Genetics Analysis of Neuronal Hypoxic Stress Resistance

神经元耐缺氧应激的遗传学分析

基本信息

批准号：
8457043
负责人：
Christopher G Rongo
金额：
$ 27.51万
依托单位：
RUTGERS, THE STATE UNIV OF N.J.
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-04-15 至 2016-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8457043
关键词：
Acute Affect Animals Behavior Behavioral Binding Biological Brain Brain Injuries Caenorhabditis elegans Calcium Cells Cellular biology Cessation of life Chimeric Proteins Defect Depressed mood Endosomes Face Generations Genes Genetic Genus Mentha Glutamate Receptor Glutamates Hippocampus (Brain)Homeostasis Hydroxylation Hypoxia Hypoxia Inducible Factor Injury Interneurons Ischemic Stroke Life Lobular Neoplasia Locomotion Mammals Measurable Mediating Mediator of activation protein Membrane Membrane Protein Traffic Mitochondria Modeling Molecular Genetics Morbidity - disease rate Movement Mutation Necrosis Nematoda Nerve Degeneration Neurons Orthologous Gene Oxygen Pathway interactions Phosphorylation Phosphorylation Site Phosphotransferases Physiological Prevention Procollagen-Proline Dioxygenase Production Proline Protein Binding Proteins Proteomics Reactive Oxygen Species Receptor Activation Recycling Regulation Resistance Signal Transduction Site Stress Stroke Structure Surface Synapses Synaptic Membranes System Tertiary Protein Structure Testing Thinking Trauma Traumatic Brain Injury base clinical application disability excitotoxicity genetic analysis hypoxia inducible factor 1 in vivo killings loss of function mutation mitochondrial dysfunction neurotransmitter release new therapeutic target novel postsynaptic prevent receptor research study response sensor trafficking

项目摘要

DESCRIPTION (provided by applicant): Traumatic brain injury (TBI) and ischemic stroke are leading causes of morbidity and disability, excitotoxically killing neurons via hypoxia. The underlying mechanism is thought to be a combination of glutamate receptor overactivation, deregulated calcium homeostasis, and mitochondrial dysfunction. Specifically, the hypoxia resulting from trauma or stroke results in membrane depolarization and hence the release of the neurotransmitter glutamate from affected neurons. High levels of acute glutamate overactivate receptors on neighboring neurons, thereby resulting in calcium influx and excitotoxicity. Mitochondrial dynamics become altered, influencing the production of ATP, as well as the release of calcium and Reactive Oxygen Species (ROS) from neuronal mitochondria. Agents that directly interfere with glutamate receptor activation have had limited clinical applicability because of their dramatic effect on receptor physiological function. Thus, it is important to identify new therapeutic targets in order to mitigate excitotoxicity after TBI or stroke. The discovery that regulated trafficking of glutamate receptors can modify synaptic efficacy has changed the thinking about mechanisms by which receptors contribute to excitotoxicity after neuronal trauma. Many species, including mammals, have mechanisms by which they protect themselves from glutamate-mediated excitotoxicity, although these mechanisms are poorly understood. Indeed, the movement of glutamate receptors into and out of synaptic membranes after post-trauma hypoxia in some cultured neuronal systems can modulate excitotoxicity. Do changes in glutamate receptor trafficking contribute to neuronal death in the intact animal, or are they part of a neuroprotective response to hypoxia? What factors regulate glutamate receptor trafficking in response to hypoxia? How else does hypoxia alter the cell biology of neurons? This proposal takes genetic, molecular, cell biological, and electrophysiological approaches in C. elegans to understand how hypoxia impacts neuron function. In Aim 1, it examines how hypoxia and components of the known hypoxia response pathway alter the membrane trafficking of receptors. In Aim 2, it characterizes how EGL-9, a prolyl hydroxylase that senses oxygen levels and responds to hypoxia, regulates LIN-10, a PTB/PDZ- domain protein (orthologous to the Mints) known to regulate glutamate receptor trafficking. In Aim 3, it examines how hypoxia and EGL-9 regulate mitochondrial dynamics through their regulation of DRP-1, a mediator of mitochondrial fission. In Aim 4, it examines the effects of this novel pathway on neuron survival in several neurodegenerative models. The proposed experiments advance the field in several ways. First, they identify a novel hypoxia response pathway. Second, they demonstrate how neurons use this novel pathway to protect themselves from hypoxia. Third, they show that regulated receptor trafficking and regulated mitochondrial dynamics are the underlying mechanism. Finally, they provide potential new therapeutic targets for minimizing brain damage following TBI and ischemic stroke.

描述（由申请人提供）：创伤性脑损伤（TBI）和缺血性中风是发病和残疾的主要原因，通过缺氧以兴奋性毒性方式杀死神经元。其潜在机制被认为是谷氨酸受体过度激活、钙稳态失调和线粒体功能障碍的综合作用。具体来说，创伤或中风引起的缺氧会导致膜去极化，从而从受影响的神经元中释放神经递质谷氨酸。高水平的急性谷氨酸过度激活邻近神经元上的受体，从而导致钙流入和兴奋性毒性。线粒体动力学发生改变，影响 ATP 的产生以及神经元线粒体钙和活性氧 (ROS) 的释放。直接干扰谷氨酸受体激活的药物因其对受体生理功能的显着影响而具有有限的临床应用性。因此，确定新的治疗靶点以减轻 TBI 或中风后的兴奋性毒性非常重要。调节谷氨酸受体的运输可以改变突触功效的发现改变了对受体在神经元创伤后导致兴奋性毒性机制的思考。许多物种，包括哺乳动物，都有保护自己免受谷氨酸介导的兴奋性毒性的机制，尽管人们对这些机制知之甚少。事实上，在一些培养的神经元系统中，创伤后缺氧后，谷氨酸受体进出突触膜的运动可以调节兴奋性毒性。谷氨酸受体运输的变化是否会导致完整动物的神经元死亡，或者是它们是对缺氧的神经保护反应的一部分吗？哪些因素调节谷氨酸受体运输以应对缺氧？缺氧还会如何改变神经元的细胞生物学？该提案采用秀丽隐杆线虫的遗传、分子、细胞生物学和电生理学方法来了解缺氧如何影响神经元功能。在目标 1 中，它研究了缺氧和已知缺氧反应途径的组成部分如何改变受体的膜运输。在目标 2 中，它描述了 EGL-9（一种感知氧水平并对缺氧做出反应的脯氨酰羟化酶）如何调节 LIN-10（一种已知调节谷氨酸受体运输的 PTB/PDZ 结构域蛋白（与 Mints 直系同源））。在目标 3 中，它研究了缺氧和 EGL-9 如何通过调节线粒体裂变介质 DRP-1 来调节线粒体动力学。在目标 4 中，它研究了这种新途径对几种神经退行性模型中神经元存活的影响。所提出的实验在几个方面推动了该领域的发展。首先，他们确定了一种新的缺氧反应途径。其次，他们展示了神经元如何利用这种新途径来保护自己免受缺氧的影响。第三，他们表明受调节的受体运输和受调节的线粒体动力学是潜在的机制。最后，它们为最大限度地减少 TBI 和缺血性中风后的脑损伤提供了潜在的新治疗靶点。