[Bone marrow mesenchymal stem cell therapy on diabetic nephropathy in rats]

To test the effectiveness of bone marrow mesenchymal stem cell (MSC) transplantation on diabetic nephropathy in rats.

A single intraperitoneal injection of STZ (60 mg/kg) was given to Sprague-Dawley (SD) rats. Four weeks after the occurrence of diabetes, the rats with diabetic nephropathy were randomly divided into two groups: diabetic nephropathy control group (DN, n = 12) and MSCs transplantation group (MSC, n = 12). Six rats served as normal controls. MSCs were cultured, identified and labeled by 5-bromo-2'-deoxyuridine (BrdU) in vitro, which were then transplanted to the rats in the MSC group via introcardiac infusion(2 x 10(6) MSCs/200 microL). The same procedure was repeated one week later. The blood glucose, body weight (BW), kidney weight (KW), urine protein, endogenous creatinine clearance rate (Ccr) and profile of kidney hypertrophy (KW/BW) were tested and the renal morphology and labeled cells were examined in the kidney, one, two, and eight weeks after the second transplantation.

Mesenchymal cell phenotype was expressed by the cultured MSCs, which could be multidifferentiated into osteogenic and adipogenic cells. The labeled MSCs were detected in the kidney of nephropathic rats, but no proliferation of the stem cells was found. The rats in the MSC and DN groups had higher blood glucose, urine protein, Ccr and KW/BW and lower BW than the normal controls (P < 0.05). One week after the transplantation, the rats in the MSC group showed lower blood glucose than the rats in the DN group [(26.7 +/- 2.8) vs (29.9 +/- 1.6) mmol/L, P < 0.05], but was still higher than the normal controls (6.0 +/- 0.7 mmol/L). The urine protein appeared similar in the MSC and DN groups two weeks and eight weeks after transplantation. After two weeks of transplantation, the rats in the MSC group showed lower Ccr (8.6 +/- 1.9) and KW/BW (5.5 +/- 0.1) than the rats in the DN group (17.1 +/- 1.6 for Ccr and 6.2 +/- 0.3 for KW/BW respectively, P < 0.05).

Cardiac injected bone marrow mesenchymal stem cells can track to the kidney of rats with diabetic nephropathy, which attenuates diabetic nephropathy temporarily.