中文摘要：

目的 研究N-乙酰基-丝氨酰-天门冬氨酰-赖氨酰-脯氨酸（Ac-SDKP）通过对乙酰化微管蛋白α（Ac-Tub α）的调控,抑制矽肺肌成纤维细胞转化的作用及机制.方法 构建矽肺大鼠模型,分为对照组（4、8周）、矽肺模型组（4、8周）、Ac-SDKP抗纤维化治疗组和预防治疗组;原代肺成纤维细胞分为对照组、血管紧张素（Ang）Ⅱ诱导组、Ac-SDKP预处理组、血管紧张素Ⅱ受体1（AT1）阻滞剂（缬沙坦）预处理组、组蛋白去乙酰化酶（HDAC）6选择性抑制剂（TCS HDAC6 20b）预处理组.免疫组化及免疫荧光染色法观察Ac-Tub α、α-平滑肌肌动蛋白（α-SMA）在肺组织或细胞中的表达与定位.免疫印迹法检测肺组织或细胞中Ⅰ型胶原、α-SMA、Ac-Tubα、HDAC6蛋白的表达.结果 免疫组化结果显示,矽肺模型组矽结节和间质纤维化区域Ac-Tubα表达缺如,α-SMA阳性表达.Ac-SDKP能够抑制Ⅰ型胶原、α-SMA、HDAC6蛋白的表达,其中抗纤维化治疗组与矽肺模型8周组比较下降至48.39％、52.63％和70.18％,预防治疗组与矽肺模型8周组比较下降至32.26％、64.91％和54.39％;在Ac-SDKP抗纤维化治疗组和预防治疗组Ac-Tub α蛋白表达为矽肺模型8周组的3.00和2.90倍,以上结果经方差分析差异均有统计学意义（P＜0.05）.Ang Ⅱ诱导组Ac-Tubα表达减弱为对照组的44.44％.而AngⅡ诱导组的α-SMA、HDAC6和Ⅰ型胶原表达增多,分别是对照组的1.66、3.56和4.00倍（P＜0.05）.予以Ac-SDKP、缬沙坦或TCSHDAC6 20b预处理,能明显抑制该变化.结论 Ac-SDKP抑制矽肺大鼠肌成纤维细胞转化和胶原沉积,发挥抗矽肺纤维化的作用,可能与下调HDAC6和促进Ac-Tub α的表达有关。

英文摘要：

Objective To explore the inhibition effect and mechanism of N-acetyl-seryl-aspartyl-lysyl-proline （Ac-SDKP） on myofibroblast differentiation via regulating acetylated tubulin α （Ac-Tub α） in vivo and in vitro.Methods Silicotic model were made by SiO2 douched and divided into 6 groups as follows：control （4w,8w） group,silicotic model （4w,8w） group and post-or pre-treatment by Ac-SDKP group.Pulmonary fibroblasts were divided into 5 groups：（1） control;（2） Ang Ⅱ;（3） Ang Ⅱ＋Ac-SDKP;（4） Ang Ⅱ＋Valsartan;（5）Ang Ⅱ＋ TCS histone deacetylase （HDAC） 6 20b.The localization of Ac-Tub α and α-smooth muscle actin（SMA） were observed by immunohistochemical （IHC） and immunofluorescence staining.The protein levels of Ac-Tub α,α-SMA,collagen type Ⅰ （col Ⅰ） and HDAC6 were measured by western blot.Results In silicotic nodules and interstitial fibrosis area,positive expression of α-SMA,a classical marker of myofibroblast,was observed by IHC,accompanied with absence expression of Ac-Tub α.Furthermore,Ac-SDKP post-treatment could attenuate the levels of col Ⅰ,α-SMA and HDAC6 to 48.39%,52.63% and 70.18% compared with the silicotic 8w group respectively.And in Ac-SDKP pre-treatment group,compared with the silicotic 8w group,these protein levels were decreased to 32.26%,64.91% and 54.39% respectively （P〈0.05）.The up-regulation of Ac-Tub α was found in Ac-SDKP post-and pre-treatment and increased to 3.00 and 2.90 folds compared with the silicotic 8w group.Compared with control group,the levels of α-SMA,HDAC6 and col Ⅰ in Ang Ⅱ group were up-regulated to 1.66,3.56 and 4.00 folds accompanied with down-regulation of Ac-Tub by 44.44% （P〈0.05）.Pre-treatment with Valsartan,TCS HDAC6 20b or Ac-SDKP could inhibited all this changes induced by Ang Ⅱ in vitro.Conclusion Ac-SDKP can inhibit the myofibroblast differentiation and collagen deposition via suppress HDAC6 and up-regulate the expression of Ac-Tub α in vivo and in vitro.