Dietary Modulation of Cellular Oxidative Stress in Aging

衰老过程中细胞氧化应激的饮食调节

• 批准号: 6784082
• 负责人: RAJINDAR S SOHAL
• 金额: $ 40.63万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-04-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6784082
• 关键词: DNA damage; age difference; antioxidants; caloric dietary content; carbonyl group; cell senescence; dietary restriction; free radical oxygen; immunochemistry; laboratory mouse; longevity; matrix assisted laser desorption ionization; nutrition of aging; nutrition related tag; oxidative stress; protein sequence; protein structure function

DESCRIPTION (provided by applicant): The long-term goal of the proposed study is to understand the nature of the mechanisms by which caloric restriction prolongs the life span of animals. The specific hypothesis to be tested is that "extension of life span of mice by caloric restriction is dependent upon attenuations of oxidative stress and the rate of accrual of oxidative damage to specific proteins." The experimental approach to test the hypothesis will involve two different strains of mice. One strain, C57BL/6, exhibits life span extension as a result of caloric restriction, while the other, DBA/2, shows no such effect. Thus, both a positive and negative control for the caloric restriction (CR) regimen will be used. The mean and maximum life span of ad libitum-fed (AL) DBA/2 mice are similar to those of AL C57BL/6 mice. Comparisons will be made between AL and CR mice, within each strain and between the two strains of mice, in order to determine whether CR attenuates: (a) the age related elevations in the level of oxidative stress and (b) the accrual of oxidative damage and loss of catalytic activity of specific proteins. The key question will be whether these effects occur in both strains or only in C57BL/6, which shows life span prolongation by CR. The hypothesis will be supported if CR lowers the level of oxidative stress and attenuates oxidative damage to selective proteins in C57BL/6 mice, which show life span prolongation by CR, but not in DBA/2 mice, in which CR has no effect. The level of oxidative stress will be determined using a battery of tests involving measurements of generation of reactive oxygen species, antioxidative enzymes, glutathione disulfide/glutathione redox couple, and amounts of glutathionylated proteins. Proteins exhibiting oxidative modifications such as carbonylation, 4-hydroxy 2-nonenal adducts, malondialdehyde adducts and 3-nitro modification of tyrosine residues will be detected immunochemically. Proteins will be identified by microsequencing and/or mass spectrometry. The significance of this study is that the results should provide important new knowledge about: (1) mechanisms linking oxidative stress to the losses in physiological functions during aging, and (2) the identity of specific targets of protein oxidative damage during aging and the consequent metabolic failures. Thus, it will also provide a further critical test of the validity of oxidative stress hypothesis of aging.

描述（由申请人提供）：拟议研究的长期目标是了解热量限制延长动物寿命的机制的性质。要测试的特定假设是“通过热量限制，小鼠的寿命延长取决于氧化应激的衰减以及对特定蛋白质的氧化损伤率的速率。”检验假设的实验方法将涉及两种不同的小鼠菌株。一种菌株C57BL/6由于热量限制而表现出寿命的延长，而另一个DBA/2则没有这种影响。因此，将使用热量限制（CR）方案的阳性和负面对照。自由喂养（Al）DBA/2小鼠的平均寿命和最大寿命与Al C57BL/6小鼠的平均寿命相似。为了确定CR是否减弱：（a）与年龄相关的氧化应激水平和（b）特定蛋白质催化活性的应计。关键问题将是这些效应是在菌株中还是仅发生在C57BL/6中，这表明Cr的寿命延长。如果CR降低氧化应激水平并减轻C57BL/6小鼠选择性蛋白的氧化损伤，该假设将得到支持，这表明Cr的寿命延长，但在DBA/2小鼠中却没有氧化，而CR无效。氧化应激水平将使用一系列测试确定，涉及测量活性氧，抗氧化酶，谷胱甘肽二硫化物/谷胱甘肽氧化还原夫妇以及谷胱甘肽量的含量。表现出表现出氧化修饰的蛋白质，例如羰基化，4-羟基2-非加合物，丙二醛加合物和酪氨酸残基的3-硝基修饰。蛋白质将通过微链测序和/或质谱法鉴定。这项研究的意义在于，结果应提供有关：（1）将氧化应激与衰老过程中生理功能损失联系起来的机制，以及（2）衰老期间蛋白质氧化损伤的特定靶标的身份以及随后的代谢失败。因此，它还将对衰老的氧化应激假说的有效性提供进一步的批判性检验。