Mercedes-Benz 2006 SLK - ragtop.org · Mercedes-Benz 2006 SLK-Class SLK 280 SLK 350 SLK 55 AMG
Novel investigation of the importance of Ste20-like kinase, SLK, in murine placentation
1
placenta in nutrient transport, and underscores its importance in main- tenance of optimal nutrient supply during pregnancy. http://dx.doi.org/10.1016/j.placenta.2013.06.241 P2.76. EFFECTS OF FOLIC ACID SUPPLEMENTATION ON PLACENTAL HEALTH AND FUNCTION Tasfia Ahmed, Ilan Fellus, Bénédicte Fontaine-Bisson, Shannon Bainbridge University of Ottawa, Ottawa, Ontario, Canada Background: Though all flour products have been fortified with folic acid (FA) in North America, daily FA supplementation throughout pregnancy is commonly recommended to decrease the rate of neural tube defects in newborns. However, it is estimated that many pregnant North American women taking supplements in addition to their diet, have FA intakes that exceeds the tolerable upper intake level (UL). Human and animal studies have shown that excessive FA intake may be associated with increased insulin resistance, respiratory impairment, mammary tumorigenesis, and impede embryonic development. However, effects of excessive FA on the feto-placental unit are unclear. It is hypothesized that exceeding the UL for FA may negatively impact placental health and function, putting the developing fetus at increased risk for adverse health outcomes. Methodology: Two human trophoblast cell lines (HTR8 and Bewo) were exposed to increasing concentrations of FA (20-4000 ng/mL) over a 48- hour incubation period (N¼3). Dose-response experiments were per- formed at both 1% and 21% oxygen. Cell counts were performed and cell viability was assessed using trypan blue exclusion. Placental cell function was assessed in the HTR8 cell line using the matrigel coated Boyden chamber invasion assay (N¼3), and through measurement of hCG pro- duction in the Bewo cell line (N¼3). Results: No differences in total cell number or cell viability were observed across the increasing doses of FA in either cell line. Oxygen tension also had no effect on these parameters. Measurements of cellular invasion and hCG production are currently ongoing. Conclusion: High concentrations of FA do not seem to affect placental cell health as measured by cellular viability. Investigations into the potential effects of these concentrations of FA on placental cell function are ongoing. Additional research is needed to confirm that FA intake past the currently established UL for pregnancy does not harm the feto-placental unit. http://dx.doi.org/10.1016/j.placenta.2013.06.242 P2.77. NOVEL INVESTIGATION OF THE IMPORTANCE OF STE20-LIKE KINASE, SLK, IN MURINE PLACENTATION Prabhjot Sekhon 1, 2 , Khalid Al-Zahrani 1, 2 , Daniel Tessier 1 , Julien Yockell-Lelièvre 1 , Luc A. Sabourin 1 , Andrée Gruslin 1, 3 1 Ottawa Hospital Research Institute, Ottawa, Canada; 2 University of Ottawa, Ottawa, Canada; 3 The Ottawa Hospital, Ottawa, Canada Objectives: Proper placentation is essential for successful pregnancy, and disruptions in placental development will have important implications for fetal development and pregnancy. The purpose of this novel investigation is to assess the potential importance of the Ste20-like kinase, SLK, in the context of murine placentation. Key processes in normal placenta devel- opment include cell migration/invasion, vascular remodelling, and apoptosis. These processes have also been associated with SLK regulation, where this Ste20-like kinase acts by activating its downstream substrates in their respective pathways. As such, we propose that reduced SLK expression will disrupt proper placental development in the mouse model. Methods: The SLK-LacZ fusion expression was achieved using a gene-trap approach, prior to this investigation. Standard IHC (SLK and Caspase-3 primary antibodies) and H&E protocols were used. Images were analyzed using ImageJ and Aperio ImageScope software. Results: SLK expression was qualitatively shown to be reduced in het- erozygote and SLK/LacZ fusion placentae, with the fusion protein showing very minimal expression. SLK/LacZ fusion placentae showed hypo- vascularity, as well as abnormal cell differentiation and gaps. Results from the apoptosis analysis were not significant. Conclusion: SLK appears to have an important role in proper vascularity, and cell proliferation and differentiation in the placenta. As these processes are essential for proper placental development and functioning, the deficiencies observed in the matching fetuses may be attributed to disrupted placental functioning. Further work includes examining the possibility of increased apoptosis in SLK/LacZ fusion placentae using alternative methods. Future work assessing SLK in human samples may further knowledge and understanding, as well as have important implications for human placenta health and disease. http://dx.doi.org/10.1016/j.placenta.2013.06.243 P2.78. DEVELOPMENT OF NOVEL NANOCARRIERS DISPLAYING TUMOUR HOMING PEPTIDES FOR TARGETED DELIVERY OF DRUGS TO THE PLACENTA Anna King, Francesco Cellesi, John Aplin, Lynda Harris University of Manchester, Manchester, UK Introduction: Vasodilators and insulin-like growth factors (IGFs) improve pregnancy outcome in animal models of pre-eclampsia (PE) and intrauterine growth restriction (IUGR), but cannot be systemically administered to humans because of the risk of teratogenesis. Recently, a number of tumour-homing peptide sequences have been identified that selectively target the placenta, specifically binding to the syncytio- trophoblast (STB) of human placenta and the murine uterine spiral ar- teries and placental labyrinth. By combining these homing peptides with a biocompatible nanoparticle, targeted placental delivery has been achieved. Methods: Liposomes were synthesized from distearoylphosphotidylcho- line, cholesterol and polyethylene glycol. Fluorescent tumour homing peptides were covalently coupled to maleimide groups on the liposomal surface, and carboxyfluorescein, a fluorescent drug analogue, was encap- sulated inside. The targeting ability and drug release kinetics were examined by incubating liposomes with human placental explants or via intravenous injection of pregnant mice, and compared to liposomes dis- playing a non-targeting peptide sequence. Results: Targeted liposomes accumulated in the STB of human placental explants, confirming that the targeting properties of the homing peptides were maintained when displayed on the liposome's surface. Co-local- isation of carboxyfluorescein and the homing peptide was observed in the STB until 48h of culture, after which time the drug penetrated the un- derlying villous stroma, indicating liposomal release. Placental delivery was also observed when targeting liposomes were administered to preg- nant mice. Non-targeting liposomes did not bind to the STB and drug release was not observed. Discussion: A targeted liposome decorated with tumour homing peptides has been developed in which to deliver drugs selectively to the materno- fetal interface, to enable treatment of PE and IUGR. Future work will characterise the pharmacokinetics of encapsulated drugs and examine whether targeted drug delivery enhances placental function, alleviates maternal symptoms and improves fetal outcome in mouse models of pregnancy complications. http://dx.doi.org/10.1016/j.placenta.2013.06.244 Abstracts / Placenta 34 (2013) A1–A99 A82
Transcript of Novel investigation of the importance of Ste20-like kinase, SLK, in murine placentation
Abstracts / Placenta 34 (2013) A1–A99A82
placenta in nutrient transport, and underscores its importance in main-tenance of optimal nutrient supply during pregnancy.
http://dx.doi.org/10.1016/j.placenta.2013.06.241
P2.76.EFFECTS OF FOLIC ACID SUPPLEMENTATION ON PLACENTAL HEALTHAND FUNCTION
Tasfia Ahmed, Ilan Fellus, Bénédicte Fontaine-Bisson, Shannon Bainbridge
University of Ottawa, Ottawa, Ontario, Canada
Background: Though all flour products have been fortified with folic acid(FA) in North America, daily FA supplementation throughout pregnancy iscommonly recommended to decrease the rate of neural tube defects innewborns. However, it is estimated that many pregnant North Americanwomen taking supplements in addition to their diet, have FA intakes thatexceeds the tolerable upper intake level (UL). Human and animal studieshave shown that excessive FA intake may be associated with increasedinsulin resistance, respiratory impairment, mammary tumorigenesis, andimpede embryonic development. However, effects of excessive FA on thefeto-placental unit are unclear. It is hypothesized that exceeding the UL forFA may negatively impact placental health and function, putting thedeveloping fetus at increased risk for adverse health outcomes.Methodology: Two human trophoblast cell lines (HTR8 and Bewo) wereexposed to increasing concentrations of FA (20-4000 ng/mL) over a 48-hour incubation period (N¼3). Dose-response experiments were per-formed at both 1% and 21% oxygen. Cell counts were performed and cellviability was assessed using trypan blue exclusion. Placental cell functionwas assessed in the HTR8 cell line using the matrigel coated Boydenchamber invasion assay (N¼3), and through measurement of hCG pro-duction in the Bewo cell line (N¼3).Results: No differences in total cell number or cell viability were observedacross the increasing doses of FA in either cell line. Oxygen tension also hadno effect on these parameters. Measurements of cellular invasion and hCGproduction are currently ongoing.Conclusion: High concentrations of FA do not seem to affect placental cellhealth as measured by cellular viability. Investigations into the potentialeffects of these concentrations of FA on placental cell function are ongoing.Additional research is needed to confirm that FA intake past the currentlyestablished UL for pregnancy does not harm the feto-placental unit.
http://dx.doi.org/10.1016/j.placenta.2013.06.242
P2.77.NOVEL INVESTIGATION OF THE IMPORTANCE OF STE20-LIKE KINASE,SLK, IN MURINE PLACENTATION
Prabhjot Sekhon 1,2, Khalid Al-Zahrani 1,2, Daniel Tessier 1,Julien Yockell-Lelièvre 1, Luc A. Sabourin 1, Andrée Gruslin 1,3
1Ottawa Hospital Research Institute, Ottawa, Canada; 2University of Ottawa,Ottawa, Canada; 3 The Ottawa Hospital, Ottawa, Canada
Objectives: Proper placentation is essential for successful pregnancy, anddisruptions in placental development will have important implications forfetal development and pregnancy. The purpose of this novel investigationis to assess the potential importance of the Ste20-like kinase, SLK, in thecontext of murine placentation. Key processes in normal placenta devel-opment include cell migration/invasion, vascular remodelling, andapoptosis. These processes have also been associated with SLK regulation,where this Ste20-like kinase acts by activating its downstream substratesin their respective pathways. As such, we propose that reduced SLKexpressionwill disrupt proper placental development in themousemodel.
Methods: The SLK-LacZ fusion expression was achieved using a gene-trapapproach, prior to this investigation. Standard IHC (SLK and Caspase-3primary antibodies) and H&E protocols were used. Images were analyzedusing ImageJ and Aperio ImageScope software.Results: SLK expression was qualitatively shown to be reduced in het-erozygote and SLK/LacZ fusion placentae, with the fusion protein showingvery minimal expression. SLK/LacZ fusion placentae showed hypo-vascularity, as well as abnormal cell differentiation and gaps. Results fromthe apoptosis analysis were not significant.Conclusion: SLK appears to have an important role in propervascularity, and cell proliferation and differentiation in the placenta.As these processes are essential for proper placental developmentand functioning, the deficiencies observed in the matching fetusesmay be attributed to disrupted placental functioning. Further workincludes examining the possibility of increased apoptosis in SLK/LacZfusion placentae using alternative methods. Future work assessingSLK in human samples may further knowledge and understanding, aswell as have important implications for human placenta health anddisease.
http://dx.doi.org/10.1016/j.placenta.2013.06.243
P2.78.DEVELOPMENT OF NOVEL NANOCARRIERS DISPLAYING TUMOURHOMING PEPTIDES FOR TARGETED DELIVERY OF DRUGS TO THEPLACENTA
Anna King, Francesco Cellesi, John Aplin, Lynda Harris
University of Manchester, Manchester, UK
Introduction: Vasodilators and insulin-like growth factors (IGFs)improve pregnancy outcome in animal models of pre-eclampsia (PE) andintrauterine growth restriction (IUGR), but cannot be systemicallyadministered to humans because of the risk of teratogenesis. Recently, anumber of tumour-homing peptide sequences have been identified thatselectively target the placenta, specifically binding to the syncytio-trophoblast (STB) of human placenta and the murine uterine spiral ar-teries and placental labyrinth. By combining these homing peptides witha biocompatible nanoparticle, targeted placental delivery has beenachieved.Methods: Liposomes were synthesized from distearoylphosphotidylcho-line, cholesterol and polyethylene glycol. Fluorescent tumour homingpeptides were covalently coupled to maleimide groups on the liposomalsurface, and carboxyfluorescein, a fluorescent drug analogue, was encap-sulated inside. The targeting ability and drug release kinetics wereexamined by incubating liposomes with human placental explants or viaintravenous injection of pregnant mice, and compared to liposomes dis-playing a non-targeting peptide sequence.Results: Targeted liposomes accumulated in the STB of human placentalexplants, confirming that the targeting properties of the homing peptideswere maintained when displayed on the liposome's surface. Co-local-isation of carboxyfluorescein and the homing peptide was observed in theSTB until 48h of culture, after which time the drug penetrated the un-derlying villous stroma, indicating liposomal release. Placental deliverywas also observed when targeting liposomes were administered to preg-nant mice. Non-targeting liposomes did not bind to the STB and drugrelease was not observed.Discussion: A targeted liposome decorated with tumour homing peptideshas been developed in which to deliver drugs selectively to the materno-fetal interface, to enable treatment of PE and IUGR. Future work willcharacterise the pharmacokinetics of encapsulated drugs and examinewhether targeted drug delivery enhances placental function, alleviatesmaternal symptoms and improves fetal outcome in mouse models ofpregnancy complications.
http://dx.doi.org/10.1016/j.placenta.2013.06.244
