基于MLCK/ROCK信号通路探讨艾灸对UC大鼠肠黏膜屏障损伤的预防和修复

Ulcerative Colitis (UC) is a chronic non-specific inflammatory bowel disease，which is rated as one of the stubborn disease by the WHO. The intestinal mucosal barrier dysfunction is considered to be the main factors for UC，increased epithelial cell permeability caused by damage of intercellular tight junction and intestinal mucosal inflammation are the key points for the barrier dysfunction. MLCK/ROCK signaling pathways has close relationship with intestinal mucosal permeability of epithelial cells and the intestinal mucosal inflammation. .Under the guidance of prevention theory of traditional Chinese medicine, the research aims to explore prevention and effect of different moxibustion and the regulating mechanism involved in the tight junction and intestinal mucosal inflammation from the point of increased epithelial cell permeability through the MLCK/ROCK signaling pathway. This study tries to elucidate the key points on the MLCK/ROCK signaling pathway for repair and protection of UC barrier dysfunction, and also tries to discuss the endogenous repair and protection mechanism of moxibustion for UC.

溃疡性结肠炎（UC）是一种慢性非特异性炎症性肠病，被世界卫生组织列为难治病之一。目前认为肠黏膜屏障功能障碍是UC发病的主要因素，肠黏膜上皮细胞间紧密连接破坏和肠黏膜炎症反应所致的肠黏膜上皮通透性增高，是导致肠黏膜功能障碍的关键环节。MLCK／ROCK信号通路与肠黏膜通透性、上皮细胞间紧密连接、肠黏膜炎症密切相关。本研究以艾灸有效病症UC为载体，基于中医“治未病”理论，以MLCK／ROCK信号通路异常激活介导肠黏膜通透性改变为切入点，探讨不同灸法对UC肠黏膜屏障损伤的预防和治疗效应，以及不同灸法防治UC肠黏膜屏障损伤，改善肠黏膜上皮细胞间紧密连接，缓解肠黏膜炎症的作用机制，阐释艾灸通过调节MLCK／ROCK信号通路改善UC肠黏膜屏障功能的关键靶点，揭示艾灸对UC肠黏膜屏障损伤的内源性修复作用和保护机制。

溃疡性结肠炎（UC）是一种病因未明的慢性非特异性炎症性肠病,艾灸疗法具有疗效优势。近年来肠黏膜屏障功能障碍被认为是UC发病的主要因素。本项目拟观察和比较隔药灸和温和灸对正常和UC大鼠的效应及差异。在艾灸对UC大鼠肠黏膜屏障内源性修复效应的基础上，以MLCK／ROCK信号通路异常激活所致肠黏膜通透性改变为切入点，通过观察不同灸法在疾病发生前后不同时机干预对该通路相关蛋白、肠黏膜屏障通透性相关调控蛋白以及肠黏膜炎症因子的调节作用，拟探讨艾灸对UC肠黏膜屏障内源性修复和保护作用机制。结果显示：1）隔药饼灸及温和灸均可下调UC大鼠结肠组织、肌球蛋白II、MLCK、ROCK蛋白表达，上调UC大鼠结肠组织TGF-β、JAM、MUC2蛋白表达。温和灸还可以下调UC大鼠结肠组织肌球蛋白II mRNA、ROCK mRNA表达，上调UC大鼠结肠组织occludin mRNA表达。2）经隔药灸和温和灸预处理后，两种灸法均可下调UC大鼠结肠组织TNF-α、肌球蛋白II、MLCK、ROCK蛋白表达，上调UC大鼠结肠组织JAM、MUC2、occludin、claudin和ZO-1蛋白表达；温和灸预处理还可以下调UC大鼠结肠组织MLCK mRNA表达。综上所述，MLCK／ROCK信号通路异常激活与UC发病密切相关，艾灸能有效调节UC大鼠肠黏膜屏障紧密连接相关蛋白的表达，增强对肠黏膜屏障的保护作用，同时减少促炎因子TNF-α、IFN-γ及增加炎症修复因子TGF-β的表达，减轻UC炎症反应；隔药灸预处理、温和灸预处理均能升高大鼠肠黏膜屏障相关蛋白的表达，并能降低肠黏膜组织中炎症因子的表达，两种艾灸预处理的方法在保护肠黏膜屏障和降低炎症反应中并无明显差异，表明艾灸预处理可能通过预防肠黏膜屏障中相关蛋白的破坏，保护和维持肠黏膜屏障的完整性和通透性来抑制UC的炎症反应。