细胞因子信号传导抑制蛋白1对糖基化终末产物诱导的肾小管细胞转分化的影响

Influence of SOCS-1 on AGEs-induced renal tubular epithelial-myofibroblast transdifferentiation

目的观察细胞因子信号传导抑制蛋白1(SOCS-1)对糖基化终末产物(AGEs)诱导肾小管上皮细胞(HKC)转分化及JAK/STAT信号通路的影响。方法体外培养人肾小管上皮细胞(HKC),应用脂质体2000分别转染pCR3.1/SOCS-1表达质粒和pCR3.1空质粒载体,G418筛选阳性克隆。分别采用白蛋白和AGEs进行刺激。采用Western印迹检测SOCS-1、α-SMA、E-钙黏着糖蛋白(E-cadherin)、Ⅰ型胶原(collagenI,ColI)、信号转导和转录活化因子1、3(STAT1、STAT3)及其磷酸化蛋白(p-STAT1、p-STAT3)的表达;酶联免疫吸附实验(ELISA)测定细胞上清液中转化生长因子-β1(TGF-β1)的分泌;逆转录-聚合酶链反应(RT-PCR)检测α-SMA和E-cadherin mRNA的表达。结果与对照组相比,AGEs组肾小管细胞α-SMA和ColI蛋白表达明显上调,细胞培养上清中TGF-β1含量增加,α-SMA mRNA的表达增加,而E-cadherin蛋白和mRNA表达下调。SOCS-1过表达能够抑制AGEs刺激引起的HKC细胞α-SMA和ColI的表达及STAT1和STAT3的磷酸化,减少TGF-β1的含量,下调AGEs刺激引起的HKC细胞α-SMA mRNA的表达,同时能够逆转AGEs刺激引起的HKC细胞E-cadherin蛋白和mR-NA的下调表达。结论SOCS-1过表达抑制AGEs诱导的肾小管上皮细胞转分化可能是通过抑制JAK/STAT信号通路活化实现的。

Aim To investigate the effects of suppressor of cytokine signaling-1 （ SOCS-1 ） on advanced glycation end products （AGEs）induced-renal tubular epithelial-myofibroblast transdifferentiation and activation of JAK/STAT in cultured human renal tubular epithelial cells （HKC）. Methods Stable transfections of HKC with pCR3. 1 vector and pCR3. 1/SOCS-1 were performed with Lipofectamine 2000, and cells were selected with geneticin. Cells were stimulated with BSA and AGEs. The protein expressions of SOCS-1, α-SMA, Ecadherin, Col l, signal transducer and aetivatior of transcription 1,3 （ STAT1, STAT3 ）, p-STAT1 and p-STAT3 were observed by Western blot. The protein synthesis of TGF-β1 in the supernatants of the HKC was detected by enzyme-linked immunoadsorbent assay （ELISA）. α- SMA and E-cadherin mRNA were measured by reverse transcription and polymerase chain reaction （RTPCR）. Results pression levels of were significantly Compared with control group, the expression levels of α-SMA protein and mRNA and Col I increased in HKC with AGEs stimu-lation and there was a higher concentrations of TGF-β1 in the supernatants. However, the expression of E-cadherin protein and mRNA were decreased with AGEs stimulation. Overexpression of SOCS-! inhibited AGEsinduced activation of STAT1 and STAT3 and high expression of α-SMA protein and mRNA and Col I, and reversed the expression of E-cadherin protein and mRNA induced by AGEs. Meanwhile, overexpression of SOCS-1 reduced the concentration of TGF-β1 in the supernatants of HKC with AGEs stimulation. Conclusion Overexpression of SOCS-1 inhibits AGEs-induced renal tubular epithelial-myofibroblast transdifferentiation maybe partly through blocking activation of JAK/STAT.