Mitochondrial DNA Deletion Mutation Frequency as a Metric of Biologic Age

项目总结/摘要 由于老年科学的进步，老龄化必须被认为是一个可改变的风险因素的主要原因， 死亡针对人类衰老的干预措施正在进行中，但缺乏预测生物标志物， 评估这些干预措施的有效性。随着年龄的增长，体细胞来源的线粒体DNA（mtDNA） 缺失在各种组织中的单个细胞内克隆积累。获得高细胞内 当线粒体DNA丰度增加时，线粒体DNA缺失破坏氧化磷酸化、细胞功能并导致细胞死亡。我们 假设人类mtDNA缺失频率预测发病率和死亡率的风险， 干预改变健康寿命。 我们已经开发了一种数字PCR检测方法，可以使用总DNA样本定量mtDNA缺失频率 任何啮齿类动物和人类的组织。该测定提供绝对定量，适用于96孔板， 格式，与随后的细胞表型（包括细胞死亡）密切相关，并具有检测 低于百万分之一。线粒体DNA缺失突变频率随年龄呈指数增加， 增加与年龄诱导的功能障碍细胞的积累、组织变性和死亡平行。这 该项目将进一步开发和验证mtDNA缺失频率作为人类衰老中细胞死亡的衡量标准。 我们正在根据FDA生物分析测定指南对该检测进行验证。我们正在测量 mtDNA缺失频率在许多人体组织和生物流体在整个人类寿命，并将 建立mtDNA缺失频率与年龄、临床和生理之间的关系 结果和针对人类老龄化的干预措施。

PROJECT SUMMARY/ABSTRACT Due to advances in geroscience, aging must be considered a modifiable risk factor for the major causes of death. Interventions targeting human aging are ongoing, but there is a lack of predictive biomarkers to measure the effectiveness of these interventions. With age, somatically-derived mitochondrial DNA (mtDNA) deletions clonally accumulate within individual cells across a variety of tissues. Attaining high intracellular abundance, mtDNA deletions disrupt oxidative phosphorylation, cellular function, and result in cell death. We hypothesize that human mtDNA deletion frequency predicts the risk of morbidity and mortality and responds to interventions that alter healthspan. We have developed a digital PCR assay that quantifies mtDNA deletion frequency using total DNA samples from any tissue in rodents and humans. This assay provides absolute quantitation, is amenable to a 96-well format, correlates strongly with the subsequent cellular phenotypes including cell death, and has a detection limit below one part per million. MtDNA deletion mutation frequency increases exponentially with age and this increase parallels the age-induced accumulation of dysfunctional cells, tissue degeneration, and mortality. This project will further develop and validate mtDNA deletion frequency as a measure of cell death in human aging. We are validating the test in accordance with FDA guidelines for bioanalytical assays. We are measuring mtDNA deletion frequency in a number of human tissues and biofluids across the human lifespan and will establish the relationship between mtDNA deletion frequency, chronological age, clinical and physiological outcomes, and interventions targeting human aging.