Ac-SDKP 通过调节HDAC6 和HSP90抑制矽肺纤维化的机制研究

Effect of Ac-SDKP on expressions of HDAC6 and HSP90 in lungs of rats with silicosis

摘要:

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 HDAC6 20b 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 HDAC6 20b 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。

Abstract:

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 pretreated with TCS HDAC6 20b, 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 HDAC6 20b 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.