Acquired Mitochondrial DNA Mutations in the Brain

大脑中获得性线粒体 DNA 突变

• 批准号: 6747686
• 负责人: DAVID K. SIMON
• 金额: $ 16.5万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2007-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6747686
• 关键词: Alzheimer' s disease; Parkinson' s disease; brain; brain derived neurotrophic factor; cell differentiation; electron transport; frontal lobe /cortex; gene frequency; gene mutation; genetic markers; genetic susceptibility; guanosinetriphosphatases; human genetic material tag; human tissue; laser capture microdissection; mitochondrial DNA; neoplastic cell; neoplastic cell culture for noncancer research; neural degeneration; neuroblastoma; neurogenetics; neurons; oxidative stress; pathologic process; point mutation; polymerase chain reaction; retinoate

DESCRIPTION (provided by applicant): Mitochondrial complex I (CI) activity appears to play a key role in the pathogenesis of Parkinson?s disease (PD). Cl activity is impaired in the substantia nigra (SN) in PD, and Cl inhibitors induce parkinsonism when systemically administered in animals. Indirect evidence suggests a role for mitochondrial DNA (mtDNA) mutations. However, detection of these mutations may not be possible by standard screening techniques, particularly if they are present at low mutational burdens. We hypothesize that numerous acquired mutations, each individually present at a low mutational burden, could reach a sufficient aggregate burden to cause mitochondrial dysfunction. Such mutations are hypothesized to result from oxidative damage to mtDNA. Brain levels of 8-hydroxy-2?deoxyguanosine (OH8dG), a marker of oxidative DNA damage associated with point mutations, are 16-fold higher in mtDNA than in nuclear DNA, increase with aging, and increase further in PD. We have developed a protocol for detecting mtDNA mutations present at extremely low mutational burdens. We propose to determine the frequency of oxidative stress-induced mtDNA mutations in frontal cortex and substantia nigra in controls and in PD. Using Laser Capture Microdissection (Arcturus), we will examine the specific subpopulation of neurons susceptible in PD. Single-cell PCR will allow us to address the question of accumulation of individual acquired mutations within single neurons. We also propose to establish an in vitro system for analyzing the induction of oxidative stress-induced mutations in dividing and in post-mitotic cells by exposure to hydrogen peroxide or to agents that inhibit mtDNA repair. Collaborations have been established which will make the proposed studies possible. These studies will lay the foundation for future studies addressing the role of acquired mtDNA mutations in aging and in neurodegenerative diseases.

描述（由申请人提供）：线粒体复合物 I (CI) 活性 似乎在帕金森病 (PD) 的发病机制中发挥着关键作用。氯 PD 中黑质 (SN) 的活性受损，Cl 抑制剂 当对动物进行全身给药时，会诱发帕金森病。间接 有证据表明线粒体 DNA (mtDNA) 突变发挥了作用。然而， 通过标准筛查可能无法检测到这些突变 技术，特别是当它们存在低突变负担时。我们 假设许多获得性突变，每个突变都单独存在于 低突变负担，可能达到足够的总负担以引起 线粒体功能障碍。假设这种突变是由 线粒体DNA的氧化损伤。 8-羟基-2?脱氧鸟苷 (OH8dG) 的脑水平， 与点突变相关的氧化 DNA 损伤标记，是 16 倍 线粒体DNA高于核DNA，随年龄增长而增加，并进一步增加 在PD。我们开发了一种检测 mtDNA 突变的方案 极低的突变负担。我们建议确定频率 氧化应激诱导额叶皮层和黑质 mtDNA 突变 在控制和 PD 中。使用激光捕获显微切割 (Arcturus)，我们将 检查PD易感神经元的特定亚群。单细胞 PCR将使我们能够解决个体积累的问题 单个神经元内的获得性突变。我们还建议建立一个 用于分析氧化应激诱导突变诱导的体外系统 在分裂和有丝分裂后的细胞中，通过暴露于过氧化氢或 抑制 mtDNA 修复的药物。已经建立了合作关系 将使拟议的研究成为可能。这些研究将奠定基础 未来的研究将探讨获得性线粒体 DNA 突变在衰老和衰老过程中的作用 在神经退行性疾病中。