Microbial-derived factors regulating mucosal wound healing

项目摘要/摘要 炎症性肠病(IBD)目前在美国困扰着310多万人，其中超过10万人 每年都有新的病例。IBD患者经历持续和复发的胃肠道炎症 导致腹痛、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，随着 肠道微生物区系变化的意义。肠上皮细胞(IECS)形成动态屏障，隔离 宿主免疫系统不受外部环境的影响。反复损伤和屏障后创面快速愈合 炎症性肠病所见的破坏对于炎症消退至关重要。微生物区系的一个既定作用是生产 以短链脂肪酸(SCFA)形式存在的能量，如丁酸盐。丁酸生产种类的减少 与IBD密切相关。初步研究表明，丁酸盐增加了屏障的形成和 促进损伤后的上皮伤口愈合。无偏见的单细胞测序筛查显示 丁酸盐诱导IEC表达突触素(SYNPO)，这是一种先前的肌动蛋白相关蛋白 在肠上皮中未表现出特征。这一提议将检验这样一个假设，即微生物来源的 单链脂肪酸丁酸盐通过协调SYNPO表达和屏障促进肠道创伤愈合和屏障 在消炎和维持体内平衡方面发挥作用。三个具体目标将 指导这一项目。目标1将定义SCFA对SYNPO的调节机制，包括丁酸盐，通过 细胞培养和启动子报告分析。目标2将阐明SYNPO在IECS利用中的功能作用 击倒和过度表达细胞和免疫荧光。目标3将确定SYNPO的贡献 在健康和黏膜疾病期间使用小鼠结肠炎模型。这项工作的圆满完成将 确立微生物区系在调节伤口愈合和最终从IBD中恢复中的关键作用 一个新的目标，SYNPO。了解丁酸盐修复组织损伤和 恢复肠道屏障将有助于目前的治疗方法。 这一全面的研究培训计划将在经验丰富的赞助商的指导下提供出色的指导 在严谨的基础科学实验室的理想环境中，临床与必要的 完成这个项目的每一个方面的资源。这包括在Mucosal内部建立一个不同的指导团队 除了申请者论文委员会的指导外，还有炎症计划。这项培训将培养 申请者的研究和学术技能，以追求分子水平的交叉科学，这将促进 组织损伤修复和新的疾病靶点识别的治疗。这些机械论的研究证明 提高IBD患者生活质量的转化潜力，并提供最佳进展 作为一名内科科学家，从事平衡生物医学研究和临床实践的职业。

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.