基于Akt/mTOR通路调控巨噬细胞自噬探讨溃疡性结肠炎伏毒学说的分子机制及清解伏毒法的干预效应

Ulcerative colitis is a kind of stubborn disease in digestive system, and the prevention of its relapse is a difficulty in the traditional Chinese and western treatment. On the basis of our clinical studies for many years, the “Pathogenic Fudu” theory of the ulterative colitis (UC) has been proposed, that is, the Right qi is insufficient, which leads to Fudu inside the human body, therefore, the UC breaks out repeatedly. According to relevant preliminary study, the clinical effects of “Qing jie fu du”method are relatively good since it can reduce the relapses, and there is certain correlation between the virus of “Fudu” and the inflammatory cytokines, but the deep mechanism has not been completely revealed. It is found out in the recent studies that autophagy is closely related to inflammatory bowel diseases, and its dysfunction is one of the major risk factors for chronicity of intestinal inflammation. A hypothesis is accordingly proposed: there is certain internal relation between the nature of UC “Fudu” and the autophagy. This topic starts from the pathogenesis of UC and macrophagic autophagy mediated by Akt /mTOR pathway, simultaneously examines the expression levels of key proteins of chronic relapsing type UC patients and rats such as Akt & mTOR in colonic mucosa tissues as well as related pheripheral blood cytokines, probes into the intervention effect of Tiao Chang Xiao Yan Pian as the prescription based on “Qing jie fu du” method on Akt/mTOR autophagy regulatory pathway and related cytokines, and illustrates the molecular biological mechanism of UC “Pathogenic Fudu” theory in terms of autophagy, thus providing new ideas for treating UC.

溃疡性结肠炎是消化系统疑难病，防止复发是中西医治疗难点。我们在多年临床研究的基础上提出溃疡性结肠炎（UC）“伏毒致病”学说，正气不足，伏毒在里，故反复发作。相关前期研究显示“清解伏毒”有较好的临床疗效，能减少复发，且“伏毒”之“毒”与炎性细胞因子存在一定相关性，但其深层次机制尚未完全揭示。新近研究发现细胞自噬与炎症性肠病密切相关，其功能障碍是肠道炎症慢性化的主要危险因素之一。据此我们提出假说：UC“伏毒”的本质与细胞自噬存在某种内在关联。本课题拟以Akt /mTOR通路介导的巨噬细胞自噬与UC的发病机制为切入点，通过同步检测慢性复发型UC患者和大鼠结肠黏膜组织Akt、mTOR等关键蛋白及外周血相关细胞因子的表达水平，探讨以“清解伏毒”法立方的调肠消炎片对Akt /mTOR自噬调控通路及相关细胞因子的干预作用，从细胞自噬方面阐释UC“伏毒致病”学说的分子生物学机制，为治疗UC提供新思路。

溃疡性结肠炎是消化系统疑难病，我们在多年临床研究的基础上提出溃疡性结肠炎（UC）“伏毒致病”学说，正气不足，伏毒在里，故反复发作。相关前期研究显示“清解伏毒”有较好的临床疗效，且“伏毒”之“毒”与炎性细胞因子存在一定相关性，但其深层次机制尚未完全揭示。我们基于巨噬细胞自噬及溶酶体功能调控，探索“清解伏毒”法立方的调肠消炎片可能的作用机制，阐释UC“伏毒致病”学说的分子生物学机制。.研究提示调肠消炎片能有效能降低UC患者的Mayo评分，显著促进UC模型大鼠结肠黏膜修复，能升高抑炎因子水平，降低促炎因子水平，抑制炎症反应。.机制研究方面，基于Akt/mTOR通路调控巨噬细胞自噬角度研究，我们发现调肠消炎片降低UC大鼠模型结肠组织LC3B的表达，但电镜下未能找到结肠组织巨噬细胞的自噬小体，提示调肠消炎片对巨噬细胞自噬的调控作用机制可能并非直接调控Akt/mTOR通路介导自噬小体的形成，而是通过调控结肠黏膜巨噬细胞溶酶体功能来实现的。.我们研究也证实调肠消炎片可减轻UC模型大鼠结肠黏膜组织中CD11c+巨噬细胞的浸润，减轻结肠黏膜炎症，其机制可能与调肠消炎片通过阻滞TLR9/MyD88/IRAK信号通路的信号传导，进而促进巨噬细胞内溶酶体活化有关。.同时调肠消炎片作用具有一定的剂量依赖性，随着用量的增加，结肠黏膜的CD11c+巨噬细胞的浸润显著减少，结肠黏膜炎症减轻。同时细胞实验也发现随着剂量增大，调肠消炎片阻滞TLR9/MyD88/IRAK信号通路，增强巨噬细胞内溶酶体活性，减少CD11c+巨噬细胞分化的作用越强。.综上，本项目研究证实调肠消炎片治疗UC具有良好的疗效，为其应用推广提供了依据。也初步阐明了调肠消炎片可通过促进或恢复结肠巨噬细胞溶酶体活化，进而促进结肠黏膜巨噬细胞活化及免疫监视功能从而发挥疗效。结直肠巨噬细胞溶酶体功能异常可能是UC“伏毒”的微观体现。