Effects of erythropoietin on expression of SDF-1 and its receptor in peripheral blood endothelial progenitor cells from rats with chronic renal failure

AIM:To investigate the effects of erythropoietin (EPO) on the expression of homing factors in peripheral blood endothelial progenitor cells (EPCs) from rats with chronic renal failure (CRF). METHODS:The CRF model was established by a two-stage 5/6 nephrectomy procedure in rats. Experimental rats were randomly divided into three groups: sham operation group, CRF model group and EPO treatment group. From the third week after the second stage of 5/6 nephrectomy procedure, rats in EPO treatment group received subcutaneous injection of human recombinant EPO at 50 U/kg every time and three times a week for 6 weeks, and then all the rats were sacrificed. EPCs were isolated from rat peripheral blood and primarily cultured. The mobilization, angiogenesis and functional activity of EPCs in vitro were detected. The mRNA and protein expression of EPO, EPO receptor (EPOR), stromal cell-derived factor 1 (SDF-1) and CXC chemokine receptor 4 (CXCR4) in EPCs was also detected by the methods of real-time PCR and Western blotting. RESULTS:Compared with CRF model group, the expression of EPO and EPOR in EPCs in EPO treatment group was significantly up-regulated (P<0.05). Moreover, the expression of SDF-1 and its receptor CXCR4 in EPCs was also up-regulated by administration of EPO (P<0.05). CONCLUSION: EPO can mobilize EPCs from CRF rat peripheral blood, which may be associated with the increased expression of SDF-1 and its receptor CXCR4.