PROTECTION FROM ENDOTOXIN SHOCK BY ACTIVATED PROTEIN C

活化蛋白 C 防止内毒素休克

• 批准号: 3293271
• 负责人: FLETCHER B TAYLOR
• 金额: $ 11.6万
• 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 1989-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3293271
• 关键词: Cercopithecidae; Escherichia coli; Escherichia coli infections; antibody; anticoagulants; blood coagulation disorders; clotting factor; macrophage; monoclonal antibody; monocyte; protein C; protein S; receptor; thromboplastin; tissue /cell culture; tumor necrosis factor alpha; vascular endothelium

The responses associated with E. coli sepsis and shock are numerous making it difficult to single out the important mediators and target tissues from epiphenomena. Three recent observations, however, provide an opportunity to study further, mechanisms and regulation of septic shock. First, Beutler et. al showed that antibody against tumor necrosis factor (TNF) protect a significant number of mice from endotoxin shock. Second, we showed that activated protein C also completely protects baboons from endotoxin/E. coli shock. Third, we showed that cultured endothelial cells have the protein S cofactor necessary for expression of the anticoagulant activity of activated protein C, and that exposure of these cells to TNF completely suppresses this protein S cofactor (anticoagulant) activity while expressing tissue factor (coagulation) activity. Since protein S on the endothelial cell is influenced favoring coagulation by TNF and favoring anticoagulation by activated protein C, we hypothesize that the coagulopathic and lethal effects of endotoxin are mediated through TNF and that they might be blocked by activated protein C acting through the endothelial cell-protein S assembly. Our first aim, therefore, is to determine if the protective effects, like the anticoagulant effects, are receptor mediated and require protein S. We also will determine if aortic endothelium in response to E. coli loses protein S while gaining tissue factor activity at the time systemic coagulopathy is most severe. We will then determine if activated protein C prevents both the systemic coagulopathy and the change in the activities of aortic endothelium. Finally, we will determine how late following E. coli infusion, activated protein C can be started and still protect the animals from shock. We want to know if failure to protect coincides with loss of S cofactor activity of aortic endothelium. Our second aim is to study the role of TNF in E. coli shock and determine if activated protein C inhibits any of its effects as it does those of E. coli. We will determine if TNF levels rise following E. coli infusion and if activated protein C blocks this rise. We will than infuse TNF directly, compare its effects with those of E. coli and find which of these effects are inhibited by activated protein C. Finally, assuming that activated protein C not only acts to prevent perturbation of endothelium by TNF, but also inhibits its synthesis, we will study the in vitro effect of activated protein C on endotoxin induced elaboration of TNF by cultures of monocyte/macrophages.

与E.大肠杆菌败血症和休克是 众多，很难挑出重要的 介质和靶组织的副作用。 最近的三 然而，观察提供了进一步研究的机会， 感染性休克的机制和调控。 首先，Beutler et. al显示抗肿瘤坏死抗体 TNF-α保护大量小鼠免受内毒素的侵害 冲击. 其次，我们发现活化蛋白C也 完全保护狒狒免受内毒素/E。大肠杆菌休克 第三、 我们发现培养的内皮细胞有蛋白S 表达抗凝血活性所必需的辅因子 活化蛋白C，这些细胞暴露于TNF 完全抑制这种蛋白S辅因子（抗凝剂） 活性，同时表达组织因子（凝血）活性。 由于内皮细胞上的蛋白S受到影响， TNF促凝，激活的 蛋白C，我们假设凝血病和致命的 内毒素的作用通过TNF介导， 可能会被激活的蛋白C阻断， 内皮细胞-蛋白S组装。 因此，我们的首要目标是确定是否有保护作用， 与抗凝作用一样，是受体介导的， 蛋白S。 我们还将确定主动脉内皮细胞是否 对E.大肠杆菌在获得组织因子的同时失去蛋白S 在系统性凝血病最严重时的活动。 我们 然后将确定活化蛋白C是否阻止了 系统性凝血病与主动脉活性的变化 内皮细胞 最后，我们将确定如何晚以下E。 大肠杆菌输注，活化蛋白C可以启动，仍然保护 动物从休克。 我们想知道如果保护不力 与主动脉内皮细胞S辅因子活性的丧失相一致。 我们的第二个目的是研究TNF在E.大肠杆菌休克和 确定活化蛋白C是否抑制其任何作用，因为它 E的那些。杆菌 我们将确定肿瘤坏死因子水平是否上升 继E.如果活化的蛋白C阻断了这一过程 上升. 我们将直接注入TNF，比较其效果， E.大肠杆菌，并找出这些影响被抑制 活化蛋白C 最后，假设活化蛋白C 不仅可以防止TNF对内皮的干扰， 也抑制它的合成，我们将研究在体外的影响， 活化蛋白C对内毒素诱导的TNF产生的影响 单核细胞/巨噬细胞的培养物。