中文摘要：

目的 研究N-乙酰基-丝氨酰-天门冬酰-赖氨酰-脯氨酸（Ac-SDKP）是否能够通过对转化生长因子-β1（TGF-β1）介导的ROCK通路的调节,抑制肺成纤维细胞向肌成纤维细胞的分化.方法 胰酶消化法原代培养肺成纤维细胞,取4代肺成纤维细胞分为对照组、TGF-β1诱导分化组、Y-27632干预组和Ac-SDKP干预组.激光共聚焦扫描显微镜观察ROCK、SRF以及d-SMA在细胞内的定位与分布情况;蛋白免疫印迹法（Western Blot）检测ROCK、SFR、α-SMA、Ⅰ型、Ⅲ型胶原蛋白在肺成纤维细胞的表达;实时定量荧光聚合酶链反应法（Real time PCR）检测ROCK、SFR、α-SMA mRNA的表达.结果 与对照组相比较,给予TGF-β1诱导刺激后,激光共聚焦扫描显微镜显示胞体内出现大量平行或交叉排列的α-SMA抗体标记的肌丝,诱导刺激6、12、24 h后,ROCK、SRF、α-SMA蛋白和mRNA以及Ⅰ型和Ⅲ型胶原蛋白表达均增强,差异均有统计学意义（P＜0.05）.与TGF-β1诱导分化组比较,给予Y-27632干预后,在相应时间点ROCK、SRF、d-SMA蛋白和mRNA以及Ⅰ型和Ⅲ型胶原蛋白表达均明显降低,差异均有统计学意义（P＜0.05）.给予Ac-SDKP干预后,在相应时间点ROCK、SRF、α-SMA蛋白和mRNA以及Ⅰ型和Ⅲ型胶原蛋白表达也较TGF-β1诱导分化组明显降低,差异均有统计学意义（P＜0.05）.结论 Ac-SDKP能够通过对TGF-β1介导的ROCK信号转导通路的调控,阻抑大鼠成纤维细胞向肌成纤维细胞的分化和抑制胶原蛋白的合成,可能是Ac-SDKP发挥其抗（矽）肺纤维化的作用机制之一.

英文摘要：

Objective To investigate whether N-acetyl-seryl-aspartyl-lysyl-proline （Ac-SDKP） can inhibit the differentiation of pulmonary fibroblasts into myofibroblasts by regulating Rho-associated coiled-coil forming protein kinase （ROCK） pathway mediated by transforming growth factor-β1 （TGF-β1）.Methods Primary culture of pulmonary fibroblasts was performed by trypsinization method.Four generations of pulmonary fibroblasts were divided into control group,TGF-β1-induced differentiation group,Y-27632 treatment group,and Ac-SDKP treatment group.The intracellular distributions of ROCK,serum response factor （SRF）,and α-smooth muscle actin （α-SMA） were observed by confocal laser scanning microscopy.The protein expression of ROCK,SFR,α-SMA,and type Ⅰ and type Ⅲ collagen in pulmonary fibroblasts was measured by Western blot.The mR-NA expression of ROCK,SFR,and α-SMA was measured by real-time quantitative PCR.Results Compared with the control group,the pulmonary fibroblasts stimulated by TGF-β1 had a lot of α-SMA antibody-labeled myofilaments in parallel or cross arrangement,as observed by confocal laser scanning microscopy,and the mRNA and protein expression of ROCK,SRF,and α-SMA and protein expression of type Ⅰ and type Ⅲ collagen increased significantly after 6,12,and 24 h of stimulation （P＜0.05）.Compared with the TGF-β1-induced differentiation group,the Y-27632 treatment group and Ac-SDKP treatment group had significantly decreased mRNA and protein expression of ROCK,SRF,and α-SMA and protein expression of type Ⅰ and type Ⅲ collagen at the same time point （P＜0.05）.Conclusion Ac-SDKP can inhibit the differentiation of pulmonary fibroblasts into myofibroblasts and the synthesis of collagen in rats by regulating the ROCK pathway mediated by TGF-β1.That may be one of the mechanisms by which Ac-SDKP acts against （silicotic） pulmonary fibrosis.