Microbial-derived factors regulating mucosal wound healing

项目总结/摘要 炎症性肠病（IBD）目前在美国折磨着超过310万人，其中超过10万人患有IBD。 每年都有新病例。IBD患者经历持续性和复发性胃肠道炎症 引起腹痛出血腹泻和体重减轻IBD的病因虽然未知，但主要集中在 肠道屏障完整性的丧失，包括遗传和环境因素， 肠道微生物群变化的重要性。肠上皮细胞（IEC）形成了隔离肠上皮细胞的动态屏障。 免疫系统从外部环境。伤口反复损伤后快速愈合和屏障 在IBD中观察到的破坏对于炎症消退至关重要。微生物群的既定作用是产生 能量以短链脂肪酸（SCFAs）的形式存在，如丁酸盐。减少产丁酸物种 与IBD密切相关。初步研究表明，丁酸盐增强屏障形成， 促进损伤后上皮伤口愈合。无偏单细胞测序筛选显示， 丁酸诱导IEC表达突触足蛋白（SYNPO），一种肌动蛋白相关蛋白， 在肠上皮中没有特征的。这项提议将检验微生物来源的 SCFA丁酸盐通过协调SYNPO表达促进肠创伤愈合和屏障， 在炎症消退以及稳态维持的背景下起作用。三个具体目标将 指导这个项目。目的1将通过以下方式来定义SCFAs（包括丁酸盐）对SYNPO调节的机制： 细胞培养和启动子报告基因分析。目的2阐明SYNPO在IEC利用中的功能作用 敲低和过表达细胞以及免疫荧光。目标3将决定SYNPO的贡献 在健康和粘膜疾病期间使用鼠结肠炎模型。这项工作的顺利完成将 建立微生物群在调节伤口愈合和最终从IBD恢复中的关键作用， 一个新的靶点SYNPO。了解丁酸盐修复组织损伤的机制， 恢复肠道屏障将有助于目前的治疗方法。 这个全面的研究培训计划将提供优秀的导师与经验丰富的赞助商 在严格的基础科学实验室的理想环境中， 完成本项目的各个方面的资源。这包括一个独特的导师团队内的muccraft 炎症程序除了申请人的论文委员会的指导。这项培训将促进 申请人的研究和学术技能，以追求交叉分子水平的科学，将推进 用于组织损伤修复和新疾病靶点鉴定的治疗剂。这些机械研究 转化潜力，以改善IBD患者的生活质量，并提供最佳进展， 平衡生物医学研究和临床实践的职业生涯作为一名医生科学家。

PROJECT SUMMARY/ABSTRACT Inflammatory bowel disease (IBD) currently afflicts more than 3.1 million people in the U.S. with over 100,000 new cases each year. Patients with IBD experience persistent and relapsing gastrointestinal tract inflammation causing abdominal pain, bleeding, diarrhea, and weight loss. The etiology of IBD, while unknown, centers around the loss of intestinal barrier integrity, and comprises both genetic and environmental factors, with emerging significance of shifts in the gut microbiota. Intestinal epithelial cells (IECs) form the dynamic barrier isolating the host immune system from the external environment. Rapid wound healing after the repeated damage and barrier disruption seen in IBD is crucial to inflammatory resolution. An established role of the microbiota is production of energy in the form short-chain fatty acids (SCFAs), such as butyrate. Decreases in butyrate-producing species are strongly associated with IBD. Preliminary studies show that butyrate augments barrier formation and enhances epithelial wound healing following injury. An unbiased single cell sequencing screen revealed that butyrate induces IEC expression of synaptopodin (SYNPO), an actin-associated protein previously uncharacterized in the intestinal epithelium. This proposal will test the hypothesis that the microbial-derived SCFA butyrate promotes intestinal wound healing and barrier through coordination of SYNPO expression and function in the context of inflammation resolution as well as homeostatic maintenance. Three specific aims will guide this project. Aim 1 will define the mechanisms of SYNPO regulation by SCFAs, including butyrate, through cell culture and promoter reporter analysis. Aim 2 will elucidate the functional role of SYNPO in IECs utilizing knockdown and overexpression cells and immunofluorescence. Aim 3 will determine the contribution of SYNPO in health and during mucosal disease using murine colitis models. Successful completion of this work will establish a critical role for the microbiota in regulating wound healing and ultimately recovery from IBD through a novel target, SYNPO. Understanding the mechanisms through which butyrate repairs tissue damage and restores the intestinal barrier will contribute to current therapeutic approaches. This comprehensive research training plan will provide outstanding mentorship with an experienced sponsor in the ideal environment of a rigorous basic science lab that is well-integrated clinically with the necessary resources for completing each aspect of this project. This includes a distinct mentorship team within the Mucosal Inflammation Program in addition to the guidance of the applicant’s thesis committee. This training will foster the applicant’s research and academic skills to pursue cross-cutting molecular level science that will advance therapeutics for tissue damage repair and novel disease target identification. These mechanistic studies hold translational potential to improve the quality of life for IBD patients and provide the optimal progression towards a career balancing biomedical research and clinical practice as a physician scientist.