MITOCHONDRIAL DISEASES AND NEURODEGENERATION

线粒体疾病和神经变性

• 批准号: 2415031
• 负责人: NEIL N HOWELL
• 金额: $ 22.64万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-05-01 至 1999-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2415031
• 关键词: Krebs' cycle; apoptosis; biochemical evolution; bioenergetics; cellular respiration; family genetics; fibroblasts; gene frequency; gene mutation; genetic disorder; human genetic material tag; human population study; human tissue; hybrid cells; mitochondria; mitochondrial DNA; molecular pathology; neoplastic cell culture for noncancer research; neural degeneration; nucleic acid sequence; optic nerve disorder; oxidative phosphorylation; phenotype; tissue /cell culture

The long-term goal of this research program is to understand the etiology and pathophysiology of mitochondrial genetic disorders. From this understanding, it may be possible to define the role of mitochondrial respiratory chain dysfunction ina broad range of neurodegenerative disorders. A number of disorders are now known to be caused by mutations in the mitochondrial genome. The pathophysiology most often involves the nervous system although other systems can also be affected, particularly skeletal and cardiac muscle. In addition to the genetically-defined mitochondrial disorders, there is substantial experimental evidence that mitochondrial dysfunction is a pathophysiological component of the late- onset neurodegenerative diseases of Parkinson, Alzheimer, and Huntington. During the previous period of effort, the mitochondrial mutations that are th primary pathogenic factors in Leber hereditary optic neuropathy (LHON), one of a broad group of optic atrophies, have been identified. LHON may now be the neurodegenerative disorder with the best-defined genetic basis. As such, LHON is a good model system by which the mechanisms of neurodegeneration can be elucidated and studied. One aim of the proposed experiments is to undertake a detailed analysis of the phenotypic effects of primary LHON mutations on cellular energy metabolism. Biochemical and metabolic analyses will be carried out with fibroblast cell cultures to test the effects of primary LHON mutations upon mitochondrial respiratory chain function and citric acid cycle activity. In addition, neuronal cell lines that lack mitochondrial DNA will be developed. These mtDNA-less sublines will then be used for cybrid fusions to enucleated LHON fibroblasts. The resulting cybrids, neuronal cells that carry LHON mutations in their mtDNA, will be used to determine, for the first time, the effects of known pathogenic mitochondrial mutations upon energy metabolism in neuronal cells and upon the expression of neuronal characteristics. The hypothesis will be tested that the pathogenicity of primary LHON mutations is due to an reduction in oxidative phosphorylation. We will also determine whether respiratory chain impairment in these cybrid cells predisposes neuronal cells to neurodegeneration through activation of apoptosis or programmed cell death. Finally, phylogenetic analysis will be used to study the origin and spread of primary LHON mutations throughout the human population during evolution, and the etiological role of secondary LHON mutations.

该研究计划的长期目标是了解病因 和线粒体遗传疾病的病理生理学。 从这里 理解后，也许可以定义线粒体的作用 广泛的神经退行性疾病中的呼吸链功能障碍 失调。 现在已知许多疾病是由突变引起的 在线粒体基因组中。 病理生理学最常涉及 神经系统，尽管其他系统也可能受到影响，特别是 骨骼肌和心肌。 除了基因决定的 线粒体疾病，有大量实验证据表明 线粒体功能障碍是晚期疾病的病理生理学组成部分 帕金森病、阿尔茨海默病和亨廷顿病的发病神经退行性疾病。 在前一段时间的努力中，线粒体突变 莱伯遗传性视神经病（LHON）的主要致病因素， 已确定为一大类视神经萎缩之一。 LHON 可能 现在是具有最明确的遗传基础的神经退行性疾病。 因此，LHON 是一个很好的模型系统，通过它的机制 神经变性是可以阐明和研究的。 拟议的目标之一 实验是对表型效应进行详细分析 原发性 LHON 突变对细胞能量代谢的影响。 生化和 将使用成纤维细胞培养物进行代谢分析，以 测试初级 LHON 突变对线粒体呼吸的影响 链功能和柠檬酸循环活性。 此外，神经元细胞 缺乏线粒体 DNA 的细胞系将被开发出来。 这些无线粒体DNA 然后，亚系将用于与去核的 LHON 进行细胞杂合融合 成纤维细胞。 由此产生的 cybrids，携带 LHON 的神经元细胞 他们的 mtDNA 突变将首次用于确定 已知致病性线粒体突变对能量的影响 神经元细胞的代谢及其表达 特征。 将检验该假设的致病性 原发性 LHON 突变是由于氧化磷酸化减少所致。 我们还将确定这些细胞中的呼吸链是否受损 细胞通过激活神经元细胞而导致神经变性 细胞凋亡或程序性细胞死亡。 最后，系统发育分析将 用于研究原发性 LHON 突变的起源和传播 人类在进化过程中的作用及其病因学作用 继发性 LHON 突变。