Histone Acetyltransferase Inhibitor C646 Reverses Epithelial To Mesenchymal Transition Of Human Peritoneal Mesothelial Cells Via Blocking TGF-?1/Smad3 Signaling Pathway In Vitro

Objective:Peritoneal fbrosis resulting from long-term peritoneal dialysis is a major cause of failure of peritoneal ultrafltration function and main reason of dropout from peritoneal dialysis. High sugar, peritonitis, etc are main reason of peritoneal fibrosis. Epithelial-mesenchymal transition(EMT) of peritoneal mesochelial cells(HPMCs) is a major contributor of peritoneal fbrosis. Recently, the association be- tween histone acetylation and kinds of fbrosis including liver, lung and kidney fbrosis is well established. Thus, in this study we tried to profle whether histone acetylation is also operates EMT process in HPMCs and what's the regulatory mechanism.Method:We treat peritoneal mesothelium cell as the research object. We established an EMT model of HPMCs through high glucose treatment, and treated with C646. We used CCK-8(Beyotime, China) to evaluate the proliferation. We used Western blotting analysis E-cadherin, ?-SMA, Collagen I, fibronection, Smad3, p-Smad3, TGF-?1, Acety-H3, Acety-H4 and ?-Actin. HAT activity was determined using HAT activity colorimetric assay kit. We used Quantitative real-time RT-PCR analysis the expression of p300 and GCN5. We used Chromatin immunoprecipitation(CHIP) assay and quantitative real-time polymerase chain reaction(QPCR) valuate the various signal level of target genes.Result:The expression of E-cadherin was significantly decreased and the expression of ?-SMA, Collagen I and fibronection were significantly increased in D-glucose treated cells. High glucose induced epithelial-to-mesenchymal transition(EMT) in human peritoneal mesothelial cells(HPMCs). An increase in histone H3 acetylation was found at high glucose treated groups in a dose-dependent manner. However, the histone H4 acetylation was not noticed. The HAT activity was increased in the presence of high glucose in cells. And the expression levels of p300 were significantly increased in high glucose treated cells. In high glucose-induced HPMCs, C646 treatment resulted in down-regulation of histone H3 acetylation. With high glucose along, the expression of TGF-?1 and p-Smad3 were significantly increased. However, after treatment with C646 in high glucose-treated cells, the over-expression of TGF-?1 and p-Smad3 were inhibited. The HAT inhibitor C646 blocks TGF-?1/Smad3 signaling in HG-induced HPMCs.Conclusion: 1. Highly acetylated H3 histone induces EMT of peritoneal fibrosis. 2. Histone H3 acetylation activated TGF-?1/Smad3 signaling during EMT of HPMCs, and C646 can rescue the mesenchymal phenotype transition.