VITAMIN C, GLUTATHIONE, AND ENDOTHELIAL CELL FUNCTION

维生素 C、谷胱甘肽和内皮细胞功能

• 批准号: 2600735
• 负责人: BALZ B FREI
• 金额: $ 20.09万
• 依托单位: OREGON STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-05-10 至 2000-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2600735
• 关键词: antioxidants; ascorbate; atherosclerosis; cell adhesion; cell adhesion molecules; cytotoxicity; glutathione; high performance liquid chromatography; human subject; human tissue; low density lipoprotein; luminescence; macrophage; monocyte; nuclear factor kappa beta; nutrition related tag; oxidation; oxidative stress; peroxidation; reduction; superoxides; tissue /cell culture; vascular endothelium; vascular endothelium permeability; vitamin metabolism

This project is based upon the hypothesis that intracellular antioxidants can prevent endothelial dysfunction related to the initiation of atherosclerosis. Oxidative stress (an imbalance between oxidants and antioxidants in favor of the former) has been implicated as an etiologic factor in human atherosclerosis, both through the oxidative modification of low-density lipoprotein (LDL) and the stimulation of monocyte-endothelial interactions. While our and other investigators' previous studies have evaluated the effects of LDL-associated and extracellular antioxidants on these pro-atherogenic, redox-sensitive processes, little is known about the role of intracellular antioxidants. Vitamin C and glutathione are accumulated and synthesized by human cells, respectively, and play a central role in cellular antioxidant defenses, and thus cellular integrity and survival. Therefore, the overall objective of this proposal is to identify the role of intracellular vitamin C and glutathione in endothelial cell-mediated LDL oxidation and endothelial dysfunction. The experimental model will be cultured human aortic endothelial cells (HAECs). The first aim is to characterize athe transport kinetics and intracellular metabolism of vitamin C by these cells. The interrelationships of intracellular vitamin C and glutathione will be studied by examining the effects of cellular vitamin C loading on the levels and redox status of intracellular glutathione, and conversely the effects of manipulating cellular glutathione status on dehydroascorbic acid reduction, an important step in vitamin C metabolism. Next, we will identify the role of intracellular vitamin C and glutathione in HAEC- mediated LDL oxidation. Cellular superoxide generation, metal ion reduction, and thiol production will be studied as possible mechanisms for any observed effects. Finally, in the third aim we will determine the role of cellular vitamin C and glutathione status in HAEC dysfunction as manifested by increased monocyte adhesion. Possible mechanisms will be explored by studying expression of vascular cell adhesion molecule-1 (VCAM- 1) and intercellular adhesion molecule-1 (ICAM-1), and activation and nuclear translocation of the redox-sensitive transcription factor nuclear factor kappaB (NFkappaB). This information will provide a better understanding of the mechanisms by which antioxidants modify the initial events of atherogenesis.

该项目基于以下假设：细胞内抗氧化剂 可以防止与启动有关的内皮功能障碍 动脉粥样硬化。 氧化应激（氧化剂与 有利于前者的抗氧化剂已被视为一种病因 人动脉粥样硬化的因素，均通过氧化的修饰 低密度脂蛋白（LDL）和单核细胞内皮的刺激 互动。 而我们和其他调查人员以前的研究已经 评估了LDL相关和细胞外抗氧化剂对 这些亲动力的，对氧化还原敏感的过程，对 细胞内抗氧化剂的作用。 维生素C和谷胱甘肽是 分别由人类细胞积累和合成，并发挥作用 在细胞抗氧化剂防御中的中心作用，因此细胞完整性 和生存。 因此，该提议的总体目标是 确定细胞内维生素C和谷胱甘肽在内皮中的作用 细胞介导的LDL氧化和内皮功能障碍。 实验模型将进行培养的人主动脉内皮细胞 （Haecs）。 第一个目的是表征Athe The The The The Transport动力学和 这些细胞对维生素C的细胞内代谢。 这 细胞内维生素C和谷胱甘肽的相互关系将是 通过检查细胞维生素C负载对 细胞内谷胱甘肽的水平和氧化还原状态，相反 操纵细胞谷胱甘肽状态对脱氢抗坏血酸的影响 还原，维生素C代谢的重要一步。 接下来，我们会的 确定细胞内维生素C和谷胱甘肽在Haec-中的作用 介导的LDL氧化。 细胞超氧化物产生金属离子 减少和硫醇的产生将作为可能的机制 任何观察到的效果。 最后，在第三个目标中，我们将确定角色 HAEC功能障碍中的细胞维生素C和谷胱甘肽状态 表现为单核细胞粘附的增加。 可能的机制将是 通过研究血管细胞粘附分子1的表达（VCAM-- 1）和细胞间粘附分子1（ICAM-1），以及激活和 氧化还原敏感转录因子核的核易位 因子kappab（nfkappab）。 此信息将通过 哪种抗氧化剂改变了动脉粥样硬化的初始事件。