Enteroendocrine cells sense gut bacteria and activate a gut-brain pathway

项目摘要 肠道内的微生物对大脑功能和行为有着重要的影响。 微生物-肠-脑通讯的干扰被认为参与了众所周知的 肠-脑疾病如肠易激综合征（IBS）和相关的功能性GI疾病。但 缺乏对精确的微生物机制和细胞途径的理解， 与大脑交流。为了解决这一关键的知识缺口，申请人率先将斑马鱼 研究微生物-肠道-大脑通讯的系统。使用细胞活性的体内实时测量 在斑马鱼中，申请人最近的研究表明，特定的肠道细菌直接激活专门的 在肠上皮感觉细胞，肠内分泌细胞（EECs），通过受体瞬时受体 潜在锚蛋白A1（Trpa 1）。Trpa 1 +EECs的微生物、药理学或光遗传学直接激活 激活肠神经元并刺激迷走神经感觉神经节。初步研究确定了一个独特的子集 细菌衍生的色氨酸催化剂作为新的激动剂，有效地激活Trpa 1。的目的 拟议的研究是确定肠道细菌激活EEC的精确分子机制， 迷走神经感觉通路来调节大脑活动。核心假设是细菌分泌色氨酸 钙激活剂通过一种新的EEC分泌信号刺激内皮细胞Trpa 1激活迷走神经感觉神经元 肽，垂体腺苷酸环化酶激活多肽（Pacap）。为了验证这一点，申请人将首先使用 分子微生物学和斑马鱼的gnotobiotic方法，以确定微生物的途径和机制 激活EEC Trpa 1信号。其次，申请人将使用体内迷走神经钙成像、光化学 和遗传操作，以鉴定将肠道细菌信息传递给 迷走神经最后，申请人将使用药物、基因和细胞移植方法来确定 将细菌信息从肠腔传递到迷走神经的EEC信号肽。拟议 这项研究有望为我们理解分子机制做出新的重大贡献。 以及肠道细菌与大脑交流的细胞途径。跨学科实验 这种方法与全面的职业发展计划一起，将把申请人的培训从 从胃肠病学到迷走神经和脑生理学以及分子微生物学。一个多元化的团队， 在杜克大学和剑桥查佩尔山建立了调查人员，他们的专业知识包括宿主微生物 互动肠脑生理学细菌学，将监督申请人的职业发展期间， 奖励期间，通过贡献智力，她的研究培训，提供导师，并提供职业生涯 建议.这个为期5年的职业发展奖将为申请人提供必要的专业和 科学技能是一个独立的和成功的微生物肠道脑科学家。

PROJECT SUMMARY Microorganisms residing in the intestinal lumen have a significant impact on brain function and behavior. Perturbation of microbe-gut-brain communication is believed to be involved in the pathogenesis of well-known gut-brain disorders such as irritable bowel syndrome (IBS) and related functional GI disorders. However, there is lack of understanding of the precise microbial mechanisms and the cellular pathways that allow gut microbes to communicate with the brain. To address this critical knowledge gap, the applicant has pioneered the zebrafish system for the study of microbe-gut-brain communication. Using in vivo real-time measurements of cell activity in zebrafish, the applicant’s recent research revealed that specific gut bacteria directly activate specialized sensory cells in the intestine epithelium, enteroendocrine cells (EECs), through the receptor transient receptor potential ankyrin A1 (Trpa1). Microbial, pharmacological, or optogenetic activation of Trpa1+EECs directly activates enteric neurons and stimulates vagal sensory ganglia. Preliminary studies identified a distinct subset of bacterial derived tryptophan catabolites as novel agonists that potently activate Trpa1. The objective of the proposed research is to determine the precise molecular mechanism by which enteric bacteria activate the EEC- vagal sensory pathway to modulate brain activity. The central hypothesis is that bacterial secreted tryptophan catabolites stimulate Trpa1 in EECs to activate vagal sensory neurons through a novel EEC secreted signal peptide, pituitary adenylate cyclase activating polypeptide (Pacap). To test this, the applicant will first use molecular microbiology and zebrafish gnotobiotic approaches to define the microbial pathway and mechanism that activates EEC Trpa1 signaling. Second, the applicant will use in vivo vagal calcium imaging, optochemical and genetic manipulation to identify the specific subtype of EECs that transmit enteric bacterial information to the vagus. Finally, the applicant will use pharmaceutical, genetic and cell transplantation approaches to define the EEC signaling peptide that transmits bacterial information from the gut lumen to the vagus. The proposed research is expected to make a significant new contribution to our understanding of the molecular mechanisms and cellular pathways by which enteric bacteria communicate with the brain. The interdisciplinary experimental approach together with the comprehensive career development plan will extend the applicant’s training from gastroenterology into vagal and brain physiology as well as molecular microbiology. A diverse team of established investigators at Duke University and UNC Chapel Hill, with expertise ranging from host-microbe interaction to gut-brain physiology to bacteriology, will oversee the applicant’s career development during the award period by contributing intellectually to her research training, providing mentorship, and offering career advice. This 5-year career development award will provide the applicant with the necessary professional and scientific skills to be an independent and successful microbiota-gut-brain scientist.