转化生长因子β1和波形蛋白及结蛋白在糖尿病大鼠肾皮质中早期表达的研究

目的:探讨糖尿病大鼠早期不同阶段转化生长因子β1(TGF-β1)和波形蛋白(vimentin)、结蛋白(desmin)在大鼠肾皮质中表达的变化规律及其相互关系.方法:建立STZ诱导的SD大鼠糖尿病模型;用RT-PCR法半定量检测早期各观察时点糖尿病大鼠肾皮质中TGF-β1和vimentin、desmin mRNA的表达水平.结果:①随着糖尿病病情的进展,TGF-β1和vimentin mRNA的表达量分别从模型建立后第7 d和第14 d起逐渐增多(P=0.001),desmin mRNA表达从第14 d起却逐渐减少(P＜0.05).②糖尿病组的TGF-β1与vimentin的mRNA表达呈正相关(r＝0.740,P=0.000),desmin与TGF-β1的mRNA表达呈负相关(r＝-0.695,P=0.000),desmin与vimentin的mRNA表达也呈负相关(r＝-0.591,P=0.002).结论:糖尿病大鼠早期肾皮质中TGF-β1和vimentin的表达逐渐增多,desmin的表达却逐渐减少,提示TGF-β1可能促进小管上皮细胞向成纤维细胞转化.

Early expression of TGF-β1,vimentin and desmin genes in renal cortex of diabetic rats

OBJECTIVE: To study the expression of TGF-beta(1)vimentin and desmin in the renal cortex of diabetic rats induced by STZ. METHODS: Diabetes was induced in 24 male SD rats by single intraperitoneal injection of 1.0%STZ (70 mg/kg). Twenty-four age, weight and sex matched SD rats were used as controls. The expression of TGF-beta(1),vimentin and desmin mRNA in the renal cortex were detected by RT-PCR on the 3rd, the 7th, the 14th and the 30th day after the DM rat model established. RESULT: (1)The expression of TGF-beta(1), vimentin mRNA in the renal cortex of diabetic rats gradually increased respectively from the 7th day and the 14th day after the model established, and the expressive intensity was significantly greater than that in controls (P<0.05 or P<0.01). However,the expression of desmin mRNA in the renal cortex of diabetic rats gradually decreased from the 14th day after the model established, and the expressive intensity was significantly less than that in controls (P<0. 05 or P<0.01). (2) The expression of TGF-beta(1)mRNA correlated positively to that of vimentin mRNA (r 0.740 P=0.000), while the expression of desmin mRNA correlated negatively to that of TGF-beta(1)mRNA (r 0.695 P=0.000) and to that of vimentin mRNA (r 0.591 P=0.002). CONCLUSION: The expression of renal cortical TGF-beta(1) and vimentin mRNA gradually increase while the expression of desmin mRNA gradually decrease during the first month of the diabetic model established suggest TGF-beta(1) may play a role in the transformation of renal tubular epithelial cells into fibroblast during the progressive interstitial fibrosis of diabetic nephropathy.