Interaction Between DNA Repair and Antioxidant Genes During Aging

衰老过程中 DNA 修复与抗氧化基因之间的相互作用

• 批准号: 7498608
• 负责人: CARLOS A TORRES-RAMOS
• 金额: $ 11.25万
• 依托单位: UNIVERSITY OF PUERTO RICO MED SCIENCES
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-01 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7498608
• 关键词: Aging; Animal Model; Antioxidants; Base Excision Repairs; Biological Assay; Cell Survival; Cell physiology; Cells; Complex; DNA; DNA Damage; DNA Repair; DNA-(apurinic or apyrimidinic site) lyase; Data; Development; Development Plans; Environment; Enzymes; Erythromycin; Excision; Exhibits; Exposure to; Faculty; Genes; Genetic Transcription; Genome Stability; Genomic Instability; Goals; Grant; Hydrogen Peroxide; Knockout Mice; Lead; Lesion; Liver; Measures; Membrane Potentials; Mitochondria; Mitochondrial DNA; Mus; Mutation; Organism; Oxidants; Oxidative Stress; Oxygen Consumption; Pathway interactions; Polymerase Chain Reaction; Predisposition; Publications; Reactive Oxygen Species; Research Project Grants; Research Proposals; Resistance; Role; SOD2 gene; Saccharomyces cerevisiae; Score; Source; Superoxide Dismutase; System; Technology Transfer; Testing; Tissues; Training; Work; Yeasts; age related; base; improved; macromolecule; mitochondrial DNA mutation; mitochondrial dysfunction; mitochondrial membrane; mouse model; repaired; response; theories

DESCRIPTION (provided by applicant): The oxidative theory of aging proposes that declines in cellular function associated with aging are due to the accumulation of damaged macromolecules. Mitochondria are the main source of endogenous reactive oxygen species (ROS), which inflict damage to macromolecules, particularly to mitochondria! DNA (mtDNA). DMA lesions are deleterious to cells because they halt transcription, replication, and can generate mutations. Cells have evolved several mechanisms to deal with oxidative damage. One line of defense is represented by the antioxidant defense system, which includes among others, the superoxide dismutase (SOD) enzymes. The second line of defense is DNA repair, particularly base excision repair (BER). Although the enzymatic components of both defense systems are known, it is not understood how the systems interact to maintain mitochondrial genomic stability. The main hypothesis in this research proposal is that the BER pathway and the antioxidant defense system have cooperative roles in protecting against mitochondrial genomic instability induced by oxidative stress. Oxidative stress will be considered under two situations: during aging and after an environmentally induced insult. To test this hypothesis we will use two model organisms, a simple eukaryotic organism, the yeast Saccharomyces cerevisiae, and a more complex mammalian organism, a knockout mouse heterozygous for Ape1, the main AP endonuclease that participates in BER. The following specific aims will be used as criteria to test our hypothesis: (1) To determine whether yeast cells harboring simultaneous mutations in the APN1 and SOD2 genes exhibit enhanced mtDNA damage and mitochondrial dysfunction after oxidative stress; (2) To determine whether the levels of mtDNA lesions increase in an age dependent fashion in yeast cells harboring simultaneous mutations in the APN1 and SOD2 genes, and if levels of mtDNA lesions correlate with mitochondrial dysfunction; (3) To determine whether mitochondrial DNA damage increases in an age-dependent fashion in a BER deficient mouse model. Finally, we propose a developmental plan whose objective is to lead the PI to improve his publication record and generate the preliminary data necessary for the submission of non-SCORE competitive research grants.

描述（由申请人提供）：衰老的氧化理论提出，与衰老相关的细胞功能下降是由于受损大分子的积累。线粒体是内源性活性氧（ROS）的主要来源，ROS对大分子物质尤其是线粒体造成损伤。DNA（mtDNA）。DMA损伤对细胞是有害的，因为它们停止转录，复制，并可能产生突变。细胞已经进化出几种机制来处理氧化损伤。抗氧化防御系统是一条防御线，其中包括超氧化物歧化酶（SOD）酶。第二道防线是DNA修复，特别是碱基切除修复（BER）。虽然这两种防御系统的酶组分是已知的，但尚不了解系统如何相互作用以维持线粒体基因组稳定性。本研究的主要假设是BER途径和抗氧化防御系统在保护线粒体免受氧化应激诱导的基因组不稳定性方面具有协同作用。将在两种情况下考虑氧化应激：老化期间和环境诱导的损伤后。为了验证这一假设，我们将使用两个模型生物，一个简单的真核生物，酵母酿酒酵母，和一个更复杂的哺乳动物生物，敲除小鼠Ape 1，主要的AP核酸内切酶，参与BER杂合子。本研究的主要目的是：（1）确定APN 1和SOD 2基因同时突变的酵母细胞在氧化应激后是否表现出线粒体DNA损伤和线粒体功能障碍;（2）为了确定在APN 1和SOD 2基因同时突变的酵母细胞中mtDNA损伤水平是否以年龄依赖性方式增加，以及线粒体DNA损伤水平是否与线粒体功能障碍相关;（3）确定BER缺陷小鼠模型中线粒体DNA损伤是否以年龄依赖性方式增加。最后，我们提出了一个发展计划，其目标是引导PI改善他的出版记录，并生成提交非SCORE竞争性研究赠款所需的初步数据。