A C. ELEGANS MODEL FOR NMNAT1-MEDIATED HYPOXIC PROTECTION AND LIFESPAN EXTENSION

NMNAT1 介导的缺氧保护和寿命延长的线虫模型

• 批准号: 8573890
• 负责人: C. Michael Crowder
• 金额: $ 13.91万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8573890
• 关键词: Aging; Animal Model; Apoptosis; Biological; Biological Models; Biological Process; Biology; Caenorhabditis elegans; Cell Aging; Cell Death; Cell Hypoxia; Cells; Cessation of life; Complement; Cytoprotection; Data; Development; Disease; Enzymes; Genes; Genetic; Genetic Models; Genetic Screening; Glutamate-ammonia-ligase adenylyltransferase; Human; Hypoxia; Injury; Investigation; Lead; Life; Longevity; Mediating; Methods; Mitochondria; Modeling; Morbidity - disease rate; Mus; Muscle Cells; Mutant Strains Mice; Mutate; Mutation; Myocardial Infarction; Nematoda; Neuroglia; Neurons; Nicotinamide Mononucleotide; Normal Cell; Nuclear; Organism; Pathologic Processes; Pathway interactions; Phenotype; Physiological Processes; Process; Proteins; Relative (related person); Reporting; Resistance; Role; Stroke; Testing; Toxic effect; Transgenes; Transgenic Mice; Transgenic Organisms; Ubiquitination; Wallerian Degeneration; Whole Organism; axonal degeneration; cell age; cell injury; cell type; fly; insight; mortality; mutant; neonatal hypoxic-ischemic brain injury; novel; overexpression; promoter; protective effect; protein misfolding; public health relevance; research study; response; screening; therapy development; tool

DESCRIPTION (provided by applicant): Hypoxic cellular injury and axonal degeneration are two of the most devastating causes of morbidity and mortality in the US. Despite a tremendous longstanding scientific effort, no treatment has proven to be effective at ameliorating either hypoxic injury or axonal degeneration in humans. The NAD biosynthetic enzyme nicotinamide mononucleotide adenylyl transferase 1 (Nmnat1) has been shown to block both axonal degeneration and hypoxic injury in mouse. Despite the profound medically relevant phenotype, the mechanism whereby Nmnat1 protects from either hypoxic injury or axonal degeneration is obscure. This application proposes to utilize the powerful genetic model organism C. elegans to develop a new model to study the cytoprotective mechanisms of Nmnat1. Preliminary experiments from my lab have shown that expression in C. elegans of a mutant form of mouse Nmnat1 protects the nematode from hypoxic injury. In addition, we have discovered that Nmnat1 more than doubles lifespan in C. elegans, demonstrating a strong cytoprotective function of Nmnat1 against aging. This project will develop additional tools in C. elegans to study the function of mouse Nmnat1 and answer fundamental questions about the protective mechanisms of Nmnat1 against hypoxic injury and aging. Completion of aim 1 will determine in what cell types Nmnat1 expression provides protection from hypoxic cellular injury and organismal aging. Additionally, we will determine whether Nmnat1 acts to protect only the cells in which it is expressed (cell autonomous activity) or whether Nmnat1 acts to protect cells in which it is not expressed (cell non-autonomous function). Aim 1 will also define when Nmnat1 functions to protect from hypoxia and extend lifespan, in particular, before or after the hypoxic insult and early or late in life, respectively. Aim 2 will use transgenic strains generated in aim to test a specific Nmnat1 mechanistic hypothesis suggested by our preliminary results. We will ask if the mitochondrial unfolded protein response is required for the protective action of Nmnat1 and whether Nmnat1 regulates the activity of the mitochondrial unfolded protein response. Completion of these aims will develop a powerful new model to study this important enzyme and may define a mechanism whereby Nmnat1 protects from hypoxia and lengthens lifespan.

描述（由申请人提供）：缺氧细胞损伤和轴突变性是美国发病和死亡的两个最具破坏性的原因。尽管长期以来进行了大量的科学努力，但没有任何治疗方法被证明可以有效改善人类缺氧损伤或轴突变性。 NAD 生物合成酶烟酰胺单核苷酸腺苷酸转移酶 1 (Nmnat1) 已被证明可以阻止小鼠的轴突变性和缺氧损伤。尽管具有深刻的医学相关表型，但 Nmnat1 防止缺氧损伤或轴突变性的机制尚不清楚。本申请拟利用强大的遗传模型生物线虫开发一种新模型来研究 Nmnat1 的细胞保护机制。我实验室的初步实验表明，在线虫中表达小鼠 Nmnat1 突变体可以保护线虫免受缺氧损伤。此外，我们发现Nmnat1使秀丽隐杆线虫的寿命延长了一倍多，这表明Nmnat1具有强大的细胞保护功能，可以抵抗衰老。该项目将在秀丽隐杆线虫中开发额外的工具来研究小鼠 Nmnat1 的功能，并回答有关 Nmnat1 对抗缺氧损伤和衰老的保护机制的基本问题。目标 1 的完成将确定 Nmnat1 表达在哪些细胞类型中提供针对缺氧细胞损伤和机体衰老的保护。此外，我们将确定 Nmnat1 是否仅起到保护其表达的细胞（细胞自主活性）的作用，还是 Nmnat1 是否起到保护其不表达的细胞（细胞非自主功能）的作用。目标 1 还将定义 Nmnat1 何时发挥作用以防止缺氧并延长寿命，特别是分别在缺氧损伤之前或之后以及生命早期或晚期。目标 2 将使用生成的转基因菌株来测试我们初步结果提出的特定 Nmnat1 机制假设。我们将询问线粒体未折叠蛋白反应是否是 Nmnat1 的保护作用所必需的，以及 Nmnat1 是否调节线粒体未折叠蛋白反应的活性。完成这些目标将开发一个强大的新模型来研究这种重要的酶，并可能定义 Nmnat1 防止缺氧和延长寿命的机制。