Molecular mechanisms of sensory transduction in the gut

肠道感觉转导的分子机制

• 批准号: 9770841
• 负责人: Nicholas Bellono
• 金额: $ 24.9万
• 依托单位: HARVARD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9770841
• 关键词: Ablation; Address; Affect; Afferent Neurons; Area; Attention; Award; Biological; Biological Assay; Biophysics; Calcium; Cell Communication; Cell physiology; Cells; Chemicals; Data; Detection; Development; Diet; Disease; Electrophysiology (science); Elements; Enterobacteria phage P1 Cre recombinase; Enterochromaffin Cells; Environment; Epithelial Cells; FLP recombinase; Foundations; Functional disorder; Gastrointestinal Physiology; Gated Ion Channel; Genetic; Goals; Histologic; Human body; Hypersensitivity; Image; Inflammatory; Intestines; Ion Channel Gating; Irritable Bowel Syndrome; Irritants; Label; Laboratories; Learning; Measurement; Measures; Mechanics; Mediating; Mentors; Mentorship; Molecular; Mus; Nerve; Nerve Fibers; Nervous system structure; Neural Pathways; Neurosciences; Nutrient; Organ; Organoids; Pain; Pain Disorder; Pathway interactions; Phase; Physiological; Physiology; Preparation; Property; Regulation; Research; Role; Sensory; Sensory Receptors; Serotonin; Signal Transduction; Stimulus; Surface; Synapses; System; Technology; Testing; TimeLine; Tissues; Training; Training Support; Transgenic Mice; Visceral pain; Work; afferent nerve; cell type; detector; experience; fluorophore; gastrointestinal epithelium; genetic approach; in vivo; interest; intersectionality; microbial; microbiota; neuroregulation; novel; patch clamp; programs; receptor; recombinase; relating to nervous system; sensory mechanism; therapeutic development; tool; transcriptome sequencing; voltage

Project Summary Specialized sensory organs contain functionally dedicated cell types that detect relevant stimuli and relay information to the nervous system. In this proposal, we ask if this concept also pertains to the gut epithelium, which constitutes one of the largest exposed surface areas of the human body and is in contact with a diverse chemical environment. Indeed, numerous chemical changes in the gut lumen have been associated with visceral pain, including irritants, endogenous inflammatory molecules, and microbiota-produced metabolites. Despite growing interest in the gut-neural axis, relatively little is known about molecular mechanisms underlying chemosensory transduction by the gut epithelium, or how this information is transmitted to the nervous system. Serotonergic enterochromaffin (EC) cells are rare, but highly specialized entities within the gut epithelium that have been implicated in visceral pain but have eluded detailed characterization due, in part, to their paucity. To circumvent these limitations, we generated intestinal organoids from a transgenic mouse in which EC cells are marked with a fluorophore, enabling us to carry out detailed single-cell profiling of these cells in the context of a native tissue environment. Our preliminary data show that these cells are electrically excitable, polymodal chemosensory detectors of the gut that engage in direct synaptic interactions with sensory nerve fibers to transduce information about intestinal state. In these proposed studies, we will define intrinsic EC cell electrophysiological properties, chemosensory transduction mechanisms, and serotonin release mechanisms (Aim 1) and utilize this information to investigate the physiological effects of EC activation on and associated neural pathways (Aim 2). Finally, we will obtain genetic access to EC cells and use chemogenetic tools to examine their contribution to visceral pain (Aim 3). This work will elucidate EC cell chemosensory mechanisms and examine their role in visceral pain to provide a mechanistic foundation for understanding how the gut epithelium communicates with the nervous system. This molecular foundation is critical for uncovering basic mechanisms that contribute to pathophysiology underlying visceral pain disorders, such as irritable bowel syndrome. Proposed experimental approaches for this award combine my expertise in cellular physiology and biophysics with new training in genetics and GI physiology, allowing me to address significant biological questions and identify novel molecular mechanisms. A unique mentorship team with extensive experience in signal transduction, pain, synaptic physiology, and GI physiology will provide expert guidance and an ideal environment for proposed scientific and professional development. Thus, the training supported by this award will be critical to establishing a unique and important independent research program in neuroscience and gastrointestinal physiology.

项目摘要 专门的感觉器官包含功能上专用的细胞类型，它们检测相关的刺激并传递 传递给神经系统的信息。在这项提议中，我们问这个概念是否也适用于肠道上皮， 它构成了人体最大的暴露表面积之一，并与不同的 化学环境。事实上，肠腔中的许多化学变化都与 内脏疼痛，包括刺激物、内源性炎症分子和微生物区系产生的代谢物。 尽管人们对肠道神经轴的兴趣与日俱增，但对其分子机制知之甚少。 肠道上皮的潜在化学感觉转导，或该信息是如何传递到 神经系统。5-羟色胺能肠嗜铬细胞(EC)很少见，但在肠道内是高度特化的实体。 上皮与内脏疼痛有牵连，但由于部分原因，未能得到详细的描述 他们的匮乏。为了绕过这些限制，我们从一只转基因小鼠身上产生了肠道器官。 哪些EC细胞用荧光团标记，使我们能够对这些细胞进行详细的单细胞图谱分析 在自然组织环境中的细胞。我们的初步数据显示，这些电池是电性的 肠道中参与直接突触相互作用的可兴奋的多模式化学感觉探测器 感觉神经纤维传递有关肠道状态的信息。在这些拟议的研究中，我们将界定 EC细胞固有的电生理特性、化学感觉转导机制和5-羟色胺 释放机制(目标1)，并利用这一信息来研究EC激活的生理效应 On和相关神经通路(目标2)。最后，我们将获得获得EC细胞的遗传途径，并使用 检查它们对内脏疼痛的贡献的化学发生工具(目标3)。这项工作将阐明EC细胞 并研究它们在内脏疼痛中的作用，为以下方面提供机制基础 了解肠道上皮如何与神经系统沟通。这个分子基础是 对于揭示导致内脏疼痛障碍的基本机制至关重要， 比如肠易激综合征。 建议的实验方法结合了我在细胞生理学和生物物理学方面的专业知识 通过新的遗传学和胃肠道生理学培训，使我能够解决重要的生物学问题和 确定新的分子机制。一支在Signal领域拥有丰富经验的独特的指导团队 转导、疼痛、突触生理学和胃肠道生理学将提供专家指导和理想的 为拟议的科学和专业发展提供环境。因此，该奖项支持的培训 将对建立一个独特而重要的神经科学和 胃肠生理学。