糖尿病大鼠肾脏色素上皮衍生因子和转化生长因子-β1蛋白表达及罗格列酮的干预作用

Effect of rosiglitslzone on expression of pigment epithelium-derived factor and transforming growth factor-β1 in kidney of diabetic rats

目的 观察罗格列酮对糖尿病大鼠肾脏色素上皮衍生因子和转化生长因子-β1蛋白表达的影响.方法 健康雄性SD大鼠42只(体重180～200 g),采用随机数字表法分为正常对照组(n=14)、糖尿病组(n=14)和罗格列酮干预组(n=14).腹腔注射链脲佐菌素,建立糖尿病大鼠模型.造模成功后,罗格列酮干预组给予罗格列酮5μ·g-1·d-1灌胃治疗12周,正常对照组注射等体积柠檬酸缓冲液.12周末检测各组大鼠血糖、血脂、肝功能、肾脏指数、肾功能、24h尿白蛋白排泄率及血清色素上皮衍生因子含量.采用HE染色观察大鼠肾脏组织形态学变化,应用免疫组织化学法和Western blot检测肾脏色素上皮衍生因子和转化生长因子-β1蛋白表达水平.运用t检验和方差分析进行数据统计.结果 与正常对照组比较,糖尿病组大鼠肾小球肥大,基底膜增厚,系膜区基质明显增生,部分肾小管呈空泡变性,转化生长因子-β1蛋白表达水平明显升高(免疫组织化学分析:4.60 ±0.14、1.57±0.14,t=3.052,P<0.01;Western blot:1053±64、462±70,t=2.817,P<0.01),而色素上皮衍生因子蛋白表达水平显著降低(免疫组织化学分析:1.53±0.12、3.96±0.18,t=2.845,P<0.01:Western blot:228±275、698±120,t=3.152,P<0.01).与糖尿病组比较,罗格列酮干预组大鼠肾小球肥大,基底膜增厚,系膜区基质增生程度明显减轻,转化生长因子-β1蛋白表达水平明显降低(免疫组织化学分析:2.79±0.16、4.60±0.14,t=2.964,P<0.01;Western blot:753±81、1053±64,t=2.884,P<0.01),色素上皮衍生因子蛋白表达水平显著升高(免疫组织化学分析:2.64±0.32、1.53±0.12,t=2.347,P<0.05;Western blot:473±127、228±275,t=2.334,P<0.05).结论 罗格列酮可通过下调糖尿病大鼠肾脏转化生长因子-β1蛋白表达、上调色素上皮衍生因子蛋白表达来发挥肾脏保护作用.

Objective To investigate the effect of rosiglitazone on the expression of pigment epithelium-derived factor(PEDF) and transforming growth factor-β1(TGF-β1)in the kidney of diabetic rats.Methods A total of 42 healthy male SD rats(180 to 200g)were randomly assigned to the normal control(NC)group(n=14),diabetes mellitus(DM)group(n=14),and rosiglitazone(RSG)treatment group(n=14).Diabetes was induced by an intraperitoneal injection of 55μ/g streptozotocin.The rats in the RSG group were given rosiglitazone sodium 5μg·g-1·d-1．At the end of 12 weeks，fasting blood glucose,kidney mass,kidney/body mass,24-hour urinary albumin excretion(UAE),serum triglyceride (TG),total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),very low-density lipoprotein cholesterol(VLDL-C),hish-density lipoprotein cholesterol(HDL-C),BUN,SCr and PEDF were measured.The expression of TGF-β1 and PEDF in the kidney was determined by immunohistochemical analysis and Western blot.Statistical analysis was performed using two-tail Student's t test.Results Compared with the NC group,the DM group was characterized by the glomerular hypertrophy,mesangial expansion and glomerular basement membrane thickening;the protein expression of TGF-β1 was significantly increased(immunohistochemical analysis:4.6±0.14 vs 1.57±0.14,t=3.052,P<0.01:Western blot:1053±64 vs 462±70,t=2.817,P<0.01).whereas the protein expression of PEDF was significantly decreased(immunohistochemical analysis:1.53±0.12 vs 3.96±0.18,t=2.845,P<0.01;Western blot:228±275 vs 698±120,t=3.152,P<0.01)in the DM group.Compared with the DM group,the glomerular hypertrophy, mesangial expansion and glomerular basement membrane thickening were significantly ameliorated in the RGS group;the protein expression of TGF-Bβ1 was significantly lower (immunohistochemical analysis:2.79±0.16 vs 4.60±0.14,t=2.964,P<0.01;Western blot:753 ±81vs1053±64,t=2.884,P<0.01),whereas the protein expression of PEDF was significantly higher (immunohistochemical analysis:2.64±0.32 vs 1.53±0.12,t=2.347,P<0.05;Western blot:473±127 vs 228±275,t=2.334,P<0.05)in the RSG treatment group.Conclusion Renoprotection of rosiglitazone on diabetic rats may be mediated by decreased expression of TGF-β1 and increased expression of PEDF.