Microbiota-sourced purines in gut health and disease

项目总结 为了保护宿主并发挥共生作用，肠道上皮细胞分泌大量的 高度糖化的粘蛋白到物理距离，但提供细菌栖息地和燃料，同时建立顶端 调节营养和废物通量的连接复合体。作为回报，健康的微生物群提供了 上皮细胞所依赖的代谢物。我们最近发表的研究表明，嘌呤次黄嘌呤(HPX)是一种 黏膜能量平衡、屏障功能和创伤所依赖的微生物衍生代谢物 愈合，提示HPX是动态平衡粘膜代谢和功能的限制底物。在不偏不倚的 作为这项工作的延伸，我们证明了HPX可诱导TP53诱导的糖酵解和细胞凋亡调节 (TIGAR)在体外和体内表达并激活AMP激活的激酶(AMPK)。TIGAR增长 代谢产物通过戊糖磷酸途径流动，而AMPK是代谢的主要调节器， 促进能量平衡。我们假设HPX通过TIGAR从根本上影响上皮新陈代谢 和AMPK作为支持肠道内环境稳定和伤口愈合的机制。在这种情况下，嘌呤耗尽 并通过定植实验对富含HPX产物的突变大肠杆菌进行重组 用来确定微生物源HPX对粘膜能量代谢、屏障的影响 功能，和伤口愈合。 申请者李博士已经建立了一个科学利基，在这个利基中建立了一个独立的 微生物衍生的嘌呤在肠道粘膜能量代谢和功能中的作用研究。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 奖项的期限，以提供研究反馈，批评研究计划，监督 出版物，并提供职业建议。科尔根和李博士还发现了微生物学和免疫学 课程，以促进李博士在基本肠道过程中的基础知识的扩展，以及 建立了用于研究和组织病理学分析的结肠小肠收集/培养方面的监护。李博士 将提交他的工作，并在专门针对他的研究的会议上发表，以便与他人分享他的研究和网络 同事和潜在合作者，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膜炎症计划(MIP)，这是一项多学科的 发起了多部门的学科计划，以研究粘膜炎症和消退的机制。 MIP培养了一个独特的实验室环境，供内科科学家、临床医生和 为青年科研人员的成长和发展营造良好的环境。这个 为李博士提供的设施和资源以及为李博士制定的发展计划提供了理想的环境和 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.