Disintegrin Metalloprotease and Endothelial Dysfunction in Sepsis

项目总结/摘要 蛇咬伤的受害者经常出现败血症样症状，如水肿和呼吸窘迫综合征。 对蛇毒的分析已经鉴定了一个蛋白酶家族，其特征是去整合素金属蛋白酶 （亚当斯）具有切割跨膜分子的能力。我们以前的工作得到了这笔赠款的支持 一直专注于这个家族的一个独特成员，ADAM 15，就其分子结构和功能而言， 调节内皮屏障特性。我们报道了肺和血管组织中的ADAM 15上调， 在炎症过程中，它增加内皮通透性，并通过Src- 依赖于由其胞质结构域转导的信号传导。在这次更新申请中，我们计划将我们的 通过检测具有高翻译活性的新型分子靶点，将ADAM 15的研究推向新的水平。 价值和治疗潜力。这些研究将集中在内皮糖萼，一种屏障保护结构 由与跨膜蛋白聚糖和糖蛋白连接的糖胺聚糖链组成， 在受伤或大手术后流入血液循环。要测试的中央通路是在脓毒症期间 损伤时，ADAM 15切割这些跨膜分子，导致糖萼降解。的曝光 内皮细胞与循环细胞和试剂，沿着作为高渗透性因子的脱落产物， 促进血浆渗漏和白细胞渗出。提出了三个具体目标：1）表征 脓毒症时ADAM诱导的糖萼损伤; 2）阐明ADAM诱导脓毒症时糖萼损伤的分子机制， 导致糖萼降解;和3）测试靶向ADAM-糖萼的治疗潜力 治疗败血症的途径。我们将采用互补的方法，整合生理反应 以及器官、组织和细胞水平的分子反应。创新的实验模型和疗法将成为 测试.独特的设计是在临床相关条件下表征肺病理生理学， 利用由联邦认证的器官提供的可用的完整可行的人体器官， 采购组织。从拟议的工作中获得的数据将为研究 脓毒症的分子发病机制。这项研究也将有助于识别和发展的小说 用于治疗与感染、创伤或大手术相关的血管炎性损伤的治疗靶点。

PROJECT SUMMARY/ABSTRACT Snakebite victims often present with sepsis-like symptoms, such as edema and respiratory distress syndrome. Analyses of snake venoms have identified a family of proteases characteristic of disintegrin metalloproteases (ADAMs) with the capability to cleave transmembrane molecules. Our previous work supported by this grant has focused on a unique member of this family, ADAM15, with respect to its molecular structure and function in regulating endothelial barrier property. We reported ADAM15 upregulation in the lungs and vascular tissues during inflammation, where it increases endothelial permeability and promotes leukocyte migration via Src- dependent signaling transduced by its cytoplasmic domain. In this renewal application, we plan to bring our investigation on ADAM15 to the next level by examining its novel molecular targets with high translational values and therapeutic potential. The studies will focus on endothelial glycocalyx, a barrier protective structure composed of glycosaminoglycan chains linked to transmembrane proteoglycans and glycoproteins, which are shed into the circulation following injury or major surgery. The central pathway to be tested is that during septic injury, ADAM15 cleaves these transmembrane molecules leading to glycocalyx degradation. The exposure of endothelium to circulating cells and agents, along with shedding products acting as hyperpermeability factors, promotes plasma leakage and leukocyte diapedesis. Three specific aims are proposed: 1) to characterize ADAM-induced glycocalyx injury during sepsis; 2) to elucidate the molecular mechanisms by which ADAM causes glycocalyx degradation; and 3) to test the therapeutic potential of targeting the ADAM-glycocalyx pathway for treating sepsis. We will employ complementary approaches that integrate physiological responses and molecular reactions at organ, tissue, and cell levels. Innovative experimental models and therapies will be tested. A unique design is the characterization of lung pathophysiology under clinically relevant conditions, taking advantage of the available intact viable human organs provided by a federally certified organ procurement organization. Data derived from the proposed work will provide new mechanistic insights into the molecular pathogenesis of sepsis. The study will also assist in the identification and development of novel therapeutic targets for treating vascular inflammatory injury associated with infection, trauma or major surgery.