Control of motility in the lower esophageal sphincter

控制下食管括约肌的运动

• 批准号: 10472008
• 负责人: Caroline Ann Cobine
• 金额: $ 44.63万
• 依托单位: UNIVERSITY OF NEVADA RENO
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10472008
• 关键词: Achalasia; Address; Animals; Antibodies; Barrett Esophagus; Biochemical; CLCA2 gene; Calcium; Cells; Chest; Chronic; Complex; Coupled; Data; Defect; Deglutition; Development; Digestion; Distal; Drug usage; Equilibrium; Esophagus; Food; Foundations; Functional disorder; Future; Gene Expression; Generations; Genetic; Giant Cells; Human; Hypotensives; Image; Immunohistochemistry; Inferior esophageal sphincter structure; Inflammatory; Ingestion; Interstitial Cell of Cajal; Investigation; Label; Lead; Macaca; Macaca fascicularis; Maintenance; Measurement; Mediating; Medical; Metabolic; Molecular; Monitor; Mucous Membrane; Mus; Muscle; Neurons; Nitric Oxide; Nitroxidergic Nerves; Nutrient; Outcome; PDGFRB gene; Pain; Paper; Pathway interactions; Patients; Phosphorylation; Physiological; Primates; Principal Investigator; Probability; Process; Reflex action; Reflux; Regulation; Relaxation; Resolution; Respiratory Diaphragm; Respiratory System; Role; Smooth Muscle Myocytes; Stomach; Stomach Content; Structure; Techniques; Transgenic Mice; base; carcinogenesis; cell motility; experience; experimental study; interstitial cell; motility disorder; mouse model; neuroregulation; neurotransmission; new therapeutic target; novel; novel therapeutics; optogenetics; oxidative DNA damage; preclinical study; prevent; programs; protein expression; relating to nervous system; response; voltage; ward

Program Director/Principal Investigator (Last, First, Middle): Cobine, Caroline, A Project Summary The lower esophageal sphincter (LES) is a thickened region of muscle between the distal esophagus and proximal stomach. The LES develops contractile tone that forms a protective barrier and restricts acidic contents of the stomach from being refluxed into and damaging the esophagus. LES tone is thought to be ‘myogenic’, but LES muscles are not just composed of smooth muscle cells (SMCs) and neurons. Rather, interstitial cells of Cajal (ICC) are electrically coupled to SMCs and regulate the excitability of SMCs. For example, we found that responses to nitrergic input, an important regulator of relaxation after swallowing, are reduced in animals with loss of ICC (W/WV mice). This concept was criticized because manometric measurements in W/WV mice displayed evidence of nitrergic relaxation. An important observation in these studies, but not investigated or discussed in terms of mechanism, was that the LES in W/WV mice is hypotensive, suggesting that ICC provide important functions in the LES, such as development and maintenance of tone. This project seeks to better understand the mechanism of LES tone. Preliminary findings suggest that activation of Ca2+-dependent Cl- channels (CaCC encoded by Ano1), most highly expressed by ICC in the LES, are responsible for a significant portion of tone in these muscles. Ano1 channels are activated by spontaneous Ca2+ transients in ICC. The inward current activated by Ca2+ causes depolarization of the syncytium and increases the open probability of voltage-dependent Ca2+ channels in SMCs. The degree of contraction by this mechanism appears also to be regulated by a mechanism known as Ca2+ sensitization, a process suggested in previous papers, but previous findings are subject to other explanations. Here we propose to investigate the following: 1. Determine the molecular and functional apparatus responsible for the electromechanical and pharmacomechanical regulation of tone in the LES, 2. Examine how inputs from intrinsic neurons modulate the electromechanical and pharmacomechanical mechanisms underlying LES tone. This study will utilize a variety of cutting-edge techniques, such as transgenic mice, optogenetic monitoring of Ca2+ transients and biochemical analysis of phosphorylation steps that either increase or inhibit Ca2+ sensitivity in SMCs. Many of these pre-clinical studies will be performed on mice, but we will also perform parallel studies on Cynomolgus monkey LES, a primate with significant genetic homology to humans. OMB No. 0925-0001/0002 (Rev. 03/2020 Approved Through 02/28/2023) Page Continuation Format Page

项目总监/首席研究员（最后、第一、中间）：Cobine, Caroline, A 项目概要 下食管括约肌 (LES) 是远端食管和食管之间的肌肉增厚区域。 近端胃部 LES 产生收缩张力，形成保护屏障并限制酸性内容物。 胃部反流并损害食管的 LES 音被认为是“肌源性”的。 但 LES 肌肉不仅由平滑肌细胞 (SMC) 和神经元组成，而且还由间质细胞组成。 Cajal (ICC) 与 SMC 电耦合并调节 SMC 的兴奋性。 患有以下疾病的动物对氮能输入的反应减弱，氮能输入是吞咽后放松的重要调节剂 ICC 损失（W/WV 小鼠）这一概念受到批评，因为 W/WV 小鼠的压力测量。 显示了氮能松弛的证据，这是这些研究中的一个重要观察结果，但尚未进行调查或研究。 就机制而言，W/WV 小鼠的 LES 是低血压的，这表明 ICC 提供 LES 中的重要功能，例如语气的开发和维护，该项目旨在更好地实现。 了解 LES 音调的机制 初步研究结果表明 Ca2+ 依赖性 Cl- 的激活。 通道（由 Ano1 编码的 CaCC），在 LES 中由 ICC 表达最高，负责显着的 这些肌肉中的 Ano1 通道的部分音调由 ICC 中的自发 Ca2+ 瞬变激活。 Ca2+激活的内向电流导致合胞体去极化并增加合胞体的开放概率 SMC 中电压依赖性 Ca2+ 通道的收缩程度似乎也是如此。 由一种称为 Ca2+ 敏化的机制调节，这是之前论文中提出的过程，但之前 调查结果可能需要其他解释。在此，我们建议调查以下内容： 1. 确定 负责机电和药物机械调节的分子和功能装置 LES 中的音调，2. 检查内在神经元的输入如何调节机电和 LES 音调的药效机制 本研究将利用多种尖端技术。 技术，例如转基因小鼠、Ca2+瞬变的光遗传学监测和生物化学分析 许多这样的临床前研究都增加或抑制了 SMC 中 Ca2+ 敏感性的磷酸化步骤。 将在小鼠身上进行，但我们还将对食蟹猴 LES 进行平行研究，食蟹猴 LES 是一种灵长类动物，具有 与人类有显着的遗传同源性。 OMB 编号 0925-0001/0002（修订版 03/2020 已批准至 02/28/2023） 页面延续格式页面