Role of Mitochondrial DNA Mutations in Aging in Neuronal Cells

我们的长期目标是研究线粒体在衰老中的作用。这项拨款申请的总体目标是 检测线粒体研究衰老的机制，特别是研究线粒体DNA（mtDNA）的作用 老鼠大脑在衰老过程中的突变。作为最受欢迎的假设之一，线粒体理论 衰老，预测体细胞线粒体DNA（mtDNA）突变随时间积累， 这些突变导致线粒体功能受损，从而导致各种衰老 表型然而，还没有关于线粒体DNA总体积累的全面研究 衰老过程中的突变，以及衰老相关的mtDNA突变的生理后果在很大程度上是 不清楚我们最近建立了一种从小鼠神经末梢转移mtDNA的方法，即，突触体 我们已经改进了分离和表征mtDNA突变的方法。结合 建立了线粒体分子遗传和生化技术，我们可以，第一次， 研究衰老过程中神经细胞mtDNA突变的积累， 在这个提议中要检验的特殊假设是， 线粒体基因组在小鼠神经元细胞衰老过程中积累;这些mtDNA突变反过来 损害线粒体功能，并可能导致各种细胞成分的氧化损伤 包括神经细胞中的线粒体DNA。我们将对与衰老相关的线粒体DNA进行遗传和功能分析， 通过将突触体mtDNA转移到细胞系系统中进行突变。这将揭示低频率mtDNA 其他方法无法识别的突变。通过生成携带有 与衰老相关的mtDNA突变，我们还将描述突变的生理后果， 特别是与氧化损伤有关的那些。这个项目的成功完成不仅有助于测试 衰老的线粒体理论，但也可以提供对衰老的潜在机制的见解， 过程

Our long-term goal is to study the role of mitochondria in aging. The overall goal of this grant application is to test the mitochondria! theror/ of aging and, in particular, to investigate the role of mitochondrial DNA(mtDNA) mutations in mouse brain during aging. As one of the most favored hypotheses, the mitochondrial theory of aging, predicts that somatic mitochondria DNA (mtDNA) mutations accumulate with time, and the compromised mitochondrial function resulting from these mutations is then responsible for various aging phenotypes. However, there has been no comprehensive study of the overall accumulation of mtDNA mutations during aging, and the physiological consequences of aging-related mtDNA mutations are largely unclear. We recently established a method to transfer mtDNA from mouse nerve endings, i.e., synaptosomes to a cell system, and we have improved methods to isolate and characterize mtDNA mutations. Combined with established mitochondrial molecular genetic and biochemical technologies, we can, for the first time, investigate the accumulation of mtDNA mutations in neuronal cells during aging by evaluating individual mtDNA from the synaptosomes.The particular hypothesis to be tested in this proposal is that mutations in the mitochondrial genome accumulate during aging in mouse neuronal cells; these mtDNA mutations in turn compromise mitochondrial function and may result in oxidative damage to various cellular components including mtDNA in neuronal cells. We will perform genetic and functional analyses of aging-related mtDNA mutations by transferring synaptosomal mtDNA to a cell line system. This will reveal low frequncy mtDNA mutations that could not be identified by other methods. By generating neuronal cell models that carry aging-related mtDNA mutations, we will also charaterize the physiological consequences of the mutations, in particular those related to oxidative damage. The successful completion of this project will not only help to test the mitochondrial theory of aging, but could also provide insights into the underlying mechanisms of the aging process.