Paneth细胞ERS-IRE1/JNK通路对应激时CRH调控IBD肠道黏膜屏障功能的作用及机制研究

Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the colon and small intestine. The pathogenesis of IBD is not fully understood but it is suggested impaired intestinal barrier integrity plays a central role in the development of IBD. Our previous study showed acute stress could impair intestinal barrier, increase the intestinal permeability, and induce intestinal inflammation through CRH pathway. It is well known that Paneth cell is essential to the integrity of intestinal barrier, and it is reported that abnormal endoplasmic reticulum stress (ERS) - autophagy pathway of Paneth cell may contribute to the impaired intestinal barrier function. It has been noted that CRH could cause the decrease of number of IECs, and recently the findings of our study indicated the number and function of Paneth cell changed after acute stress, but the role of Paneth cell in regulating the reactivation of IBD during acute stress has not been studied yet. We speculate that CRH may influence the Paneth cell ERS- autophagy pathway and cause intestinal barrier dysfunction, and regulate the reactivation of IBD. In present study, we will use DSS and TNBS to induce colitis, then stress of water avoidance will be applied, and through RT-PCR, Western-Blot, ELISA as well as other molecular biology and morphology methods, we aim to determine the changes of CRH, Paneth cell ERS - autophagy pathway and related inflammatory cytokines, alteration of intestinal mucosal barrier and intestinal microflora. Overall the present study focuses on the role of CRH-Paneth cell ERS - autophagy pathway in the pathogenesis of IBD, and provide target for future treatment.

肠道屏障功能障碍是炎症性肠病(IBD)重要发病机制，本小组研究发现应激通过促肾上腺皮质激素释放激素(CRH)破坏肠道黏膜屏障、介导炎症形成。已知Paneth细胞对维持肠道屏障功能起关键作用，而Paneth细胞内质网应激(ERS)-自噬通路异常可造成肠道屏障功能受损。已知CRH可造成肠道上皮细胞减少，近期本小组研究证实Paneth细胞在应激后数量及功能改变，但Paneth细胞ERS-自噬通路在应激后IBD再激活中的作用尚无研究，我们推测CRH通过作用Paneth细胞ERS-自噬通路、引起肠道屏障功能障碍、调控IBD再激活。本研究在建立结肠炎模型后给予避水应激，以免疫荧光、RT-PCR、Western-Blot等方法观察CRH、Paneth细胞ERS-自噬通路及炎症因子的表达，肠道屏障功能及肠道微生态的变化，课题将明确干预CRH-Paneth细胞ERS-自噬通路是否可减少IBD的再激活。

研究背景：社会心理压力是炎症性肠病（inflammatory bowel diseases, IBD）的关键诱发因素，而自噬是可能参与IBD发生发展的新靶点。本课题旨在探讨应激是否通过自噬调节态促进炎症性肠病的发生发展。.研究方法：收集23名IBD患者的应激等临床信息、活检标本，确定应激与肠道自噬的相关性。 DSS建立IBD小鼠模型，CRH模拟应激刺激，LPS刺激骨髓来源的巨噬细胞（BMDM），采用分子实验技术评估自噬和肠道微生态等改变。同时应用氯喹和雷帕霉素在体内和体外阻断或诱导自噬。.研究结果：机体应激与IBD患者肠道的炎症呈正相关，且应激可显著提高IBD患者肠道组织的自噬水平。CRH可显着加重IBD小鼠肠道炎症、促进结肠Paneth细胞的化生、提高肠道自噬水平，并且CRH加剧了IBD小鼠肠道微生态的紊乱。在细胞水平，CRH显著提高M1 / M2极化的比例并加重肠道炎症。给予氯喹阻断自噬后，可以缓解CRH对IBD炎症的加重以及Paneth细胞的化生；给予自噬诱导剂雷帕霉素，进一步证明CRH通过诱导自噬参与对IBD的调控。.研究结论： CRH通过调节肠道自噬影响肠道微生物态并促进炎症的发展。本研究的数据显示自噬是心理社会应激相关IBD的有希望的治疗靶点，而针对自噬的相关研究和治疗手段有望成为对现有治疗方法的重要补充和发展。