Long-lived proteins as pillars of mitochondrial architecture in rodent brains

长寿蛋白质作为啮齿动物大脑线粒体结构的支柱

基本信息

批准号：
10698113
负责人：
Jeffrey Nicholas Savas
金额：
$ 20万
依托单位：
NORTHWESTERN UNIVERSITY AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-15 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10698113
关键词：
Aging Animals Architecture Biochemical Biology Brain Calcium Cell Death Cell Survival Cell division Cell physiology Cells Chemicals Complex Crista ampullaris Deoxyribonucleosides Deterioration Diffusion Docking Dyes Ensure Eye Fluorescence Genetic Goals Half-Life Health Heart Homeostasis Impairment Individual Inner mitochondrial membrane Isotopes Knowledge Label Liquid Chromatography Longevity Maintenance Maps Mass Fragmentography Mass Spectrum Analysis Measures Membrane Membrane Potentials Metabolic Metabolism Methods Mitochondria Mitochondrial DNA Mitochondrial Proteins Molecular Molecular Target Monitor Mus Nature Nerve Degeneration Neurodegenerative Disorders Neurodevelopmental Disorder Neurons Nuclear Pore OPA1 gene Organelles Pathway interactions Physiologic pulse Play Process Production Proteins Proteome Proteomics Quality Control Rattus Rejuvenation Research Risk Rodent Role Shapes Sorting Structure System Time Tissues age related age related neurodegeneration brain cell cell type crosslink fitness mitochondrial dysfunction mitochondrial fitness mitochondrial membrane mouse model nervous system disorder novel postmitotic prevent stable isotope

项目摘要

ABSTRACT Mitochondria are multifaceted organelles that play vital roles in a myriad of cellular functions, including energy production, metabolism, calcium homeostasis, and cell death. It is generally accepted that a decline in mitochondria quality is a key contributor to mitochondrial dysfunction, aging, and represents a key point of convergence for several neurological disorders. Yet, precisely how dysfunctional mitochondria contribute to these conditions remains elusive. Proper mitochondrial function and fitness depends on a healthy proteome. Therefore, the mitochondrial proteome is monitored by an elaborate and integrated protein quality control network. Recent studies in mice have found that, on average, half-lives of mitochondrial proteins in the brain vary from minutes to days. Notably, our own recent discovery-based proteomic analysis revealed that a small subset of mitochondrial proteome persists for months in brain, heart, and eyeball in mice and rats. Given the vital role of mitochondria in cell health and survival, and the highly dynamic nature of mitochondria our discovery that mitochondrial proteins can persist for months in healthy tissues is unexpected and of potential importance. The overarching goal of this project is to characterize mitochondrial long-lived proteins (mt-LLPs) in the context of mitochondrial homeostasis. Our current understanding of mt-LLPs are based on composite measures from tissue homogenates and we lack an understanding of which specific cell types harbor these exceptional proteins. Several lines of evidence point to an inevitable dichotomy of proteins with exceptionally long lifespans. On one hand, due to their persistence, mt-LLPs serve as pillars of mitochondrial architecture, providing structural stability ensure a compact energy generating chemical reactor. At the same time, their long-term persistence puts LLPs at an inherently increased risk for age-related deterioration. Thus, our overall objectives are to use whole- animal stable isotope pulse labelling combined with biochemical and proteomic analyses to identify the brain cell types harboring mt-LLPs (Aim 1) and in parallel investigate mtDNA lifetime (Aim 2). Finally, we aim to determine if cristae structural integrity is required for mt-LLP persistence (Aim 3.1) and correlate the presence of mt-LLPs with mitochondrial membrane potential (Aim 3.2). Understanding the cells and structures harboring mt-LLPs, and the effect on mitochondrial fitness, could open new avenues of research and provide molecular targets for modulating mitochondrial network dynamics in the process of age-related neurodegeneration.

抽象的线粒体是多方面的细胞器，在无数的细胞功能中起着至关重要的作用，包括能量生产，代谢，钙稳态和细胞死亡。人们普遍认为下降线粒体质量是线粒体功能障碍，衰老的关键因素，并且代表了一个关键点几种神经系统疾病的收敛。然而，正是功能失调的线粒体如何贡献这些条件仍然难以捉摸。正确的线粒体功能和适应性取决于健康的蛋白质组。因此，线粒体蛋白质组通过精致且集成的蛋白质质量控制来监测网络。对小鼠的最新研究发现，平均而言，大脑中线粒体蛋白的半衰期从几分钟到几天不等。值得注意的是，我们自己最近基于发现的蛋白质组学分析表明，一个小的线粒体蛋白质组的子集在小鼠和大鼠的大脑，心脏和眼球中持续数月。鉴于至关重要线粒体在细胞健康和生存中的作用，线粒体的高度动态性质我们发现线粒体蛋白可以在健康组织中持续数月是出乎意料的，并且潜在的重要性。该项目的总体目标是在上下文中表征线粒体长寿命蛋白（MT-LLP）线粒体体内平衡。我们目前对MT-LLP的理解是基于复合措施组织匀浆，我们对哪种特定细胞类型具有这些特殊蛋白质的了解。几条证据表明，蛋白质的不可避免的蛋白质具有极长的寿命。一个手，由于其持久性，MT-LLP是线粒体建筑的支柱，提供结构稳定性确保紧凑的能源产生化学反应器。同时，他们的长期持久性使LLP 固有地增加了与年龄相关的恶化的风险。因此，我们的总体目标是使用整个动物稳定的同位素脉冲标记与生化和蛋白质组学分析相结合，以鉴定脑细胞带有MT-LLP的类型（AIM 1），并并行研究MTDNA寿命（AIM 2）。最后，我们旨在确定如果MT-LLP持久性需要CRISTAE结构完整性（AIM 3.1）并将MT-LLP的存在相关具有线粒体膜电位（AIM 3.2）。了解带有MT-LLP的细胞和结构，以及对线粒体适应性的影响，可以打开研究的新途径，并为分子靶标提供在与年龄相关的神经变性过程中调节线粒体网络动力学。