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）：线粒体对于正常能量代谢至关重要，因为它们容纳了产生细胞主要能货币ATP的氧化磷酸化（OXPHOS）系统。他们还执行数百个其他代谢功能，并密切参与钙稳态和凋亡。然而，线粒体也是损害细胞成分，促进氧化应激并引起与线粒体功能障碍相关的病理学的有毒活性氧（ROS）的主要来源。线粒体包含一个圆形线粒体DNA（mtDNA）基因组，该基因组编码了13个Oxphos亚基，突变或耗竭的13种引起复杂疾病和与年龄相关的病理学。哺乳动物细胞包含数千份mtDNA，每个组织的特征性拷贝数是根据其特定能量需求和专业功能量身定制的。 ATM检查点信号转导激酶中的突变引起多方面和致命性性疾病 - telangicotia（A-T），其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异常mtDNA拷贝数，mtDNA诱变增加和细胞ROS积累。我们还发现，ATM NULL小鼠A-T患者细胞和组织中的常见缺陷是核糖核苷酸还原酶R1亚基（RNR）的显着耗竭，这是使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途径在mtDNA调节和稳定性中的作用，并检验新的假设，即线粒体功能障碍有助于A-T的氧化应激相关病理。拟议项目的具体目的是1）确定ATM信号的损失如何影响mtDNA稳态，并使用培养的细胞有助于细胞氧化应激，在该细胞上抑制ATM在药理学上或RNAi，RNAi，2）定义与Vivo中与A-T相关的线粒体病理的定义，并在体内繁殖，并在体内增加了跨度的影响，并在体内繁殖的范围增加了典型的影响。通过RNR亚基R1或mtDNA调节因子MTTFA的过表达，野生型和ATM无效小鼠。这项研究的广泛含义是，我们将学习有关如何在体内调节mtDNA的不可思议的数量，以及如何利用ATMRNRNR-MTDNA途径作为A-T，线粒体疾病和老化的治疗途径。