Glutathione, Oxidative Stress, and Aging

这项研究的首要目标是直接测试氧化应激的有效性。 通过确定抗氧化防御的遗传操作的影响， 果蝇在本研究中要检验的具体假设是， 谷胱甘肽（GSH）- NADPH系统的增强将降低氧化应激水平， 减缓老化过程的速度，而该系统效率的降低将提高 氧化应激水平，加速衰老过程。GSH和NADPH提供了大部分的 降低细胞中的能量并协同作用以消除各种活性氧（ROS）。 通过转基因技术可以提高细胞合成GSH和NADPH的能力。 γ-谷氨酸-半胱氨酸连接酶亚基（GCL）和葡萄糖-6-磷酸脱氢酶的过表达 （G6 PH），在D.黑腹菌四个具体的目标是：（一）确定过度和 根据GCL在机体不同部位的表达及在生命周期的不同时期对衰老的影响 过程(II)确定葡萄糖-6-磷酸脱氢酶过度表达和表达不足的影响 （G6 PD）在身体的不同区域和生命周期的不同时期对衰老过程的影响。 (Ill)确定GCL和G6 PD的共过表达对小鼠的寿命和模式的影响。 生理老化(IV)确定GCL和G6 PD的过度表达和表达不足对细胞氧化还原的影响。 组织状态由GSH、GSSG、混合蛋白二硫化物、NADPH、NADP+、NADH和NAD+表示。的 这些研究最令人信服的理由是，我们最近的发现表明，GCL的过度表达， （催化亚基）和G6 PD使相对长寿的果蝇品系的寿命增加高达50%。结果 的前瞻性研究将直接测试衰老的氧化应激假设的预测， 表明细胞还原能力的增强是否能显著延长果蝇的寿命。

The overarching goal of the proposed research is to directly test the validity of the oxidative stress hypothesis of aging by determining the effects of genetic manipulations of the antioxidative defenses in Drosophila melanogaster. The specific hypothesis to be tested in the present study is that experimental augmentation of the glutathione (GSH) - NADPH system would lower the level of oxidative stress thereby slowing the rate of the aging process, while a decrease in the efficiency of this system would elevate the level of oxidative stress and accelerate the aging process. GSH and NADPH provide the bulk of the reducing power in cells and act in concert to eliminate various reactive oxygen species (ROS). Enhancement of cellular ability to synthesize GSH and NADPH will be achieved by transgenic overexpression of y-glutamate-cysteine ligase subunits (GCL) and glucose-6-phosphate dehydrogenase (G6PH), respectively, in D. melanogaster. The four specific aims are: (I) Determine the effects of over and under expression of GCL in different regions of the body and at different periods of life cycle on the aging process. (II) Determine the effects of over and under expression of glucose-6-phosphate dehydrogenase (G6PD) in different regions of the body and at different periods of the life cycle on the aging process. (Ill) Determine the effects of co-overexpression of GCL and G6PD on the life span and patterns of physiological aging. (IV) Determine the effects of over and under expression of GCL and G6PD on the redox state of tissues indicated by GSH, GSSG, mixed protein disulfides, NADPH, NADP+, NADH and NAD+. The most compelling rationale for these studies is that our recent findings indicate that overexpression of GCL (catalytic subunit) and G6PD increases life span of relatively long-lived strains of flies by up to 50%. Results of the prospective studies would directly test the predictions of the oxidative stress hypothesis of aging and indicate whether augmentation of cellular reductive capacity can significantly extend the life span of flies.