B细胞活化因子在类风湿关节炎FLS炎性变中作用与机制研究

The abnormal proliferation, over-activation and secretion of high levels of inflammatory factors of Fibroblast-like synoviocytes (FLS) are closely involved in the occurrence and development of rheumatoid arthritis (RA) synovitis. Our group found that FLS can secrete BAFF and also express BAFF-R. B cell-activating factor of the TNF family (BAFF) is an important factor regulating the development, proliferation and activation of B cells, which can activates TRAF / NF-κB signaling via BAFF-R to regulate immune cell proliferation and activation. BAFF overexpression is closely relatedwith RA disease activity and local joint damage. Whether is BAFF involved in FLS inflammatory process? Whether is BAFF involved in FLS inflammatory process through the BAFF-R / TRAF / NF-κB signaling pathways? It has not been reported. Experimental joint mouse models will be established with DBA/1 mice and BAFFR - / + knockout mice. Then to reveal that the molecular mechanism of BAFF involving in FLS inflammatory changes in vivo and vitroby cell flow cytometry, Transwell method and gene silencing technology and further reveal the pathological mechanism of RA and provide a theoretical basis to find a new target for drug.

成纤维样滑膜细胞（FLS）异常增殖、过度活化和分泌高水平炎症因子等密切参与类风湿关节炎(RA)滑膜炎的发生发展。本课题组发现FLS可分泌B细胞活化因子（BAFF）并表达其受体BAFF-R。BAFF过表达与RA疾病活动度及局部关节受损密切相关。BAFF是调控B细胞发育、增殖、活化的重要因子，其可通过BAFF-R激活TRAF/NF-κB信号通路调控免疫细胞增殖活化。那么BAFF是否参与FLS炎性变过程？BAFF是否通过BAFF-R/TRAF/NF-κB信号通路参与FLS炎性变过程？目前国内外未见文献报道。本项目拟采用DBA/1小鼠和BAFFR-/+基因敲除小鼠，建立实验性关节小鼠模型，利用细胞流式术、Transwell法和基因沉默等技术，在体内外揭示BAFF参与FLS炎性变的分子机制，为进一步揭示RA病理机制，发现药物新靶点提供理论依据。

成纤维样滑膜细胞(FLS)在类风湿关节炎(RA)的发病机制中起重要作用。B细胞活化因子(BAFF)已被发现在调节B细胞的发育、增殖和活化中发挥重要作用。FLS可分泌BAFF，也可表达BAFFR。然而，BAFF是否促进FLS的功能还不清楚。本课题研究了BAFF和BAFF信号分子在RA-FLS和佐剂性关节炎（AA）-FLS中的表达，BAFF对FLS功能的影响以及BAFF诱导FLS功能的机制。本研究采用高内涵法检测FLS增殖，Transwell法检测了FLS的迁移能力，免疫荧光法检测了FLS中BAFFR的表达。Western blot法检测了BAFF信号分子的表达。结果表明，与对照组相比，BAFFR在RA/AA-FLS中的表达水平较高，信号分子TRAF2、NIK、P100和P52在RA/AA-FLS中的表达水平较高，TRAF3表达水平较低。BAFF促进了FLS增殖，上调FLS中BAFFR、TRAF2、NIK、P-IKKa、IKKa、P100和P52分子的表达，下调TRAF3分子的表达水平。同时，BAFFR- siRNA抑制了FLS的增殖和BAFF诱导的NF-κB信号通路的激活。由此，我们认为BAFF可能是通过BAFF介导的NF-κB信号通路促进FLS活化而发挥作用，这将有助于揭示RA的病理机制。这些结果可能为RA治疗新药的开发提供科学依据。