Trauma and Shock-Induced Microvascular Dysregulation and Coagulopathy

项目负责人/主要研究者（最后，第一，中间）：Kozar RA/ Dong JF 项目摘要 创伤是可预防死亡的主要原因，大多数死亡是由出血和 血管损伤导致的相关并发症（出血性休克[HS]）。当出血导致 在凝血因子和血小板的快速损失，越来越多的证据表明，继发性凝血功能障碍， 从创伤引起的高凝状态发展，迅速转变为消耗性凝血病， 是由于HS诱导的低灌注和组织缺血引起的微血管内皮病的组成部分。的 内皮病产生了炎症和氧化应激环境，其中内皮细胞（EC） 激活，屏障功能被破坏。这种微血管失调的一个标志是血管内皮细胞的丢失。 内皮糖萼，通过多配体蛋白聚糖-1锚定到内皮的碳水化合物的保护层。的 糖萼保护内皮细胞免受血液和血浆因子的影响，并具有抗炎，抗血栓形成， 和抗氧化应激分子。在HS后丢失，伴随多配体蛋白聚糖-1胞外域的脱落， 金属蛋白酶ADAM-17。糖萼的缺失使抗凝血和抗炎的内皮细胞 高度促凝血和促炎。关键的问题是什么触发脱落及其病理性 后果我们最近的数据表明，粘附配体血管性血友病因子（VWF）和 细胞外囊泡（EV）在内皮病和继发于创伤和由此产生的HS的凝血病中的作用。在这 在这项研究中，我们提出了以下假设：1）syndecan-1脱落与进行性内皮细胞 由过度粘附的VWF和病理性EV的释放引起的调节异常，2）触发syndecan-1脱落 通过与膜脂筏中的ADAM-17聚集，和3）暴露受体结合A1结构域， 高粘附性VWF通过将炎性细胞和EV束缚于糖萼而增强内皮病， 剥离的内皮。我们进一步假设，糖萼损失， 高粘附性VWF和EV可以被阻断以防止内皮病。我们建议测试这些假设 通过分析来自创伤患者的血浆样品和临床信息，确定导致创伤的途径， syndecan-1脱落和VWF体外超粘附活性的结构基础，并测试新的和 在HS小鼠模型中的创新治疗策略有以下三个目的：目的1： 出血性脑损伤患者进行性微血管失调导致血液衰竭 目的2：研究syndecan-1在体外脱落的途径和高粘附性VWF的结构， 目的3：测试新的治疗剂以减轻小鼠创伤诱导的微血管失调 HS模型我们的提案提出了创新的概念和新的机制，提供了一个新的范例 用于逆转内皮病和凝血病，可为开发 作为复苏剂的创新疗法可进一步降低出血性休克相关的发病率， mortality. OMB编号0925-0001/0002（修订版03/2020批准至02/28/2023）页码继续格式页码

Program Director/Principal Investigator (Last, First, Middle): Kozar RA/ Dong JF Project Summary Trauma is the leading cause of preventable death, with the majority of deaths caused by hemorrhage and associated complications due to injury to the vasculature (hemorrhagic shock [HS]). While hemorrhage results in the rapid loss of coagulation factors and platelets, increasing evidence suggests that secondary coagulopathy develops from a trauma-induced hypercoagulable state that rapidly turns into consumptive coagulopathy, and is an integral part of microvascular endotheliopathy due to HS-induced hypoperfuson and tissue ischemia. The endotheliopathy creates an inflammatory and oxidative stress environment where endothelial cells (ECs) are activated and their barrier function disrupted. A hallmark of this microvascular dysregulation is loss of the endothelial glycocalyx, a protective layer of carbohydrates anchored to the endothelium by syndecan-1. The glycocalyx shields endothelial cells from blood and plasma factors and hosts anti-inflammatory, anti-thrombotic, and anti-oxidative stress molecules. It is lost following HS with shedding of the syndecan-1 ectodomain by the metalloprotease ADAM-17. Loss the of glycocalyx makes the anti-coagulant and anti-inflammatory endothelium highly procoagulant and proinflammatory. The critical question is what triggers shedding and its pathological consequences. Our recent data suggests causal roles of the adhesive ligand von Willebrand factor (VWF) and extracellular vesicles (EVs) in endotheliopathy and coagulopathy secondary to trauma and resultant HS. In this study, we propose to test the hypotheses that: 1) syndecan-1 shedding with progressive endothelial dysregulation caused by release of hyperadhesive VWF and pathologic EVs, 2) syndecan-1 shedding is triggered by clustering with ADAM-17 in membrane lipid rafts, and 3) exposure of the receptor-binding A1 domain on hyperadhesive VWF enhances endotheliopathy by tethering inflammatory cells and EVs to the glycocalyx- stripped endothelium. We further hypothesize that the synergistic interplay between glycocalyx loss, hyperadhesive VWF, and EVs can be blocked to prevent endotheliopathy. We propose to test these hypotheses by analyzing plasma samples and clinical information from trauma patients, defining pathways leading to syndecan-1 shedding and the structural basis of VWF hyperadhesive activity in-vitro, and testing new and innovative therapeutic strategies in mouse models of HS in the following three aims: Aim 1: To determine the progressive microvascular dysregulation culminating in blood failure of injured patients with hemorrhagic shock; Aim 2: To study the pathway of syndecan-1 shedding and the structure of hyperadhesive VWF in-vitro, and Aim 3: To test new therapeutic agents to mitigate trauma-induced microvascular dysregulation in mouse models of HS. Our proposal puts forth innovative concepts and novel mechanisms that offer a new paradigm for the reversal of endotheliopathy and coagulopathy that can establish the foundation for the development of innovative therapeutics as resuscitation adjuncts to further reduce hemorrhagic shock-related morbidity and mortality. OMB No. 0925-0001/0002 (Rev. 03/2020 Approved Through 02/28/2023) Page Continuation Format Page