MOBILITY AND ADHESION OF SICKLE MEMBRANE COMPONENTS

人红细胞膜与其相互作用的研究 细胞内和细胞外环境对正常红细胞的调节 循环中的动态平衡和异常的红细胞病理。 血红蛋白S在镰状红细胞内的聚合导致一系列 细胞膜紊乱，包括蛋白质-蛋白质和蛋白质- 脂类相互作用，影响分子的流动性和表面分布 主要的跨膜蛋白，血糖素和带3.变化 在含血糖素的负电荷的表面分布中可能 影响镰状红细胞与血管内皮细胞的黏附 可能进而引发血管闭塞危机。第三个频带的形成 镰刀状红细胞膜中的聚集体可能促进自体红细胞膜的结合 这些细胞的抗体，促进它们的过早去除 单核细胞和巨噬细胞。磷脂酰丝氨酸的异常暴露 镰刀状红细胞表面也可能介导与单核细胞的黏附和 巨噬细胞。在这项提议中，高速激光和视频显微镜 技术被用来测量横向活动度，旋转活动度， 和跨膜蛋白和脂类的表面分布 个体镰状红细胞膜和镰状红细胞膜 黏附培养中的内皮细胞、外周血单核细胞和 固定化血浆蛋白可能在促进镰刀的形成中起重要作用 RBC-EC粘附性。这些蛋白质包括纤维蛋白、纤维蛋白原、纤维连接蛋白、 凝血酶原蛋白、维生素C和血管性血友病因子。我们的目标是测试 假设：1)镰状RBC带3的特异性异常， 血糖素与磷脂迁移率和表面分布 在单个镰刀状红细胞的水平上，与增加的约束力相关 自身抗体和对单核细胞、巨噬细胞的粘附率增加， 和内皮细胞；2)特定的血浆蛋白是重要的介体。 镰刀状RBC-EC黏附。这些研究的结果预计将 阐明镰状红细胞膜上直接存在的分子缺陷 参与镰刀状红细胞溶血和血管生成的病理生理学 闭塞危机。

Interactions between the human red blood cell (RBC) membrane and its intracellular and extracellular environment mediate both normal RBC homeostasis and abnormal RBC pathology in the circulation. Polymerization of hemoglobin S within sickle RBCs leads to a spectrum of membrane derangements, including changes in protein-protein and protein- lipid interactions, that affect the mobility and surface distribution of the major transmembrane proteins, glycophorin and band 3. Alterations in the surface distribution of glycophorin-bearing negative charges may influence sickle RBC adherence to vascular endothelial cells (ECs), which may, in turn, initiate vaso-occlusive crisis. Formation of band 3 aggregates in sickle RBC membranes may promote the binding of autologous antibody to these cells, facilitating their premature removal by monocytes and macrophages. Abnormal exposure of phosphatidylserine at the surface of sickle RBCs may also mediate adherence to monocytes and macrophages. In this proposal high-speed laser and video microscopy techniques are used to measure the lateral mobility, rotational mobility, and surface distribution of transmembrane proteins and lipids in individual sickle RBC membranes and in the membranes of sickle RBCs adherent to ECs in culture, to peripheral blood monocytes, and to immobilized plasma proteins that may be important in facilitating sickle RBC-EC adhesion. These proteins include fibrin, fibrinogen, fibronectin, thrombospondin, vitronectin, and von Willebrand factor. We aim to test the hypotheses that: 1) specific abnormalities in sickle RBC band 3, glycophorin, and phospholipid mobility and surface distribution correlate, at the level of individual sickle RBCs, with increased binding of autologous antibody and increased adherence to monocytes, macrophages, and ECs; and 2) specific plasma proteins serve as important mediators of sickle RBC-EC adhesion. Results from these studies are expected to elucidate molecular defects in the sickle RBC membrane that are directly involved in the pathophysiology of sickle RBC hemolysis and vaso- occlusive crisis.