Snail1/IGF-1信号通路介导高糖诱导的肾小管上皮细胞EMT

目的:观察高糖诱导大鼠肾小管上皮细胞NRK-52E中锌指转录因子Snail1和胰岛素样生长因子1(insulin-like growth factor-1,IGF-1)的表达变化,并初步探讨Snail1与IGF-1在糖尿病肾脏病(diabetic kidney disease,DKD)上皮-间充质转化(epithelial to mesenchymal transition,EMT)过程中的关系.方法:高糖培养大鼠近端肾小管上皮细胞系NRK-52E 72 h后,给予Snail1 siRNA和IGF-1 siRNA处理,分为高糖组、non-targeting (NT) siRNA组、Snail1 RNAi组和IGF-1 RNAi组,并设置对照组.于转染后48和72 h两个时点收获细胞.分别用实时荧光定量PCR检测细胞Snail1、IGF-1、E-钙黏蛋白(E-cadherin)和纤维连接蛋白(fibronectin,FN)的mRNA表达,用免疫荧光方法检测各蛋白的表达.结果:高糖诱导NRK-52E细胞E-cadherin的mRNA和蛋白表达明显降低(P＜0.01),FN的mRNA和蛋白表达明显升高(P＜0.01);同时,Snail1和IGF-1的mRNA和蛋白表达也明显升高(P＜0.o1).Snail1 RNAi组与高糖组比较,细胞中E-cadherin的mRNA和蛋白表达明显升高(P＜0.01),FN、Snail1和IGF-1的mRNA和蛋白表达明显降低(P ＜0.01),Snail1的mRNA表达减少62.8％.与高糖组比较,IGF-1 RNAi组细胞IGF-1的mRNA表达减少61.1％,E-cadherin的mRNA和蛋白表达明显升高(P＜0.01),FN的mRNA和蛋白表达明显降低(P＜0.01).NT组E-cadherin、FN、Snail1及IGF-1的mRNA和蛋白表达与高糖组比较差异无统计学显著性.Pearson相关性分析显示,NRK-52E细胞中Snail1与IGF-1蛋白的表达呈显著正相关(r=0.852,P＜0.01).结论:Snail1及IGF-1的mRNA和蛋白在高糖诱导的肾小管上皮细胞EMT过程中表达升高,且沉默Snail1基因,IGF-1表达随之减少,提示Snail1/IGF-1可能促进DKD时肾小管上皮细胞EMT.