RhoA调控系统性红斑狼疮I型干扰素通路异常活化的机制研究

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by abnormal activation of type I interferon (IFN) pathway，which results in tissue inflammation and organ damage. Our previous studies have found that RhoA, a member of the Rho-GTPases family, displayed significantly higher levels in the peripheral blood cells of SLE patients than healthy controls, was positively correlated with IFN score,SLE disease activity index(SLEDAI)score and parameters of degree of renal injury(Renal-SLEDAI score)in the patients with SLE. We hypothesize that overexpression of RhoA might lead to pathogenic activation of IFN pathway,but the specific regulatory mechanism is still unknown.In this project,we will use transcriptional regulation,signal transduction and molecular interations studies, combined with the study of clinical biological samples to demonstrate the function of RhoA. We expect to explore the molecular regulatory mechanism of RhoA in type I IFN pathway and the effect of intervention RhoA and RhoA/ROCK signaling pathway on type I IFN pathway activation. This project, for the first time, identifies the role of RhoA in type I IFN pathway of SLE disease. The expected results of this project will contribute to a better understanding of RhoA involved in SLE and provide a new direction for understanding the pathogenesis of SLE and developing novel therapeutic strategy.

系统性红斑狼疮（SLE）是一类多脏器受累的自身免疫性疾病，以I型干扰素（IFN）通路异常活化为主要特征。我们前期的研究发现RhoGTP酶家族成员RhoA在SLE患者的外周血中显著上调，与反映疾病活动度SLEDAI积分、肾脏损害程度SLEDAI-LN积分及IFN积分呈明显正相关，我们推测RhoA可能参与SLE患者I型干扰素信号通路的异常活化，影响狼疮的疾病活动及肾脏损害，但相关的调控机制尚不明确。本项目拟通过转录调控、信号传导及分子相互作用的研究，结合临床生物样本的分析，阐明RhoA调控系统性红斑狼疮I型干扰素信号通路异常活化的分子机制，并探讨干预RhoA或使用RhoA/ROCK通路抑制剂对I型干扰素信号通路活化的影响。本研究项目将有助于更好的理解RhoA参与SLE疾病发生的分子机制，为发展新的红斑狼疮治疗靶点和防治措施提供新的方向。

背景：系统性红斑狼疮(SLE)是一种以I型干扰素(IFN)通路异常激活为特征的自身免疫性疾病，导致组织炎症和器官损伤。我们探索了RhoA GTPase在I型IFN激活通路中的作用，为靶向GTPase信号通路治疗SLE提供了潜在的基础。.研究内容：从SLE患者和健康对照组的外周血单个核细胞(PBMCs)中提取总RNA，采用SYBR Green定量逆转录-聚合酶链反应检测RhoA和IFN诱导基因的mRNA表达水平。通过IFN刺激反应元件(ISRE)-荧光素酶报告基因检测和Western blotting评价RhoA的生物学功能。酶联免疫分析法(ELISA)检测C-X-C基序趋化因子配体10(CXCL10)蛋白表达。.结果：我们的研究表明，RhoA在SLE患者外周血单核细胞中的表达明显高于健康对照组，并与I型IFN评分和I型IFN刺激基因(ISGs)表达水平呈正相关。siRNA介导的RhoA的敲除和RhoA/ROCK抑制剂Y27632降低了I型IFN诱导的ISRE的活性、STAT-1磷酸化以及CXCL10和(OAS1的表达。最后，我们证实Y27632可显著下调SLE患者外周血单核细胞中OAS1和CXCL10的表达水平。.结论：我们的研究表明RhoA正调控I型IFN反应通路的激活。降低RhoA的表达水平可抑制I型IFN系统的异常激活，RhoA/ROCK抑制剂Y27632可降低SLE PBMCs中异常的I型IFN信号，提示靶向RhoA GTPase治疗SLE的可能性。