Mitochondrial control of neuronal excitotoxicity

神经元兴奋性毒性的线粒体控制

• 批准号: 6359927
• 负责人: David Nicholls
• 金额: $ 40.1万
• 依托单位: BUCK INSTITUTE FOR RESEARCH ON AGING
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-15 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6359927
• 关键词: NMDA receptors; adenosine triphosphate; bioenergetics; biological signal transduction; calcium flux; cell death; cerebellum; confocal scanning microscopy; cytochrome c; fluorescent dye /probe; free radical oxygen; glutamates; intracellular transport; membrane potentials; mitochondria; mitochondrial disease /disorder; mitochondrial membrane; neurons; oxidative phosphorylation; receptor expression; tissue /cell culture; NMDA receptors; adenosine triphosphate; bioenergetics; biological signal transduction; calcium flux; cell death; cerebellum; confocal scanning microscopy; cytochrome c; fluorescent dye /probe; free radical oxygen; glutamates; intracellular transport; membrane potentials; mitochondria; mitochondrial disease /disorder; mitochondrial membrane; neurons; oxidative phosphorylation; receptor expression; tissue /cell culture

DESCRIPTION (Provided by the Applicant): In the USA stroke kills 155,000 people per annum and is the third largest cause of death, after diseases of the heart and cancer. Furthermore 4,000,000 stroke survivors in the USA alone are coping with its debilitating effects. Stroke rates rise sharply with age, thus the increasing aging population will further increase its incidence. There is a brief window of opportunity in the hours following stroke during which the damage to the brain can be kept to a minimum, but the design of rational therapy would be facilitated if we had greater understanding of the underlying processes. Neuronal damage following stroke is amplified by the pathological release of glutamate (excitotoxicity), the consequent chronic activation of NMDA selective glutamate receptors and the influx of calcium into the cell. Mitochondrial calcium loading and consequent dysfunction is implicated not only in stroke but also in chronic neurodegenerative disorders such as Parkinson's and Huntington's diseases. The long term goal of this study is therefore to develop a comprehensive understanding of the acute and chronic consequences for the mitochondrion and neuron of pathological NMDA receptor activation, to use this information to devise and test neuroprotective strategies for the brief therapeutic window following stroke, and to relate these findings to the slow neurodegenerative disorders in which mitochondrial dysfunction is implicated. Mitochondria generate ATP, but also detoxify reactive oxygen species produced by the respiratory chain, control the cellular redox state and regulate cytoplasmic Ca2+. Any combination of these pathways may dysfunction in these disorders and the challenge is to unravel their complex interactions to identify primary lesions and suggest therapeutic and preventative strategies. The hypothesis that this application will test is that changes in mitochondrial bioenergetics function initiated during brief glutamate exposure continue even in the absence of receptor activation and are responsible for the delayed death of the neuron. To test this hypothesis we propose studies with the following specific aims. 1. To establish the immediate and delayed bioenergetics consequences of transient pathological NMDA receptor activation for cultured cerebellar granule neurons and their in situ mitochondria. While the granule cell in vivo is relatively resistant to excitotoxicity, the extensive existing information on the bioenergetics properties of these cells, coupled with their tolerance to a range of mitochondrial inhibitors makes the preparation suitable to establish principles applicable to neurons in general. 2. To establish the mechanism by which the initial transient exposure to glutamate initiates the subsequent mitochondrial dysfunction. 3. To test hypotheses that the lethality of glutamate in this model can be affected by controlling membrane potential and respiratory chain capacity. 4. To test the hypothesis that mitochondria at specific intracellular locations may be selectively vulnerable to glutamate excitotoxicity because of their proximity to NMDA receptors, or their location in regions of high-energy demand.

描述（由申请人提供）：在美国，中风杀死155,000人 每年，是造成心脏疾病的第三大死亡原因 和癌症。此外，仅在美国，就有4,000,000个中风幸存者正在应对 具有令人衰弱的效果。中风率随着年龄的增长而急剧上升，因此 人口老龄化的增加将进一步增加其发病率。有一个 在中风之后的几个小时内的短暂机会之窗，在此期间 对大脑的损害可以保持最低，但理性的设计 如果我们对基础有更多的了解，将促进治疗 过程。中风后的神经元损伤被病理扩增 谷氨酸释放（兴奋性），随之而来的慢性激活 NMDA选择性谷氨酸受体和钙流入细胞中。 线粒体钙负荷和随之而来的功能障碍不仅涉及 在中风，但也从慢性神经退行性疾病（例如帕金森氏症） 和亨廷顿的疾病。因此，这项研究的长期目标是 对急性和慢性后果的全面了解 病理NMDA受体激活的线粒体和神经元，用于使用 这些信息以设计和测试简要的神经保护策略 中风后的治疗窗口，并将这些发现与慢 线粒体功能障碍与神经退行性疾病有关。 线粒体会产生ATP，但也会产生活性氧 通过呼吸链，控制细胞氧化还原状态并调节 细胞质Ca2+。这些途径的任何组合都可能在这些途径中功能障碍 疾病和挑战是将它们复杂的互动揭开 确定原发性病变并提出治疗和预防策略。 该应用将测试的假设是线粒体的变化 在短暂谷氨酸暴露期间启动的生物能功能甚至继续 在没有受体激活的情况下，负责延迟死亡 神经元。为了检验这一假设，我们提出了以下研究 具体目标。 1。建立直接和延迟的生物能学 临时病理NMDA受体激活对培养的后果 小脑颗粒神经元及其原位线粒体。而颗粒 体内细胞对兴奋性毒性相对抗性，这是广泛的现有 有关这些细胞的生物能特性的信息，并与其 对一系列线粒体抑制剂的耐受性使制剂合适 建立适用于神经元的原理。 2。建立 初始瞬时暴露于谷氨酸的机制引发了 随后的线粒体功能障碍。 3。检验杀伤力的假设 该模型中谷氨酸的谷氨酸可能会受到控制膜电位的影响 和呼吸链能力。 4。检验线粒体的假设 特定的细胞内位置可能有选择地容易受到谷氨酸的影响 兴奋性毒性是因为它们靠近NMDA受体或其位置 在高能需求的地区。