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（由适用提供）：我是范德比尔特大学医学院儿科重症监护室的助理教授。作为儿科强化主义者，我定期遇到患者，患有与疾病相关的感染（医疗领域的目的地进展）仍然导致了明显的发病率和死亡率。我一直对免疫，感染和血管生物学有浓厚的兴趣。我以前的工作检查了脂多糖（LPS）诱导的血栓形成的血小板依赖性机制。在此期间，我专注于在内毒素血症动物模型中使用插入式显微镜和血小板聚集的微血管血栓形成的Toll样接收器4（TLR4）依赖性机制。该奖项将使我能够继续探索炎症机制，特别是在感染过程中调节内皮损伤的机制。同样重要的是，本奖项期间的活动将通过结构化的课程来增强我作为身体科学家的职业发展，并进行监督，以帮助我实现成功的研究独立性。医院可获得的感染是批判性IMH患者发病和死亡率的主要原因，其中危及烧伤的患者特别容易受到伤害。严重的感染引起明显的内皮功能障碍和损伤，这是一氧化氮和活性氧产生的改变的结果。但是，尚不清楚感染如何在内皮细胞中特异性调节这些途径。此外，目前没有可用于调节感染过程中内皮损伤的预防策略。在此提案中，我们将重点关注内皮一氧化氮合酶（ENOS） - 感染过程中内皮功能的依赖性变化，并应用TLR4定向的调节剂单磷酸脂质A（MPLA）。目标1：建立内皮TLR4信号传导改变eNOS函数的机制。这些实验的重点将是定义一种机制，该机制通过TLR4激活诱导了一氧化氮和活性氧的产生的eNOS功能障碍和相关的改变。目标2：确定内皮细胞中MPLA诱导的炎症调节的机制。我们将确定微生物挑战之前MPLA处理的机制会引起对人内皮细胞的受保护作用。目标3：定义MPLA在烧伤感染的情况下防止内皮功能障碍的能力。在这些研究中，我们将研究MPLA如何防止在烧伤缠绕感染的临床相关动物模型中，在临床相关的动物模型中阻止系统性内皮依赖性血管功能障碍。这项研究的目的是了解导致内皮功能障碍的细胞内机制，并定义感染引起的eNOS依赖性信号的作用。如果可以通过MPLA调节对内皮的负面影响，则该发现将具有直接的治疗潜力。烧伤受到感染的炎症反应是独一无二的，因为这些脆弱的患者通常在感染显着之前就会接受医疗救助。因此，它非常适合预防 治疗。