骨髓间充质干细胞治疗大鼠糖尿病肾病初探

目的 探索骨髓间充质干细胞(MSCs)经体外扩增培养后移植入糖尿病肾病大鼠体内能否改善或者治疗糖尿病肾病.方法 SD大鼠60 mg/kg STZ一次性腹腔注射,糖尿病成模后4周,成功制备糖尿病肾病大鼠被随机分为:糖尿病肾病对照组(n=12)和干细胞移植组(n=12),另选6只正常大鼠作为对照组.MSCs经体外培养、鉴定、BrdU标记后,心脏注射到干细胞移植组大鼠体内(2×106 MSCs/200 μL),一周后再次注射等量干细胞.于末次注射后1、2、8周测定大鼠血糖、体质量、24 h尿总蛋白、肌酐清除率、肾脏肥大指数,观察大鼠肾脏病理变化和标记干细胞体内作用情况.结果 MSCs体外扩增培养后表达间充质细胞的表型抗原,能多向分化为成骨、成脂细胞.在体内能趋化到受损肾脏,但在干细胞定植部位未发现增殖细胞.干细胞移植组和糖尿病肾病对照组在各观察时点血糖、尿总蛋白、肌酐清除率、肾脏肥大指数均明显高于正常对照组(P<0.05), 体质量均低于正常对照组(P<0.01).干细胞治疗后1周移植组较糖尿病肾病对照组血糖降低(26.7±2.8) vs (29.9±1.6) mmol/L,P<0.05].在第2、8周,移植组较糖尿病肾病对照组24 h尿总蛋白降低,但差异无统计学意义.干细胞移植组肌酐清除率低于糖尿病肾病对照组,在治疗后2周两组差异有统计学意义(8.6±1.9) vs (17.1±1.6) mL/min,P<0.05].在第2周干细胞移植组的肾脏肥大指数较糖尿病肾病对照组减少(5.5±0.1 vs 6.2±0.3, P<0.05),但高于正常对照组(3.2±0.2).结论 发现MSCs经体外培养标记后在体内能趋化到糖尿病肾病大鼠肾脏,可以暂时改善糖尿病肾病.

Bone Marrow Mesenchymal Stem Cell Therapy on Diabetic Nephropathy in Rats

Objective To test the effectiveness of bone marrow mesenchymal stem cell (MSC) transplantation on diabetic nephropathy in rats. Methods 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, w=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(2×10~6MSCs/200μL). 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. Results 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). Conclusion Cardiac injected bone marrow mesenchymal stem cells can track to the kidney of rats with diabetic nephropathy, which attenuates diabetic nephropathy temporarily.