胞内氯离子通道蛋白调控NLRP3炎症小体活化的机制研究

The activation of NLRP3 inflammasome is responsible for the maturation and release of proinflammatory cytokines, such as interleukin 1β (IL-1β) and IL-18. So NLRP3 inflammasome plays critical role in host defense and is involved in the pathogenesis of various inflammatory diseases. Due to the diverse characteristics and structures of the agonists that activate NLRP3 inflammasome, how NLRP3 inflammasome is activated is not clearly understood. The present study suggests that the disturbance of the intracellular ion homeostasis is essential for the activation of NLRP3 inflammasome. Our previous studies found that inhibition of the activity or expression of CLICs can significantly suppress NLRP3 inflammasome activation and interleukin-1β secretion. Mechanistically, we found that the agonists induced chloride efflux and subsequent NLRP3 inflammasome activation, which is mediated by CLICs. Furthermore, we will investigate the potential cellular and molecular mechanisms of chloride efflux induced NLRP3 inflammasome activation. Also, we will study the role of CLICs in the pathogenesis of several NLRP3 inflammasome associated inflammatory diseases through animal experiment.

NLRP3炎症小体活化后介导炎性细胞因子，如IL-1β和IL-18的成熟与分泌，其对于机体抵抗病原微生物感染至关重要。同时NLRP3炎症小体的过度活化与许多炎症性疾病的发生发展息息相关。由于活化NLRP3炎症小体的激动剂多种多样且特征和结构各异，因此NLRP3炎症小体的活化机制目前并不十分明确。已有研究表明，胞内离子平衡的打破对NLRP3炎症小体的活化至关重要。我们前期的研究显示抑制胞内氯离子通道蛋白(CLICs)的活性或降低其蛋白表达可显著抑制NLRP3炎症小体的活化及其介导的IL-1β分泌。进一步机制探究表明NLRP3激动剂通过CLICs介导胞内氯离子的外流进一步促进NLRP3炎症小体的活化。接下来，我们将在细胞和蛋白质分子水平对胞内氯离子外流活化炎症小体的具体分子机制展开研究，并在整体动物水平探究胞内氯离子通道蛋白介导NLRP3炎症小体活化的疾病相关性。

胞内离子的平衡对于NLRP3炎症小体的活化至关重要。有研究表明氯离子外流可能有助于激活NLRP3炎症小体，但氯离子通道和氯离子外流调节NLRP3炎症小体活化的具体机制尚不清楚。本课题致力于探究胞内氯离子通道蛋白（CLICs）介导的氯离子外流在NLRP3炎症小体组装和活化过程中所起的作用。首先，我们发现NLRP3炎症小体的活化依赖于胞内氯离子通道蛋白（CLICs），降低CLICs的蛋白表达或抑制其活性可显著抑制NLRP3炎症小体的活化及其介导的Caspase-1的激活和IL-1β分泌。进一步发现，线粒体ROS的上调促进CLICs转移到细胞膜，介导胞内氯离子的外流，进一步促进NEK7-NLRP3的相互作用与NLRP3炎症小体的组装。另外，CLICs对MSU诱导的小鼠急性腹膜炎起重要作用。我们的数据表明，CLICs所介导的氯离子外流位于钾离子外流和线粒体ROS产生的下游，介导NLRP3炎症小体的活化。本课题的研究不仅有助于解释CLICs的功能机制，阐明NLRP3炎症小体激活的相关调控机制，而且有利于明确炎症相关重大疾病的发病机制，为炎症相关疾病的治疗提供新的治疗靶点和策略。