MECHANISMS OF MICROVASCULAR THROMBOSIS

微血管血栓形成的机制

• 批准号: 2444643
• 负责人: FLETCHER B TAYLOR
• 金额: $ 40.41万
• 依托单位: OKLAHOMA MEDICAL RESEARCH FOUNDATION
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-12-01 至 1999-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2444643
• 关键词: Escherichia coli infections; anticoagulants; baboons; binding proteins; blood coagulation; coagulation factor X; complement; disease /disorder model; fibrinogen; hemolytic anemia; inflammation; interleukin 6; luminescence; monoclonal antibody; neutrophil; opsonin; plasminogen activator; platelets; protein C; protein S; protein structure function; receptor expression; renal failure; tumor necrosis factor alpha; venous thrombosis

In studies of the role of C4b binding protein (C4bBP) in the baboon response to E. coli, we observed a microvascular thrombotic (MVT) variant which mimics the hematolytic uremic syndrome (HUS). We identified the key inflammatory and coagulant mediators (ie. tumor necrosis factor, tissue factor, etc.) and anticoagulant regulators (ie. protein C and S, etc.). We established that inflammatory mediators initiated the coagulant response. We did not, however, establish how the inflammatory, coagulant, and anticoagulant systems interacted. In this proposal, we hypothesize that coagulant mediators can amplify inflammatory activity, and that as a consequence, anticoagulants also act as anti-inflammatory regulators. Conversely, we hypothesize that these inflammatory mediators decrease anticoagulant activity. This is a circle in which the regulator systems are influenced by disturbances in the two mediator systems and visa versa. We will ask the following three questions: First, does C4bBP neutralization of anticoagulant protein S affect platelet/coagulant status, and is the stage set for an increased inflammatory (MVT) response to TNF, I1-6, etc.? Second, conversely do these cytokines disable the normal regulatory protein C anticoagulant/fibrinolytic response to factor Xa phospholipid (XaPCPS) and "tip the balance" in favor of MVT? Third, do these or similar events involving these mediator/regulator systems occur in a baboon model of MVT/HUS induced by Shiga-like toxin? The coagulant, anticoagulant, and inflammatory (neutrophil), responses to C4bBP alone will be studied. These studies will include determination of neutrophil opsonin/receptor expression by blood luminescence analysis, and appearance of enzyme/inhibitor complexes composed of components of regulator systems. Platelet receptor, and, neutrophil receptor participation will be assessed using appropriate Fab monoclonal antibodies. Both the C4bBP and XaPCPS models will be perturbed with TNF and I1-6, etc., to determine the effect of the absence of protein C and S on the response to these mediators and their effect on a stressed, but compensated, anticoagulant/fibrinolytic response to XaPCPS. We will determine whether the compensated response to XaPCPS can be converted into a response by these cytokines and/or by coinfusion of antibodies to both protein C and tissue plasminogen activator. The experience and techniques used in the above intervention and reconstitution studies will be applied to mechanistic, diagnostic and treatment studies of the fully expressed Shiga-like toxin model of HUS/MVT.

在研究C4 b结合蛋白（C4 bBP）在狒狒中的作用时， 对E.大肠杆菌，我们观察到一个微血管血栓（MVT）的变异 其与溶血性尿毒综合征（HUS）相似。我们找到了钥匙 炎症和凝血介质（即，肿瘤坏死因子，组织 因素等）和抗凝剂调节剂（即，蛋白质C和S等）。 我们确定炎症介质启动凝血剂 反应 然而，我们并没有确定， 凝血剂和抗凝剂系统相互作用。 在这个建议中，我们假设凝血介质可以放大 炎症活性，因此，抗凝剂也起作用 作为抗炎调节剂。相反，我们假设这些 炎症介质降低抗凝活性。这是一个圆圈 其中调节器系统受两个系统中的干扰的影响， 调解人系统，反之亦然。 我们将提出以下三个问题：第一，C4 bBP是否 抗凝血蛋白S对血小板/凝血因子的中和作用 状态，并且是炎症反应增加（MVT）的阶段 TNF、I1-6等？第二，相反，这些细胞因子是否会使 正常调节蛋白C抗凝/纤溶反应因子 Xa磷脂（XaPCPS）和“倾斜平衡”有利于MVT？第三、 这些或类似的事件是否涉及这些中介/调节系统 发生在由志贺样毒素诱导的MVT/HUS狒狒模型中？ 凝血、抗凝和炎症（中性粒细胞）反应 C4 bBP单独进行研究。这些研究将包括确定 通过血液发光分析的中性粒细胞调理素/受体表达， 和酶/抑制剂复合物的出现，所述复合物由以下组分组成： 调节系统。血小板受体和中性粒细胞受体 将使用适当的Fab单克隆抗体评估参与情况。 抗体的C4 bBP和XaPCPS模型都将受到TNF干扰 和I1-6等，以确定缺乏蛋白C的影响， S的反应，这些调解人和他们的影响，强调，但 对XaPCPS的代偿性抗凝/纤溶反应。 我们将 确定是否可以转换对XaPCPS的补偿响应 通过这些细胞因子和/或通过共输注抗体， 蛋白C和组织型纤溶酶原激活剂。 在上述干预中使用的经验和技术， 重建研究将应用于机械，诊断和 完全表达的志贺样毒素模型的治疗研究 HUS/MVT。