MOLECULAR BASIS OF THE PLATELET STORAGE LESION

血小板储存病变的分子基础

• 批准号: 6184711
• 负责人: THERESE WIEDMER
• 金额: $ 30.85万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-30 至 2002-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6184711
• 关键词: SDS polyacrylamide gel electrophoresis; cell membrane; complement; densitometry; enzyme activity; fluorescence microscopy; fluorescent dye /probe; human tissue; immunoaffinity chromatography; immunoprecipitation; lipid bilayer membrane; lipid transport; membrane permeability; oxidation; phosphatidylethanolamines; phosphatidylserines; phospholipids; plasmin; platelets; thrombin; western blottings

Collection and in vitro storage of blood platelets results in the progressive movement of phosphatidylserine (PS) and phosphatidylethanolamine (PE) from inner to outer leaflet of the platelet plasma membrane. This loss of normal plasma membrane phospholipid (PL) asymmetry with exposure of these aminophospholipids on the platelet surface is implicated in the formation of thrombin, in the activation of complement, and in hepato-splenic sequestration and accelerated clearance of platelets following transfusion. This Project aims to identify the mechanism(s) responsible for this abnormal transbilayer movement of plasma membrane phospholipids in stored platelets and to deduce conditions of storage that will preserve normal sequestration of PS and PE to the inner leaflet. The Specific Aims include: (1) To determine whether the progressive movement of PS to the surface of platelets during storage in autologous plasma reflects membrane reorganization induced through mechanical shear, a decrease in activity of the platelet plasma membrane aminophospholipid translocase, and/or inappropriate activation of the platelet plasma membrane phospholipid scramblase; (2) To determine the relative contributions of altered cytosolic Ca2+, ATP, and pH to the accelerated transbilayer movement of platelet plasma membrane phospholipids; (3) To determine how oxidative changes in either PL scramblase or aminophospholipid translocase during cell storage affect transbilayer distribution of plasma membrane phospholipids; (4) To determine the role of plasma components contained in platelet concentrates to the accelerated movement of aminophospholipids to the platelet surface. Of particular interest is the role of thrombin, plasmin and the C5b-9 components of complement; (5) To identify storage conditions optimized to maintain the normal sequestration of platelet plasma membrane aminophospholipids. Those conditions are considered optimal that maximize the activity of aminophospholipid traslocase and minimize that of the intracellular Ca2+-activated PL scramblase.

血小板的采集和体外储存导致 磷脂酰丝氨酸（PS）的渐进运动和 磷脂酰乙醇胺 (PE) 从内叶到外叶 血小板质膜。 正常质膜的丧失 暴露这些氨基磷脂导致磷脂 (PL) 不对称 血小板表面的凝血酶参与凝血酶的形成， 补体的激活以及肝脾隔离和 输血后加速血小板清除。 本项目 旨在确定导致这种异常的机制 储存中质膜磷脂的跨双层运动 血小板并推断出能够保持正常的储存条件 PS 和 PE 隔离到内层。 具体目标 包括： (1) 判断PS是否渐进运动到 自体血浆储存过程中血小板表面反映 通过机械剪切诱导膜重组，减少 血小板质膜氨基磷脂转位酶的活性， 和/或血小板质膜的不适当激活 磷脂扰乱酶； (2) 确定相对贡献 改变胞质 Ca2+、ATP 和 pH 值以加速跨双层 血小板质膜磷脂的运动； (3) 确定如何 PL 扰乱酶或氨基磷脂的氧化变化 细胞储存期间的易位酶影响跨双层分布 质膜磷脂； (4) 确定血浆的作用 浓缩血小板中所含成分加速 氨基磷脂移动至血小板表面。 特别是 人们感兴趣的是凝血酶、纤溶酶和 C5b-9 成分的作用 补充; (5) 确定优化的储存条件以维持 血小板质膜氨基磷脂的正常隔离。 这些条件被认为是最大化活性的最佳条件 氨基磷脂转运酶并最大限度地减少细胞内的转运酶 Ca2+ 激活 PL 扰乱酶。