REGULATION OF NEUTROPHIL-MEDIATED INJURY BY PLATELETS

中性粒细胞被认为是急性胰腺炎的主要细胞介质。 与细菌性心内膜炎、免疫性血管炎相关的血管损伤， 缺血性心脏病与成人呼吸窘迫综合征(ARDS) 通过它们在血管系统中隔离的能力和 通过释放有毒氧气导致随后的内皮损伤 自由基和溶酶体酶。与血小板密切相关的 这些疾病中的中性粒细胞提示在 发炎。然而，人们对血小板衍生的作用知之甚少。 中性粒细胞介导的内皮损伤的调节因素。我们有 最近描述了血小板衍生蛋白以及 腺嘌呤核苷酸对中性粒细胞炎症的调节作用 功能。我们现在寻求对提纯和生化特性的支持 蛋白质抑制剂(S)和确定蛋白质如何作用的机制 抑制物(S)和腺嘌呤核苷酸调节中性粒细胞介导的损伤 内皮细胞。拟议研究的目标是测试 血小板衍生因子抑制中性粒细胞介导的假说 血管内皮细胞损伤导致通透性水肿增加。这个 该项目的具体目标是：1)净化到同质性 并检测血小板衍生中性粒细胞抑制因子的作用 这些抑制剂在体外对中性粒细胞功能的影响；2)测定 这些血小板衍生因子对中性粒细胞介导的损伤和 培养内皮细胞的功能改变，以及3)检测 这些血小板衍生因子抑制的细胞机制 中性粒细胞介导的内皮细胞损伤。我们将使用C5a和 F-Met-Leu-Phe(FMLP)，刺激细胞快速释放 产品和佛波酯(PMA)可导致更长时间的 释放产物，如活性氧种。我们将建立 每种血小板衍生因子的剂量反应和动力学曲线 评估它们对刺激的中性粒细胞功能和损伤的影响。 内皮细胞屏障功能。中性粒细胞的调节机制 每一种血小板衍生因子的研究将通过测量 它们对涉及中性粒细胞激活的不同步骤的影响。结果 从这些研究中应该可以提供有用的关于 血小板衍生因子在血管紧张素转换酶启动和分解中的作用 中性粒细胞介导的血管疾病。这些研究的结果应该是 也为预防和治疗措施提供了新的可能性 用于ARDS等炎症性疾病。

Neutrophils have been implicated as the major cellular mediator of acute vascular injury associated with bacterial endocarditis, immune vasculitis, ischemic heart disease and the adult respiratory distress syndrome (ARDS) by virtue of their ability to become sequestered in the vasculature and cause subsequent damage to the endothelium by release of toxic oxygen radicals and lysosomal enzymes. The close association of platelets with neutrophils in these disorders suggests potential interactions during inflammation. Yet, little is known about the role of platelet-derived factors in regulating neutrophil-mediated injury to endothelium. We have recently described the ability of platelet-derived proteins as well as adenine-containing nucleotides to regulate neutrophil inflammatory functions. We now seek support to purify and biochemically characterize the protein inhibitor(s) and to determine mechanisms of how the protein inhibitor(s) and adenine nucleotides regulate neutrophil-mediated injury to endothelial cells. The objective of the proposed research is to test the HYPOTHESIS that platelet-derived factors inhibit neutrophil-mediated endothelial cell injury resulting in increased permeability edema. The SPECIFIC AIMS of the project are: 1) to purify to homogeneity the platelet-derived neutrophil inhibitory factors and to examine the effect of these inhibitors on neutrophil functions in vitro; 2) to determine the effect of these platelet-derived factors on neutrophil-mediated injury and functional alterations of cultured endothelial cells, and 3) to examine the cellular mechanisms by which these platelet-derived factors inhibit neutrophil-mediated injury to endothelial cells. We will employ C5a and F-Met-Leu-Phe (FMLP), stimuli that induce rapid release of cellular products, and phorbol myristate acetate (PMA) that induces a more prolonged release of products such as reactive oxygen species. We will establish dose response and kinetic curves for each of the platelet-derived factors to assess their effect on stimulated neutrophil functions and injury of endothelial cell barrier function. The mechanisms of neutrophil regulation by each of the platelet-derived factors will be studied by measurement of their effect on distinct steps involved in neutrophil activation. Results from these studies should provide useful new information on the role of platelet-derived factors on the initiation and resolution of neutrophil-mediated vascular disorders. Results of these studies should also provide new possibilities for prophylactic and therapeutic measures for inflammatory disorders such as ARDS.