Prevention of Endothelial Injury by Toll-like Receptor 4 Modulators

Toll 样受体 4 调节剂预防内皮损伤

• 批准号: 9252090
• 负责人: Ryan J Stark
• 金额: $ 9.17万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-20 至 2019-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9252090
• 关键词: Prevention; Endothelial; Injury; Toll; like

 DESCRIPTION (provided by applicant): I am an Assistant Professor in the Division of Pediatric Critical Care at Vanderbilt University School of Medicine. As a Pediatric Intensivist, I encounter patients on a regular basis that suffer from disease-related inflammation, which despite advances in the medical field, still lead to significant morbidity and mortality. I have always had a strong interest in immunity, inflammation and vascular biology. My previous work examined platelet-dependent mechanisms of lipopolysaccharide (LPS)-induced thrombosis. During that time, I focused on toll-like receptor 4 (TLR4)-dependent mechanisms of microvascular thrombosis using intravital microscopy and platelet aggregometry in animal models of endotoxemia. This award will allow me to continue to explore mechanisms of inflammation, specifically the modulation of endothelial injury during infections. Equally important, the activities pursued during this award will enhance my career development as a physician-scientist through a structured curriculum and mentored oversight to help me achieve successful research independence. Hospital-acquired infections are a leading cause of morbidity and mortality in critically-ill patients, among which critically-injured burn patients ar particularly vulnerable. Severe infections cause significant endothelial dysfunction and injury that is a consequence of alterations within nitric oxide and reactive oxygen species generation. However, it is unclear how infections specifically modulate these pathways in endothelial cells. Furthermore, there are no current preventative strategies available to modulate endothelial injury during infection. In this proposal, we will focus on endothelial nitric oxide synthase (eNOS)- dependent changes in endothelial function during infection and apply a TLR4-directed modulator, monophosphoryl lipid a (MPLA). Aim 1: Establish the mechanism by which endothelial TLR4 signaling alters eNOS function. The focus of these experiments will be to define the mechanisms by which eNOS dysfunction and associated alterations in nitric oxide and reactive oxygen species generation are induced by TLR4 activation. Aim 2: Determine the mechanism of MPLA-induced inflammatory modulation in endothelial cells. We will determine the mechanisms by which MPLA treatment prior to microbial challenge induces a protective effect on human endothelial cells. Aim 3: Define the ability of MPLA to prevent endothelial dysfunction in the setting of a burn-wound infection. In these studies, we will examine how MPLA prevents systemic endothelial- dependent vascular dysfunction in a clinically relevant animal model of burn-wound infection. The goal of this study is to understand the intracellular mechanisms leading to endothelial dysfunction and define the role of eNOS-dependent signals induced by infection. If the negative effects on the endothelium can be modulated with MPLA, this finding will have immediate therapeutic potential. The inflammatory response of burn injury with acquired infection is unique because these vulnerable patients typically come to medical attention before the infection becomes significant. It is therefore highly amenable to preventative therapy.

 描述（由申请人提供）：我是范德比尔特大学医学院儿科重症监护科的助理教授。作为一名儿科重症监护医师，我经常遇到患有疾病相关炎症的患者，尽管医学领域取得了进步，但仍然导致显著的发病率和死亡率。我一直对免疫、炎症和血管生物学有浓厚的兴趣。我以前的工作研究了脂多糖（LPS）诱导血栓形成的血小板依赖性机制。在此期间，我专注于Toll样受体4（TLR4）依赖性机制的微血管血栓形成，使用活体显微镜和血小板聚集在动物模型的内毒素血症。这个奖项将使我能够继续探索炎症的机制，特别是在感染过程中内皮损伤的调节。同样重要的是，在此奖项期间开展的活动将通过结构化的课程和指导监督来促进我作为一名医生科学家的职业发展，帮助我实现成功的研究独立性。医院获得性感染是危重患者发病和死亡的主要原因，其中危重烧伤患者尤为脆弱。严重感染引起显著的内皮功能障碍和损伤，这是一氧化氮和活性氧产生改变的结果。然而，目前尚不清楚感染如何特异性地调节内皮细胞中的这些通路。此外，目前还没有可用于调节感染期间内皮损伤的预防策略。在这项提案中，我们将集中在内皮型一氧化氮合酶（eNOS）依赖性的变化，在感染过程中的内皮功能，并应用TLR4定向调节剂，单磷酰脂质（MPLA）。目的1：建立内皮细胞TLR4信号通路改变eNOS功能的机制。这些实验的重点是定义TLR 4激活诱导eNOS功能障碍以及一氧化氮和活性氧产生相关变化的机制。目的2：探讨MPLA诱导内皮细胞炎症反应的机制。我们将确定微生物挑战前MPLA治疗诱导对人内皮细胞的保护作用的机制。目的3：确定MPLA在烧伤伤口感染情况下预防内皮功能障碍的能力。在这些研究中，我们将研究MPLA如何在临床相关的烧伤伤口感染动物模型中预防全身性内皮依赖性血管功能障碍。本研究的目的是了解导致内皮功能障碍的细胞内机制，并确定由感染诱导的eNOS依赖性信号的作用。如果对内皮细胞的负面影响可以用MPLA调节，这一发现将具有直接的治疗潜力。烧伤合并获得性感染的炎症反应是独特的，因为这些脆弱的患者通常在感染变得严重之前就就医。因此，它非常适合预防 疗法