EGCG对肾小管上皮细胞转分化过程中MMP9与Cyclin D1表达的影响及意义

目的探讨表没食子儿茶素没食子酸酯(EGCG)对肾小管上皮细胞转分化的作用机制。方法培养大鼠肾小管上皮细胞株NRK-52E,将其分成4组。1组:正常对照组(N),以DMEM培养液为空白对照。2组:转化生长因子(TGF-β1)诱导组;3组:EGCG200μg/L干预组;4组:EGCG400μg/L干预组。各细胞组在作用48 h后,应用免疫组化检测平滑肌肌动蛋白(α-SMA)和角蛋白(CK-18),Western-blot分析胞浆蛋白细胞周期素D1(Cyclin D1)、基质金属蛋白酶9(MMP9)含量,实时荧光定量PCR法测Cyclin D1、MMP9mRNA的相对表达量。结果 NRK细胞被TGF-β1诱导48 h后,胞浆中出现α-SMA蛋白高表达,CK-18蛋白表达明显减少;Cyclin D1、MMP9蛋白及其mRNA出现了高表达;EGCG干预组上述改变明显减轻。结论 EGCG以剂量依赖方式抑制TGF-β1诱导的NRK细胞的转分化,其机制可能是通过抑制Cyclin D1、MMP9蛋白及mRNA表达而实现的。

Effects of EGCG on expression of MMP9 and cyclin D1 in the transdifferentiation of renal tubular epithelial cell and its significance

Objective To explore the effect and mechanism of epigallocatechin-3-gallate(EGCG)on the transdifferentiation of renal tubular epithelial cells.Methods Tubular epithelial cell of rat(NRK-52E)was cultured and then were divided into four groups.Group one:Normal control(N),Group two:TGF-β1 induction group,Group three:200 μg/L EGCG experimental group,Group four:400 μg/L EGCG experimental group.The protein expression of α-SMA,CK-18 were detected by immunostaining,cyclin D1,MMP9 were detected by Western-blotting,and the mRNA expression of cyclin D1,MMP9 from cell line were detected by real-time PCR at 48 hours after treatment.Results When the NRK cells were induced by TGF-β1 for 48 hours,the cytoplasmic protein α-SMA began expression and the expression of CK-18 reduced,the protein and mRNA expression of cyclin D1,MMP9 were up-regulated,such changes in the EGCG group were slight.Conclusion EGCG can inhibit the transdifferentiation induced by TGF-β1 of NRK cells in a concentration-dependent manner.The mechanism may be the inhibition of protein and mRNA expression of MMP9 and cyclin D1.