migration of transplanted bone marrow mesenchymalstem cells towards the pancreas in rats with acute pancreatitisrdquoMolecular Medicine Reports vol 9 no 5 pp 1575ndash1582 2014
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
Stem Cells International 19
[12] B Yang B Bai C X Liu et al ldquoEffect of umbilical cordmesenc-hymal stem cells on treatment of severe acute pancreatitis inratsrdquo Cytotherapy vol 15 no 2 pp 154ndash162 2013
[13] J Yu M Li Z Qu D Yan D Li and Q Ruan ldquoSDF-1CXCR4-mediated migration of transplanted bone marrow stromal cellstoward areas of heart myocardial infarction through activationof PI3KAktrdquo Journal of Cardiovascular Pharmacology vol 55no 5 pp 496ndash505 2010
[14] H D Theiss M Vallaster C Rischpler et al ldquoDual stem celltherapy after myocardial infarction acts specifically byenhanced homing via the SDF-1CXCR4 axisrdquo Stem CellResearch vol 7 no 3 pp 244ndash255 2011
[15] R Salcedo K Wasserman H A Young et al ldquoVascularendothelial growth factor and basic fibroblast growth factorinduce expression of CXCR4 on human endothelial cells Invivo neovascularization induced by stromal-derived factor-1alphardquo American Journal of Pathology vol 154 no 4 pp 1125ndash1135 1999
[16] L Du P Yang and S Ge ldquoStromal cell-derived factor-1significantly induces proliferation migration and collagentype i expression in a human periodontal ligament stem cellsubpopulationrdquo Journal of Periodontology vol 83 no 3 pp379ndash388 2012
[17] K-I Hiasa M Ishibashi K Ohtani et al ldquoGene transferof stromal cell-derived factor-1120572 enhances ischemic vascu-logenesis and angiogenesis via vascular endothelial growthfactorendothelial nitric oxide synthase-related pathway next-generation chemokine therapy for therapeutic neovasculariza-tionrdquo Circulation vol 109 no 20 pp 2454ndash2461 2004
[18] D Mukherjee and J Zhao ldquoThe role of chemokine receptorCXCR4 in breast cancer metastasisrdquo The American Journal ofCancer Research vol 3 no 1 pp 46ndash57 2013
[19] X Xu F Zhu M Zhang et al ldquoStromal cell-derived factor-1 enhances wound healing through recruiting bone marrow-derivedmesenchymal stem cells to the wound area and promot-ing neovascularizationrdquo Cells Tissues Organs vol 197 no 2 pp103ndash113 2013
[20] J X Yu X F Huang W M Lv et al ldquoCombination of stromal-derived factor-1120572 and vascular endothelial growth factor gene-modified endothelial progenitor cells is more effective forischemic neovascularizationrdquo Journal of Vascular Surgery vol50 no 3 pp 608ndash616 2009
[21] J-M Tang J-NWang L Zhang et al ldquoVEGFSDF-1 promotescardiac stem cell mobilization and myocardial repair in theinfarcted heartrdquoCardiovascular Research vol 91 no 3 pp 402ndash411 2011
[22] R Sun J Dittrich M Le-Huu et al ldquoPhysical and biologicalcharacterization of superparamagnetic iron oxide- and ultra-small superparamagnetic iron oxide-labeled cells a compari-sonrdquo Investigative Radiology vol 40 no 8 pp 504ndash513 2005
[23] E Pawelczyk A S Arbab A Chaudhry A Balakumaran P GRobey and J A Frank ldquoIn vitro model of bromodeoxyuridineor iron oxide nanoparticle uptake by activated macrophagesfrom labeled stem cells implications for cellular therapyrdquo StemCells vol 26 no 5 pp 1366ndash1375 2008
[24] A S Arbab L A Bashaw B R Miller et al ldquoCharacterizationof biophysical and metabolic properties of cells labeled withsuperparamagnetic iron oxide nanoparticles and transfectionagent for cellular MR imagingrdquo Radiology vol 229 no 3 pp838ndash846 2003
[25] A Balakumaran E Pawelczyk J Ren et al ldquoSuperparamagneticiron oxide nanoparticles labeling of bone marrow stromal
(Mesenchymal) cells does not affect their lsquosternnessrsquordquoPLoSONEvol 5 no 7 Article ID e11462 2010
[26] G Perides G J D vanAcker JM Laukkarinen andM L SteerldquoExperimental acute biliary pancreatitis induced by retrogradeinfusion of bile acids into the mouse pancreatic ductrdquo NatureProtocols vol 5 no 2 pp 335ndash341 2010
[27] E Mezey ldquoThe therapeutic potential of bone marrow-derivedstromal cellsrdquo Journal of Cellular Biochemistry vol 112 no 10pp 2683ndash2687 2011
[28] L C Amado A P Saliaris K H Schuleri et al ldquoCardiac repairwith intramyocardial injection of allogeneic mesenchymal stemcells after myocardial infarctionrdquo Proceedings of the NationalAcademy of Sciences of the United States of America vol 102 no32 pp 11474ndash11479 2005
[29] Y-T Lin Y Chern C-K J Shen et al ldquoHuman mesenchy-mal stem cells prolong survival and ameliorate motor deficitthrough trophic support in Huntingtonrsquos disease mouse mod-elsrdquo PLoS ONE vol 6 no 8 Article ID e22924 2011
[30] L E Reid and N I Walker ldquoAcinar cell apoptosis and theorigin of tubular complexes in caerulein-induced pancreatitisrdquoInternational Journal of Experimental Pathology vol 80 no 4pp 205ndash215 1999
[31] G-S Wang L Rosenberg and F W Scott ldquoTubular complexesas a source for islet neogenesis in the pancreas of diabetes-proneBB ratsrdquo Laboratory Investigation vol 85 no 5 pp 675ndash6882005
[32] J A Burger and T J Kipps ldquoCXCR4 a key receptor in thecrosstalk between tumor cells and their microenvironmentrdquoBlood vol 107 no 5 pp 1761ndash1767 2006
[33] R E Bachelder M A Wendt and A M Mercurio ldquoVascularendothelial growth factor promotes breast carcinoma invasionin an autocrine manner by regulating the chemokine receptorCXCR4rdquo Cancer Research vol 62 no 24 pp 7203ndash7206 2002
[34] T Kitaori H Ito E M Schwarz et al ldquoStromal cell-derivedfactor 1CXCR4 signaling is critical for the recruitment ofmesenchymal stem cells to the fracture site during skeletalrepair in a mouse modelrdquo Arthritis and Rheumatism vol 60no 3 pp 813ndash823 2009
[35] LWei J L Fraser Z-Y Lu XHu and S P Yu ldquoTransplantationof hypoxia preconditioned bone marrow mesenchymal stemcells enhances angiogenesis and neurogenesis after cerebralischemia in ratsrdquoNeurobiology of Disease vol 46 no 3 pp 635ndash645 2012
[36] D J Ceradini A R Kulkarni M J Callaghan et al ldquoProgenitorcell trafficking is regulated by hypoxic gradients through HIF-1induction of SDF-1rdquoNatureMedicine vol 10 no 8 pp 858ndash8642004
[37] J M Laukkarinen G J D van Acker E R Weiss M L Steerand G Perides ldquoA mouse model of acute biliary pancreati-tis induced by retrograde pancreatic duct infusion of Na-taurocholaterdquo Gut vol 56 no 11 pp 1590ndash1598 2007
[38] S Voronina R Longbottom R Sutton O H Petersen and ATepikin ldquoBile acids induce calcium signals in mouse pancreaticacinar cells implications for bile-induced pancreatic pathol-ogyrdquo Journal of Physiology vol 540 no 1 pp 49ndash55 2002
[39] C B Hughes A B M El-Din M Kotb L W Gaber and A OGaber ldquoCalcium channel blockade inhibits release of TNF120572 andimproves survival in a ratmodel of acute pancreatitisrdquoPancreasvol 13 no 1 pp 22ndash28 1996
[40] Y Anzai ldquoSuperparamagnetic iron oxide nanoparticles nodalmetastases and beyondrdquo Topics in Magnetic Resonance Imagingvol 15 no 2 pp 103ndash111 2004
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
20 Stem Cells International
[41] S Yano S Kuroda H Shichinohe K Hida and Y Iwasaki ldquoDobone marrow stromal cells proliferate after transplantation intomice cerebral infarctmdasha double labeling studyrdquo Brain Researchvol 1065 no 1-2 pp 60ndash67 2005
[42] H Ittrich K Peldschus N Raabe M Kaul and G AdamldquoSuperparamagnetic iron oxide nanoparticles in biomedicineapplications and developments in diagnostics and therapyrdquoRoFo vol 185 no 12 pp 1149ndash1166 2013
[43] J Kijowski M Baj-Krzyworzeka M Majka et al ldquoThe SDF-1-CXCR4 axis stimulates VEGF secretion and activates integrinsbut does not affect proliferation and survival in lymphohe-matopoietic cellsrdquo Stem Cells vol 19 no 5 pp 453ndash466 2001
[44] A V Benest A H Salmon W Wang et al ldquoVEGF andangiopoietin-1 stimulate different angiogenic phenotypes thatcombine to enhance functional neovascularization in adulttissuerdquoMicrocirculation vol 13 no 6 pp 423ndash437 2006
[45] T Nakamura and S Mizuno ldquoThe discovery of hepatocytegrowth factor (HGF) and its significance for cell biologylife sciences and clinical medicinerdquo Proceedings of the JapanAcademy Series B Physical and Biological Sciences vol 86 no6 pp 588ndash610 2010
[46] L Bai D P Lennon A I Caplan et al ldquoHepatocyte growthfactor mediates mesenchymal stem cell-induced recovery inmultiple sclerosis modelsrdquo Nature Neuroscience vol 15 no 6pp 862ndash870 2012
[47] K Chen J LMehta D Li L Joseph and J Joseph ldquoTransform-ing growth factor 120573 receptor endoglin is expressed in cardiacfibroblasts and modulates profibrogenic actions of angiotensinIIrdquo Circulation Research vol 95 no 12 pp 1167ndash1173 2004
[48] M M Chen A Lam J A Abraham G F Schreiner and AH Joly ldquoCTGF expression is induced by TGF-120573 in cardiacfibroblasts and cardiac myocytes a potential role in heartfibrosisrdquo Journal of Molecular and Cellular Cardiology vol 32no 10 pp 1805ndash1819 2000
[49] D J Grainger ldquoTransforming growth factor beta and athe-rosclerosis so far so good for the protective cytokine hypoth-esisrdquo Arteriosclerosis Thrombosis and Vascular Biology vol 24no 3 pp 399ndash404 2004
[50] J Dabek A Kułach B Monastyrska-Cup and Z GasiorldquoTransforming growth factor 120573 and cardiovascular diseasesthe other facet of the ldquoprotective cytokinerdquordquo PharmacologicalReports vol 58 no 6 pp 799ndash805 2006
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology
Submit your manuscripts athttpwwwhindawicom
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Anatomy Research International
PeptidesInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporation httpwwwhindawicom
International Journal of
Volume 2014
Zoology
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Molecular Biology International
GenomicsInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioinformaticsAdvances in
Marine BiologyJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Signal TransductionJournal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
BioMed Research International
Evolutionary BiologyInternational Journal of
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Biochemistry Research International
ArchaeaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Genetics Research International
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Advances in
Virolog y
Hindawi Publishing Corporationhttpwwwhindawicom
Nucleic AcidsJournal of
Volume 2014
Stem CellsInternational
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
Enzyme Research
Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014
International Journal of
Microbiology