MEGAKARYOCYTE PROTEOGLYCANS AND HYPERCHOLESTEROLEMIA

这个项目的目标是了解蛋白多糖在蛋白质中的作用 正常的巨核细胞和血小板发育，以及 高胆固醇血症。我们观察到，随着血脂的变化 新陈代谢、(S35)硫酸盐掺入血小板的变化 高胆固醇血症动物，提示合成发生实质性变化 巨核细胞中蛋白多糖和其他硫酸化蛋白的含量 高胆固醇血症动物。目前的提案将延长这些 学习。(1)蛋白多糖的合成和代谢将在#年研究 正常和高胆固醇血症巨核细胞的体外培养 豚鼠。这些细胞将与(S35)硫酸盐孵育。 (H3)氨基葡萄糖和(H3)亮氨酸标记蛋白多糖和透明质酸 酸。蛋白多糖将被表征，其时间进程 各种分子的合成和周转率将是 确定，硫化分子的亚细胞位置将被确定 通过用可能释放标记的试剂处理细胞进行评估 分子选择性地来自细胞颗粒或表面。 高胆固醇血清对蛋白多糖合成的调节作用 在新鲜分离的巨核细胞和长期骨髓中都进行了研究 文化。(2)巨核细胞蛋白多糖的合成 将在体内研究血小板的蛋白多糖含量，使用 正常和高胆固醇血症患者巨核细胞和血小板的分离 注射(S35)硫酸盐的豚鼠。的时间进程 将放射性标记掺入特定的蛋白多糖和其他硫酸盐化 巨核细胞和血小板中的大分子将在一年多的时间里被研究 为期五天，以便提供资料说明是否 不同成熟阶段的巨核细胞合成不同类型 硫酸盐分子，以及图案是否在 高胆固醇血症。不同硫酸盐的亚细胞定位 分子将在体内标记的巨核细胞和血小板中进行探测。 蛋白多糖在豚鼠血小板中的功能作用将是 评估过了。(3)豚鼠蛋白多糖的质量分布 将测定正常和正常的小核细胞和巨核细胞 高胆固醇血症动物。(4)研究将扩展到分析 来自正常人和高胆固醇血症患者的血小板蛋白多糖。 这项研究预计将定义人们鲜为人知的 巨核细胞和血小板生物学和发育中的蛋白多糖，以及 它们在患者发生血小板异常中的重要性 患有高胆固醇血症。

The goal of this project is to understand the role of proteoglycans in normal megakaryocyte and platelet development and in disorders such as hypercholesterolemia. We have observed, along with changes in lipid metabolism, changes in (S35) sulfate incorporation into platelets of hypercholesterolemic animals which suggest substantial changes in synthesis of proteoglycans and other sulfated proteins in the megakaryocytes of the hypercholesterolemic animals. The current proposal will extend these studies. (1) Proteoglycan synthesis and metabolism will be studied in vitro in megakaryocytes isolated from normal and hypercholesterolemic guinea pigs. The cells will be incubated with (S35) sulfate. (H3)glucosamine and (H3)leucine to label the proteoglycans and hyaluronic acid. The proteoglycans will be characterized, the time course of synthesis and the turnover rates of the various molecules will be determined, and the subcellular locations of the sulfated molecules will be assessed by treating the cells with agents which may release labeled molecules selectively from either the granules or surface of the cells. The regulation of proteoglycan synthesis by hypercholesterolemic serum will be studied both in freshly-isolated megakaryocytes and in long-term marrow cultures. (2) Proteoglycan synthesis in megakaryocytes and the proteoglycan content of platelets will be studied in vivo, using megakaryocytes and platelets isolated from normal and hypercholesterolemic guinea pigs which have been injected with (S35)sulfate. The time course of incorporation of radiolabel into specific proteoglycans and other sulfated macromolecules will be studied in both megakaryocytes and platelets over a period of five days in order to provide information concerning whether megakaryocytes at different stages of maturation synthesize different types of sulfated molecules, and whether the pattern is changed in hypercholesterolemia. The subcellular localization of the various sulfated molecules will be probed in megakaryocytes and platelets labeled in vivo. The functional role of proteoglycans in guinea pig platelets will be assessed. (3) The mass distribution of proteoglycans of guinea pig blatelets and megakaryocytes will be determined for both normal and hypercholesterolemic animals. (4) The studies will be extended to analysis of proteoglycans of platelets from normal and hypercholesterolemic humans. This research is expected to define the poorly-understood role of proteoglycans in megakaryocyte and platelet biology and development, and their importance in the development of platelet abnormalities in patients with hypercholesterolemia.