诃子宁通过芳香烃受体通路抑制NF-κB活化拮抗实验性关节炎的分子机制研究

Rheumatoid arthritis is one of the most serious autoimmune diseases with high morbidity and disability. The NF-κB signaling pathway plays a key role in the pathogenesis of this disease. The pro-inflammatory factors can be reduced by inhibiting the NF-κB activity and result in alleviating the symptoms and reducing the morbidity. Terminalia chebula Retz is a widely used Tibetan medicine with an extensive range of biological activities which can be called as “the king of Tibetan medicines”. Previous studies had demonstrated that chebulanin (one of the active ingredients isolated from seeds of Terminalia chebula Retz) significantly alleviated the symptoms of collagen induced arthritis, which can be attributing to inhibit the NF-κB activity via aryl hydrocarbon receptor (AhR). Considering that AhR have multiple signaling pathways, we hypothesis chebulanin may promote the formation of AhR/RelA, AhR/p50/Stat1 complexes therefore competitive inhibit NF-κB activity. The Western blot, RT-PCR, Co-IP, Co focal, EMSA and BLI technologies will be utilized to clarify the molecular mechanism and figure out the potential target. Such study will make a contribution to the research and development of Terminalia chebula Retz and will also provide new strategies for the treatment of rheumatoid arthritis.

类风湿性关节炎是以发病率高、致残率高为主要特征的自身免疫性疾病。NF-κB信号通路在该病的发生发展中起关键作用；抑制NF-κB可有效降低促炎因子的表达，缓解症状及降低发生率。藏药诃子有“藏药之王”的称号，课题组前期从诃子中分离纯化其主要活性物质诃子宁，发现能显著缓解实验性关节炎，其作用主要通过芳香烃受体（AhR）介导从而发挥抑制NF-κB活性，结合AhR在细胞核内存在多条信号通路的特点，提出"诃子宁通过促进细胞核内AhR/RelA、AhR/p50/Stat1复合物形成进而抑制NF-κB活性的科学假设。本项目拟采用WB、RT-PCR、免疫共沉淀、激光共聚焦、EMSA以及生物膜层干涉测量等技术手段，从分子水平、细胞水平和整体动物水平阐明诃子宁通过AhR防治关节炎的具体分子机制和可能靶点。为将藏药诃子开发为抗类风湿性关节炎新药奠定基础，为类风湿性关节炎的治疗提供新思路和新策略。

类风湿性关节炎（Rheumatoid arthritis, RA）是一种以多关节滑膜炎、骨及软骨破坏为主要特征的全身性自身免疫性疾病。诃子是藏药中常用的一味药材，有“藏药之王”的称号。项目组前期从藏药诃子中提取分离得到单体化合物诃子宁，本项目旨在探讨诃子宁抗实验性关节炎的作用机制。研究通过以胶原蛋白诱导的小鼠关节炎模型为体内炎症模型，以LPS诱导的RAW264.7细胞炎症模型和IL-1β诱导的MH7A（类风湿关节炎成纤维样滑膜细胞）细胞炎症模型为体外模型，借助Western blot、Micro-CT、免疫共沉淀、EMSA等技术手段，证实了诃子宁防治实验性关节炎的作用效果，并验证了诃子宁可通过促进胞内AhR与p65结合，竞争性抑制AhR与ARNT结合发挥抗炎作用。此外，本项目还进一步阐明诃子宁还可通过抑制MAPK通路发挥抗炎作用。本项目使我们对藏药诃子及其有效成分诃子宁的抗关节炎作用有了更进一步的认知，为将诃子开发为安全有效的RA治疗候选药物奠定基础。