NLRP3炎症小体在主动脉瓣钙化中的作用及机制研究

钙化性主动脉瓣膜病(CAVD)严重危害人类健康，目前缺乏有效的药物干预措施。NLRP3炎症小体作为炎症和细胞凋亡的重要调节因子，活化后可激活Caspase-1,促进IL-1β和IL-18成熟分泌，参与多种炎症相关性疾病。然而，目前未见NLRP3炎症小体与CAVD关系的报道。我们前期研究发现：钙化主动脉瓣中NLRP3炎症小体表达显著增加；NLRP3定位于瓣膜间质细胞和巨噬细胞；沉默NLRP3或Caspase-1可减轻瓣膜间质细胞钙化；IL-18可诱导瓣膜间质细胞成骨样分化和钙化，提示NLRP3炎症小体极有可能参与主动脉瓣钙化发生发展。本项目拟检测人体瓣膜标本、利用多种基因敲除小鼠，结合瓣膜间质细胞和巨噬细胞培养、干预，探讨NLRP3炎症小体在主动脉瓣钙化中的作用，重点研究其在瓣膜炎症、细胞凋亡、巨噬细胞表型分化与瓣膜间质细胞相互作用中的机制，为主动脉瓣钙化的发病机制和药物靶点研究提供新思路。

Calcific aortic valve disease (CAVD) is a common clinical problem with high morbidity and mortality, and to date there are no effective pharmacological interventions. As a key regulatory factor of inflammation and apoptosis, NLRP3 inflammasome promotes activation of caspase-1, resulting in the mature and secretion of IL-1β and IL-18. NLRP3 inflammasome has been implicated in the pathogenesis of various inflammatory diseases, however, the association between NLRP3 inflammasome and CAVD remains unclear. Our previous work found that calcified aortic valves had higher levels of NLRP3 components (NLRP3, ASC, Caspase-1) than that in normal valves, and NLRP3 located in both valvular interstitial cells and macrophages. Silencing NLRP3 or caspase-1 attenuated calcium deposits in cultured human valvular interstitial cells (VICs) and IL-18 induced osteogenic differentiation and calcification of VICs. These data implies that NLRP3 inflammasome is most likely involved in the pathogenesis of aortic valve calcification. In the present project, we try to explore the role of NLRP3 inflammasome in aortic valve calcification by means of human valve specimens, gene knockout mice as well as cell culture (valvular interstitial cells and macrophages). The emphasis will be focused on the effect of NLRP3 inflammasome on vavular inflammation, cell apoptosis, macrophage phenotype transition and its interaction with valvular interstitial cells. Our research will shed light on the pathogenesis of aortic valve calcification and provide the theoretical and experimental basis for drug interventions of CAVD.