Modulators of DNA damage associated nucleo-mitochondrial communication in aging

摘要： 这个项目的目标是检验这样一种假设，即核内的遗传毒性应激会触发 导致功能失调的线粒体积累的信号事件，进而驱动 细胞衰老和衰老。这一假说得到了初步数据的支持 细胞和小鼠中DNA修复内切酶ERCC1-XPF的耗尽导致 氧化DNA损伤的积累，细胞的过早衰老和衰老，而且 令人惊讶的是线粒体功能障碍和活性氧增加。此外， 缺失ERCC1的线虫也显示出线粒体功能障碍的证据。ERCC1- XPF只有在修复核基因组时才需要，这表明核应激可以 导致线粒体异常。在小鼠模型中也有类似的观察结果 共济失调、毛细血管扩张症和Hutchinson-Gilford Progeria综合征的人类细胞。在此，我们 提出定义核基因组不稳定性的分子机制(S) 线粒体功能障碍使用强大的基因工具的创新组合。这个 这些研究的意义在于有可能确定新的信号机制， 可以在治疗上有针对性地预防细胞衰老、衰老和衰老相关疾病 这是细胞随机损伤的结果。这一方法将是全基因组的 在ERCC-1线虫中进行RNAi筛选以确定抑制Complex 1功能障碍的基因 变种蠕虫。这种无偏见的方法将产生影响线粒体功能的途径 对内源性遗传毒性应激的反应和毫无疑问的关于机制的新假设 衰老的问题。这将推动我转变为一名独立调查员，第二次 这个项目的重要目标。一项有针对性的初步筛查确定了 方法，发现了几个对DNA损伤反应和有丝分裂至关重要的基因， 包括ATM、P53、Drp1和PINK1，它们调节ERCC-1蠕虫的线粒体功能。 这些在线虫中发现的细胞核和线粒体之间的新联系将是 在小鼠和小鼠细胞中被追踪。发挥两个优势的创新途径 非常强大的模型系统将允许识别新的分子靶标和支持 将这一新知识迅速转化为人类衰老。

Abstract: The goal of this project is to test the hypothesis that genotoxic stress in the nucleus triggers signaling events that result in accumulation of dysfunctional mitochondria, which in turn drives cellular senescence and aging. The hypothesis is supported by preliminary data demonstrating that depletion of the DNA repair endonuclease ERCC1-XPF in cells and mice causes accumulation of oxidative DNA damage, premature cellular senescence and aging, but also surprisingly mitochondrial dysfunction and increased reactive oxygen species. Moreover, ERCC1-deficient C. elegans also show evidence of mitochondrial dysfunction. ERCC1- XPF is required only for the repair of the nuclear genome, suggesting that nuclear stress can drive mitochondrial abnormalities. Similar observations have been made in murine models and human cells of ataxia telangiectasia and Hutchinson-Gilford Progeria syndrome. Herein we propose to define the molecular mechanism(s) by which nuclear genomic instability triggers mitochondrial dysfunction using an innovative combination of powerful genetic tools. The significance of these studies is the possibility of identifying novel signaling mechanisms that could be targeted therapeutically to prevent cell senescence, aging and age-related diseases arising as a consequence of stochastic damage to cells. The approach will be a genome-wide RNAi screen in ercc-1 C. elegans to identify genes that suppress Complex 1 dysfunction in mutant worms. This unbiased approach will yield pathways that impact mitochondrial function in response to endogenous genotoxic stress and undoubtedly new hypotheses about mechanisms of aging. This will fuel my transition to becoming an independent investigator, a second important goal of this project. A targeted preliminary screen established the feasibility of the approach and revealed several genes critical for the DNA damage response and mitophagy, including ATM, p53, DRP1 and PINK1,that regulate mitochondrial function in ercc-1 worms. These novel links between the nucleus and mitochondria identified in nematodes will be pursued in mice and murine cells. The innovative approach of exploiting the strengths of two very powerful model systems will allow identification of novel molecular targets and support rapid translation of this new knowledge to human aging.