PLATELET-ENDOTHELIAL CELL INTERACTIONS

血小板-内皮细胞相互作用

• 批准号: 3344691
• 负责人: Eric Franklin Grabowski
• 金额: $ 13.15万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-01 至 1992-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3344691
• 关键词: anticoagulants; blood coagulation tests; blood viscosity; cardiovascular disorder chemotherapy; cardiovascular pharmacology; cell adhesion; cell cell interaction; coagulation factor VIII; eicosanoid metabolism; fluorescence microscopy; granulocyte; human subject; immunofluorescence technique; leukocytes; phantom model; platelet aggregation; prostacyclins; prostaglandin E; prostaglandin inhibitors; radioimmunoassay; thrombosis; tissue /cell culture; vascular endothelium; vasculitis; video recording system

Clinical experience over the last two decades has shown that antiplatelet--therapy is often not effective in the treatment of arterial thrombotic disorders. Patients on aspirin and other agents which impair platelet cyclooxygenase and the platelet release reaction continue to suffer recurrent episodes of myocardial ischemia or recurrent stroke. We therefore hypothesize that some arterial thrombotic disorders are in part due to the procoagulant activity (PCA) of a stimulated, inflammed or injured vessel wall. This view is in keeping with recent in vitro data that vascular endothelium, when stimulated by inflammatory/immune mediators such as interleukin-l (IL-l), tissue necrosis factor (TNF), lymphotoxin or hepatic stimulating factor, can become prothrombotic by generating, for example, tissue factor and molecules adhesive for granulocytes. Simultaneously, vasculitis and/or vessel wall injury may diminish the production of substances of arachidonate (prostacyclin and PGE2) and non-arachidonate (endothelial cell relaxing factor) metabolism which normally modulate leukocyte-platelet adhesion/aggregation. The experimental approach taken here to evaluate this hypothesis is to simulate in vitro flow through a microvessel. We do so by utilizing a flow chamber which incorporates whole blood, arterial-like shear rates, a flow path of thickness 290 um, and in situ epifluorescence video- microscopy of leukocyte-platelet adhesion/aggregation to a defined injury site on an endothelial cell monolayer. Our aims include 1) establishing the effects of flow (shear rate and shear stress) on PCA; 2) determining the dependence on flow of granulocyte adhesion to non-injured endothelium; and 3) determining the flow dependence of leukocyte-platelet adhesion/aggregation to a site of defined injury to endothelium. PCA will be measured with flowing, cell- free media and a radiometric assay for Factor Xa conversion. For imaging purposes,platelets will be labelled with a fluorescein- conjugated monoclonal antibody (TAB) to glycoprotein IIB, while monocyte-granulocytes will be labelled with a rhodamine-conjugated monoclonal antibody directed against the Mo5 antigen. In particular, we seek a rational basis for the use of anticoagulant therapy in certain cases of arterial thrombosis.

过去二十年的临床经验表明， 抗血小板治疗在治疗慢性阻塞性肺疾病中往往无效 动脉血栓性疾病。服用阿司匹林和其他药物的患者 损害血小板环氧合酶和血小板的药物 释放反应继续遭受反复发作的 心肌缺血或反复中风。因此，我们假设 一些动脉血栓形成障碍的部分原因是 刺激、炎症或损伤患者的促凝血活性(PCA) 血管壁。这一观点与最近的体外数据是一致的 当受到炎症/免疫刺激时，血管内皮细胞 白介素L、组织坏死因子等介质 (肿瘤坏死因子)，淋巴毒素或肝刺激因子，可以成为 通过产生例如组织因子和 分子对粒细胞有粘附性。同时，血管炎 和/或血管壁损伤可能会减少物质的产生 花生四烯酸(前列环素和前列腺素E_2)和非花生四烯酸 (内皮细胞松弛因子)代谢正常 调节白细胞-血小板的黏附/聚集。实验性的 这里采用的评估该假设的方法是在 体外流经微血管。我们通过利用流来实现这一点 包括全血、动脉样切变率的腔室， 厚度为290微米的流动路径，以及原位荧光视频- 白细胞-血小板黏附/聚集的显微镜观察 内皮细胞单层上的损伤部位。我们的目标包括1) 建立流动(剪切速率和剪切应力)对 PCA；2)确定粒细胞黏附对流量的依赖性 无损伤内皮细胞；3)确定血流依赖性 白细胞-血小板黏附/聚集到一个特定的部位 血管内皮细胞损伤。PCA将用流动的，细胞- 自由介质和Xa因子转换的放射测定法。为 为了成像的目的，将用荧光素标记血小板- 糖蛋白IIB的结合型单抗(TAB)，而 单核细胞-粒细胞将用罗丹明标记 针对MO5抗原的单抗。在……里面 特别是，我们为抗凝剂的使用寻求合理的依据 治疗某些动脉血栓形成的病例。