干扰素调控NLRP3参与系统性红斑狼疮发生的作用机制研究

In our previous work, we found NLRP3 inflammasome components were significantly down-regulated in the peripheral blood mononuclear cells of systemic lupus erythematosus (SLE) patients, and their expression were negatively correlated with SLE disease activities. Interestingly, we also found decreased expression of NLRP3 inflammasome was associated with increased expression of interferon (IFN). Recently, researchers have focused on the study of NLRP3 activation. However, little is known about its negative regulation. Our previous work suggests that interferon might down-regulate NLRP3 in SLE. In the current project, we will firstly verify the interferon signal pathway on the regulation of NLRP3 in cultured mononuclear cells of SLE patients. We will further explore its role in SLE pathogenesis using pristane-induced SLE mice. Finally, we will discuss the predicting role of IFN/NLRP3 relating to SLE disease activities and therapy response. With the study on SLE patient blood and kidney samples, as well as gene knockout mouse models, we are trying to elucidate the signal pathway of IFNα/β on the negative regulation of NLRP3 in SLE pathogenesis. Moreover, we will explore the molecular mechanism of IFNλ1 on the regulation of NLRP3 for the first time. Completion of this project will provide a new way for the mechanism study of NLRP3 regulation.

我们前期研究发现NLRP3炎性体在SLE患者外周血单个核细胞表达明显降低，且表达水平与病情活动性负相关。同时发现NLRP3炎性体各组分低表达与Ⅰ型干扰素高表达密切相关。NLRP3炎性体的活化机制研究是目前的研究热点，但缺乏NLRP3负向调控的机制研究。我们推测可能存在干扰素抑制NLRP3活化的机制参与SLE的发生。本项目拟分离SLE患者外周血单核细胞，体外验证干扰素负向调控NLRP3炎性体的分子机制；继而通过敲基因小鼠狼疮诱导模型探讨干扰素负向调控NLRP3在SLE发生中的作用；最后探讨IFN/NLRP3炎性体在狼疮病情进展和治疗反应中的意义。我们将从SLE 患者临床外周血和肾活检标本、敲基因小鼠狼疮诱导模型等方面设计实验，进一步明确Ⅰ型干扰素（IFNα/β)调控NLRP3的信号通路，并首次探讨IFNλ1调控NLRP3的分子机制。本研究有望为NLRP3调控机制研究提供新思路。

NLRP3炎性小体在自身免疫性疾病中占有重要地位，然而NLRP3在系统性红斑狼疮（SLE）发病与进展中的作用机制不明。本研究通过对SLE患者外周血单个核细胞（PBMC）与MRL/lpr狼疮小鼠肾组织进行检测，发现NLRP3在SLE中低表达，并很可能受I型干扰素的负向调控。进一步研究表明，NLRP3在SLE患者CD14+单核细胞低表达，基于WGCNA、GO富集分析和免疫荧光共定位发现NLRP3很可能通过竞争结合HSP70，抑制HSP70介导的CAM（分子伴侣介导的自噬）活性，降低LAMP2A标记的溶酶体活性及其自身抗原提成能力。NLRP3的缺失在SLE发病过程中发挥重要作用。此外，我们基于二代测序技术与VarScan、GATK分析平台检测了SLE合并股骨头坏死（osteonecrosis of the femoral head；ONFH）的遗传背景倾向，结果表明CR2、NOS3、COL2A1基因单核苷酸变异可能参与发病，对于SLE合并股骨头坏死的筛查具有一定的指导意义。另外，我们初步探索了CXCL16在肺泡上皮细胞中的表达以及CXCL16在肺纤维化中调节上皮间质转化通路(epithelial-mesenchymal transition, EMT)的作用，结果证实CXCL16可通过TGF-β1/Smad3信号通路促进EMT过程，从而促进肺纤维化。为肺纤维化的治疗提供潜在靶向位点。