Recombinant human erythropoietin attenuates hepatic injury induced by ischemia/reperfusion in an isolated mouse liver model.
BACKGROUND
Apoptosis is a central mechanism of cell death following reperfusion of the ischemic liver. Recombinant human erythropoietin (rhEPO) have an important role in the treatment of myocardial ischemia/reperfusion (I/R) injury, by preventing apoptosis. The aim of the study was to investigate the effect of different regimens of rhEPO in preventing apoptosis following I/R-induced hepatic injury.


METHODS
Isolated mouse livers were randomly divided into five groups: (1) control group, perfused for the whole study period (105 min); (2) 30-min perfusion followed by 90 min of ischemia and 15 min of reperfusion; (3), (4) and (5) like group 2, but with administration of rhEPO 5,000 units/kg i.p. at 30 min, 24 h, or both 30 min and 24 h respectively, before induction of ischemia. Perfusate liver enzyme levels and intrahepatic caspase-3 activity were measured, and apoptotic cells were identified by morphological criteria, TUNEL assay, and immunohistochemistry for caspase-3. Using immunoblot the expression of the proapoptotic JNK and inhibitor of NFkappaB (IkappaBalpha) were also evaluated. von Willebrand factor (vWF) immunohistochemistry was used as a marker of endothelial cells.


RESULTS
Compared to the I/R livers, all 3 rhEPO pretreated groups showed: a significant reduction in liver enzyme levels (P < 0.05) and intrahepatic caspase-3 activity (P < 0.05), fewer apoptotic hepatocytes (P < 0.05) and positive vWF staining in numerous endothelial cells lining the sinusoids. EPO decreased JNK phosphorylation and the degradation of the inhibitor of NFkappaB (IkappaBalpha) during I/R. There was no added benefit of the multiple- over the single-dose rhEPO regimen.


CONCLUSIONS
Pretreatment with one dose of rhEPO can attenuate post-I/R hepatocyte apoptotic liver damage. NFkappaB and JNK activation is likely to play a pivotal role in the pathophysiology of I/R hepatic injury and might have a key role in EPO-mediated protective effects. This effect is associated with the increase in sinusoidal vWF immunostaining suggests an additional effect of rhEPO in liver angiogenesis recovery. These findings have important implications for the potential use of rhEPO in I/R injury during liver transplantation.
Hochhauser
Edith
E
Cardiac Research Laboratory of Department of Cardiothoracic Surgery, Rabin Medical Center, Beilinson Campus, Petah Tiqva and Sackler School of Medicine,Tel Aviv University, Tel Aviv, Israel.
Pappo
Orit
O
Ribakovsky
Evgeni
E
Ravid
Amiram
A
Kurtzwald
Efrat
E
Cheporko
Yelena
Y
Lelchuk
Shlomo
S
Ben-Ari
Ziv
Z
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism*; D004195:Disease Models, Animal; D004921:Erythropoietin / Q000494:pharmacology*; D006801:Humans; D007511:Ischemia; D008099:Liver / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology*; D048670:MAP Kinase Kinase 4 / Q000378:metabolism*; D008297:Male; D051379:Mice; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011897:Random Allocation; D011994:Recombinant Proteins; D015424:Reperfusion; D015427:Reperfusion Injury / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D014841:von Willebrand Factor / Q000378:metabolism; D000097782:NF-kappaB-Inducing Kinase
D053148:Caspase 3; D004921:Erythropoietin; D048670:MAP Kinase Kinase 4; D017346:Protein Serine-Threonine Kinases; D011994:Recombinant Proteins; D014841:von Willebrand Factor; D000097782:NF-kappaB-Inducing Kinase