活性维生素D3对TGF-β1诱导人肾小管上皮细胞转分化的作用

摘要

目的 研究活性维生素D3(1,25(OH)2D3)对TGF-β1诱导的人肾小管上皮细胞转分化的作用,并探讨其作用机制.方法 体外培养正常人近端肾小管上皮细胞(HK-2),随机分为5组:空白对照组(N)、TGF-β1 (5ng/ml)诱导组(T)、TGF-β1(5ng/ml)+1,25(OH)2D3(10-9mol/L)低浓度处理组(D1)、TGF-β1(5ng/ml)+1,25 (OH)2D3(10-8mol/L)中浓度处理组(D2)、TGF-β1(5ng/ml)+1,25(OH)2D3(10-7mol/L)高浓度处理组(D3),分别于12h、24h、48h、72h用免疫组化法检测α-SMA、E-cadherin蛋白的表达变化,用Real-time PCR法检测VDR mRNA的表达变化.结果 免疫细胞化学检测显示除D1组在培养12h和24h后α-SMA、E-cadherin蛋白表达与T组相比没有统计学意义外,其余各1,25(OH)2D3干预组α-SMA蛋白的表达下调,E-cadherin蛋白的表达则明显上调,且呈剂量依赖关系;Real time-PCR结果提示T组VDR mRNA表达均减少,呈时间依赖性,D1组在培养48h后上调VDR mRNA的表达,D2、D3各组VDR mRNA的表达均明显上调,亦呈剂量依赖关系.结论 活性维生素D3可抑制TGF-β1诱导的人肾小管上皮细胞转分化,且呈剂量依赖关系,其抑制作用可能与上调VDR的表达有关.%Objective To explore the effect of 1,25(OH)2D3 on transdifferentiation of human renal tubular epithelial cells induced by TGF-β1 and to study the mechanism.Methods Human proximal tubular epithelial cell line (HK-2) was cultured in vitro in 5 groups re-spectively:control group (group N),TGF-β1 (5ng/ml) induced group (group T),TGF-β1 of low-dose group (group D1),TGF-β1 of medi-um-dose group (group D2) and TGF-β1 of high-dose group (group D3);at the time point of 12 hours,24 hours,48 hours and 72 hours af-ter the culture,immunohistochemical detection was made to the expressions ofα-SMA and E-cadherin protein while Real-time PCR de-tection was made to the expressions of VDR mRNA.Results The immunohistochemical detection showed that no difference with statis-tical significance was found in the expressions ofα-SMA and E-cadherin protein at the time point of 12 hours and 24 hours after the cul-ture in group T while down-regulated expressions ofα-SMA and up-regulated expressions of E-cadherin protein were found in the left 4 groups in a dose-dependent manner; Real-time PCR detection showed that the expressions of VDR mRNA decreased in group T in a time-dependent manner while that in group D1 increased at the time point of 48 hours after the culture and those in group D2 and group D3 increased obviously in a dose-dependent manner.Conclusions 1,25(OH)2D3 can inhibit the transdifferentiation of human renal tubu-lar epithelial cells induced by TGF-β1 in a dose-dependent manner,which may be related to the up-regulation of VDR.