Mitochondrial Dysfunction and Oxidative Stress in Ataxia Telangiectasia

共济失调毛细血管扩张症的线粒体功能障碍和氧化应激

基本信息

批准号：
8103622
负责人：
GERALD SHADEL
金额：
$ 8.12万
依托单位：
YALE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-06-01 至 2012-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8103622
关键词：
ATM Signaling Pathway ATM null mice Address Age Animal Model Apoptosis Ataxia Ataxia Telangiectasia Brain Breeding Calcium Cell Line Cell physiology Cells Characteristics Chronic Complex Cultured Cells DNA Damage DNA biosynthesis DNA copy number Defect Disease Doxycycline Energy Metabolism Enzymes Event Functional disorder Gene Expression Genome Goals Homeostasis Housing Human Cell Line Learning Mammalian Cell Metabolic Mitochondria Mitochondrial DNA Mitochondrial Diseases Mus Mutagenesis Mutant Strains Mice Mutation Null Lymphocytes Oxidative Phosphorylation Oxidative Stress Pathologic Pathology Pathway interactions Patients Phenotype Phosphotransferases Physiological Production RNA Interference Reactive Oxygen Species Regulation Research Personnel Ribonucleotide Reductase Ribonucleotide Reductase Subunit Role Signal Transduction Source Specificity Stress System Testing Therapeutic Tissues Transgenic Mice Transgenic Organisms age related base human RRM1 protein in vivo mitochondrial dysfunction mtTF1 transcription factor novel overexpression oxidative damage programs repaired

项目摘要

DESCRIPTION (provided by applicant): Mitochondria are critical for normal energy metabolism because they house the oxidative phosphorylation (OXPHOS) system that produces the cell's primary energy currency, ATP. They also perform hundreds of other metabolic functions and are intimately involved in calcium homeostasis and apoptosis. However, mitochondria are also a primary source of toxic reactive oxygen species (ROS) that damage cellular components, promote oxidative stress, and cause pathology associated with mitochondrial dysfunction. Mitochondria contain a circular mitochondrial DNA (mtDNA) genome that encodes thirteen OXPHOS subunits, mutation or depletion of which causes complex diseases and age-related pathology. Mammalian cells contain thousands of copies of mtDNA, with each tissue having a characteristic copy number tailored to its particular energy demands and specialized functions. Mutations in the ATM checkpoint signaling kinase cause the multi-faceted and fatal disease Ataxia-Telangiectasia (A-T), a key pathologic feature of which is oxidative stress. Our preliminary results show that disruption of ATM signaling causes aberrant mtDNA copy number, increased mtDNA mutagenesis, and cellular ROS accumulation. We have also discovered that a common defect in A-T patient cells and tissues of ATM null mice is significant depletion of the R1 subunit of ribonucleotide reductase (RNR), an enzyme required to make deoxynucleotides needed for DNA replication and repair. The overall goal of this proposal is to understand the role of the ATM pathway in mtDNA regulation and stability and to test the novel hypothesis that mitochondrial dysfunction contributes to the oxidative stress-associated pathology of A-T. The specific aims of the proposed project are 1) To determine how loss of ATM signaling impacts mtDNA homeostasis and contributes to cellular oxidative stress using cultured cells in which ATM is inhibited pharmacologically or by RNAi, 2) To define the mitochondrial pathology associated with A-T in vivo, and 3) To determine the physiological and potentially therapeutic consequences of increasing mtDNA copy number and stability in transgenic wild-type and ATM null mice via overexpression of RNR subunit R1 or the mtDNA-regulatory factor, mtTFA. The broad implications of this study are that we will learn an incredible amount about how mtDNA is regulated in vivo, and how the ATMRNR- mtDNA pathway can be exploited as a therapeutic avenue for A-T, mitochondrial diseases, and aging.

描述（由申请人提供）：线粒体对于正常的能量代谢至关重要，因为它们拥有氧化磷酸化 (OXPHOS) 系统，该系统可产生细胞的主要能量货币 ATP。它们还执行数百种其他代谢功能，并密切参与钙稳态和细胞凋亡。然而，线粒体也是有毒活性氧（ROS）的主要来源，它会损害细胞成分，促进氧化应激，并导致与线粒体功能障碍相关的病理。线粒体含有环状线粒体 DNA (mtDNA) 基因组，编码 13 个 OXPHOS 亚基，其突变或耗竭会导致复杂的疾病和与年龄相关的病理。哺乳动物细胞含有数千个线粒体DNA拷贝，每个组织都有一个根据其特定能量需求和专门功能定制的特征拷贝数。 ATM 检查点信号激酶突变会导致多方面的致命疾病共济失调毛细血管扩张症 (A-T)，其一个关键病理特征是氧化应激。我们的初步结果表明，ATM 信号传导的破坏会导致 mtDNA 拷贝数异常、mtDNA 突变增加和细胞 ROS 积累。我们还发现，A-T 患者细胞和 ATM 缺失小鼠组织中的一个常见缺陷是核糖核苷酸还原酶 (RNR) 的 R1 亚基显着缺失，RNR 是一种制造 DNA 复制和修复所需的脱氧核苷酸所需的酶。该提案的总体目标是了解 ATM 通路在 mtDNA 调节和稳定性中的作用，并检验线粒体功能障碍导致 A-T 氧化应激相关病理学的新假设。该项目的具体目标是 1) 使用 ATM 受到药物或 RNAi 抑制的培养细胞，确定 ATM 信号传导的丧失如何影响 mtDNA 稳态并导致细胞氧化应激，2) 定义与 A-T 相关的线粒体病理学3) 确定通过过表达 RNR 亚基 R1 或 RNR 亚基 RNR 亚基 R1 或线粒体DNA调节因子，mtTFA。这项研究的广泛意义在于，我们将了解大量有关 mtDNA 在体内如何调节的知识，以及如何利用 ATMRNR-mtDNA 途径作为 A-T、线粒体疾病和衰老的治疗途径。