TLR2 in Sepsis-Induced Coagulopathy, Endothelial Leak, and Pulmonary Dysfunction

TLR2 在脓毒症引起的凝血病、内皮渗漏和肺功能障碍中的作用

基本信息

批准号：
7860482
负责人：
Judith Hellman
金额：
$ 34.52万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-06-01 至 2012-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7860482
关键词：
Acute Lung Injury Adherence Agonist Albumins Anticoagulants Anticoagulation Antithrombin III Bacterial Counts Blood Blood Coagulation Disorders Blood Platelets Blood Vessels Blood coagulation Coagulation Process Complex Data Edema Endothelial Cells Endothelium Family Fibrin fragment D Fibrinogen Fibrinolysis Fibrinolytic Agents Functional disorder Gram-Negative Bacteria Histologic Human Hypoxia Immune response In Vitro Infection Inflammation Inflammatory Knock-out Knockout Mice Life Ligands Lipoproteins Lung Measures Mediating Mediator of activation protein Modeling Mus Nitric Oxide Nitrites Organ failure Pathway interactions Peritonitis Permeability Plasma Plasminogen Activator Inhibitor 1 Pneumonia Process Protein C Pulmonary Edema Receptor Activation Relative (related person)Respiratory Failure Respiratory physiology Role Sepsis Shock Signal Pathway System TFPI Testing Thromboplastin Thrombosis Time Toll-Like Receptor 2 Toll-like receptors Toxic effect Vascular Permeabilities Weight Wild Type Mouse in vivo inflammatory marker inhibitor/antagonist insight microbial microorganism monolayer mortality neutrophil respiratory response treatment effect vasoconstriction wet lung

项目摘要

The central hypothesis is that activation of Toll-like receptor (TLR) 2 contributes to the connected processes of endothelial dysfunction, coagulopathy, and increased vascular permeability in sepsis. TLR2 mediates the inflammatory effects of bacterial lipoproteins. The studies will define mechanisms by which TLR2 agonists modulate coagulation pathways in endothelial cells, and will assess the functional significance of TLR2 activation on endothelial permeability and coagulopathy in sepsis. These studies will provide insights into the mechanisms of coagulopathy, vascular leak, and respiratory dysfunction in sepsis. TLR2 agonists are present in all of the major classes of microorganisms that cause sepsis. Thus if TLR2 is important in sepsis-induced coagulopathy, vascular leak or respiratory failure, then TLR2 signaling pathways could be suitable targets for sepsis therapies. Specific Aim #1: Define mechanisms by which TLR2 activation modulates endothelial cell (EC) expression of coagulation pathway factors in vitro. Studies will test the hypotheses that TLR2 agonists alter expression of factors involved in coagulation, anticoagulation, and fibrinolysis: 1) through NF-B, and 2) through additional mediators, including TGF-, TNF, and/or NO. EC will be treated with TLR2 agonists, and expression of tissue factor (TF), tissue factor pathway inhibitor (TFPI), and plasminogen activator inhibitor type 1 (PAI-1) will be quantified. Mechanisms by which TLR2 agonists modulate coagulation pathways will be defined using EC from knockout mice, and using targeted inhibitors with human endothelial cells. Specific Aim #2: Assess the effects of TLR2 activation on endothelial permeability in vitro. Studies will test the hypotheses that TLR2 activation increases endothelial leakiness, as assessed by permeability of EC monolayers to albumin. Specific Aim #3: Define the functional significance of TLR2 activation on coagulopathy and on lung vascular permeability in sepsis. Sepsis will be induced in mice using peritonitis and pneumonia models. Studies will compare responses of TLR2 knockout mice with those of wild-type mice, and will assess the relative importance of TLR2 in the pathophysiology of Grampositive versus Gram-negative sepsis. Blood coagulation times will be measured, and levels of factors involved in coagulation and fibrinolysis will be quantified in blood and in lung. Lung vascular leakiness will be assessed using lung wet:dry weight ratios and permeability to albumin. Histologic analyses will assess for microvascular thrombosis, architectural changes, evidence of pulmonary edema, and lung expression of PAI-1 and TF.

中心假设是，Toll样受体（TLR）2的激活有助于内皮功能障碍，凝血病和败血症中血管通透性增加的连接过程。 TLR2介导细菌脂蛋白的炎症作用。这些研究将定义TLR2激动剂调节内皮细胞中的凝血途径的机制，并将评估TLR2激活对内皮渗透性和脓毒症中凝血病的功能意义。这些研究将提供有关脓毒症中凝血病，血管泄漏和呼吸功能障碍的机制的见解。 TLR2激动剂存在于引起脓毒症的所有主要微生物中。因此，如果TLR2在败血症诱导的凝血病，血管泄漏或呼吸衰竭中很重要，那么TLR2信号通路可能是败血症疗法的合适靶标。特定目的＃1：定义TLR2激活调节体外凝结途径因子的内皮细胞（EC）表达的机制。研究将测试TLR2激动剂改变涉及凝血，抗凝和纤维蛋白溶解因素的表达的假设：1）至NF-B，以及2）通过包括TGF-，TNF和/或NO的其他介体。 EC将用TLR2激动剂治疗，将量化组织因子（TF），组织因子途径抑制剂（TFPI）和纤溶酶原激活物抑制剂1型（PAI-1）的表达。 TLR2激动剂通过敲除小鼠的EC定义凝血途径的机制，并使用具有人类内皮细胞的靶向抑制剂来定义。特定目标＃2：评估TLR2激活对体外内皮通透性的影响。研究将测试TLR2激活会增加内皮泄漏的假设，这是通过EC单层对白蛋白的渗透性所评估的。特定目的＃3：定义TLR2激活对凝血病和败血症中肺血管通透性的功能意义。使用腹膜炎和肺炎模型，将在小鼠中诱导败血症。研究将将TLR2基因敲除小鼠与野生型小鼠的反应进行比较，并将评估TLR2在Grampositive与革兰氏阴性败血症的病理生理学中的相对重要性。将测量血液凝血时间，并在血液和肺中量化凝血和纤维蛋白溶解的因素水平。肺血管渗漏将使用肺湿：干重比和与白蛋白的渗透性进行评估。组织学分析将评估微血管血栓形成，建筑变化，肺水肿的证据以及PAI-1和TF的肺表达。