SURGICAL STUDIES ON MUCOSAL HOMEOSTASIS

粘膜稳态的外科研究

• 批准号: 7924913
• 负责人: Rao N. Jaladanki
• 金额: --
• 依托单位: BALTIMORE VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7924913
• 关键词: Acute; Aging; Area; Bacteria; Blood; Burn injury; CAV1 gene; Cell Proliferation; Cell membrane; Cells; Chronic; Confocal Microscopy; Coupling; Critical Illness; Development; Disease; Endoplasmic Reticulum; Epithelial; Epithelial Cells; Fluorescence; Functional disorder; Genes; Goals; Healed; Hemorrhage; Homeostasis; Image Analysis; Immunohistochemistry; In Vitro; Injury; Intestinal Mucosa; Intestines; Maintenance; Measurement; Measures; Mediating; Membrane Microdomains; Modality; Modeling; Molecular; Morbidity - disease rate; Mucous Membrane; Mus; Operative Surgical Procedures; Organ; Patients; Play; Poison; Polyamines; Population; Process; Proteins; Regulation; Role; Sarcoplasmic Reticulum; Sepsis; Series; Shock; Signal Pathway; Signal Transduction; Small Interfering RNA; Stream; Stress; TRPC1 protein; Techniques; Testing; Transfection; Trauma; Work; abstracting; base; caveolin 1; cell motility; cellular imaging; design; digital; effective therapy; gastrointestinal epithelium; healing; heat injury; human tissue; in vivo; mortality; novel; operation; overexpression; receptor; repaired; research study; response

DESCRIPTION (provided by applicant): Abstract Patients with critical surgical disorders such as trauma, thermal injury, shock, sepsis, and massive surgical operations are commonly complicated with gut mucosal injury and bleeding, but effective therapies to preserve the epithelial integrity are limited to date. Delayed mucosal repair causes disruption of mucosal epithelial integrity in patients with critical surgical stress, thus contributing to the morbidity and mortality. Early rapid epithelial restitution is an important primary repair modality in the gut mucosa and plays a critical role in maintaining mucosal integrity, but the exact mechanism underlying this process remains unclear. Epithelial restitution occurs as a consequence of cell migration over the damaged area after superficial injury, a process that is independent of cell proliferation. Our previous studies have shown the importance of canonical transient receptor potential-1 (TRPC1)-mediated Ca2+ signaling in regulating intestinal epithelial restitution after mucosal injury and that TRPC1 activation is crucial for stimulation of intestinal epithelial cell (IEC) migration after wounding. However, the exact signals initiating TRPC1 channel activation after mucosal injury remain elusive and are the focus of this application. Our preliminary results further indicate that a) intestinal mucosa highly expresses a novel protein caveolin-1 (Cav1); b) Cav1 silencing not only decreases store depletion-induced Ca2+ influx but also represses cell migration in cells overexpressing TRPC1; and c) Cav1 level is tightly regulated by cellular polyamines. Based on these exciting observations, we HYPOTHESIZE that Cav1 plays an important role in promoting gut epithelial restitution after mucosal injury by activating TRPC1 channel activity. Three specific aims are proposed to test the hypothesis: 1) to characterize the functional expression of the Cav1 gene in IECs; 2) to determine if Cav1 activation plays a role in stimulation of IEC migration after mucosal injury in critical surgical conditions; and 3) to define the mechanism underlying Cav1 expression during epithelial restitution, with particularly focusing on cellular polyamines. Completion of this study will provide a fundamental base for development of new therapies to protect the gut mucosa in critical surgical conditions and facilitate repair of damaged mucosa. PUBLIC HEALTH RELEVANCE: Patients with critical surgical disorders such as trauma, thermal injury, shock, sepsis, and massive surgical operations are commonly complicated with gut mucosal injury and bleeding, but effective therapies to preserve the epithelial integrity are limited to date. Delayed mucosal repair causes disruption of mucosal epithelial integrity, thus contributing to the morbidity and mortality. Although mucosal restitution is critical for maintaining epithelial integrity during critical surgical stress, the exact mechanism underlying this process remains unclear. Goal of this study is to define the cellular and molecular mechanism by which damaged mucosa is rapidly repaired by testing a novel hypothesis that caveolin-1, an important protein that is involved Ca2+-signaling, plays a role in the regulation of gut mucosal restitution after wounding through interaction with Ca2+-permeable channel TRPC1. Completion of this study will provide a fundamental base for development of new therapies to protect the gut mucosa in critical surgical conditions and facilitate repair of damaged mucosa.

描述（由申请人提供）： 摘要 患有创伤、热损伤、休克、脓毒症和大型外科手术等重大外科疾病的患者通常会并发肠粘膜损伤和出血，但迄今为止保留上皮完整性的有效治疗方法有限。粘膜修复延迟会导致患有严重手术应激的患者粘膜上皮完整性破坏，从而导致发病率和死亡率。早期快速上皮恢复是肠道粘膜重要的初级修复方式，在维持粘膜完整性方面发挥着关键作用，但这一过程的确切机制仍不清楚。上皮恢复是表面损伤后细胞迁移到受损区域的结果，这是一个独立于细胞增殖的过程。我们之前的研究表明，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，并且 TRPC1 激活对于刺激受伤后肠上皮细胞 (IEC) 迁移至关重要。然而，粘膜损伤后启动 TRPC1 通道激活的确切信号仍然难以捉摸，也是本应用的重点。我们的初步结果进一步表明，a）肠粘膜高度表达一种新型蛋白caveolin-1（Cav1）； b) Cav1沉默不仅减少储存耗尽引起的Ca2+流入，而且抑制过表达TRPC1的细胞中的细胞迁移； c) Cav1 水平受到细胞多胺的严格调节。基于这些令人兴奋的观察结果，我们假设 Cav1 通过激活 TRPC1 通道活性在促进粘膜损伤后肠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）表征 IEC 中 Cav1 基因的功能表达； 2) 确定Cav1激活是否在关键手术条件下粘膜损伤后刺激IEC迁移中发挥作用； 3) 定义上皮恢复过程中 Cav1 表达的机制，特别关注细胞多胺。这项研究的完成将为开发新疗法奠定基础，以在危急手术条件下保护肠道粘膜并促进受损粘膜的修复。 公共卫生相关性： 患有创伤、热损伤、休克、脓毒症和大规模外科手术等严重外科疾病的患者通常会并发肠粘膜损伤和出血，但迄今为止，保护上皮完整性的有效疗法有限。粘膜修复延迟会导致粘膜上皮完整性破坏，从而导致发病率和死亡率。尽管粘膜恢复对于在关键手术应激期间维持上皮完整性至关重要，但该过程背后的确切机制仍不清楚。本研究的目的是通过测试一个新的假设来确定受损粘膜快速修复的细胞和分子机制，即 Caveolin-1（一种涉及 Ca2+ 信号传导的重要蛋白质）在肠道粘膜恢复的调节中发挥作用。通过与 Ca2+ 通透通道 TRPC1 相互作用而造成伤害。这项研究的完成将为开发新疗法奠定基础，以在危急手术条件下保护肠道粘膜并促进受损粘膜的修复。