ABSTRACT
Objective To investigate the effects of the erythropoietin (EPO) on ischemia reperfusion injury (IRI) in rats with nephron-sparing surgery (NSS). Methods Fifty-four Sprague Dawley rats were divided into 3 groups randomly after right kidney nephrectomy: Sham group, NSS group (PBS+NSS) and EPO group (EPO+NSS). During NSS, renal artery was clamped for 40 min to induce IRI. Sham group just adopted exposure renal artery without vascular clamped. Rats in NSS group were injected intraperitoneally with PBS for 3 days before NSS. Rats in EPO group were injected intraperitoneally with EPO for 3 days before NSS. After 12 h, 24 h, 72 h, blood sample and renal tissues were collected. The serum creatinine (Scr) and urea nitrogen (BUN) were evaluated. The pathology injury was evaluated by HE staining. The CD24/CD133 double-positived renal progenitor cells (RPCs) were tested by flow cytometry. The CD133 and PCNA protein were quantified by immunohistochemical staining. The expressions of Wnt7b and β-catenin protein were detected by Western blotting. Results Rats in NSS group had more elevated Scr, BUN and pathology injury scores 12 h, 24 h and 72 h after operation than those in Sham group (all P<0.05). Compared with those in the NSS group, the Scr and BUN in the EPO group were significantly lower 24 h after the surgery (all P<0.05), and the pathology injury score also decreased (P<0.05). The proportion of RPCs, expressions of CD133 and PCNA, and expressions of Wnt7b and β-catenin protein were significantly higher after 24 h of the surgery in NSS group than those in the Sham group (all P<0.05). While compared with those in the NSS group, the proportion of RPCs and expressions of CD133, PCNA, Wnt7b and β-catenin increased at the EPO group (all P<0.05). Conclusions EPO can reduce the IRI after NSS, and its mechanism may be related to the mobilization of the RPCs by the Wnt7b/β-catenin signal pathway.