Mechanotransduction in Intestinal Smooth Muscle Cells

肠平滑肌细胞的力转导

• 批准号: 10452931
• 负责人: Arthur Beyder
• 金额: $ 54.94万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 2026-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10452931
• 关键词: Affect; Animal Model; Bathing; Biological Assay; Cell physiology; Cells; Cellular biology; Chronic; Clinical; Complex; Constipation; Data; Diagnosis; Disease; Drug Targeting; Drug usage; Electrophysiology (science); Enterochromaffin Cells; Functional Gastrointestinal Disorders; Functional disorder; Gastrointestinal Diseases; Gastrointestinal Motility; Gastrointestinal Physiology; Gastrointestinal tract structure; Gene Expression Profile; Genetic Transcription; Goals; Grant; Health; Health Care Costs; Heart; Human; Image; Immune; Infection; Inflammation; Integral Membrane Protein; Interstitial Cell of Cajal; Intestines; Ion Channel; Ions; Knowledge; Large Intestine; Mechanical Stimulation; Mechanical Stress; Mechanics; Molecular; Molecular Target; Morbidity - disease rate; Movement; Mus; Muscle; Muscle function; Neuroglia; Neurons; Obstruction; Outcome; Patients; Permeability; Population; Process; Quality of life; Reflex action; Regulation; Research; Role; Small Intestines; Smooth Muscle; Smooth Muscle Myocytes; Stretching; Structure; Sturnus vulgaris; Techniques; Testing; Therapeutic; Time; Tissues; Tomatoes; Vascular Smooth Muscle; Vascular System; Visceral; Visceral Myopathies; biophysical properties; cell motility; cell type; diagnostic strategy; experience; experimental study; gastrointestinal; gastrointestinal function; gastrointestinal system; imaging approach; in vivo; innovation; knock-down; mechanical force; mechanical stimulus; mechanotransduction; motility disorder; new therapeutic target; novel; novel diagnostics; productivity loss; response; sensor; transcriptomics

PROJECT SUMMARY/ABSTRACT Coordinated gastrointestinal (GI) tract motility is fundamental for normal GI tract function. Several cell types combine to regulate GI motility, with the smooth muscle cell (SMC) as the workhorse required to provide the physical power for contractions. Disruptions in SMC function contribute to common GI disorders, may occur after infections and inflammation, and associate with rare but devastating GI motility disorders like visceral myopathies and pseudo-obstruction. The gut wall is a highly complex multilayered structure under mechanical stress at baseline and constantly moving. Therefore, cells in the GI tract experience a range of types and amounts of mechanical stimuli. The normal coordinated motility requires an ability to sense and adjust to forces. In multiple cycles of this grant, we have dissected mechanisms of smooth muscle mechanotransduction, have made discoveries that advanced GI physiology and pathophysiology, and provided novel drug targets. However, our current understanding of SMC mechanosensing remains incomplete. It is established that SMCs, even as single cells, adjust their contractions in response to force in a process called the myogenic reflex. In vascular SMCs, the myogenic reflex depends on mechanogated ion channels, but in the GI tract, cellular and molecular mechanisms remain poorly understood. Therefore, the overall objective of our research is to determine the primary mechanogated ion channels involved in GI SMC mechanosensitivity. For this proposal, we created novel animal models and used cutting-edge techniques to generate compelling preliminary data. Our preliminary studies show that a recently discovered mechanogated ion channel Tmem63a is expressed in a subpopulation of SMCs, which are optimized for force sensing and distributed across the tissue to detect force. Indeed mechanosensitive ionic currents in a population of primary mouse GI SMCs have unique biophysical properties consistent with Tmem63a, the activation of which by force leads to a Ca2+ increase, modulating small and large bowel contractions and whole gut transit time. Interestingly, our data also show that patients with slow transit constipation have a decrease in Tmem63a. Thus, the central hypothesis that a mechanogated ion channel Tmem63a significantly contributes to the myogenic reflex will be tested in two Aims. In Aim 1, we determine Tmem63a function, its response to force, and its role in GI SMCs using conventional and cutting-edge techniques electrophysiology and Ca2+ imaging approaches. In Aim 2, we propose experiments to define the Tmem63a+ SMC population and to determine the role of Tmem63a SMCs in regulating GI smooth muscle function. Since Tmem63a is found in a subpopulation of SMCs, we use single-cell and spatial transcriptomics, novel Ca2+ imaging, smooth muscle contractility assays and in vivo whole gut transit. Successful completion of the proposed innovative experiments has both basic significance and clinical impact, evaluating and establishing a novel SMC mechanogated ion channel which contributes to SMC function and the myogenic reflex and, in the long term, may provide a novel target for functional and motility GI disorders.

项目摘要/摘要 协调的胃肠道（GI）道运动对于正常的胃肠道功能至关重要。几种细胞类型 结合使用平滑肌细胞（SMC）作为提供的主力 宫缩的物理力量。 SMC功能的中断会导致常见的GI疾病，可能会发生 感染和炎症，并与罕见但毁灭性的胃肠道疾病（如内脏肌病）相关 和伪obstruction。肠壁是在机械应力下的高度复杂的多层结构 基线并不断移动。因此，胃肠道中的细胞经历了一系列类型和数量 机械刺激。正常的协调运动需要感知和适应力的能力。在多个 这笔赠款的循环，我们已经解剖了平滑肌机械转移的机制，已使 发现了提高GI生理学和病理生理学的发现，并提供了新的药物靶标。但是，我们的 当前对SMC机械感应的理解仍然不完整。已经确定SMC，即使是单身 细胞，在称为肌原性反射的过程中调整其收缩以响应力。在血管SMC中， 肌原性反射取决于机械的离子通道，但在gi段，细胞和分子中 机制仍然很少理解。因此，我们研究的总体目标是确定 涉及GI SMC机械敏感的主要机械化离子通道。对于这个建议，我们创作了小说 动物模型和使用尖端技术来生成引人注目的初步数据。我们的初步 研究表明，最近发现的机械离子通道TMEM63A在亚群中表达 SMC的作用，用于优化用于力传感并在整个组织中分布以检测力。的确 原代小鼠胃肠道中的机械敏感离子电流具有独特的生物物理特性 与TMEM63A一致，其激活通过力导致Ca2+增加，调节大小 肠收缩和整个肠道运输时间。有趣的是，我们的数据还表明过境缓慢的患者 便秘的TMEM63A降低。因此，机械离子通道的中心假设 TMEM63A显着促进肌源性反射，以两个目标进行测试。在AIM 1中，我们确定 TMEM63A功能，其对力的响应及其在GI SMC中的作用，使用常规和尖端技术 电生理学和CA2+成像方法。在AIM 2中，我们提出了定义TMEM63A+的实验 SMC种群并确定TMEM63A SMC在调节GI平滑肌功能中的作用。自从 在SMC的亚群中发现了TMEM63A，我们使用单细胞和空间转录组学，新型Ca2+ 成像，平滑的肌肉收缩力测定和整个肠道过境。成功完成拟议的 创新的实验既具有基本意义和临床影响，又评估和建立了新的SMC 有助于SMC功能和肌源反射的机械化离子通道，从长远来看 可能为功能性和运动性GI疾病提供新的目标。