Aging Mitochondrial Interactome

线粒体在与年龄相关的病理、韧性丧失和生活质量下降中发挥核心作用。 上了年纪的人。随着我们年龄的增长，线粒体功能的变化会导致氧化还原和能量平衡的破坏， 代谢产物水平改变，钙调节受损，对通透性转换的敏感性增加，所有这些都是 这会导致组织功能障碍。线粒体是不断适应变化的动态细胞器 通过改变蛋白质组装和相互作用来改变其功能的细胞需求。尽管很明显 关于线粒体蛋白相互作用中与年龄相关的变化是如何导致变化的，我们知之甚少。 在功能上。为了解决这个基本问题，我们建议应用最先进的小说量化 化学交联-质谱法(XL-MS)定量测定线粒体的变化 随着年龄的增长，心脏和骨骼肌间的相互作用。通过将这种创新的XL-MS方法与目标 在过去的几年中开发了功能分析和干预来操纵体内线粒体和 在体外，我们在鉴定线粒体蛋白相互作用的变化方面具有独特的地位，这些变化是年龄- 相关的线粒体功能障碍。我们的初步数据表明多个蛋白质相互作用的特定破坏 参与ADP转运、ATP合成、谷氨酸代谢和电子复合体的网络 随年龄增长的运输系统。XL-MS表明，这些蛋白质复合体中的许多在老化过程中直接被破坏 与我们已经证明的线粒体靶向肽SS-31相互作用逆转线粒体功能障碍 在心脏和骨骼肌中。我们的总体假设是线粒体相互作用组的变化是由 线粒体氧化还原应激增加是导致ATP生成减少和代谢物水平改变的原因 来自老化心脏和骨骼肌的线粒体。在目标1中，我们将应用XL-MS和现场特定分析来 测量老年小鼠心脏和骨骼线粒体中相互作用体与功能之间的联系 肌肉。作为对这种方法提供的新机制洞察力的具体测试，我们将使用基因编辑的IPSC 用来检测谷氨酸相互作用改变之间的因果关系 脱氢酶调节区，这是在老年线粒体相互作用组中发现的最大变化，以及 谷氨酸和α-酮戊二酸代谢受损。在目标2中，我们将使用线粒体靶向干预来 逆转线粒体功能障碍，SS-31和AAV-线粒体靶向过氧化氢酶，并诱导线粒体 氧化还原应激以确定线粒体相互作用组中最重要的功能变化。 目的3我们使用人类肌肉活检来测试是否在AIMS中发现了线粒体相互作用组的变化。 1和2翻译成衰老的人类骨骼肌。我们将把老年人分为低绩效和高绩效两类 将线粒体的相互作用和功能与年轻人进行比较。来自这些的结果 实验将对该领域产生变革性的影响，通过提供第一个窗口来了解 线粒体蛋白相互作用网络与年龄相关性线粒体功能障碍。 1

Mitochondria play a central role in age-related pathologies, loss of resilience, and the decline in quality of life in older adults. As we age changes in mitochondrial function lead to disruption of redox and energy homeostasis, altered metabolite levels, impaired calcium regulation, 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 underlie changes in function. To address this fundamental question we propose to apply a state of the art novel quantitative chemical cross-linking with mass spectrometry approach (XL-MS) to quantify the changes in the mitochondrial interactome in heart and skeletal muscles with age. By combining this innovative XL-MS approach with targeted functional assays and interventions developed over the last several years to manipulate mitochondria in vivo and in vitro we are uniquely positioned to identify the changes in mitochondrial protein interactions that underlie age- related mitochondrial dysfunction. Our preliminary data indicate specific disruption of multiple protein interaction networks involved in ADP transport, ATP synthesis, glutamate metabolism, and complexes of the electron transport system with age. Many of these protein complexes that XL-MS indicates are disrupted in aging directly interact with the mitochondrial targeted peptide SS-31 that we have shown reverses mitochondrial dysfunction in heart and skeletal muscle. Our overall hypothesis is that changes in the mitochondrial interactome driven by elevated mitochondrial redox stress underlie decreased ATP production and altered metabolite levels in mitochondria from aged heart and skeletal muscle. In aim 1 we will apply XL-MS and site-specific assays to measure the link between the interactome and function in mitochondria from aged mouse heart and skeletal muscle. As a specific test of new mechanistic insights available from this approach we will use gene-edited iPSC derived cardiomyocytes to test the causal relationship between altered interactions in the glutamate dehydrogenase regulatory region, the largest change identified in the aged mitochondrial interactome, and impaired glutamate and α-ketoglutarate metabolism. In aim 2 we will use mitochondrial targeted interventions to reverse mitochondrial dysfunction, SS-31 and AAV-mitochondrial targeted catalase, and induce mitochondrial redox stress to identify the most functionally important changes in the mitochondrial interactome from aim 1. In aim 3 we use human muscle biopsies to test whether changes in the mitochondrial interactome identified in aims 1 and 2 translate into aged human skeletal muscle. We will separate older adults into low and high performing groups to compare the mitochondrial interactomes and function with those of young adults. Results from these experiments will have a transformative impact on the field by providing the first window into the links between the mitochondrial protein interaction network and age-related mitochondrial dysfunction. 1