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 测试线粒体！衰老，特别是研究线粒体DNA(MtDNA)的作用。 老化过程中小鼠大脑的突变。作为最受欢迎的假说之一，线粒体理论 衰老，预测体细胞线粒体DNA(MtDNA)突变随着时间的推移而积累，并且 这些突变导致的线粒体功能受损会导致各种衰老。 表型。然而，目前还没有关于线粒体dna整体积累的全面研究。 衰老过程中的突变以及与衰老相关的线粒体DNA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方法来转移小鼠神经末梢的mtDNA，即突触体 到细胞系统，我们已经改进了分离和鉴定线粒体DNA突变的方法。与 建立了线粒体分子遗传和生化技术，我们可以第一次， 通过评估个体在衰老过程中神经细胞mtDNA突变的积累情况 来自突触体的线粒体DNA。这一提议中要检验的特定假设是， 线粒体基因组在小鼠神经细胞老化过程中积累；这些线粒体DNA突变依次 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。我们将进行与衰老相关的线粒体DNA的遗传和功能分析 通过将突触体mtDNA转移到细胞系系统而发生突变。这将揭示低频率的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，在 尤其是与氧化损伤有关的那些。该项目的成功完成不仅将有助于测试 线粒体衰老理论，但也可以提供对衰老的潜在机制的见解 进程。

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.