Mechanisms of essential calcium signaling during gastric epithelial wound healing

 描述（由申请方提供）：消化性溃疡疾病和上消化道刺激是美国医疗保健系统和全球范围内的重大负担，主要由摄入的非甾体抗炎药（NSAID）和病原体H.幽门。我们工作的基本原理是，改进或替代的治疗策略可以基于对胃防御机制的理解，这些机制可以对抗这些挑战。初步研究表明，细胞内和细胞外Ca 2+动员在胃表面上皮修复中起重要作用。我们假设这种Ca 2+动员是修复的中心调节因子，是调节修复过程的各种激动剂作用的基础，并且这种途径可以被NSAID和H.幽门。本申请的目的是使用新发现的Ca 2+信号作为预兆，以确定潜在的上游和下游机制介导的胃修复，并作为一种工具，以调查是否NSAID和/或H. pylori通过这些途径损害修复。我们开创了光学技术，可以实时创建病灶损伤和持续量化修复。我们专注于体内局灶性病变修复的工作将外推到评估溃疡的实验中，以增强与临床观察到的胃病理学的相关性，并研究胃类器官作为胃上皮功能的潜在强大的新模型。我们的第一个目标是确定损伤组织中刺激Ca 2+动员和胃修复的起始细胞外信号。我们将专注于TFF 2和三尖杉酯碱，被证明是必不可少的胃修复，但其在Ca 2+信号转导的作用是未经测试的。第二个目标是建立Ca 2+依赖的细胞内信号通路的层次结构，这是必不可少的，以允许修复。实验是基于初步的发现，表明磷脂酶C和蛋白激酶C是需要有效的胃修复在完整的胃。我们的第三个目标是评估Ca 2+依赖性信号传导的下游靶点，这些靶点执行胃修复的工作。我们将评估NHE 2 Na/H交换剂的作用，NHE 2 Na/H交换剂作为TFF 2的下游效应物对胃修复至关重要。我们还将评估钙依赖的调节肌动蛋白细胞骨架，紧密连接，和小GTP酶，调节这些细胞结构在修复过程中。所有的目的都集中在环氧化酶（考克斯）/前列腺素途径的作用，抑制NSAID，和第一和第三个目的，另外检查所研究的途径的变化引起的感染H。幽门。这些结果将为了解胃发病机制的早期因素提供一个独特的窗口，这有可能导致新的目标和新的干预策略，可以最大限度地减少胃损伤和加速愈合。

 DESCRIPTION (provided by applicant): Peptic ulcer disease and upper GI irritation are a significant burden in the US healthcare system and worldwide, caused in large part by the upper GI toxicity of ingested non-steroidal anti-inflammatory drugs (NSAIDs) and the pathogen H. pylori. The rationale for our work is that improved or alternative therapeutic strategies can be based on understanding the mechanisms of gastric defense rallied against such challenges. Preliminary studies show an essential role for both intracellular and extracellular Ca2+ mobilization in gastric repair of the surface epithelium. We hypothesize that this Ca2+ mobilization is a central regulator of repair that underlies the effects of diverse agonists shown to modulate the repair process, and that this pathway can be disrupted by NSAIDs and H. pylori. The objective of this application is to use the newly identified Ca2+ signals as heralds to identif the underlying upstream and downstream mechanisms mediating gastric repair, and as a tool to investigate if NSAIDs and/or H. pylori compromise repair via these pathways. We have pioneered optical technologies that allow real-time creation of focal damage and continual quantification of repair. Our work focusing on the repair of focal lesions in vivo will be extrapolated to experiments evaluating ulceration to enhance relevance to gastric pathologies observed clinically, and to study of gastric organoids as a potentially powerful new model of gastric epithelial function. Our first aim is to identify the initiating extracellular signals in damaged tissue that stimulate Ca2+ mobilization and gastric repair. We will focus on TFF2 and prostaglandins, shown to be essential to gastric repair, but whose role in Ca2+ signaling is untested. The second aim establishes the hierarchy of Ca2+-dependent intracellular signaling pathways that are essential to allow repair. Experiments are based on preliminary findings that show phospholipase C, and protein kinase C are required for efficient gastric repair in the intact stomach. Our third aim evaluates the downstream targets of Ca2+- dependent signaling that perform the work of gastric repair. We will evaluate the role of the NHE2 Na/H exchanger, shown to be essential for gastric repair as a downstream effector of TFF2. We will also evaluate Ca2+ -dependent regulation of the actin cytoskeleton, tight junctions, and the small GTPases that regulate these cellular structures during repair. All aims focus on the role of the cyclooxygenase (COX)/prostaglandin pathway inhibited by NSAIDs, and the first and third aims additionally examine changes in the studied pathways caused by infection with H. pylori. The outcomes will provide a unique window into understanding early factors in gastric pathogenesis, which have potential to lead to new targets and new strategies for interventions that can minimize gastric damage and speed healing.