基于MSP/RON通路探讨桂皮醛抑制破骨细胞活化干预类风湿性关节骨破坏的作用机制研究

关节骨破坏是类风湿性关节炎（RA）的主要病理特征，其危害极大。RA归属于中医痹症，温经通脉治疗可显著改善RA患者的症状。我们的前期结果提示，桂枝的主要成分桂皮醛具有抗炎作用并可显著改善RA关节软骨的破坏；生物信息学预测确定桂皮醛与促进破骨细胞活化的巨噬细胞刺激蛋白MSP高度相关，酪氨酸激酶受体RON特异性表达在成熟破骨细胞表面，MSP是RON目前已知的唯一配体；经实验发现桂皮醛可抑制体外MSP诱导的骨吸收。因此，我们推测桂皮醛可靶向调控MSP/RON信号通路抑制破骨细胞活化。本项目拟在动物模型中以影像学、骨组织计量学等手段系统评价桂皮醛对炎性环境下关节软骨及骨组织的保护作用，结合体外骨陷窝实验等证实其抑制破骨细胞活化的作用，借助免疫共沉淀、免疫荧光及表面等离子体共振等技术系统阐明桂皮醛对MSP/RON的调控机制。为探索RA关节骨破坏防治的新途径和发展新型的RON靶向抑制剂提供实验依据。

Rheumatoid arthritis (RA) is a complex multi-system inflammatory disorder characterized by progressive joint destruction. Recent studies have revealed that osteoclasts are involved in the pathogenesis of bone destruction in RA and considered as a potential therapeutic target of the disease. Recently, it was demonstrated the role of macrophage-stimulating protein (MSP) and its receptor, RON tyrosine kinase in the signal pathway of osteoclast activation. Ramulus Cinnamomi, a traditional Chinese herb is widely recognized for their various applications in the medicine based on its antioxidant, antipyretic, anti-inflammatory, and antineoplastic activities. Cinnamaldehyde has been extensively investigated and considered to be the characteristic active constituents of Cinnamomi cassia. Guided by the results of bioinformatics predictions, we proposed the therapeutic potential of targeting MSP in RA using cinnamaldehyde. Our preliminary results provide compelling evidence that cinnamaldehyde could significantly reduce the damage of articular cartilage in Collagen induced arthritis (CIA) animal model. We have also observed that blockade of MSP-induced osteoclast activity reduces bone resorption in vitro. These data lead to our hypothesis that cinnamaldehyde can inhibit osteoclast activation by regulating MSP/RON signaling pathway. .In this study, we plan to systematically assess the effect of cinnamaldehyde on preventing articular cartilage and bone damage in inflammatory environment by MRI, micro-CT and bone histomorphometry in CIA animal models. We investigate the regulation of MSP/RON signaling pathway by cinnamaldehyde using western blot and immunofluorescence. In addition, we will explore the mechanisms of action of cinnamaldehyde–protein interactions by surface plasmon resonance and immunoprecipitation. Our study will provide a potential selectively inhibitor of Ron target for therapeutic of RA bone resorption.