Microbiota in Intestinal Fibrosis

项目总结 该项目提出了一个全面的五年指导研究发展计划，并过渡到 独立。研究计划调查严重的肠道纤维化和狭窄的临床问题。 炎症性肠病(IBD)的形成。它探索了一种全新的概念，即 肠道间充质细胞是主要的促纤维化细胞类型，在体外和体内的细菌成分。我们 发现人类肠道肌成纤维细胞对细菌感知模式识别的激活做出反应 受体，但只有鞭毛增加细胞外基质(ECM)成分纤维连接蛋白和 这种反应是转录后调节的，并依赖于caspase 1，这意味着 肠纤维化中的炎症体。因此，我们建议探索以下假设：肠道 微生物区系通过鞭毛蛋白介导的途径诱导肠道纤维化。这一假设将是 通过三个相互关联但独立的特定目标进行测试：(1)定义鞭毛蛋白的机制- 体外诱导细胞外基质分泌的转录后调节(2)确定鞭毛蛋白的作用 人原代间充质细胞促纤维化反应中介导的炎性小体激活 (3)探讨鞭毛信号在实验性肝纤维化中的作用。 活体期间诱导和消退肠纤维化。转录后调控和 通过caspase1激活炎性小体是肠纤维化的两种完全原始的机制。我们将使用 尖端转基因小鼠模型，可控制体内细菌传感缺失的时间 尤其是间充质细胞。这使得能够探索微生物传感在预防和 肠纤维化的消退。这项研究将在勒纳的菲奥奇医学博士的实验室进行 克利夫兰临床研究所(LRI)，并将由一个国际专家小组在人类和 实验性肝纤维化、翻译调控和微生物区系。咨询小组已经制定了一项 有组织的职业发展计划，包括微生物学、翻译法规方面的正式课程 和统计数据。LRI在当地建立了理想的智力和技术环境。我的职业目标是 建立和领导一个独立的研究计划，以促进科学知识和患者护理 肠纤维化领域。我以前在人体细胞系统和动物模型方面的经验给了我 成为成功的K08获奖者的理想基础。这项拟议的研究将为直接 微生物区系在肠间充质细胞诱导的纤维化和狭窄形成中的作用。这些 这些发现可能导致一种全新的针对微生物区系的方法，作为一种治疗策略 消除纤维化。

PROJECT SUMMARY This project proposes a comprehensive five-year mentored research development program with transition to independence. The research plan investigates the severe clinical problem of intestinal fibrosis and stricture formation in inflammatory bowel diseases (IBD). It explores the entirely novel concept of a direct effect of bacterial components on intestinal mesenchymal cells, the chief pro-fibrotic cell type, in vitro and in vivo. We found that human intestinal myofibroblasts respond to activation of bacterial sensing pattern recognition receptors, but only flagellin increases secretion of the extracellular matrix (ECM) components fibronectin and collagen 1. This response is post-transcriptionally regulated and dependent on caspase 1, implicating the inflammasome in intestinal fibrosis. Therefore, we propose to explore the following hypothesis: the gut microbiota induces intestinal fibrosis through a flagellin mediated pathway. This hypothesis will be tested through three interrelated, but indepedent specific aims: (1) to define the mechanisms of flagellin- induced post-transcriptional regulation of ECM secretion in vitro (2) to determine the role of flagellin mediated inflammasome activation in the pro-fibrogenic responses in primary human mesenchymal cells in vitro and (3) to explore the effect of abrogating flagellin signaling in experimental fibrosis in vivo during induction and resolution of intestinal fibrosis. Post-transcriptional regulation and inflammasome activation via caspase 1 are two entirely original mechanisms of intestinal fibrosis. We will use a cutting edge transgenic mouse model that allows control of the timing of deletion of bacterial sensing in vivo specifically in mesenchymal cells. This enables exploration of microbial sensing in the prevention and resolution of intestinal fibrosis. The research will be carried out in the laboratory of Dr. Fiocchi MD, Lerner Research Institute (LRI), Cleveland Clinic, and will be advised by a panel of international experts in human and experimental fibrogenesis, translational regulation and the microbiota. The advisory panel has worked out a structured career development program, including formal coursework in microbiology, translational regulation and statistics. An ideal intellectual and technical environment is in place locally in the LRI. My career goal is to build and lead an independent research program that will advance scientific knowledge and patient care in the field of intestinal fibrosis. My prior experience with primary human cell systems and animal models gives me the ideal basis to be a successful K08 awardee. The proposed study will provide novel evidence for the direct effect of the microbiota in intestinal mesenchymal cell induced fibrogenesis and stricture formation. These findings could lead to a completely novel approach of targeting the microbiota as a therapeutic strategy to abrogate fibrosis.