Mechanisms of SOD1 toxicity in ALS

SOD1 在 ALS 中的毒性机制

• 批准号: 7535552
• 负责人: JEFFREY L ELLIOTT
• 金额: $ 30.91万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7535552
• 关键词: Accounting; Address; Affect; Amyotrophic Lateral Sclerosis; Applications Grants; Biochemical; Biochemistry; Copper; Cytochrome-c Oxidase Deficiency; Disease; Disulfides; Familial Amyotrophic Lateral Sclerosis; Fractionation; Genes; Genetic Transcription; Grant; Human; Immunoelectron Microscopy; In Vitro; Lead; Mitochondria; Molecular; Molecular Chaperones; Mus; Mutation; Neurologic; Oxidases; Pathology; Pathway interactions; Phenotype; Process; Property; Proteins; Respiratory physiology; Spinal Cord; Tissues; Toxic effect; Transgenic Mice; base; complex IV; copper oxidase; copper zinc superoxide dismutase; disulfide bond; heme a; improved; in vitro Model; in vivo; insight; mitochondrial dysfunction; mutant; nervous system disorder; prevent; protein complex; protein function

DESCRIPTION (provided by applicant): Although the factors that regulate SOD1 entrance, processing and aggregation within mitochondria are not fully understood, copper chaperone for SOD1 (CCS), appears to be an important determinant of SOD1 presence within mitochondria. In vitro evidence suggests that direct CCS interaction with SOD1 facilitates the conversion of immature apo-SOD1, that is capable of transit into mitochondria, to a mature holo-SOD1 form that is retained within mitochondria. Whether over-expressing CCS in vivo will alter the sub-cellular distribution of SOD1 in a way that favors intra-mitochondrial SOD1 retention and consequently impact mutant SOD1 induced disease is unknown. To address these key questions of SOD1 biochemistry in vivo, we have generated transgenic mice expressing human CCS in high levels within the CNS and crossed them to G93A-SOD1 or wild type (WT) SOD1 transgenic mice. Both CCS transgenic mice and CCS/WT-SOD1 dual transgenic mice are neurologically normal. In contrast, CCS/G93A-SOD1 dual transgenic mice develop accelerated neurological deficits, with a mean survival of 36 days compared to 242 days for G93A-SOD1 mice. Immuno-electron microscopy and sub-cellular fractionation studies on spinal cord show that G93A-SOD1 is enriched within mitochondria in the presence of CCS over-expression. Our results indicate that CCS over-expression in G93A-SOD1 mice produces severe mitochondrial pathology and accelerates disease course. The extent of these changes tells us that over-expressing CCS is changing a fundamental principle of G93A SOD1 induced neurological disease and raises two central questions. How is G93A SOD1 altered by CCS over-expression? How does this change in G93A SOD1 lead to the severe mitochondrial phenotype? Answering these two questions forms the basis for this grant proposal. Completion of the proposed aims in this grant will provide insights into the cellular and molecular mechanisms underlying one form of familial amyotrophic lateral sclerosis (ALS) related to mutations in the copper, zinc superoxide dismutase gene.

描述（由申请人提供）：尽管调节线粒体内SOD 1进入、加工和聚集的因素尚未完全了解，但SOD 1的铜分子伴侣（CCS）似乎是线粒体内SOD 1存在的重要决定因素。体外证据表明，CCS与SOD 1的直接相互作用促进了能够转运到线粒体中的未成熟的apo-SOD 1转化为保留在线粒体内的成熟的holo-SOD 1形式。体内过表达CCS是否会以有利于线粒体内SOD 1保留的方式改变SOD 1的亚细胞分布并因此影响突变体SOD 1诱导的疾病尚不清楚。为了解决体内SOD 1生物化学的这些关键问题，我们已经产生了在CNS内高水平表达人CCS的转基因小鼠，并将它们与G93 A-SOD 1或野生型（WT）SOD 1转基因小鼠杂交。CCS转基因小鼠和CCS/WT-SOD 1双转基因小鼠神经系统均正常。相比之下，CCS/G93 A-SOD 1双转基因小鼠出现加速的神经功能缺损，平均生存期为36天，而G93 A-SOD 1小鼠为242天。脊髓免疫电镜和亚细胞分级研究表明，G93 A-SOD 1在CCS过表达的存在下富集在线粒体内。我们的研究结果表明，CCS在G93 A-SOD 1小鼠中的过表达产生严重的线粒体病理学并加速疾病进程。这些变化的程度告诉我们，过度表达CCS正在改变G93 A SOD 1诱导的神经系统疾病的基本原理，并提出了两个中心问题。CCS过表达如何改变G93 A SOD 1？G93 A SOD 1的这种变化如何导致严重的线粒体表型？对这两个问题的思考构成了这项赠款提案的基础。完成这项资助的拟议目标将深入了解一种与铜锌超氧化物歧化酶基因突变相关的家族性肌萎缩侧索硬化症（ALS）的细胞和分子机制。