OBJECTIVETo investigate the potential effect of homologous bone marrow mesenchymal stem cells (MSCs) on repairing peri-tubular capillary cluster (PTCC), and on improving renal tubular and mesenchymal hypoxia condition.

METHODSMonocyte was purified from bone marrow, amplified and identified as MSCs in vitro. Thirty female Wistar rats were randomly divided into 3 groups, the normal control group (Group A), MSCs transplanted group (Group B) and un-transplanted group (Group C). Rats in Group A was administered with drinking water by gastrogavage for 12 weeks, while those in Group B and C were administered with Aristolochia Decoction for 12 weeks to establish chronic aristolochic acid nephropathy (CAAN) model. At the end of the 12th week, 1 ml of MSCs was injected through caudal vein to the rats in Group B, while to those in Group A and C normal saline was injected instead. Blood, urine and kidney tissue of rats were collected at the end of the 16th week for examination, and their kidney tissue were made into serial section for determining the distribution of Y chromosome and CD34 double positive cells, and the pathological, immunohistochemical changes were observed using Western blotting and RT-PCR, etc.

RESULTSY chromosome and CD34 double positive cells could be seen in MSCs transplanted renal tissue in group B. At the end of the 16th week, the PTCC density in Group C and B was (26.47 +/- 1.56)/ 0.13 mm2 and (5.26 +/- 0.78)/0.13 mm2 respectively, and the IOD value of hypoxia inducible factor-1alpha (HIF-1alpha) in them was (6.74 +/- 0.67) x 10(3) and (25 27 +/- 1.46) x 10(3) respectively, all showing significant difference between the two groups (P < 0.01). The content of CD34 was higher in Group B than that in Group C (P < 0.01).

CONCLUSIONHomologous MSCs can enhance the vascular endothelial cells differentiation to repair the PTCC, thus to improve the renal tubular and mesenchymal hypoxia status.