Proteomic analysis to display the effect of low doses of erythropoietin on rat liver regeneration

Aims: Several groups found different impact of erythropoietin (EPO) on liver regeneration. Both proproliferative as well as anti-proliferative and non-proliferative activities have been reported using high dosage of EPO. Systemic administration of high doses of this cytokine is a clinical concern due to risk of thrombosis. Herein, we applied EPO in low dosages and investigated whether it can stimulate liver regeneration after liver resection. Main methods: Parameters of liver regeneration were assessed 3 days after 70% hepatectomy by means of immunochemistry and proteomics. EPO was given twice in low dosages (200 and 600 IU/kg BW). Key findings: We showed that EPO facilitated hepatic regeneration in rats. Enhanced hepatocyte proliferation (Ki67, BrdU-positive cells) was observed in all EPO-treated groups. By performing Differential Proteomic analysis, we identified two proteins which resulted sensitive to EPO treatment after hepatectomy: Peroxiredoxin-1 and glutathione S-transferase Mu 1. Significance: Based on our results, low doses of rhEPO increase the hepatic regenerative capacity after partial hepatectomy in rats by enhancing hepatocyte proliferation and acting on antioxidant enzymes. Both proteins identified by proteomic analysis have not previously been associated with liver regeneration and will aid in the understanding of EPO's regenerative response having clinical implications to treat liver failure. (C) 2011 Published by Elsevier Inc.