Ac-SDKP通过调节HDAC6和HSP90抑制矽肺纤维化的机制研究

摘要

Objective To investigate the effect of N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) on the expressions of histone deacetylase 6 (HDAC6) and heat shock protein 90 (HSP90) in the process of fibroblast differentiation. Methods Rats were instilled with silica through trachea to establish silicotic models. The rats were divided into 4-week control group, 4-week silicosis group, 8-week control group, 8-week silicosis group, Ac-SDKP treatment group and Ac-SDKP pre-treatment group. Myofibroblasts induced by TGF-β1 were pre-treated with TCS HDAC620b, the specific inhibitor of Ac-SDKP and HDAC6. Routine HE staining was used to observe the pathomorphology. The expressions of α-SMA, collagen I, HDAC6 and HSP90 were measured by immunohistochemistry and Western blot. Results The expressions of HDAC6 and HSP90 were increased in the silicotic nodules of the rat lungs; upon the treatment or pre-treatment with Ac-SDKP, the expressions of collagen I, α-SMA, HDAC6 and HSP90 were decreased. TGF-β1 induced the α-SMA expression in rat fibroblasts and up-regulated the expressions of HDAC6 and HSP90; moreover, pre-treatment with Ac-SDKP or TCS HDAC620b inhibited the TGF-β1-induced expressions of these factors. Conclusions Ac-SDKP inhibits myofibroblast differentiation and collagen deposition, which is related with regulation of HDAC6 and HSP90.%目的 探讨Ac-SDKP通过对组蛋白去乙酰化酶6(HDAC6)、热休克蛋白90(HSP90)的调节,抑制大鼠矽肺纤维化的作用机制.方法 非暴露式支气管内灌注法复制大鼠矽肺模型,分为对照4周组、矽肺模型4周组、对照8周组、矽肺模型8周组、Ac-SDKP抗纤维化治疗组和Ac-SDKP预防治疗组.采用转化生长因子-β1(TGF-β1)诱导原代培养新生大鼠肺成纤维细胞向肌成纤维细胞分化,并予以Ac-SDKP和HDAC6特异性抑制剂TCS HDAC620b预处理.采用苏木精-伊红染色法观察病理形态变化,免疫组织化学法、Western blot检测Ⅰ型胶原、α-平滑肌肌动蛋白(α-SMA)、HDAC6及HSP90的表达.结果 免疫组织化学法结果显示,HDAC6和HSP90阳性表达主要位于矽结节内,给予Ac-SDKP抗纤维化治疗或预防治疗均能抑制Ⅰ型胶原、α-SMA、HDAC6及HSP90蛋白表达的上调.而TGF-β1能诱导大鼠成纤维细胞 α-SMA阳性表达,同时伴随HDAC6和HSP90蛋白表达上调,而予以TCS HDAC620b或Ac-SDKP预处理均能抑制该变化.结论 Ac-SDKP能够通过对HDAC6和HSP90信号的调节,在体内外抑制矽肺大鼠肌成纤维细胞分化和胶原沉积,从而发挥抗矽肺纤维化的作用.