Regulation of Intestinal Epithelial Restitution

肠上皮恢复的调节

• 批准号: 8195543
• 负责人: Jian-Ying Wang
• 金额: --
• 依托单位: BALTIMORE VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8195543
• 关键词: Acute; Area; Cell Proliferation; Cell membrane; Cells; Clinic; Clinical; Complex; Coupled; Coupling; Critical Illness; DNA; Data; Disease; EF Hand Motifs; Endoplasmic Reticulum; Epithelial; Epithelial Cells; Functional disorder; Funding; Gastritis; Gastrointestinal tract structure; General Population; Genes; Goals; Health; Hemorrhage; Image Analysis; In Vitro; Incidence; Injury; Inositol; Intestines; Knowledge; Measurement; Mediating; Military Personnel; Modality; Modeling; Molecular; Mucous Membrane; Non-Steroidal Anti-Inflammatory Agents; Operative Surgical Procedures; Patients; Pattern; Pharmaceutical Preparations; Phase; Play; Population; Population Control; Prevalence; Process; Proteins; RNA Interference; RNA-Protein Interaction; Rattus; Regulation; Reporting; Role; Series; Signal Pathway; Signal Transduction; Stream; Stress; TRPC1 protein; Techniques; Testing; Therapeutic; Transfection; Ulcer; Veterans; abstracting; base; cell motility; cell type; cellular imaging; combat; design; digital; effective therapy; extracellular; gastrointestinal; human STIM1 protein; improved; in vivo; injury and repair; mutant; novel; overexpression; prevent; protein function; receptor; repaired; response; sensor; stress related disorder; trafficking; voltage

DESCRIPTION (provided by applicant): Project Summary/Abstract Early mucosal restitution is an important primary repair modality in the gastrointestinal (GI) tract and its defective regulation underlies various critical pathological states such as mucosal bleeding and acute injury, disruption of GI epithelial integrity, and barrier dysfunction. Since the exact mechanisms underlying acute mucosal injury and early rapid mucosal reepithelialization after superficial wounds are still obscure, effective therapies to preserve GI epithelial integrity in clinic are limited, especially in patients with critical surgical illnesses. During previous funding period, we have established the importance of canonical transient receptor potential-1 (TRPC1)-mediated Ca2+ signaling in regulating intestinal epithelial restitution after mucosal injury. However, the exact upstream signals initiating TRPC1 channel activation after mucosal injury remain elusive and are the focus of this competitive renewal application. Recently, stromal interaction molecule 1 (STIM1) was identified in screens for molecules that are essential for the activation of store-operated Ca2+ channels (SOCs), whereas inhibition of STIM1 expression reduces store-operated Ca2+ entry (SOCE) after store depletion. Our preliminary results indicate that a) levels of levels of STIM1 at the plasma membrane increase significantly after wounding, b) overexpression of the constitutively active STIM1 EF-hand mutant increases SOCE and enhances epithelial restitution after wounding, and c) STIM1 silencing decreases SOCE and represses epithelial restitution in cells overexpressing TRPC1. Based on these exciting observations, we HYPOTHESIZE that STIM1 plays an important role in promoting GI epithelial restitution after mucosal injury by activating TRPC1 channel activity. Three specific aims are proposed to test the hypothesis. 1) To determine the pattern and role of STIM1 in gut epithelial restitution after mucosal injury in vitro as well as in vivo. 2) To characterize functional and physical interactions of STIM1 with TRPC1 in regulating SOCE during intestinal epithelial restitution. 3) To define the cellular signaling pathways regulating STIM1 subcellular redistribution and its expression after mucosal injury. Completion of these aims will identify the up stream signals initially activating TRPC1 channels after mucosal injury and also yield a novel model in which STIM1 subcellular trafficking and expression are regulated during restitution. It is hoped that our findings will provide supportive data to strengthen our long-term goal that is to develop therapeutic approaches for GI mucosal injury-related diseases and for maintaining epithelial integrity under various clinical conditions. PUBLIC HEALTH RELEVANCE: Project Narrative Immediate goal of the current study is to define the mechanisms underlying acute gut mucosal injury and repair. Various acute GI mucosal injury and gastritis are much more common at our VA patients than those observed in the general public. It has been reported that there are 24.7% prevalence of GI ulcers and injury in veteran population, compared with 10.5% in the control population. Furthermore, drugs, specifically NSAIDs, and stress as etiologic factors in GI mucosal injury and ulcerations are becoming increasing important. This is especially relevant to the new and young OEF/OIF veterans who return with a major increase in the prevalence of stress-related disorders. The incidence of stress-induced mucosal injury and ulceration in critically ill intensive patients as well as in military combat situations further aggravate the problem of GI mucosal injury and injury-related disorders in the VA population. However, the effective therapies for preventing acute gut mucosal injury and for promoting mucosal repair in clinic are limited to date, because of lacking knowledge of the mechanisms involved in gut mucosal injury and repair. Thus, improving the understanding of the processes that maintain the integrity of the gut mucosa and enhance repair is the first step towards therapeutic initiatives in this area and is the focus of the current proposal. Based on our previous studies and exciting preliminary results, studies proposed here are to determine whether a novel protein STIM1 plays an important role in promoting GI epithelial restitution after mucosal injury by Ca2+-signaling. Completion of these aims will provide supportive data to strengthen our long-term goal that is to develop therapeutic approaches for GI mucosal injury-related diseases for our VA patients.

描述（由申请人提供）： 项目摘要/摘要早期粘膜恢复是胃肠道 (GI) 中重要的主要修复方式，其调节缺陷是各种关键病理状态的基础，例如粘膜出血和急性损伤、胃肠道上皮完整性破坏和屏障功能障碍。由于急性粘膜损伤和浅表伤口后早期快速粘膜再上皮化的确切机制仍不清楚，因此临床上保护胃肠道上皮完整性的有效治疗方法有限，特别是对于患有严重外科疾病的患者。在之前的资助期间，我们已经确定了经典瞬时受体电位 1 (TRPC1) 介导的 Ca2+ 信号在调节粘膜损伤后肠上皮恢复中的重要性。然而，粘膜损伤后启动 TRPC1 通道激活的确切上游信号仍然难以捉摸，也是这一竞争性更新应用的焦点。最近，在筛选激活钙池操纵的 Ca2+ 通道 (SOC) 所必需的分子时，发现了基质相互作用分子 1 (STIM1)，而抑制 STIM1 表达会减少钙池耗尽后钙池操纵的 Ca2+ 进入 (SOCE)。我们的初步结果表明，a）受伤后质膜上的 STIM1 水平显着增加，b）组成型活性 STIM1 EF-hand 突变体的过度表达增加了 SOCE 并增强了受伤后上皮的恢复，c）STIM1 沉默降低了 SOCE 和抑制过表达 TRPC1 的细胞的上皮恢复。基于这些令人兴奋的观察结果，我们假设 STIM1 通过激活 TRPC1 通道活性在促进粘膜损伤后胃肠道上皮恢复中发挥重要作用。提出了三个具体目标来检验该假设。 1) 确定 STIM1 在体外和体内粘膜损伤后肠上皮恢复中的模式和作用。 2) 表征 STIM1 与 TRPC1 在肠上皮恢复过程中调节 SOCE 的功能和物理相互作用。 3)明确粘膜损伤后调节STIM1亚细胞重分布及其表达的细胞信号通路。完成这些目标将识别粘膜损伤后最初激活 TRPC1 通道的上游信号，并产生一种新模型，其中 STIM1 亚细胞运输和表达在恢复过程中受到调节。希望我们的研究结果将为加强我们的长期目标提供支持性数据，即开发胃肠道粘膜损伤相关疾病的治疗方法并在各种临床条件下维持上皮完整性。 公共卫生相关性： 项目叙述当前研究的直接目标是确定急性肠粘膜损伤和修复的机制。各种急性胃肠道粘膜损伤和胃炎在我们的 VA 患者中比在普通公众中观察到的更为常见。据报道，退伍军人人群中胃肠道溃疡和损伤的患病率为 24.7%，而对照人群中这一比例为 10.5%。此外，药物（特别是非甾体抗炎药）和压力作为胃肠道粘膜损伤和溃疡的病因因素变得越来越重要。这对于新的和年轻的 OEF/OIF 退伍军人尤其重要，他们回来时压力相关疾病的患病率大幅增加。重症重症患者以及军事战斗情况下应激性粘膜损伤和溃疡的发生率进一步加剧了退伍军人群体中胃肠道粘膜损伤和损伤相关疾病的问题。 然而，由于缺乏对肠粘膜损伤和修复机制的了解，迄今为止临床上预防急性肠粘膜损伤和促进粘膜修复的有效疗法有限。因此，提高对维持肠粘膜完整性和增强修复过程的理解是该领域治疗举措的第一步，也是当前提案的重点。 基于我们之前的研究和令人兴奋的初步结果，本文提出的研究旨在确定一种新型蛋白质 STIM1 是否在 Ca2+ 信号传导引起的粘膜损伤后促进胃肠道上皮恢复中发挥重要作用。这些目标的完成将为加强我们的长期目标提供支持性数据，即为我们的 VA 患者开发胃肠道粘膜损伤相关疾病的治疗方法。