Erythropoiesis - Edit 27 Sept'06

7/24/2019 Erythropoiesis - Edit 27 Sept'06

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ERYTHROPOIESISERYTHROPOIESIS

Sutaryo

Hematology-Oncology Subdivision, Pediatric

Department, Sardjito Hospital/Faculty ofMedicine, adja! Mada "niversity


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#ed cell Production#ed cell Production

$!e$!e stromal cellsstromal cellsandand immunoregulatoryimmunoregulatorycellscells contribute to localcontribute to local cyto%inecyto%ineproduction&production&

$!e reticulocytes in bone marro' ()*-*+$!e reticulocytes in bone marro' ()*-*+jamjam

)*-*+ !ours 'it! a furt!er)*-*+ !ours 'it! a furt!er decrease in siedecrease in sie

and loss of t!e reticulinand loss of t!e reticulin a maturea maturecirculating red cell&circulating red cell&


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#ed cell Production#ed cell Production

During muc! of t!is first *+ !our period outsideDuring muc! of t!is first *+ !our period outsidet!e bone marro'.t!e bone marro'. $!e cells are retained in t!e spleen$!e cells are retained in t!e spleen

surface ad!esion molecules and residual #01surface ad!esion molecules and residual #01

(reticulin are removed&(reticulin are removed&

$!e elapsed time from$!e elapsed time from pronormoblast to maturepronormoblast to maturered cellred cell 223 days&3 days&

4!en t!ere is4!en t!ere is need for increased red cellneed for increased red cell

production.production. $!e$!e timetimeto maturity can beto maturity can be s!orteneds!ortenedbyby reducingreducing

t!e inter-mitotic intervalt!e inter-mitotic interval Or byOr by s%ipping some mitotic divisions&s%ipping some mitotic divisions&


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#egulation of 5ryt!ropoeisis#egulation of 5ryt!ropoeisis

5ryt!ropoietin (5PO.5ryt!ropoietin (5PO.11 67%D gycoprotein67%D gycoprotein&&

$!e primary$!e primary !umoral regulator!umoral regulatorofof

eryt!ropoiesiseryt!ropoiesis promoting bot!promoting bot! proliferationproliferationandand survivalsurvivalof eryt!roid precursors&of eryt!roid precursors&

2289: is synt!esied in renal peritubular89: is synt!esied in renal peritubularinterstitial cells t!at respond to an Ointerstitial cells t!at respond to an O))-sensing-sensing

mec!anism&mec!anism&


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Eryrhropoietin Signaling

Within minutes

Withina few

hours

The binding between EPO and receptordimerization of the receptortransmission

of signal to the intracellular domaininitiation of signal transduction pathway

phsophorylation and activation of the Receptor, J!"#TTdimerizesmigrate

nucleusgene transcription$

Phosphorylation P%&'(inase and Rasinduce additional signaling pathways$


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Erythropoiesis - Edit 27 Sept'06

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