Novel Mechanisms in Enteric Inhibitory Neuretransmission

肠道抑制神经传递的新机制

• 批准号: 8280400
• 负责人: Violeta Mutafova-Yambolieva
• 金额: $ 18.61万
• 依托单位: UNIVERSITY OF NEVADA RENO
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8280400
• 关键词: Action Potentials; Address; Adenine; Adenosine; Adenosine Diphosphate Ribose; American; Amides; Apamin; Cells; Colon; Constipation; Cyclic ADP-Ribose; Defect; Diarrhea; Dinucleoside Phosphates; Disease; Distal; Electron Microscopy; Electrophysiology (science); Enteral; Enzymes; Excision; Exocytosis; Fecal Incontinence; Fibroblasts; Frequencies; Functional disorder; Gastrointestinal Motility; Gastrointestinal tract structure; Goals; High Pressure Liquid Chromatography; Human; Immunohistochemistry; Interstitial Cell of Cajal; Intestinal Motility; Intestines; Large Intestine; Mediating; Membrane; Metabolism; Methods; Molecular Biology Techniques; Monkeys; Motor; Motor Neurons; Mus; Muscle; Muscle Contraction; Muscle relaxation phase; Nerve; Neuroeffector Junction; Neurons; Neuropathy; Neurotransmitters; Nicotinamide adenine dinucleotide; Nucleotides; Patients; Preparation; Prevention; Process; Protein Biochemistry; Proteins; Purines; Purinoceptor; Qualifying; Quality of life; Receptor Activation; Relative (related person); Research; Role; SK potassium channel; Signal Transduction; Smooth Muscle; Smooth Muscle Myocytes; Source; Synapses; Synaptic Vesicles; Techniques; Varicosity; Work; apamin receptor; base; cell type; diabetic; extracellular; gastrointestinal; gastrointestinal function; interstitial cell; motility disorder; neuroregulation; nonhuman primate; novel; novel therapeutics; prevent; purine; receptor; relating to nervous system; tripolyphosphate; uptake; voltage

A number of motility disorders are believed to be caused by defects in the neural control of the gastrointestinal (GI) tract. However, the underlying pathophysiology remains largely undefined and often the treatment is ineffectively targeted. Our long-term goal is to develop methods for the prevention and treatment of conditions qualified as "neuropathies" based on understanding of the inhibitory purinergic signaling in the gut. The central hypothesis of this proposal is that beta-nicotinamide adenine dinucleotide ((3-NAD) is a novel inhibitory neurotransmitter in the GI tract. Particularly, we hypothesize that (3-NAD is stored in synaptic vesicles, is released upon action potential firing, activates P2Y purinergic receptors and apamin-sensitive small conductance Ca2+-activated potassium (SK) channels on either interstitial cells of Cajal (ICC), smooth muscle cells (SMC) or fibroblast-like cells (FLC), causes membrane hyperpolarization and smooth muscle relaxation, and is removed by CD38- and CD157-mediated metabolism and by uptake in nerve varicosities. The work, carried out with colon preparations from humans, non-human primates, and mice, will: (i) determine the cell types that are the primary source of release of (3-NAD and ATP during EPS of enteric nerves (Aim 1), (ii) examine whether the expression, distribution, and function of vesicular nucleotide transporter (VNUT) is consistent with the role of (3-NAD as an inhibitory motor neurotransmitter in GI muscles (Aim 2), (iii) determine the primary postjunctional targets of PNAD action (Aim 3), and (iv) examine the major mechanisms of removal of (3-NAD (i.e., enzymatic degradation or neuronal uptake), and hence of terminating its neurotransmitter actions (Aim 4). We will examine overflow of purine neurotransmitters and their metabolites using high performance liquid chromatography (HPLC) techniques along with immunohistochemistry, protein biochemistry, molecular biology techniques, electron microscopy, flow cystometry analysis, electrophysiology, and functional approaches to better understand the role of p-NAD and other purines as putative neurotransmitters. This research has the potential to fundamentally advance our understanding of enteric purinergic signaling, and could have important implications for developing novel therapeutic strategies for GI motility disorders based on defects of neural control of the GI muscles.

许多动力障碍被认为是由胃肠道神经控制缺陷引起的 （胃肠）道。然而，潜在的病理生理学在很大程度上仍然不明确，治疗方法通常是 没有得到有效的针对性。我们的长期目标是开发预防和治疗疾病的方法 基于对肠道中抑制性嘌呤能信号传导的理解，将其定义为“神经病”。中央 该提案的假设是β-烟酰胺腺嘌呤二核苷酸（(3-NAD) 是一种新型抑制 胃肠道中的神经递质。特别是，我们假设（3-NAD 储存在突触小泡中，是 动作电位激发时释放，激活 P2Y 嘌呤能受体和 apamin 敏感的小电导 Cajal 间质细胞 (ICC)、平滑肌细胞 (SMC) 或上的 Ca2+ 激活钾 (SK) 通道 成纤维细胞样细胞 (FLC)，导致膜超极化和平滑肌松弛，并被去除 通过 CD38 和 CD157 介导的代谢以及神经静脉曲张的摄取。使用冒号进行的工作 来自人类、非人类灵长类动物和小鼠的制剂将：（i）确定主要的细胞类型 肠神经 EPS 期间 (3-NAD 和 ATP) 的释放来源（目标 1），(ii) 检查是否表达， 囊泡核苷酸转运蛋白（VNUT）的分布和功能与（3-NAD作为 胃肠道肌肉中的抑制性运动神经递质（目标 2），(iii) 确定 PNAD 的主要结后目标 作用（目标 3），以及 (iv) 检查去除 (3-NAD) 的主要机制（即酶促降解或 神经元摄取），从而终止其神经递质作用（目标 4）。我们将检查溢出 使用高效液相色谱 (HPLC) 测定嘌呤神经递质及其代谢物 技术以及免疫组织化学、蛋白质生物化学、分子生物学技术、电子技术 显微镜、流式膀胱测定分析、电生理学和功能方法，以更好地了解 p-NAD 和其他嘌呤作为推定神经递质的作用。这项研究有可能从根本上 增进我们对肠道嘌呤能信号传导的理解，并可能对开发具有重要意义 基于胃肠道肌肉神经控制缺陷的胃肠道运动障碍的新治疗策略。