Microbiota-sourced purines in gut health and disease

项目摘要 为了保护宿主并发挥其共生作用，肠上皮细胞分泌大量的 高度糖基化粘蛋白在物理上保持距离，但提供细菌栖息地和燃料，同时建立顶端 连接复合体，调节营养物和废物通量。作为回报，健康的微生物群可以提供 上皮细胞功能所依赖的代谢物。我们最近发表了嘌呤次黄嘌呤（Hpx）是一种 微生物衍生的代谢物，粘膜依赖于能量平衡、屏障功能和伤口 愈合，表明Hpx作为稳态粘膜代谢和功能的限制性底物。在无偏见的 作为这项工作的延伸，我们证明了Hpx诱导TP 53诱导的糖酵解和凋亡调节因子， 在体外和体内，TIGAR表达并激活AMP激活激酶（AMPK）。TIGAR增加 通过戊糖磷酸途径的代谢物通量，而AMPK是代谢的主要调节剂， 促进能量平衡。我们假设Hpx通过TIGAR从根本上塑造上皮代谢 和AMPK作为支持肠内稳态和伤口愈合的机制。在这个例子中， 并通过定殖实验用已开发的突变体E.在Hpx生产中富集的大肠杆菌将 用于确定微生物源性Hpx对粘膜能量代谢、屏障的影响 功能和伤口愈合。 申请人，李博士，已经建立了一个科学利基，建立一个独立的基础。 研究微生物源嘌呤在肠道粘膜能量代谢和功能中的作用。李博士和 他的导师科尔根博士组建了一个咨询委员会，在整个过程中定期与李博士会面 奖励的持续时间，以提供对研究的反馈，批评研究计划，监测 出版物，并提供职业咨询。科尔根和李博士还确定了微生物学和免疫学 课程，以促进扩大李博士的基础知识，在基本的肠道过程，和 在结肠肠样收获/培养研究和组织病理学分析方面建立了指导。李博士 我将提交他的工作，目前在会议上具体到他的研究，分享他的研究和网络与 同事和潜在的合作者，并从科学界获得宝贵的反馈。李博士的 发展将受益于继续参与粘液炎症计划（MIP），一个多- 学科，多部门计划发起研究粘膜炎症和解决机制。 MIP为医生科学家、临床医生和 研究科学家，并致力于建立一个环境，为年轻的研究人员蓬勃发展。的 为李博士提供的设施和资源，以及为李博士建造的发展计划， 这是他成功过渡到独立的道路。

PROJECT SUMMARY To protect the host and perform their symbiotic role, intestinal epithelial cells secrete large amounts of highly glycosylated mucin to physically distance yet provide bacteria habitat and fuel, while establishing apical junction complexes that regulate nutrient and waste flux. In return, a healthy microbiota functions to provide metabolites the epithelium relies on for function. We recently published that the purine hypoxanthine (Hpx) is a microbiota-derived metabolite that the mucosa depends upon for energy balance, barrier function, and wound healing, suggesting Hpx as a limiting substrate for homeostatic mucosal metabolism and function. In unbiased extensions of that work, we demonstrated that Hpx induces TP53-inducible glycolysis and apoptosis regulator (TIGAR) expression and activates AMP-activated kinase (AMPK) in vitro and in vivo. TIGAR increases metabolite flux through the pentose phosphate pathway while AMPK is a master regulator of metabolism that promotes energy balance. We hypothesize that Hpx fundamentally molds epithelial metabolism through TIGAR and AMPK as mechanisms that support intestinal homeostasis and wound healing. In this, purine depletion and reconstitution by colonization experiments with a developed mutant E. coli enriched in Hpx production will be employed to determine the influence of microbiota-derived Hpx on mucosal energy metabolism, barrier function, and wound healing. The applicant, Dr. Lee, has established a scientific niche in which to build a foundation for independent research in the role of microbiota-derived purines in gut mucosal energy metabolism and function. Dr. Lee and his mentor, Dr. Colgan, assembled an advisory committee to regularly meet as a group with Dr. Lee throughout the duration of the award to provide feedback on the research, critique the research plans, monitor publications, and provide career advice. Drs. Colgan and Lee also identified microbiology and immunology courses to facilitate expansion of Dr. Lee's foundation of knowledge in fundamental intestinal processes, and established tutelage in colonic enteroid harvesting/culturing for study and in histopathological analyses. Dr. Lee will submit his work to present at conferences specific to his research to share his research and network with colleagues and potential collaborators, and get valuable feedback from the scientific community. Dr. Lee's development will benefit from continued participation in the Mucosal Inflammation Program (MIP), a multi- disciplinary, multi-departmental program initiated to study mechanisms of mucosal inflammation and resolution. The MIP fosters a unique lab environment for collaboration between physician scientists, clinicians, and research scientists, and works to establish an environment for young investigators to flourish and develop. The facilities and resources available to and development plan built for Dr. Lee provide an ideal environment and path for his successful transition to independence.