Genetic Regulation of Glutathione Redox Balance in Mice

描述（由申请人提供）：谷胱甘肽是一种三肽分子，是细胞内主要的内源性抗氧化剂。它是丰富的，并参与广泛的保护抗氧化和解毒机制。体内平衡机制维持谷胱甘肽主要处于还原状态（GSH）；谷胱甘肽的氧化导致其氧化二聚体形成GSSG的积累。因此，检测GSH:GSSG的比例是氧化应激和氧化还原维持的良好指标。许多慢性衰老疾病都有氧化应激成分，导致GSH:GSSG显著下降，使细胞和组织更容易受到进一步损伤。尽管调节谷胱甘肽平衡的生化途径是明确的，但该参数的遗传调控尚不明确，尽管有研究表明，哺乳动物的谷胱甘肽平衡是由遗传调节的。目前的项目确定调节小鼠谷胱甘肽平衡的基因。这项工作可能揭示维持疾病中谷胱甘肽平衡的新靶点，这将有可能改善人类患者的治疗、预后和生活质量。我们的实验策略是通过量化GSH和GSSG浓度，并计算几种组织中GSH:GSSG，来证实C57BL/6 （B6）和DBA/2 （D2）小鼠之间的谷胱甘肽平衡存在差异。然后，我们将分析由B6 × D2杂交产生的重组近交系小鼠（BXD小鼠），以便进行QTL分析并找到小鼠中负责GSH:GSSG的位点。同时，我们将对另外10个自交系进行菌株调查，其中包括4个野生衍生菌株，这些菌株将为本研究提供重要的遗传变异。压力与

DESCRIPTION (provided by applicant): Glutathione, a tripeptide molecule, is the primary endogenous antioxidant in cells. It is abundant and participates in a wide array of protective antioxidant and detoxification mechanisms. Homeostatic mechanisms maintain glutathione predominantly in its reduced state (GSH); oxidation of GSH causes the accumulation of its oxidized dimer form GSSG. Thus, examining the ratio of GSH:GSSG is a good indicator of oxidative stress and redox maintenance. Many chronic diseases of aging have oxidative stress components that cause significant declines in GSH:GSSG, rendering cells and tissues more susceptible to further damage. Although the biochemical pathways that regulate glutathione balance are well-defined, the genetic regulation of this parameter is not, despite findings suggesting that glutathione balance is regulated by genetics in mammals. The current project identifies genes regulating glutathione balance in mice. This work may reveal novel targets for therapies that maintain glutathione balance in disease, which would have the potential in humans to improve patient treatment, prognosis, and quality of life. Our experimental strategy is to confirm that differences in glutathione balance exist between C57BL/6 (B6) and DBA/2 (D2) mice by quantifying GSH and GSSG concentrations and calculating GSH:GSSG in several tissues. We will then analyze recombinant inbred mouse strains produced from B6 x D2 crosses (BXD mice) in order to perform QTL analysis and find loci responsible for GSH:GSSG in mice. Concurrently, we will perform a strain survey involving 10 additional inbred strains, including 4 wild-derived strains that will contribute significant genetic variation to this study. Strains with very different GSH:GSSG will be crossed and F2 progeny will be produced; QTL analysis will then proceed to confirm the loci identified with the BXD mice. Aim 1 tests if genetic regulation o GSH:GSSG ratios (as well as absolute values of [GSH] and [GSSG]) in liver, kidney, heart, and brain causes significant variation among at least 10 recombinant inbred BXD lines of mice. If this hypothesis is correct, we will use complete RI line analysis in 60 additional BXD strains to identify loci and suggest candidate genes regulating glutathione balance. Aim 2 defines glutathione balance in liver, kidney, heart, and brain in each of 12 inbred strains of mice aged 4-6 months. The set of 12 strains includes 4 wild-derived strains to maximize genetic variance and the chance of finding genetic regulators of glutathione balance in mice. We will cross mouse strains with higher and lower GSH:GSSG to produce F2 progeny and identify regulatory loci. Aim 3 compares glutathione balance in liver, kidney, heart, and brain of inbred mice in middle-aged, 14- 15 month old mice, and in young adult 3-4 month old control mice from 12 genetically diverse inbred strains. We will cross strains with important differences in aging to identify loci responsible for this difference. In all aims, gene identification will suggest clinical treatments.