Glutathione, macrophages and unstable atherosclerosis

谷胱甘肽、巨噬细胞和不稳定的动脉粥样硬化

• 批准号: 7030311
• 负责人: MICHAEL E ROSENFELD
• 金额: $ 37.01万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2008-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7030311
• 关键词: aging; apolipoprotein E; atherosclerotic plaque; bone marrow transplantation; catalyst; cell death; cholesterol; cysteine; cytotoxicity; enzyme activity; gel mobility shift assay; gene expression; glutamates; glutathione; laboratory mouse; ligase; low density lipoprotein; macrophage; oxidation; transcription factor; transfection

DESCRIPTION (provided by applicant): The death of macrophages within an atherosclerotic plaque may play a fundamental role in conversion of the plaque to an unstable plaque, one that is vulnerable to rupture and hemorrhage. It is currently unknown precisely what kills macrophages within the plaque. One likely possibility is accumulation of oxidized lipids and free cholesterol derived from lipoproteins that have been trapped and retained by the extra-cellular matrix. Accumulation of oxidized LDL by macrophages in vitro is accompanied by depletion of glutathione, the major endogenous antioxidant for most cell types. Pharmacological stimulation of glutathione synthesis protects macrophages from the cytotoxic effects of oxidized LDL. Our preliminary data suggests that overexpression of the catalytic subunit of glutamate cysteine ligase, the rate-limiting enzyme for glutathione synthesis also protects macrophages from death due to oxidized LDL, oxidized lipid moieties and other prooxidants. Oxidized LDL is also a potent inducer of the expression of both the catalytic and regulatory subunits of glutamate cysteine ligase. Thus, we hypothesize that increased stable expression of glutamate cysteine ligase in macrophages will protect the cells from pro-oxidant induced death and increase the stability of atherosclerotic plaques. To test this hypothesis and to further investigate how oxidized lipid moieties contribute to the regulation of expression of the glutamate cysteine ligase genes in macrophages, we propose the following three specific aims. 1.To determine the role of oxidized lipid components of oxidized LDL in the regulation of macrophage expression of the glutamate cysteine ligase subunit genes. 2.To determine whether ad how increased expression of GCL-c by RAW cells inhibits pro-oxidant and free cholesterol induced death. 3.To determine the effects of bone marrow transplantation of cells over-expressing GCL-c (increased capacity to make glutathione) or deficient in GCL-m (decreased capacity to make glutathione) on macrophage death and atherosclerosis in older apo E-l- mice with established lesions. Strategies such as those included in the present proposal that are designed to prevent macrophage death have a high probability of successfully stabilizing atherosclerotic plaques and should help reduce plaque rupture, occlusive thrombosis, myocardial infarction and stroke.

描述（由申请人提供）：动脉粥样硬化斑块中巨噬细胞的死亡可能在将斑块转换为不稳定的斑块中起着基本作用，该斑块容易出现破裂和出血。目前，目前未知是什么杀死斑块中的巨噬细胞。一种可能的可能性是衍生自脂蛋白的氧化脂质和游离胆固醇的积累，这些脂蛋白已被细胞外基质捕获和保留。巨噬细胞在体外积累氧化的LDL，伴随着谷胱甘肽的耗竭，谷胱甘肽是大多数细胞类型的主要内源性抗氧化剂。谷胱甘肽合成的药理刺激可保护巨噬细胞免受氧化LDL的细胞毒性作用。我们的初步数据表明，谷氨酸半胱氨酸连接酶的催化亚基过表达，谷胱甘肽合成的速率限制酶也可以保护巨噬细胞免受氧化的LDL的死亡，氧化的LDL，氧化的脂质部分和其他促脂肪剂。氧化的LDL也是谷氨酸半胱氨酸连接酶催化和调节亚基表达的有效诱导剂。因此，我们假设巨噬细胞中谷氨酸半胱氨酸连接酶的稳定表达增加将保护细胞免受氧化诱导的死亡的影响并增加动脉粥样硬化斑块的稳定性。为了检验这一假设并进一步研究氧化的脂质部分如何促进巨噬细胞中谷氨酸半胱氨酸连接酶基因表达的调节，我们提出以下三个特定目标。 1.确定氧化LDL的氧化脂质成分在调节谷氨酸半胱氨酸连接酶亚基基因的巨噬细胞表达中的作用。 2.确定AD是否会通过原细胞增加GCL-C的表达是否抑制促氧化剂和游离胆固醇诱导的死亡。 3.确定过度表达GCL-C（增加谷胱甘肽的能力）的骨髓移植的影响，或缺乏GCL-M（减少制造谷胱甘肽的能力）对巨噬细胞死亡和较老的Apo E-L小鼠巨噬细胞死亡和动脉粥样硬化的影响。 旨在防止巨噬细胞死亡的本提案中包括的策略很有可能成功地稳定动脉粥样硬化斑块，并应有助于减少斑块破裂，闭塞性血栓形成，心肌梗塞和中风。