GSDMD打孔诱导滑膜成纤维细胞焦亡在类风湿关节炎发病机制中的研究

Rheumatoid arthritis (RA) synovial fibroblasts (FLS) play a key role in the development of RA through regulating the secretion of inflammatory cytokines, cartilage degradation and bone erosion. However, the mechanism behind is still unknown. Previous studies have reported that GSDMD mediated cell pyroptosis can induce severe inflammation and stimulate the other cells to proliferate. One of the traditional upstream pathways of pyroptosis is inflammasome NLRP1, which has been proved play a key role in the pathogenesis and synovial inflammation of RA. Our study showed that pyroptosis did exist in RA joint, and the expression of both gene and protein level of inflammasome/pyroptosis was significantly higher than osteoarthritis. Moreover, TNF-α can increase the pyrotosis. So we hypothesized that GSDMD mediated pyrotosis can participate the proliferation, proinflammation and bone destruction of FLS. In this study, we plan to perform clinical study, FLS functional experiments after treated the FLS of RA with lentivirus or moleculr inhibitors, and finally, we want to use lentivirus to knockdown the genes of pyrotosis pathway in CIA mice, to evaluate the suppressive effect on joint inflammation and bone destruction. We aim to explore the mechanism of GSDMD mediating FLS pyrotosis and provide new evidence for pyrotosis-targeting therapy in RA.

类风湿关节炎(RA)滑膜成纤维样细胞(FLS)通过其促炎及骨破坏作用参与RA发病,但其机制尚不清楚。研究表明，GSDMD介导的细胞焦亡可以激发强烈的炎症反应，同时刺激其他细胞增殖；炎症小体是细胞焦亡经典的上游途径，而炎症小体NLRP1在RA发病及滑膜炎症中作用已被证实。前期工作发现，RA患者关节局部存在焦亡，炎症小体/焦亡通路相关基因及蛋白表达均高于骨关节炎，TNF-α可以诱导FLS焦亡增多。由此我们提出: 在RA中，GSDMD在NLRP1的作用下可以诱导FLS焦亡参与关节炎症及骨破坏，同时促进其他FLS增殖。本课题拟通过临床研究、应用慢病毒转染以及小分子抑制剂等来处理RASFs，观察细胞异常增殖、促炎及骨侵蚀情况；最后通过CIA小鼠转染慢病毒，观察阻断焦亡通路对小鼠关节炎及骨破坏的抑制效应。本课题旨在探讨GSDMD通过诱导细胞焦亡参与RA中FLS异常增殖、促炎及骨破坏的机制。

类风湿关节炎滑膜成纤维样细胞(RASFs)通过其促炎及骨破坏作用参与RA发病，但其机制尚未被完全阐明。. 本研究通过临床、细胞及干预研究，采用免疫荧光染色、ELISA、Western-blot、realtime-PCR、细胞迁移、侵蚀试验等方法证实，RA的滑膜组织中存在细胞焦亡NLRP1/caspase-1/GSDMD通路，且焦亡水平显著高于骨关节炎滑膜成纤维细胞（OASFs）。干扰焦亡通路关键蛋白GSDMD可一定程度上抑制焦亡的发生，进而抑制RASFs的迁移及侵袭能力。进一步研究发现，JAK抑制剂巴瑞替尼可以通过抑制NLRP1/caspase-1/GSDMD焦亡通路并抑制RASF促炎、迁移和侵袭功能，并具有浓度依赖性。. 本研究阐明了焦亡通路参与了RASF的促炎、迁移及侵袭能力。通过抑制焦亡通路亦可一定程度上抑制RA的炎症。同时对巴瑞替尼治疗RA的作用机制进行了完善和补充。