Hemostasis System in Acute Inflammation-Sepsis

急性炎症败血症的止血系统

• 批准号: 6853266
• 负责人: FRANCIS J CASTELLINO
• 金额: $ 47.25万
• 依托单位: UNIVERSITY OF NOTRE DAME
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6853266
• 关键词: animal morbidity; anticoagulants; blood coagulation; cell adhesion molecules; cellular pathology; clotting factor; disease /disorder model; endotoxins; fibrinolysis; gene expression; gene mutation; gene targeting; genetically modified animals; hemostasis; inflammation; injury; laboratory mouse; lipopolysaccharides; molecular pathology; organ; pathologic process; septic shock; septicemia; tissue /cell culture

There is a strong relationship between inflammation and hemostasis that is based on the understanding that a proinflammatory environment is also procoagulant. Events that lead to the generation of the Factor (F) Vlla/Tissue Factor (TF) complex in an acute inflammatory state, such as gram-negative sepsis, begin with endotoxin-mediated activation of ieukocytes and endothelial cells, and cytokine and chemokine upregulation from these altered cells, along with expression of TF. The consequent generation of the procoagulants, thrombin and FXa, initiates signaling pathways via interactions of these proteases with protease activated cellular receptors, and thus mediate further cellular (e.g., platelet, endothelial cell, leukocyte) responses that are involved in blood coagulation, as well as inflammation and vessel formation. The activation of these cells also results in the expression of adhesion molecules on their surfaces, thereby facilitating leukocyte binding to the endothelium. This interaction is the first step in ultimate extravasation of neutrophils and macrophages into organs, thereby causing severe organ damage in the advanced septic state. Thus, it is our basic hypothesis that attenuation of inflammation may result from inhibition of coagulation and vice versa, and sepsis models using appropriate gene-targeted mice will allow an understanding of these relationships in vivo at the level of the gene. The overall goal of this proposal is to dissect the in vivo relationships between individual genes of hemostasis and inflammation that occur in an acute model of the serious inflammatory disease, gram-negative sepsis, with its progression to severe sepsis and septic shock. Mice with single and combined genetic alterations in the pathways of hemostasis will be employed with endotoxin (LPS)-mediated models of sepsis in order to monitor the relationships between hemostasis and inflammation in the progression of the disease. Specifically, 5 highly interconnected specific aims are proposed: (1) to employ mice (and isolated endothelial cells and adherent macrophages) with genetic alterations of specific hemostasis-related genes in examining the progression of induced sepsis to severe sepsis and septic shock, and ultimate survival; (2) to assess temporal responses, after injection of LPS, of the systemic coagulation, anticoagulation, and fibrinolytic systems in these genotypically-distinct mice; (3) to measure in these same mice, the temporal plasma and organ responses of specific cytokines, chemokines, soluble adhesion proteins, and other inflammatory mediators; (4) to determine the temporal nature of organ and cell damage in tissue slices in these mice after LPS administration; and (5) to employ additional mice with combined deficiencies of hemostasis- and inflammation-related genes to further understand the in vivo mechanisms involved in their sepsis-related effects. It is expected that the results of this study will allow an in vivo evaluation of the roles of specific hemostasis- and inflammation-related genes in the development and course of this model of acute inflammatory disease, and will provide groundwork for therapeutic interventions to attenuate the morbidity and mortality associated with its downward progression.

炎症和止血之间存在牢固的关系，这是基于这样的理解，即促炎环境也是促凝的。导致急性炎症状态下因子（f）VLLA/组织因子（TF）复合物（例如革兰氏阴性败血症）的事件开始从这些改变的细胞以及TF的表达中。随之而来的促凝剂，凝血酶和FXA的产生通过这些蛋白酶与蛋白酶活化的细胞受体的相互作用启动信号通路，从而介导了与血液凝结有关的进一步的细胞（例如血小板，内皮细胞，白细胞）反应的进一步的细胞（例如血小板，内皮细胞，白细胞）反应作为炎症和血管形成。这些细胞的激活还导致表面上粘附分子的表达，从而 促进白细胞与内皮结合。这种相互作用是嗜中性粒细胞和巨噬细胞最终渗入器官的第一步，从而在晚期败血性状态下造成严重的器官损害。因此，我们的基本假设是，炎症的衰减可能是抑制凝血的抑制作用，反之亦然，使用适当的基因靶向小鼠的败血症模型将使在基因水平上的体内了解这些关系。该提案的总体目的是剖析止血和炎症的个体基因之间的体内关系，这些基因在严重的炎性疾病，革兰氏阴性败血症的急性模型中发生，其发展为严重的败血症和败血性休克。脓毒症（LPS）介导的败血症模型将采用止血途径的单一且遗传变化的小鼠，以监测疾病进展中止血与炎症之间的关系。具体而言，提出了5个高度相互连接的特定目的：（1）使用特定止血基因的遗传改变的小鼠（以及分离的内皮细胞和粘附巨噬细胞）在 检查诱发败血症到严重的败血症和败血性休克的进展，以及最终的生存； （2）评估在这些基因型赋予小鼠中的全身凝结，抗凝和纤维蛋白水解系统的LPS后的时间反应； （3）在这些相同的小鼠中测量特定细胞因子，趋化因子，可溶性粘附蛋白和其他炎症介质的颞等血浆和器官反应； （4）确定LPS给药后这些小鼠组织切片中器官和细胞损伤的时间性质； （5）采用止血和炎症相关基因缺乏的其他小鼠，以进一步了解与其脓毒症相关作用涉及的体内机制。可以预期，这项研究的结果将允许对特定止血和炎症相关基因在这种模型的发展和过程中的作用进行体内评估。 急性炎症性疾病，将为治疗干预提供基础，以减轻与其下降进展相关的发病率和死亡率。