The Function Of Acetylated α Tubulin In Ac-SDKP Inhibits Fibrosis Silicosis

Objectives To identify the role of Ac-α-Tub in anti-fibrosis effect of Ac-SDKP in fibrosis disease and the locating features of Ac-α-Tub in various organs.Methods The rats with bronchial in stillating Si O2 were divided into 6 groups: control group for 4w and 8w, silicotic model group for 4w and 8w, Ac-SDKP post-treatment and pre-treatment groups. The primary pulmonary fibroblasts were divided into 5 groups: control group, Ang II-induced group, Ac-SDKP, valsartan and TCS HDAC6 20 b treatment before Ang II-induced groups. The dust exposure of rat model lasted for 2w, 4w, 8w, 16 w and 24 w respectively. The UUO model was carried out and lasted for 1w, 2w, 3w respectively. TAA-induced liver fibrosis model was executed after 1w, 3w, 6w. The pulmonary histology was observed by HE staining. The expression of Ac-α-Tub, α-SMA, vimentin and SP-A in organs were tested by immunohistochemistry and immunofluorenscence. Western blot were used to analyze the expression of Ac-α-Tub, collegan type I, α-SMA and HDAC6.Results 1 The results of immunohistochemistry showed that Ac-α-Tub was located in bronchial epithelial cells, type II pneumonocyte, fibroblast, and endothelial cells, while it lost expression in silicotic nodules and interstitial fibrosis regions. The expressional feature tested by two commercial antibodies showed similar result. The positive expression of α-SMA was observed in silicotic nodules and interstitial fibrosis areas. Moreover, validation by immunofluorenscence showed the co-expression of Ac-α-Tub/α-SMA and Ac-α-Tub/SP-A cells in rat lung tissue. Compared to control group, the expression level of collegan type I, α-SMA and HDAC6 was up-regulated in silicotic model, accompanied with lesser expression of Ac-α-Tub. Furthermore, Ac-SDKP posttreatment and pre-treatment groups could attenuate the levels of col I, α-SMA and HDAC6(P<0.05). The levels of α-SMA, HDAC6 and col I in Ang II-induced group were up-regulated to 1.66, 3.56 and 4.00 folds in control group, accompanied with downregulation of Ac-α-Tub in Ang II-induced group by 44.44%(P<0.05). Changes induced by Ang II could be inhibited by pre-treatment with Ac-SDKP, Valsartan and TCS HDAC6 20 b. 2 The HE staining results showed that lung histology of rat exposed to Si O2 dust changed the following pattern of “cellular nodules-cellular fibrous nodules-fibrousnodules”. The vimentin labeled macrophage can be seen in central part of silicotic nodule, encircled by α-SMA labeled myofibroblast, and there existed α-SMA positively expressed in macrophages occasionally. Ac-α-Tub showed the same expressional feature as it did in bronchial instillated rat silicotic model. 3 The expression and distribution of Ac-α-Tub, measured by immunohistochemistry, was positive in proximal convoluted tubules of UUO model and hepatic stellate cell of TAA-induced liver fibrosis model, which gradually increased over time. In other organs, such as esophagus, stomach and large intestine, Ac-α-Tub was distributed in nerve cells. And furthermore, Ac-α-Tub was interspersed in liver mesenchymal cells and splenic monocytes.Conclusions 1 Ac-SDKP stabilized the expression of Ac-α-Tub, inhibited collagen deposition and myofibroblast trans-differentiation via modulating AT1 and HDAC6. 2 The differential distribution of Ac-α-Tub in multiple fibrosis models differs from each other, which may have different pathogenesis mechanism and significance.