DNA Repair Deficiency Associated with Obesity and the Metabolic Syndrome

与肥胖和代谢综合征相关的 DNA 修复缺陷

• 批准号: 8453441
• 负责人: R. Stephen Lloyd
• 金额: $ 31.68万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-20 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8453441
• 关键词: A Mouse; Adult; Affect; American; Animals; Backcrossings; Base Excision Repairs; Biological; Biological Assay; Body Composition; Cardiovascular Diseases; Cell Extracts; Cell Line; Cell Nucleus; Cell Survival; Cells; Circadian Rhythms; Complement; DNA; DNA Damage; DNA Repair; DNA Repair Disorder; DNA biosynthesis; DNA glycosylase; DNA lesion; Data; Diet; Disease; Disease Progression; Dyslipidemias; Eating; Embryo; Enzymes; Epidemic; Etiology; Evaluation; Exhibits; Experimental Designs; Exposure to; Fat-Restricted Diet; Fatty Liver; Fatty acid glycerol esters; Female; Fibroblasts; Gene Expression; Gene Mutation; Generations; Genes; Genetic Transcription; Genome; Health; Hepatic; Home environment; Homeostasis; Human; Hyperinsulinism; Hypertension; Insulin Resistance; Investigation; Knock-out; Knockout Mice; Lead; Lesion; Lipids; Liver diseases; Magnetic Resonance Imaging; Malignant Neoplasms; Malignant neoplasm of liver; Malignant neoplasm of lung; Measures; Metabolic; Metabolic syndrome; Mitochondria; Mitochondrial DNA; Molecular; Monitor; Morbid Obesity; Movement; Mus; Mutagenesis; Nitric Oxide; Non-Insulin-Dependent Diabetes Mellitus; Nonesterified Fatty Acids; Nuclear; Nucleic Acids; OGG1 gene; Obesity; Organism; Outcome; Oxidative Stress; Phenotype; Physiological; Production; Protein Isoforms; Proteins; Purines; Reactive Oxygen Species; Relative (related person); Role; Running; Shuttle Vectors; Site; Stress; Symptoms; System; Techniques; Testing; Transcript; Transgenic Mice; Variant; Vitamin K 3; Weight; base; carcinogenesis; cellular targeting; comparative; human disease; killings; lipid metabolism; liquid chromatography mass spectrometry; male; middle age; mitochondrial dysfunction; mouse model; oxidant stress; prevent; purine; repaired; response

DESCRIPTION (provided by applicant): Exposure to oxidative stress conditions and the generation of excessive reactive oxygen species (ROS) are generally hypothesized to be a common causative factor in the etiology of several human diseases including, but not limited to, fatty liver disease, dyslipidemia, insulin-resistant type 2 diabetes, cardiovascular disease/hypertension, and obesity (collectively known as Metabolic Syndrome). Although it is well established that lipids, proteins and nucleic acids are critical cellular targets for endogenously and exogenously produced ROS, until recently, deficiencies in repair of ROS-induced DNA base damage had not been considered to be key in the aforementioned diseases, while being considered central to carcinogenesis. However, two knockout mouse models (neil1 and ogg1) have been created in which the initiation of base excision repair of oxidatively-damaged DNA is defective, and in both models, mice develop subsets of symptoms consistent with Metabolic Syndrome. Disease manifestations in the neil1 knockout mice may include obesity, fatty liver disease, dyslipidemia and hyperinsulinemia, with male knockouts much more severely affected than females. In addition, analyses of nuclear DNAs isolated from these mice reveal the accumulation of high levels of ROS-damaged bases and mitochondrial DNAs (mtDNA) show both increased steady-state base damage and large deletions relative to control littermates. Since it known that excessive oxidative stress can induce symptoms of Metabolic Syndrome in repair-proficient organisms, it is hypothesized that the loss of NEIL1 or OGG1 lowers the threshold at which oxidatively stress-induced disease is manifested. In the absence of repair, the progressive accumulation of compromised mtDNA genomes leads to deficiencies in energy production, as well as alterations in free fatty acid and lipid metabolism. In order to test this hypothesis, multiple physiological parameters will be evaluated for changes in neil1-/-, ogg1-/- and neil1-/-ogg1-/- mice and their wild-type littermates during pro-oxidant challenges versus control conditions. These data will be correlated with rates of pathological changes and mitochondrial and nuclear DNA damage accumulation as measured by GC/MS and quantitative PCR. These analyses will be complemented by examining the role of NEIL1 in the modulation of survival, mutagenesis, and mitochondrial function in response to oxidative or nitric oxide stress conditions. Further, since repair of mtDNA is hypothesized to be critical in maintaining metabolic homeostasis, experimental designs are proposed to establish intracellular distribution of various NEIL1 isoforms and determine the biological consequences of expressing nuclear or mitochondrially-targeted forms of these enzymes in neil1-/- cells.

描述(由申请人提供)：暴露在氧化应激条件下和产生过量的活性氧(ROS)通常被假设为几种人类疾病的共同病因，包括但不限于脂肪肝、血脂异常、胰岛素抵抗的2型糖尿病、心血管疾病/高血压和肥胖(统称为代谢综合征)。尽管脂质、蛋白质和核酸是内源性和外源性产生ROS的关键细胞靶点，但直到最近，ROS诱导的DNA碱基损伤修复的缺陷并不被认为是上述疾病的关键，而被认为是癌症发生的中心。然而，已经建立了两个基因敲除小鼠模型(NEIL1和ogg1)，在这些模型中，氧化损伤DNA的碱基切除修复的启动是有缺陷的，在这两个模型中，小鼠都会出现与代谢综合征一致的症状亚群。NEIL1基因敲除小鼠的疾病表现可能包括肥胖、脂肪肝、血脂紊乱和高胰岛素血症，男性基因敲除小鼠受到的影响比女性严重得多。此外，对从这些小鼠分离的核DNA的分析显示，与对照小鼠相比，高水平的ROS损伤碱基和线粒体DNA(MtDNA)的积累既增加了稳态碱基损伤，又出现了大量缺失。由于已经知道过度的氧化应激可以在修复熟练的生物体中诱导代谢综合征的症状，因此假设NEIL1或OGG1的缺失降低了氧化应激诱导的疾病的出现的门槛。在缺乏修复的情况下，受损的mtDNA基因组的逐渐积累会导致能量生产的不足，以及游离脂肪酸和脂类代谢的改变。为了验证这一假设，我们将评估NEIL1-/-、ogg1-/-和NEIL1-/-ogg1-/-小鼠及其野生型窝仔在抗氧化剂挑战与对照条件下的变化。这些数据将与GC/MS和定量PCR测量的病理变化率以及线粒体和核DNA损伤堆积率相关联。这些分析将通过研究NEIL1在氧化或一氧化氮应激条件下对生存、突变和线粒体功能的调节中的作用来补充。此外，由于线粒体DNA的修复被认为是维持代谢稳态的关键，因此提出了实验设计，以建立各种NEIL1亚型在细胞内的分布，并确定在NEIL1-/-细胞中表达这些酶的核或线粒体靶向形式的生物学后果。

项目成果

8-Oxoguanine DNA glycosylase (OGG1) deficiency increases susceptibility to obesity and metabolic dysfunction.

• DOI: 10.1371/journal.pone.0051697
• 发表时间: 2012
• 期刊: PloS one
• 影响因子: 3.7
• 作者: Sampath H;Vartanian V;Rollins MR;Sakumi K;Nakabeppu Y;Lloyd RS
• 通讯作者: Lloyd RS

Deficiency of the oxidative damage-specific DNA glycosylase NEIL1 leads to reduced germinal center B cell expansion.

氧化损伤特异性DNA糖基酶NEIL1的缺乏会导致生发中心B细胞膨胀降低。

• DOI: 10.1016/j.dnarep.2009.08.007
• 发表时间: 2009-11-02
• 期刊: DNA repair
• 影响因子: 3.8
• 作者: Mori H;Ouchida R;Hijikata A;Kitamura H;Ohara O;Li Y;Gao X;Yasui A;Lloyd RS;Wang JY
• 通讯作者: Wang JY