Spatial Acetyl-CoA metabolism as a regulator of Hallmarks of Aging

摘要 遗传毒性压力是衰老的一个重要标志。有趣的是，与衰老研究密切相关的是， 损伤与多种衰老特征密不可分，包括：表观遗传学、蛋白质稳态、压力丧失 恢复力和细胞衰老。然而，在何处，何时以及如何基因毒性压力驱动其他 我们还不太了解它的特点。我们的总体前提是，乙酰辅酶A代谢是调节 这些多种老化标志并决定老化轨迹。乙酰辅酶A是一种关键代谢物， 调节几种细胞过程，包括基因转录和蛋白质稳定性。乙酰辅酶A与 在亚细胞池中调节，浓度或亚细胞通量的变化驱动其 可用性和利用率。该项目的目标是解决DNA损伤驱动的乙酰辅酶A的作用 亚细胞定位和流动作为老化标志的“枢纽”。我们假设（1）代和 乙酰辅酶A空间分布在对DNA损伤的反应中改变，和（2）乙酰辅酶A的重新连接 新陈代谢是改变衰老轨迹的必要和充分条件。我们将在多层中测试这一假设， 使用遗传、代谢和生物化学技术的创新组合的机械细节。缺乏 诱导生理相关DNA损伤的特定工具严重限制了我们理解如何 遗传毒性压力与衰老的其他标志相联系。为了解决这个问题，我们创建了一个 化学光遗传学工具以受控方式诱导氧化性DNA损伤。这一创新工具将使我们 直接测试DNA损伤是否改变了细胞自主或非细胞自主老化的标志， 方式首先，我们将确定多个细胞/组织中衰老标志的时间和层次 在正常的生命周期中，对DNA损伤的反应。此外，我们将确定一个关键的代谢的作用， 酶，ATP-柠檬酸裂解酶ACLY在DNA损伤驱动的乙酰辅酶A代谢重新布线。二是 定量剖析乙酰辅酶A亚细胞库及其对衰老和衰老的贡献 相关分泌蛋白组（SASP）。使用计算工具来建立一个统一的框架，我们将确定因果关系， 特征这项工作在技术上是创新的，用于定量研究乙酰基的亚细胞调节。 CoA对DNA损伤的反应随着年龄的增长。这个项目是智力创新的假设一本小说 持续遗传毒性应激与亚细胞乙酰辅酶A代谢的关系我们的分析，将 增加对DNA损伤诱导的乙酰辅酶A代谢之间联系的基本理解 和衰老的标志，从而可能为针对合并症的新治疗策略铺平道路， 老年人的多药治疗

ABSTRACT Genotoxic stress is a key hallmark of aging. Interestingly, and of great relevance to aging research, nuclear DNA damage is inextricably linked to multiple aging hallmarks including: epigenetics, proteostasis, loss of stress resilience and cellular senescence. However, where, when and how does genotoxic stress drive the other hallmarks is not well-understood. Our overall premise is that acetyl-CoA metabolism is the ‘hub’ that regulates these multiple aging hallmarks and determines aging trajectories. Acetyl-CoA is a critical metabolite that modulates several cellular processes including the gene transcription and protein stability. Acetyl-CoA is tightly regulated in subcellular pools and a change in concentration or subcellular flux drives quantitative changes in its availability and utilization. The goal of this project is to address the role of DNA damage-driven acetyl-CoA subcellular localization and flux as the ‘hub’ of hallmarks of aging. We hypothesize that (1) generation and spatial distribution of acetyl-CoA are altered in response to DNA damage, and (2) rewiring of acetyl-CoA metabolism is necessary and sufficient to change aging trajectories. We will test this hypothesis in multi-layer, mechanistic detail using an innovative combination of genetic, metabolic and biochemical techniques. Lack of specific tools to induce physiologically relevant DNA damage has severely limited our ability to understand how genotoxic stress communicates with the rest of the hallmarks of aging. To address this, we created a chemoptogenetic tool to induce oxidative DNA damage in a controlled manner. This innovative tool will allow us to directly test whether DNA damage alters hallmarks of aging in a cell autonomous or non-cell autonomous manner. First, we will determine the timing and hierarchy among the hallmarks of aging in multiple cells/tissues across the normal lifespan, in response to DNA damage. In addition, we will determine the role of a key metabolic enzyme, ATP-citrate lyase ACLY in DNA damage-driven acetyl-CoA metabolic rewiring. Second, we will quantitatively dissect acetyl-CoA subcellular pools and their contribution to senescence and senescence associated secretome (SASP). Using computational tools to build a unified framework, we will identify causal hallmarks. This work is technically innovative for quantitatively examining the subcellular regulation of acetyl- CoA in response to DNA damage with age. This project is intellectually innovative for hypothesizing a novel relationship between persistent genotoxic stress and subcellular acetyl-CoA metabolism. Our analysis, will increase fundamental understanding of the connection between DNA damage-induced acetyl-CoA metabolism and aging hallmarks, thus potentially paving the way for new treatment strategies targeting co-morbidities and polypharmacy in the elderly.