Mitochondrial Protein Misfolding and Aggregation after Hypoxia: Mechanisms and Mitigation

缺氧后线粒体蛋白错误折叠和聚集：机制和缓解

基本信息

批准号：
9401407
负责人：
C. Michael Crowder
金额：
$ 51.49万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-07-15 至 2022-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9401407
关键词：
Affect Animals Apoptosis Biological Biological Assay Brain Hypoxia-Ischemia Caenorhabditis elegans Calcium Cause of Death Cell Death Cell Death Process Cell Survival Cells Cessation of life Chemicals Collaborations Cytoplasm Data Disease Disease model Endoplasmic Reticulum Functional disorder Genetic Genetic Screening Goals Hippocampus (Brain)Hypoxia Injury Kinetics Lead Mammalian Cell Mediating Middle Cerebral Artery Occlusion Mind Mitochondria Mitochondrial Proteins Modeling Mus Myocardial Infarction Necrosis Nematoda Neurology Neurons Organism Oxygen Pathology Pharmacology Phenotype Potential Energy Probability Proteins Proteomics Publications Publishing Reperfusion Therapy Reporter Reporting Research Resistance Speed Stress Stroke Testing Universities Washington cell injury cell type cost disability effective therapy genetic inducer human disease improved injured misfolded protein mitochondrial dysfunction mortality mouse model mutant novel protein aggregation protein misfolding proteostasis response small molecule stroke treatment tool

项目摘要

Project Summary Hypoxia and reoxygenation create havoc in cells. This havoc if unrepaired will ultimately lead to cell dysfunction and death in diseases such as myocardial infarction and stroke, the number one causes of death and disability in the US. Unfortunately, no effective therapy for hypoxic injury, short of restoring oxygenation, has been approved, suggesting that an unrecognized aspect of hypoxic injury is not being effectively treated by previous strategies. Mitochondria have long been recognized as central to hypoxic injury. Mitochondria are the primary utilizer of oxygen in cells, converting oxygen to the chemical potential energy required for the survival of cells and the organism. Mitochondria also are central to cell death processes – in particular apoptosis and forms of calcium-mediated death including necrosis. Both necrosis and apoptosis are thought to be the most prevalent mechanisms of death after hypoxic injury. However, a full understanding of how hypoxia injures mitochondria leading to cell death is lacking. We have recently reported a novel type of hypoxia- induced mitochondrial pathology – mitochondrial protein misfolding. Our published data show that mitochondrial protein misfolding occurs early in the hypoxic injury cascade, prior to any evidence of cell death. This suggests the hypothesis that mitochondrial protein misfolding may be both a consequence of hypoxia and a cause of hypoxic cell injury and death. Consistent with this hypothesis, genetic or pharmacologic manipulations in the nematode C. elegans that activate the mitochondrial unfolded protein response (mitoUPR), an intracellular homeostatic response to mitochondrial misfolded proteins, protects from hypoxic injury and improves animal survival. Since this publication, we have developed new fluorescent mitochondrial protein reporter tools in C. elegans in order to study protein misfolding directly and have preliminary evidence that mitochondrial proteins not only misfold but aggregate after hypoxia. The goals of this project are to develop a fundamental understanding of hypoxia-induced mitochondrial protein misfolding and aggregation, to identify ways to mitigate disruption of mitochondrial proteostasis, and to determine if similar disruption can be detected and mitigated in mouse models of human disease. Our general strategy is to take advantage of the speed, low cost, and specialized cell biological tools of C. elegans for fundamental discovery and to apply where possible our discoveries to mammalian models of hypoxic disease. Our specific aims are as follows: Aim 1. Determine the identity of the misfolded and aggregated mitochondrial proteins and the kinetics, determinants, and consequences of aggregation. Aim 2. Identify genetic and pharmacological manipulations that ameliorate mitochondrial protein misfolding in C. elegans. Aim 3. Determine whether mitochondrial protein misfolding/aggregation occur in mouse models of disease. Completion of these aims will increase our understanding of a novel hypoxic pathology of the mitochondria and will potentially identify ways to mitigate it.

项目概要缺氧和复氧会对细胞造成严重破坏，如果不加以修复，这种破坏最终将导致细胞死亡。心肌梗塞和中风等疾病导致的功能障碍和死亡是第一大死亡原因不幸的是，在美国没有有效的治疗缺氧损伤的方法，无法恢复氧合，已获得批准，表明缺氧损伤的一个未被认识的方面并未得到有效治疗线粒体长期以来被认为是缺氧损伤的核心。细胞中氧气的主要利用者，将氧气转化为细胞所需的化学势能细胞和生物体的存活也是细胞死亡过程的核心，尤其是。细胞凋亡和钙介导的死亡形式（包括坏死）被认为是细胞凋亡和细胞凋亡的原因。是缺氧损伤后最普遍的死亡机制。然而，充分了解缺氧是如何发生的。我们最近报道了一种新型缺氧现象。线粒体诱发的病理学——线粒体蛋白质错误折叠。线粒体蛋白错误折叠发生在缺氧损伤级联的早期，早于任何细胞死亡的证据。这表明线粒体蛋白错误折叠可能是缺氧和缺氧的结果。缺氧细胞损伤和死亡的原因与遗传或药理学的假设一致。线虫中激活线粒体未折叠蛋白反应的操作 (mitoUPR) 是对线粒体错误折叠蛋白的细胞内稳态反应，可防止缺氧自本文发表以来，我们开发了新的荧光线粒体。秀丽隐杆线虫中的蛋白质报告工具，以便直接研究蛋白质错误折叠并获得初步证据线粒体蛋白质不仅会错误折叠，而且在缺氧后会聚集。该项目的目标是对缺氧诱导的线粒体蛋白错误折叠有基本的了解聚集，以确定减轻线粒体蛋白质稳态破坏的方法，并确定是否在人类疾病的小鼠模型中可以检测到并减轻类似的破坏。策略是利用线虫的速度、低成本和专门的细胞生物学工具基本发现并尽可能将我们的发现应用于缺氧疾病的哺乳动物模型。我们的具体目标如下：目标 1. 确定错误折叠和聚集的线粒体的身份目标 2. 识别遗传和聚集的蛋白质以及动力学、决定因素和后果。改善秀丽隐杆线虫线粒体蛋白错误折叠的药理学操作。目标 3。确定小鼠疾病模型中是否发生线粒体蛋白错误折叠/聚集。完成这些目标将增加我们对线粒体新的缺氧病理学的理解并有可能找到缓解这种情况的方法。