Aging and CR effects on the Plasma Membrane Redox System

老化和 CR 对质膜氧化还原系统的影响

• 批准号: 8552382
• 负责人: Rafael de Cabo
• 金额: $ 38.92万
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8552382
• 关键词: Age; Aging; Animal Model; Animals; Antioxidants; Bioenergetics; Biological Models; Cell membrane; Cells; Collaborations; Data; Diet; Dietary Intervention; Electron Transport; Equilibrium; Ethanol; Fatty Acids; Fatty acid glycerol esters; Generations; Homologous Gene; Insulin Receptor; Intervention; Knock-out; Laboratories; Lipid Peroxidation; Longevity; Maintenance; Mammals; Mediating; Mediator of activation protein; Membrane; Metabolism; Mitochondria; Mus; NADH; NQO1 gene; Oxidation-Reduction; Oxidative Stress; Oxidoreductase; Pathway interactions; Phospholipids; Phosphorylation; Physiological; Physiology; Prevention; Production; Rattus; Reaction; Resistance; Role; Saccharomyces cerevisiae; Stress; System; Transgenic Organisms; Ubiquinone; Up-Regulation; Yeasts; aged; base; design; mimetics; novel; overexpression; oxidative damage; prevent; protein function; pyridine nucleotide; respiratory

Data from our laboratory and others, have demonstrated that the plasma membrane redox system is, at least in part, responsible of the maintenance of the antioxidant capacity during oxidative stress challenges induced by the diet and aging. The upregulation of the plasma membrane redox system that occurs during CR decreases the levels of oxidative stress in aged membranes. CR extends life span of yeasts by decreasing NADH levels, which would connect this intervention to plasma membrane NADH-dependent dehydrogenases. CR modifies composition of fatty acid in the plasma membrane, resulting in decreased oxidative damage including lipid peroxidation. More importantly, plasma membrane redox activities and also the content of CoQ, which decline with age, are enhanced by CR providing protection to phospholipids and preventing the lipid peroxidation reaction progression. We are focusing our efforts on the generation of transgenic and knock out animals of the different dehydrogenases involved in this antioxidant system. We have successfully created NQO1 and Cyt-b5-reductase overexpressors and obtained NQO1 and NRF2 KO animals. We are setting longevity studies as well as short term interventions to fully characterize these new mouse lines. In collaboration with the laboratory of Dr. Placido Navas we have shown that the Saccharomyces cerevisiae homolog of Cyt-b5-reductase, NQR1, resides at the plasma membrane and when overexpressed extends both replicative and chronological lifespan. We demonstrated that NQR1 extends replicative lifespan in a SIR2-dependent manner by shifting cells towards respiratory metabolism and decreasing the pyridine nucleotide pool without altering the NAD+/NADH ratio. Chronological lifespan extension, in contrast, occurs via a SIR2-independent decrease in ethanol production. We conclude that NQR1 is a key mediator of lifespan extension by CR through its effects on yeast metabolism and discuss how these findings could suggest a function for this protein in lifespan extension in mammals. We now have extended our previous observations on NQO1 and we are now demonstrating an important novel physiological role for NQO1. We have determined that NQO1 is a target if the insulin receptor which shifts its cellular localization by phosphorylation. NQO1 overexpression shifted the physiology of mice on a high fat diet towards that of mice on a standard diet. These phenomena occur through the NQO1-mediated reduction in oxidative stress damage and prevention of the activation of the proinflammatory NFκβ pathway.

我们实验室和其他实验室的数据表明，质膜氧化还原系统至少部分负责在饮食和衰老引起的氧化应激挑战期间维持抗氧化能力。 CR 期间发生的质膜氧化还原系统的上调降低了老化膜中的氧化应激水平。 CR 通过降低 NADH 水平来延长酵母的寿命，这将这种干预与质膜 NADH 依赖性脱氢酶联系起来。 CR 改变质膜中脂肪酸的组成，从而减少氧化损伤，包括脂质过氧化。更重要的是，质膜氧化还原活性和 CoQ 含量随着年龄的增长而下降，通过 CR 增强，为磷脂提供保护并防止脂质过氧化反应的进展。 我们的重点是培育转基因动物并敲除参与该抗氧化系统的不同脱氢酶。我们成功创建了NQO1和Cyt-b5还原酶过表达细胞，并获得了NQO1和NRF2 KO动物。我们正在开展长寿研究以及短期干预措施，以充分描述这些新小鼠品系的特征。 通过与 Placido Navas 博士的实验室合作，我们发现 Cyt-b5 还原酶的酿酒酵母同源物 NQR1 存在于质膜上，当过度表达时，可以延长复制寿命和时间寿命。我们证明，NQR1 通过将细胞转向呼吸代谢并减少吡啶核苷酸池而不改变 NAD+/NADH 比率，以 SIR2 依赖性方式延长复制寿命。相比之下，按时间顺序的寿命延长是通过不依赖于 SIR2 的乙醇产量减少来实现的。我们得出结论，NQR1 通过其对酵母代谢的影响而成为 CR 延长寿命的关键介质，并讨论了这些发现如何表明该蛋白质在哺乳动物寿命延长中的功能。 我们现在扩展了之前对 NQO1 的观察，现在正在证明 NQO1 的重要的新颖生理作用。我们已经确定，如果胰岛素受体通过磷酸化改变其细胞定位，则 NQO1 是一个靶标。 NQO1 过度表达使高脂肪饮食小鼠的生理机能转变为标准饮食小鼠的生理机能。这些现象是通过 NQO1 介导的氧化应激损伤减少和防止促炎 NFκβ 通路激活而发生的。