Aging Mitochondrial Interactome

线粒体功能的改变在与年龄相关的病理、弹性丧失和 老年人的生活质量下降。随着我们年龄的增长，我们的线粒体会发生变化，导致我们的 产生三磷酸腺苷并增加氧化剂的产生。这些变化导致氧化还原和能量的中断。 动态平衡、代谢物水平改变和对通透性转变的敏感性增加，所有这些都有助于 到组织功能障碍。线粒体是不断适应不断变化的细胞需求的动态细胞器 通过改变蛋白质的组装和相互作用来改变它们的功能。尽管很明显很重要，但几乎没有 已知线粒体蛋白相互作用(相互作用组)中与年龄相关的变化是如何导致 随着年龄的增长而发挥作用。为了解决这个根本问题，我们建议应用最先进的量化 用化学交联质谱(QXL-MS)技术定量测定线粒体的变化 随着年龄的增长而互动。通过将这种创新的QXL-MS方法与线粒体的详细分析相结合 新陈代谢和我们在过去几年中开发的用于在体内操纵线粒体的干预措施 在体外，我们唯一的定位是确定线粒体相互作用组中分子水平的变化 与年龄相关的线粒体功能障碍是其基础。我们的初步数据显示多种蛋白质被破坏 参与ADP转运、ATP合成和底物向电子输送供应的相互作用网络 老年心脏和骨骼肌中的系统。这些更改与之前演示的 ATP产生减少，对ADP的敏感性降低。此外，我们已经证明，一个线粒体 靶向干预(SS-31)逆转心肌和骨骼肌线粒体功能障碍 与许多相同的蛋白质复合体相互作用，我们的相互作用组研究表明，这些复合体在衰老过程中被破坏， 包括ANT和电子传递系统的络合物IV和V。我们的总体假设在这里得到了检验 认为随着年龄的增长，线粒体相互作用组的变化是导致ATP产生减少和 老化的心脏和骨骼肌线粒体中氧化剂的产生增加。AIM 1应用XL-MS和 蛋白质和位点特异性线粒体分析以量化线粒体相互作用组随年龄和年龄的变化 在体内和体外，在小鼠心脏和骨骼肌中由促氧化剂处理诱导的。目标2量化 两种成熟的线粒体靶向干预SS-31对线粒体相互作用组的影响 以及线粒体靶向过氧化氢酶，以确定与年龄相关的最重要的蛋白质相互作用的变化 网络。目标3测试在目标1和2中确定的线粒体相互作用体的变化是否翻译成 衰老的人类骨骼肌。老年人线粒体相互作用组、功能及SS-31的作用 被分成低表现组和高表现组的人被与年轻人进行比较。这些实验的结果 将产生重大影响，并有可能通过提供第一个测试来改变该领域 线粒体蛋白相互作用的中断导致了与年龄相关的线粒体功能障碍。 1

Changes in mitochondrial function play a central role in age-related pathologies, loss of resilience, and the decline in quality of life in older adults. As we age there is a shift in our mitochondria toward a reduced ability to generate ATP and increased oxidant production. These changes lead to disruption of redox and energy homeostasis, altered metabolite levels, and increased sensitivity to permeability transition, all of which contribute to tissue dysfunction. Mitochondria are dynamic organelles that continuously adapt to changing cellular demands by altering protein assembly and interactions to modify their function. Despite the obvious importance, little is known about how age-related changes in mitochondrial protein interactions (interactome) underlie changes in function with age. To address this fundamental question, we propose to apply a state of the art quantitative chemical cross-linking with mass spectrometry (qXL-MS) strategy to quantify changes in the mitochondrial interactome with age. By combining this innovative qXL-MS approach with detailed assays of mitochondrial metabolism and interventions we have developed over the last several years to manipulate mitochondria in vivo and in vitro, we are uniquely positioned to identify the molecular level changes in mitochondrial interactome that underlie age-related mitochondrial dysfunction. Our preliminary data indicate disruption of multiple protein interaction networks involved in ADP transport, ATP synthesis, and substrate supply to the electron transport system in aged heart and skeletal muscle. These changes are associated with previously demonstrated decreases in ATP production and lower sensitivity to ADP. Furthermore, we have shown that a mitochondrial targeted intervention (SS-31) that reverses mitochondrial dysfunction in heart and skeletal muscle, specifically interacts with many of the same protein complexes that our interactome studies reveal are disrupted in aging, including the ANT and complexes IV and V of the electron transport system. Our overall hypothesis tested in this proposal is that changes in the mitochondrial interactome with age underlie decreased ATP production and increased oxidant production in mitochondria from aged heart and skeletal muscle. Aim 1 applies XL-MS and protein and site-specific mitochondrial assays to quantify changes in the mitochondrial interactome with age and those induced by pro-oxidant treatment in vivo and in vitro in mouse heart and skeletal muscle. Aim 2 quantifies the effect on the mitochondrial interactome of two well established mitochondrial targeted interventions, SS-31 and mitochondrial targeted catalase, to identify the most important age-related changes in the protein interaction networks. Aim 3 tests whether changes in the mitochondrial interactome identified in aims 1 and 2 translate into aged human skeletal muscle. The mitochondrial interactome, function, and effects of SS-31 from older adults separated into low and high performing groups are compared with young adults. Results from these experiments will have a significant impact and have the potential to transform the field by providing the first test of how disruption of mitochondrial protein interactions contribute to age-related mitochondrial dysfunction. 1