ENERGY METABOLISM, DOPAMINE NEURONS AND NEUROTOXICITY

能量代谢、多巴胺神经元和神经毒性

• 批准号: 2892218
• 负责人: GAIL D ZEEVALK
• 金额: $ 18.46万
• 依托单位: UNIV OF MED/DENT NJ-R W JOHNSON MED SCH
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-05-01 至 2003-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2892218
• 关键词: adenosine diphosphate; adenosine triphosphate; amine oxidase (flavin); animal genetic material tag; bioenergetics; catalase; creatine; dopamine; enzyme activity; gamma aminobutyrate; glutamate receptor; glutathione; high performance liquid chromatography; laboratory rat; membrane potentials; neurons; neurotoxicology; neurotoxins; oxidative stress; sodium potassium exchanging ATPase; tissue /cell culture

DESCRIPTION: Defects in energy metabolism have been reported in patients with Parkinson's disease (PD), thus implicating disturbances in energy metabolism as a part of the etiology. Although the presence of an energy impairment in PD is not at present identified as a primary event, it is clear that it is present at a time when dopamine neurons are declining in the PD patient. Thus, it is important to understand how metabolic stress affects DA neurons. This study will examine energy stress induced by inhibition of succinate dehydrogenase with malonate or 3-nitroproprionic acid, on DA neurons focusing on 2 areas of potential cellular mediators of the damage, i.e. glutamate receptor overstimulation and oxidative stress. in vivo (rat) and in vitro (rat mesencephalic cultures) will be used for the studies. It is hypothesized that mild metabolic stress reduces energy status (ATP/ADP), decreases Na+/K+ ATPase activity, degrades the membrane potential, which results in glutamate receptor overstimulation, generation of reactive oxygen species and an ensuing oxidative stress. Studies in aim 1 will use in vitro and in vivo approaches to temporally examine ATP/ADP status, Na+/K+ ATPase inhibition and changes in membrane potential in relationship to toxicity during energy stress induced damage. The sensitivity of DA neurons to excitotoxins and the involvement of glutamate receptors in energy stress induced damage will also be explored. Overstimulation of glutamate receptors is postulated to be a link between mild metabolic stress and generation of an oxidative stress. in vivo and in vitro studies in sub aims of 1 and 2 will temporally examine oxidized/reduced glutathione status, protein thiol loss, protein-glutathione mixed disulfide formation and lipid peroxidative damage to provide evidence of an oxidative component to toxicity due either to excitotoxicity or metabolic inhibition. The ability of spin trap agents to protect vs excitotoxicity or damage to DA neurons due to a metabolic stress will provide additional evidence of oxidative stress. It is further hypothesized that DA neurones as compared with other neuronal populations are more susceptible to a mild impairment of energy metabolism because of the intrinsic oxidative stress placed on them due to DA metabolism and oxidation. The vulnerability o DA neurons will be compared both in vivo and in vitro with the GABA population since this is a major neurotransmitter population found in the striatum and substantia nigra. In sub aims of 1 and 2, we will examine the importance of the antioxidant systems glutathione and catalase in protecting DA or GABA neurons during impaired energy metabolism by manipulating these systems to either inhibit, enhance or deplete them. The role of DA metabolism by MAO or DA oxidation will also be addressed in vivo and in vitro to determine if these events contribute to the relative vulnerability of DA neurons to energy stress. These studies will provide important information regarding the cellular mechanisms mediating damage to DA neurons to energy impairment and the possible reasons for their unique sensitivity and will provide insight into the ongoing loss of the neurons in PD.

描述：患者已经报道了能量代谢缺陷 帕金森氏病（PD），因此暗示了能量的干扰 代谢作为病因的一部分。 虽然能量的存在 目前尚未确定PD中的损伤为主要事件，它是 很明显，在多巴胺神经元下降的时候存在 PD患者。 因此，重要的是要了解如何代谢压力 影响DA神经元。 这项研究将检查由 抑制琥珀酸脱氢酶用丙酸酯或3-硝酸盐定位酶 酸，在DA神经元上，重点放在2个潜在细胞介质的区域 损伤，即谷氨酸受体过度刺激和氧化应激。 体内（大鼠）和体外（大鼠中脑培养物）将用于 研究。 假设温和的代谢应力减少了能量 状态（ATP/ADP），降低Na+/K+ ATPase活性，降解膜 潜力，导致谷氨酸受体过度刺激，产生 活性氧和随之而来的氧化应激。 瞄准中的研究 1将使用体外和体内方法进行时间检查ATP/ADP 状态，Na+/K+ ATPase抑制和膜电位变化 在能量应力引起的损害期间与毒性的关系。 这 DA神经元对兴奋毒素的敏感性和谷氨酸的参与 能量应力引起的损害中的受体也将探索。 假定谷氨酸受体的过度刺激被认为是 轻度代谢应激和氧化应激的产生。 体内和 1和2的子目标的体外研究将在时间上检查 氧化/还原的谷胱甘肽状态，蛋白质硫醇损失，蛋白质 - 谷胱甘肽 混合二硫键形成和脂质过氧化损伤以提供证据 由于兴奋性毒性或 代谢抑制。 自旋陷阱剂保护VS的能力 由于代谢压力引起的兴奋性毒性或对DA神经元的损害将 提供氧化应激的其他证据。 它是进一步假设的 与其他神经元种群相比，DA神经元更多 易受能量代谢的轻度损害 由于DA代谢和 氧化。 将在体内和 在体外与GABA种群，因为这是主要的神经递质 在纹状体和黑质中发现的人口。 在1的子目标中 2，我们将研究抗氧化剂系统谷胱甘肽和 在能量代谢受损期间保护DA或GABA神经元的过氧化氢酶 通过操纵这些系统以抑制，增强或耗尽它们。 MAO或DA氧化代谢的作用也将在 体内和体外，以确定这些事件是否有助于相对 DA神经元对能量胁迫的脆弱性。 这些研究将提供 有关介导损害的细胞机制的重要信息 能量障碍的DA神经元以及其独特的可能原因 敏感性，并将深入了解神经元持续损失 PD。