MITOCHONDRIAL CA, NEURONAL AGING AND B-AMYLOID TOXICITY

线粒体 CA、神经元衰老和 B 淀粉样蛋白毒性

• 批准号: 6098448
• 负责人: Robert W Hadley
• 金额: $ 20.95万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-12-02 至 1999-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6098448
• 关键词: Alzheimer's disease; aging; amyloid proteins; calcium flux; calcium ion; confocal scanning microscopy; cytoplasm; electrophysiology; free radical oxygen; hippocampus; homeostasis; laboratory rat; membrane potentials; membrane transport proteins; microspectrophotometry; mitochondria; neural degeneration; neuronal transport; neurons; neuropharmacology; neuroregulation; neurotoxicology; neurotoxins; oxidative stress; tissue /cell culture

The long-term objectives of this project are to define how intracellular Ca/2+ transport processes are altered by hippocampal neurons during aging and Alzheimer's disease, and to determine the role these changes in Ca/2+ homeostasis have in neurodegeneration. The project's immediate goal is to test the specific hypothesis that a common feature of both neuronal aging and the toxicity of beta-amyloid peptide is that they increase calcium-related stress on mitochondria in hippocampal neurons. The research project will address the following specific aims in order to test various features of the central hypothesis. 1) Test the hypothesis that beta-amyloid toxicity alters the functional balance between various Ca/2+ extrusion and sequestration mechanisms so as to increase the Ca/2+ load mitochondria Ca/2+ transport, increasing the time-averaged exposure of mitochondria to elevations of [Ca/2+]. 3) Evaluate the hypothesis that the likelihood that cytosolic Ca/2+ ions get taken up into mitochondria depends on the route with which the Ca/2+ ions enter the cytosol. 4) Test the hypothesis that a) aging enhances the ability of Ca/2+ ions to induce reactive oxygen species (ROS) production in hippocampal mitochondria, and b) that such Ca/2+-induced production of ROS makes an important contribution of the overall oxidative stress induces by beta-amyloid peptides. 5) Evaluate the hypothesis that aging and beta-amyloid peptides sensitize the mitochondrial permeability transition pore to intramitochondrial Ca/2+ ions. These aims will be investigated using two experimental models. Beta- amyloid toxicity will be studied in rat hippocampal neurons in primary culture, while the effects of aging will be studied in rat hippocampal "zipper" slices. Ca/2+ homeostasis will primary be studied in situ, using a combination of pharmacological, electrophysiological, microfluorimetric, and cell imaging methods. A particular strength of this project is the use of advanced confocal imaging methods to evaluate mitochondrial [Ca/2+] and membrane potentials in situ.

该项目的长期目标是定义细胞内的方式 CA/2+传输过程在海马神经元中改变了 衰老和阿尔茨海默氏病，并确定这些变化的作用 在CA/2+稳态中具有神经变性。该项目是直接的 目标是测试两者的共同特征的特定假设 神经元衰老和β-淀粉样蛋白肽的毒性是 增加与海马神经元线粒体上钙相关的应力。 研究项目将解决以下特定目标 测试中央假设的各种特征。 1）测试 β-淀粉样蛋白毒性改变功能平衡的假设 在各种CA/2+挤出和隔离机制之间 增加CA/2+负载线粒体CA/2+传输，增加 线粒体的时间平均暴露于[CA/2+]升高。 3） 评估胞质CA/2+离子的可能性 将其置入线粒体取决于CA/2+的途径 离子进入细胞质。 4）检验a）衰老增强的假设 Ca/2+离子诱导活性氧（ROS）的能力 在海马线粒体中的生产，b）这种Ca/2+诱导的 ROS的生产做出了整体的重要贡献 β-淀粉样蛋白肽诱导氧化应激。 5）评估 假设衰老和β-淀粉样蛋白肽使得 线粒体通透性过渡到室内CA/2+ 离子。 这些目标将使用两个实验模型进行研究。 β- 淀粉样蛋白毒性将在原发性大鼠海马神经元中进行研究 培养，而衰老的影响将在大鼠海马中进行研究 “拉链”切片。 CA/2+稳态将原位研究， 结合药理，电生理学， 微氟和细胞成像方法。一个特殊的优势 该项目是使用高级共聚焦成像方法评估 线粒体[CA/2+]和原位膜电位。