Role of Somatic mtDNA Mutations in Neurodegeneration

体细胞 mtDNA 突变在神经退行性疾病中的作用

• 批准号: 6635535
• 负责人: Konstantin Khrapko
• 金额: $ 26.68万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6635535
• 关键词: Alzheimer's disease; Huntington's disease; Parkinson's disease; brain mapping; cell death; cell type; cerebral cortex; gene deletion mutation; mitochondrial DNA; neural degeneration; nucleic acid amplification techniques; pathologic process; polymerase chain reaction; putamen; substantia nigra

DESCRIPTION (Adapted from the abstract provided by the applicant): The long-term goal of the proposed research is to study the mechanisms responsible for the slow progression of late-onset neurodegenerative diseases. The understanding of these mechanisms may help to find ways to make these processes even slower, thus moving the onset of these debilitating diseases outside the normal human lifespan. Specifically, we propose to test the hypothesis that accumulation of somatic mutations in mtDNA of critical cell types in the brain is one of the conditions necessary for the progression of at least some neurodegenerative processes. One of the possibilities is that once the fraction of mutated mtDNA in specific cells exceeds a certain threshold, these cells become sensitive to biochemical insults associated with some diseases. This hypothesis has arisen from the preliminary finding that individual pigmented neurons in substantia nigra accumulate very high levels of mtDNA deletions, which are highly likely to compromise cell's resistance to various stresses. Moreover, there are indications that cells with a heavy mutational load are the first to die in Parkinson's brain. It is also possible that progression of the disease accelerates accumulation of mutations thus creating a positive feedback. The efforts will be focused first on Parkinson's Disease (PD) patients and pigmented neurons of substantia nigra. Then research will be extended to Alzheimer's Disease (AD), Huntington's Disease (HD) and the various corresponding brain areas and critical cell types. The Specific Aims of the proposal are: 1) To develop and optimize the arsenal of methods necessary for the precise quantification and characterization of mtDNA mutations in single cells of the brain. These methods will include laser capture micro-dissection for single cell isolation, amplification of full-length mitochondrial genomes from single cells, single cell competitive PCR, and single cell limiting dilution PCR. 2) To identify brain areas and cell types in which mtDNA mutations are most likely to contribute to neurodegeneration. This will be done by measuring mutation load in individual cells of substantia nigra, cortex and putamen that are known to be rich in mtDNA deletions and are critical for PD, AD, and HD, respectively. 3) To test the hypothesis that clonal expansions of mtDNA mutations in individual cells contribute to mitochondrial defects and to neurodegeneration and death of neurons. This will be done by comparing the mutational load of cells that stained positive for various markers of mitochondrial dysfunction, cell degeneration and death to non-staining control cells. We will also study the distribution the mutations as a function of age and the presence and severity of the disease.

描述（根据申请人提供的摘要改编）