中文摘要：

血管外膜成纤维细胞表型转化为肌成纤维细胞是血管重塑的重要病理特征。本研究旨在探讨小分子G蛋RhoA及其下游Rho激酶信号通路在转化生长因子β1（transforming growth factorp β1，TGF-β11）诱导的血管外膜成纤维细胞／肌成纤维细胞表型转化中的作用。用10ng／mLTGF—β1诱导体外培养的大鼠胸主动脉外膜成纤维细胞表型转化为肌成纤维细胞，使用亲和沉淀法检测RhoA活性、使用免疫印迹检测RhoA、Rho激酶蛋白表达和Rho激酶活性；使用免疫印迹和免疫细胞化学检测肌成纤维细胞标记蛋白的表达。结果显示，TGF-β1上调体外培养的血管外膜成纤维细胞RhoA蛋白表达和RhoA活性。TGF-β1增NRho激酶下游底物肌球蛋白磷酸酶目标亚单位的磷酸化，但不改变Rho激酶的蛋白表达，提示TGF-β1增加Rho激酶活性。腺病毒Ad-N19RhoA—hrGFP感染和Rho激酶特异性抑制剂Y27632都呈剂量依赖性地抑制TGF-β1诱导的肌成纤维细胞标记分子α平滑肌肌动蛋白和钙结合蛋白Calponin的蛋白表达。本研究证明RhoA—Rho激酶信号通路参与yTGF-β1诱导的血管外膜成纤维细胞／肌成纤维细胞表型转化。

英文摘要：

Vascular adventitial fibroblasts （AF） differentiation to myofibroblasts （MF） is the critical physiopathologic feature of vascu- lar remodeling. This study was to investigate the role of RhoA-Rho kinase signaling pathway in AF differentiation to MF induced by transforming growth factor β1（TGF-β1）. The results showed that TGF-β1 up-regulated total RhoA protein expression and RhoA ac- tivity in cultured AF by Western blotting and Rho pull-down assay, respectively. TGF-β1 up-regulated phospho-Myosin phosphatase target subunit （MYPT1, a downstream substrate of Rho kinase） expression without altering Rho kinase protein expression, indicating TGF-β1 induced the enhancement of activity of Rho kinase. Ad-N 19RhoA-hrGFP virus infection and Y27632, a specific inhibitor of Rho kinase, dose-dependently inhibited TGF-β1-induced o,-SM-actin and Calponin expression, as markers of MF differentiation. In conclusion, the RhoA-Rho kinase pathway is involved in AF differentiation to MF induced by TGF-β1.