核心蛋白聚糖对转化生长因子-β1诱导人肾小管上皮细胞转分化的影响及其机制

Effect of Decorin on Transforming Growth Factor-β1 Triggered Tubular Epithelial-Myofibroblast Transdif-ferentiation and Its Mechanisms

目的应用转化生长因子-β1(TGF-β1)诱导人肾小管上皮细胞-肌成纤维细胞转分化(EMT),探讨核心蛋白聚糖对人肾小管上皮细胞转分化的影响及其发生机制。方法将体外培养的人肾小管上皮细胞(HK-2)分为4组:阴性对照组;100μg/L核心蛋白聚糖组;10μg/LTGF-β1组;100μg/L核心蛋白聚糖加10μg/LTGF-β1组。应用倒置相差显微镜观察其细胞形态变化;反转录聚合酶链反应、蛋白质印迹(Western blot)法检测其波形蛋白、钙黏蛋白表达水平;Western blot法检测信号通路细胞外调节蛋白激酶(ERK)磷酸化水平;实时定量聚合酶链反应检测snail mRNA表达水平。结果1.与对照组比较,TGF-β1诱导肾小管上皮细胞从原有典型的上皮细胞形态转变为长梭形肌成纤维细胞样形态;波形蛋白和snail mRNA表达上调,钙黏蛋白表达下调,ERK的磷酸化水平增高;2.单纯核心蛋白聚糖组与对照组比较无统计学差异,而核心蛋白聚糖和TGF-β1共同刺激组与TGF-β1组比较波形蛋白和snail表达下调,钙黏蛋白表达上调,ERK磷酸水平降低。结论核心蛋白聚糖能够负性调控TGF-β1诱导EMT,核心蛋白聚糖对EMT的负性调节作用可能是通过ERK信号转导途径实现的。

ObjectiveTo observe the effect of decorin on transforming growth factor（TGF）-β1 triggered tubular epithelial-myofibroblast transdifferentiation（EMT） and to explore its mechanisms.MethodsCultured HK-2 cells were divided into 4 groups：negative control group;100 μg/L decorin group;10 μg/L TGF-β1 group;100 μg/L decorin plus 10 μg/L TGF-β1 group.The morphology of transdifferen-tiate tubular cells was observed by using phase-contrast-microscopy;the expressions of vimentin and E-cadherin were detected by Western blot and RT-PCR,the level of phosphor-extracellular ergulated protein kinases（ERK） was detected by Western blot;the expression of snail mRNA was detected by real time-PCR.Results1.Compared with control group,HK-2 cells induced by TGF-β1 converted into spindle shape from typical epithelium shape,the expression of vimentin,snail mRNA and phosphor-ERK significantly increased,the expression of E-cadherin significantly decreased;2.There was no statistically significant difference between decorin treated groups and control group,compared with TGF-β1 treated groups,co-treated groups by TGF-β1 and decorin,expression of vimentin and snail and phosphor-ERK down regulated,expression of E-cadherin upregulated.ConclusionsDecorin can block EMT triggered by TGF-β1,which implies that decorin can participate in renal interstitial fibrosis as a negative regulator.The negative regulation of transdifferentiation of decorin may be partially achieved by attenuation of ERK signal transduction pathway.