SIRT1调控HMGB1-NLRP3环路减轻退行性主动脉瓣膜钙化机制研究

衰老是钙化性主动脉瓣膜病（CAVD）的重要诱因，但机制不明。去乙酰化酶SIRT1通过调控蛋白乙酰化水平在细胞生长和衰老中发挥关键作用。我们前期发现：①CAVD患者和衰老ApoE-/-小鼠钙化瓣膜中SIRT1表达降低；②SIRT1激活剂白藜芦醇可抑制瓣膜炎症，减轻钙化；③Co-IP显示SIRT1可与HMGB1结合；④沉默瓣膜间质细胞（VICs）中SIRT1，促进HMGB1分泌及NLRP3炎症小体活化。鉴于此，我们推测：衰老导致SIRT1表达及活性下降，促使HMGB1乙酰化增加并分泌至细胞外，进而激活HMGB1-NLRP3炎症环路，促进主动脉瓣膜钙化。本项目利用人体瓣膜标本、SIRT1敲除/过表达小鼠主动脉瓣膜钙化模型、VICs钙化模型及免疫沉淀、蛋白质谱等技术，研究SIRT1调控VICs衰老与HMGB1-NLRP3环路介导的炎症反应在CAVD中的作用机制，为防治CAVD提供新的理论依据。

Aging is an important inducement of calcified aortic valve disease (CAVD), however, the mechanism is unknown. SIRT1 deacetylase plays an key role in cell growth and senescence by regulating the acetylation of substrates. Our previous experiments showed that ① SIRT1 level was decreased in calcified valves of CAVD patients and aged ApoE-/- mice, ② SIRT1 activator resveratrol could inhibit valve inflammation and alleviate calcification in ApoE-/- mice,③ Immunoprecipitation showed that SIRT1 could physically bind to HMGB1, ④ Knockdown of SIRT1 in valvular interstitial cells (VICs) promoted HMGB1 secretion to extracelluar space and NLRP3 inflammasome activation. Given the above results, we hypothesized that aging leaded to decreased expression and activity of SIRT1, which resulted in acetylation of HMGB1 and secretion into the extracellular space, thereby activated the HMGB1/NLRP3 inflammatory loop and aggravated aortic valve calcification. The present study takes advantage of human valve specimens, SIRT1 knockout/transgenic mice aortic valve calcification model, VICs calcification model as well as immunoprecipitation, protein profiling and other techniques to elucidate the effect of SIRT1 on VICs senescence and HMGB1-NLRP3 loop mediated VICs inflammation in aortic valve calcification, aiming to provide theoretical basis for the prevention and treatment of CAVD.