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：
7729046
负责人：
Judith Hellman
金额：
$ 34.27万
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 2011-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7729046
关键词：
Agonist Albumins Anticoagulation Bacteria Blood Blood Coagulation Disorders Blood Vessels Blood coagulation Coagulation Process Complex Data Dose Edema Endothelial Cells Fibrin Fibrin fragment D Fibrinogen Fibrinolysis Functional disorder Gram-Negative Bacteria Histologic Human Human Resources Immune response In Vitro Infection Inflammatory Knockout Mice Laparotomy Life Lipoproteins Lung Measures Mediating Mediator of activation protein Modeling Mus Organ failure Oxygen Pathway interactions Peritoneal Peritonitis Permeability Plasma Plasminogen Activator Inhibitor 1 Pneumonia Process Protein C Pulmonary Edema Relative (related person)Respiratory Failure Role Sepsis Shock Signal Pathway Study models TFPI Techniques Testing Thromboplastin Thrombosis Time TimeLine Toll-Like Receptor 2 Vascular Permeabilities Weight Wild Type Mouse Work implantation inhibitor/antagonist insight intraperitoneal macromolecule microorganism monolayer mortality respiratory response 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.

核心假设是 Toll 样受体 (TLR) 2 的激活有助于脓毒症中内皮功能障碍、凝血病和血管通透性增加的相关过程。 TLR2 介导细菌脂蛋白的炎症作用。这些研究将确定 TLR2 激动剂调节内皮细胞凝血途径的机制，并将评估 TLR2 激活对脓毒症中内皮通透性和凝血病的功能意义。这些研究将为脓毒症中凝血病、血管渗漏和呼吸功能障碍的机制提供见解。 TLR2 激动剂存在于引起败血症的所有主要微生物中。因此，如果 TLR2 在脓毒症引起的凝血病、血管渗漏或呼吸衰竭中发挥重要作用，那么 TLR2 信号通路可能是脓毒症治疗的合适靶点。具体目标#1：定义 TLR2 激活在体外调节内皮细胞 (EC) 凝血途径因子表达的机制。研究将检验以下假设：TLR2 激动剂改变参与凝血、抗凝和纤维蛋白溶解的因子的表达：1) 通过 NF-B，2) 通过其他介质，包括 TGF-β、TNF 和/或 NO。 EC 将用 TLR2 激动剂治疗，并对组织因子 (TF)、组织因子途径抑制剂 (TFPI) 和 1 型纤溶酶原激活剂抑制剂 (PAI-1) 的表达进行定量。 TLR2 激动剂调节凝血途径的机制将使用来自基因敲除小鼠的 EC 以及使用人类内皮细胞的靶向抑制剂来定义。具体目标#2：评估 TLR2 激活对体外内皮细胞通透性的影响。研究将测试 TLR2 激活增加内皮渗漏的假设，通过 EC 单层对白蛋白的渗透性进行评估。具体目标#3：确定 TLR2 激活对脓毒症凝血障碍和肺血管通透性的功能意义。使用腹膜炎和肺炎模型在小鼠中诱导败血症。研究将比较 TLR2 敲除小鼠与野生型小鼠的反应，并将评估 TLR2 在革兰氏阳性与革兰氏阴性脓毒症病理生理学中的相对重要性。将测量血液凝固时间，并量化血液和肺中参与凝血和纤维蛋白溶解的因子水平。将使用肺湿重：干重比和对白蛋白的渗透性来评估肺血管渗漏性。组织学分析将评估微血管血栓形成、结构变化、肺水肿证据以及 PAI-1 和 TF 的肺表达。