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)： 早期粘膜修复是胃肠道一种重要的修复方式，其调节缺陷是导致胃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等多种严重病理状态的基础。由于浅表创面后急性粘膜损伤和早期快速粘膜再上皮化的确切机制尚不清楚，临床上保护胃肠道上皮完整性的有效治疗方法有限，尤其是在外科危重疾病患者中。在之前的资助阶段，我们已经确定了典型瞬时受体电位-1(TRPC1)介导的钙信号在调节粘膜损伤后肠上皮修复中的重要性。然而，在黏膜损伤后启动TRPC1通道激活的确切上游信号仍然难以捉摸，并且是这一竞争性更新应用的焦点。最近，基质相互作用分子1(STIM1)被发现在筛选对激活商店操作的钙通道(SOCs)至关重要的分子，而抑制STIM1的表达减少了商店耗尽后的商店操作的钙进入(SOCE)。我们的初步结果表明，a)创伤后质膜STIM1水平显著增加，b)过表达具有结构性活性的STIM1 EF-Hand突变体增加SOCE并促进创伤后上皮恢复，以及c)STIM1沉默降低SOCE并抑制TRPC1高表达细胞的上皮恢复。基于这些令人兴奋的观察，我们推测STIM1通过激活TRPC1通道活性，在促进粘膜损伤后胃肠道上皮修复中发挥重要作用。为了检验这一假说，本文提出了三个具体目标。1)研究STIM1在体内外黏膜损伤后肠上皮修复中的表达模式及作用。2)研究STIM1和TRPC1在肠上皮重建过程中调节SOCE的功能和物理相互作用。3)明确调控粘膜损伤后STIM1亚细胞再分布及其表达的细胞信号通路。这些目标的完成将识别粘膜损伤后最初激活TRPC1通道的上游信号，并产生一种新的模型，在该模型中，STIM1亚细胞运输和表达在修复过程中受到调控。希望我们的发现将提供支持性数据，以加强我们的长期目标，即开发治疗胃肠道粘膜损伤相关疾病的方法，并在各种临床条件下保持上皮完整性。 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道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更常见。据报道，在退伍军人中，胃肠道溃疡和损伤的患病率为24.7%，而对照人群的患病率为10.5%。此外，药物，特别是非甾体抗炎药，以及应激作为胃肠道粘膜损伤和溃疡的致病因素正变得越来越重要。这与新的和年轻的OEF/OIF退伍军人特别相关，他们返回时与压力相关的障碍的患病率大幅增加。危重病人和军事战斗中应激引起的粘膜损伤和溃疡的发生率进一步加剧了退伍军人中胃肠道粘膜损伤和损伤相关疾病的问题。然而，由于对肠粘膜损伤和修复的机制缺乏了解，临床上预防急性肠粘膜损伤和促进粘膜修复的有效治疗方法仍然有限。因此，提高对维持肠道粘膜完整性和促进修复的过程的了解是朝着这一领域的治疗举措迈出的第一步，也是当前提案的重点。基于我们以前的研究和令人振奋的初步结果，本文提出的研究旨在确定一种新的蛋白STIM1是否通过钙信号在促进粘膜损伤后GI上皮修复中发挥重要作用。完成这些目标将提供支持性数据，以加强我们的长期目标，即为我们的VA患者开发GI黏膜损伤相关疾病的治疗方法。