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：据报道患者存在能量代谢缺陷 患有帕金森病 (PD)，因此涉及能量紊乱 新陈代谢是病因学的一部分。 虽然能量的存在 PD 损伤目前尚未被确定为主要事件， 很明显，它出现在多巴胺神经元衰退的时期。 PD患者。 因此，了解代谢压力如何 影响 DA 神经元。 这项研究将检查由以下因素引起的能量压力： 用丙二酸或 3-硝基丙酸抑制琥珀酸脱氢酶 酸，作用于 DA 神经元，重点关注 2 个潜在细胞介质区域 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。 据推测，轻微的代谢压力会降低能量 状态 (ATP/ADP)，降低 Na+/K+ ATP 酶活性，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。 目标研究 1 将使用体外和体内方法暂时检查 ATP/ADP 状态、Na+/K+ ATP酶抑制和膜电位变化 与能量应激诱导损伤期间毒性的关系。 这 DA 神经元对兴奋毒素的敏感性和谷氨酸的参与 还将探索能量应激引起的损伤中的受体。 谷氨酸受体的过度刺激被认为是以下因素之间的联系： 轻度代谢应激和氧化应激的产生。 体内和体内 子目标 1 和 2 的体外研究将暂时检查 氧化/还原型谷胱甘肽状态、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提供证据 氧化成分的毒性是由于兴奋性毒性或 代谢抑制。 自旋捕获剂的保护能力 代谢应激引起的兴奋性毒性或 DA 神经元损伤将 提供氧化应激的额外证据。 进一步假设 DA 神经元与其他神经元群体相比 容易受到能量代谢轻度损害的影响 由于 DA 代谢和 氧化。 DA 神经元的脆弱性将在体内和 由于 GABA 是一种主要的神经递质，因此在体外进行 在纹状体和黑质中发现的群体。 在子目标 1 和 2、我们将研究抗氧化系统谷胱甘肽和 过氧化氢酶在能量代谢受损期间保护 DA 或 GABA 神经元 通过操纵这些系统来抑制、增强或耗尽它们。 MAO 或 DA 氧化对 DA 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 神经元对能量应激的脆弱性。 这些研究将提供 有关介导损伤的细胞机制的重要信息 DA神经元能量损伤及其独特的可能原因 敏感性并将提供对神经元持续损失的洞察 PD。