Mitochondrial Genetics and Aging

线粒体遗传学与衰老

• 批准号: 6607252
• 负责人: Douglas C Wallace
• 金额: $ 26.6万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-07-10 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6607252
• 关键词: SDS polyacrylamide gel electrophoresis; aging; catalase; cellular respiration; cytogenetics; enzyme activity; free radical oxygen; gene mutation; genetically modified animals; glutathione peroxidase; laboratory mouse; microarray technology; mitochondria; mitochondrial DNA; mitochondrial membrane; oxidative phosphorylation; polymerase chain reaction; protein biosynthesis; respiratory burst oxidase; superoxide dismutase; western blottings

DESCRIPTION (Investigator's abstract): We are testing the hypothesis that a major factor in mammalian aging is the progressive decline in mitochondrial function, resulting from the chronic toxicity of mitochondrially generated oxygen radicals. Mitochondrial oxidative phosphorylation (OXPHOS) is the major source of cellular energy and OXPHOS generates most of the cellular reactive oxygen species (ROS) as a toxic by-product. These ROS damage mitochondrial lipids, proteins, and DNA, impairing mitochondrial function. To determine the importance of mitochondrial ROS toxicity in aging we are studying knockout mice lacking the mitochondrial anti-oxidant enzymes for Manganese superoxide dismutase (MnSOD) and glutathione peroxidase 1 (GPx1). MnSOD -I- animals die soon after birth due to the superoxide inactivation of mitochondrial iron-sulfur center enzymes resulting in dilated cardiomyopathy. The GPx1-/- animals show a mild growth inhibition and reduced OXPHOS efficiency. To further clarify the role of mitochondrial ROS toxicity in aging, we propose to analyze mice with different anti-oxidant enzyme levels. Diminished enzyme activities will be created by MnSOD-/-, MnSOD1+, GPxI-/-, and MnSOD-/+ plus GPx1-/- genotypes, while enhanced enzyme activities will be generated by the adult over expression of MnSOD, MnSOD + GPx 1, and MnSOD + catalase from the ROSA26 locus, following activation using a Cre recombinase switch. Mice with reduced, normal, and increased anti-oxidant enzymes will be assessed for their age-related decline in mitochondrial function, accumulation of somatic mtDNA mutations, changes in mitochondrial gene expression, and altered longevity. The pathologic significance of the age-related somatic mtDNA mutations will be investigated by their recovery through fusion of mouse brain synaptosomes or tissue fibroblast cytoplasts to cultured mouse cells, and their subsequent introduction into the mouse germline through female ES cells. Changes in mitochondrial gene expression will be assessed using our Emory Mitochondrial Gene Chip (Mitochip), and the effect of over expression of anti-oxidant genes on longevity will be evaluated by aging studies.

描述（研究者的摘要）：我们正在检验以下假设。 哺乳动物衰老的主要因素是线粒体的逐步下降 功能，由线粒体产生的慢性毒性产生 氧自由基。线粒体氧化磷酸化（OXPHOS）是主要的 细胞能量和Oxphos的来源产生大多数细胞反应性 氧（ROS）作为有毒的副产品。这些ROS损伤线粒体 脂质，蛋白质和DNA，损害线粒体功能。确定 线粒体ROS毒性在衰老中的重要性我们正在研究基因敲除小鼠 缺少用于锰超氧化物的线粒体抗氧化酶 歧化酶（MNSOD）和谷胱甘肽过氧化物酶1（GPX1）。 mnsod -i -Animal死亡 出生后不久，由于线粒体的超氧化物失活 铁硫心中心酶导致心肌病扩张。 GPX1 - / - 动物表现出轻度的生长抑制作用和OXPHOS效率降低。进一步 阐明线粒体ROS毒性在衰老中的作用，我们建议分析 具有不同抗氧化酶水平的小鼠。酶活性减少 将由mnsod-/ - ，mnsod1+，gpxi - / - 和mnsod - /+ plus gpx1 - / - 创建 基因型，而成年人将产生增强的酶活性 从Rosa26基因座的MNSOD，MNSOD + GPX 1和MNSOD +过氧化氢酶的表达， 使用CRE重组酶开关激活后。小鼠降低，正常， 并将评估增加的抗氧化剂酶的年龄相关酶 线粒体功能的下降，体细胞mtDNA突变的积累， 线粒体基因表达的变化和寿命改变。病理 与年龄相关的体细胞mTDNA突变的重要性将通过 它们通过融合小鼠脑突触体或组织成纤维细胞的恢复 培养的小鼠细胞的细胞体，然后将其引入 小鼠通过雌性ES细胞种系。线粒体基因的变化 表达将使用我们的Emory线粒体基因芯片（Mitochip）评估， 并且抗氧化基因过度表达对寿命的影响将是 通过衰老研究评估。