DBC1对RA成纤维样滑膜细胞活化、凋亡和侵袭的调控及其机制研究

Abnormal activation, apoptosis and invasion of synoviocytes play a crucial role in the pathogenesis of rheumatoid arthritis (RA), however, the precise mechanism in regulating this cellular process is still unclear. Recent evidences show that deleted in breast cancer 1(DBC1) is involved in the manipulation of inflammatory response, apoptosis and tumor metastasis through SIRT1 and NF-κB signaling. Our previous work demonstrated that DBC1 was related to immune regulation, also highly expressed in RA synovium and fibroblast-like synoviocytes (FLS), positively correlated to synovial inflammation, suggesting that DBC1 may participate in the pathogenesis of RA. We will collect more samples to analyze the association between synovial expression of DBC1 and RA clinical profiles, and try to know whether DBC1 can regulate activation, apoptosis and invasion depending on SIRT1 and NF-κB signaling through Dbc1 gene silencing in RA-FLS in vitro. Meanwhile Dbc1 knockout mice have been constructed. Compared to Dbc1 wild-type mice, the synovitis and joint erosion may be ameliorated in collagen induced arthritis in Dbc1 knockout mice. Our study will clarify the regulation of synovitis and joint erosion in RA by DBC1. Therefore, we would provide the evidence of new target for the treatment of RA.

滑膜细胞异常活化、凋亡和侵袭在类风湿关节炎（RA）发病中起关键作用，但其调控机制尚不明确。最新研究发现乳腺癌缺失基因1(DBC1)通过SIRT1和NF-κB信号通路调控炎症反应、细胞凋亡和肿瘤转移。本项目前期研究发现DBC1不仅与免疫调节相关，还在RA滑膜组织和成纤维样滑膜细胞(FLS)高表达，并与滑膜炎症相关，提示DBC1可能参与RA发病过程。本项目拟进一步扩大临床样本，分析RA滑膜组织DBC1表达水平与临床表型的相关性；通过体外干预DBC1表达，探究DBC1对RA-FLS活化、凋亡和侵袭的调控作用及与SIRT1和NF-κB信号通路的关系；在已成功建立的Dbc1基因敲除小鼠模型基础上，观察Dbc1基因敲除对胶原诱导性关节炎小鼠滑膜炎症和关节损害的改善作用；深入研究DBC1对RA滑膜炎和关节破坏的调控作用及机制，为研制RA治疗新靶点提供理论依据。

类风湿关节炎(RA)是一种高度致残性的自身免疫性疾病，成纤维样滑膜细胞(FLS)导滑膜炎症、软骨和骨破坏是RA发病的关键，但其调控机制尚不明确。最新研究发现乳腺癌缺失基因1(DBC1)调控炎症反应、细胞凋亡和肿瘤转移。本项目旨在研究DBC1在RA滑膜炎症病理机制中的作用，以探索潜在的RA治疗新靶点。本课题首先采用免疫组织化学分析了RA滑膜组织DBC1表达水平；采用细胞流式术、免疫荧光共聚焦、蛋白印记(WB)检测RA-FLS细胞DBC1表达水平；我们证实DBC1在RA滑膜组织和FLS细胞高表达，TNF-α可促进RA-FLS细胞DBC1mRNA表达水平升高。采用siRNA方法，下调DBC1表达，可抑制RA-FLS细胞活化，产生白介素(IL)-8和IL-6下降；下调DBC1表达，RA-FLS细胞迁移能力下降，可能与RA-FLS细胞分泌基质金属蛋白酶(MMP)15下降，金属调控转录因子-1(MTF-1)产生增多有关。采用牛胶原诱导性关节炎(CIA)的方法制备关节炎动物模型，发现与Dbc1+/+DBA1/J小鼠相比，Dbc1-/-DBA1/J小鼠关节炎症和症状减轻，提示Dbc1基因敲除可延缓CIA关节炎发作，减轻滑膜炎症，抑制软骨、骨破坏。本课题阐明了DBC1参与关节滑膜炎症、关节破坏的分子机制，从而为RA的发病机制研究以及治疗靶点提供新的思路。