Epigenomic Regulation of Gene Expression in Diet Induced Obesity

饮食引起的肥胖基因表达的表观基因组调控

• 批准号: 8094794
• 负责人: David Gerard Peters
• 金额: $ 22.73万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-15 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8094794
• 关键词: Adult; Affect; Base Sequence; Bioinformatics; Biological Assay; Cardiovascular Diseases; Chronic; DNA; DNA Methylation; DNA Sequence; Data; Defect; Development; Diabetes Mellitus; Diet; Disease; Energy Metabolism; Environment; Epidemic; Epigenetic Process; Exposure to; Fatty acid glycerol esters; Gene Expression; Gene Expression Profile; Gene Expression Regulation; Genes; Genetic; Genetic Predisposition to Disease; Genetic Transcription; Genome; Hepatic; Histones; Individual; Lead; Life; Life Style; Liver; Malnutrition; Measures; Mediating; Messenger RNA; Metabolic; Metabolic syndrome; Methods; Methylation; Molecular; Non-Insulin-Dependent Diabetes Mellitus; Nuclear; Nutrient; Obesity; Overnutrition; Pathway interactions; Phenotype; Play; Post-Translational Protein Processing; Regulation; Resolution; Reverse Transcriptase Polymerase Chain Reaction; Role; Run-On Assays; Running; Sampling; Techniques; Testing; Tissues; United States; Validation; chromatin immunoprecipitation; epigenomics; follow-up; gene environment interaction; genome-wide; genome-wide analysis; mature animal; molecular phenotype; next generation; novel; obesity risk; offspring; sedentary; tool; transcription factor

DESCRIPTION (provided by applicant): Obesity and its related disorders, including type 2 diabetes mellitus, metabolic syndrome, and cardiovascular disease, have reached epidemic levels in the United States. While genetic predisposition provides a background for the expression of acquired metabolic defects in obesity and type 2 diabetes, the majority of these metabolic defects become apparent only through energy imbalance, that is, energy oversupply and/or decreased energy expenditure. Therefore, gene- environment interactions are significant in the development of these diseases and there is increasing evidence that these effects are mediated biologically at the level of epigenetics, a spectrum of largely sequence-independent regulatory influences on gene expression including DNA methylation. Epigenetic influences on phenotype are perhaps best exemplified by recent studies demonstrating that the intrauterine environment, either malnutrition or overnutrition, influences gene expression through differential methylation of genes that lead to an altered metabolic phenotype that increases the risk for obesity and obesity-related disorders in the offspring. However, very little is known about the potential for epigenetic regulation of energy metabolism and obesity in adult life. An intriguing possibility is that chronic exposure to an environment that predisposes people to obesity and diabetes, such as a high fat Western diet and sedentary lifestyle, leads to altered DNA methylation and altered phenotype of metabolically active tissues. The liver is central to metabolic regulation and, as the key distributor of most ingested nutrients due to its anatomical proximity to the gut, is an ideal candidate for testing epigenetic changes from overnutrition. We propose to test the hypothesis that the development of obesity in adulthood alters gene expression and energy metabolism in the liver at least partially through changes in DNA methylation. Aim 1 is perform a quantitative genome-wide analysis of the hepatic DNA methylome following exposure to a high fat diet, which will be accomplished using Methyl-Sensitive Cut Counting (MSCC). Aim 2 is to perform a quantitative genome-wide analysis of the hepatic transcriptome following exposure to a high-fat diet, which will be accomplished using genome-wide 5' SOLID-SAGE. Aim 3 is to determine mechanistic relationships between DNA methylation and gene expression, which will be accomplished using state of the art computational approaches to identify genes that are both differentially methylated and expressed, and then selected genes will be validated with qRT-PCR and single gene methylation analysis. Finally mechanistic relationships between transcription factor recruitment and transcriptional rate will be determined by chromatin immunoprecipitation and nuclear run-on. This project has the potential to provide groundbreaking information concerning the epigenetics of obesity. PUBLIC HEALTH RELEVANCE: Obesity and its related disorders, metabolic syndrome and cardiovascular disease, often have an underlying genetic component that only becomes apparent after exposure to overnutrition and/or sedentary lifestyle. This suggests that the environment plays an important role in the development of obesity, and biologically this may manifest as an epigenetic phenomenon; i.e., genetics affected at a level other than the sequence of the DNA. We propose to test the hypothesis that the development of obesity in adulthood alters gene expression and energy metabolism in the liver at least partially through changes in DNA methylation. Both DNA methylation and gene expression will be measured after a high fat diet at the level of the entire genome and at high resolution. Using state-of the art bioinformatic approaches and sophisticated molecular assays, we will then identify and validate individual genes that have changes in both methylation and expression after a high fat diet, and will determine how DNA methylation alters the recruitment of transcription factors and the rate of transcription. This project has the potential to provide groundbreaking information concerning how the environment (in this case a high fat diet) affects the genetics of obesity.

描述（由申请人提供）：肥胖及其相关疾病，包括 2 型糖尿病、代谢综合征和心血管疾病，在美国已达到流行水平。虽然遗传易感性为肥胖和 2 型糖尿病中获得性代谢缺陷的表达提供了背景，但这些代谢缺陷中的大多数只有通过能量失衡（即能量供应过剩和/或能量消耗减少）才会变得明显。因此，基因-环境相互作用在这些疾病的发展中非常重要，并且越来越多的证据表明这些影响是在表观遗传学水平上通过生物学介导的，表观遗传学是一系列对基因表达（包括DNA甲基化）在很大程度上与序列无关的调节影响。最近的研究也许最好地说明了表观遗传对表型的影响，这些研究表明，子宫内环境，无论是营养不良还是营养过剩，都会通过基因的差异甲基化影响基因表达，从而导致代谢表型改变，从而增加肥胖和肥胖相关疾病的风险。后代。然而，人们对成人能量代谢和肥胖的表观遗传调控潜力知之甚少。一个有趣的可能性是，长期暴露在容易导致肥胖和糖尿病的环境中，例如高脂肪的西方饮食和久坐的生活方式，会导致 DNA 甲基化改变和代谢活跃组织的表型改变。肝脏是代谢调节的核心，并且由于其在解剖学上接近肠道，因此作为大多数摄入营养物质的主要分配者，是测试营养过剩引起的表观遗传变化的理想候选者。我们建议检验以下假设：成年期肥胖的发生至少部分通过 DNA 甲基化的变化改变肝脏中的基因表达和能量代谢。目标 1 是对暴露于高脂肪饮食后的肝脏 DNA 甲基化组进行定量全基因组分析，这将使用甲基敏感切割计数 (MSCC) 来完成。目标 2 是对暴露于高脂肪饮食后的肝脏转录组进行定量全基因组分析，这将使用全基因组 5' SOLID-SAGE 来完成。目标 3 是确定 DNA 甲基化和基因表达之间的机制关系，这将使用最先进的计算方法来实现，以识别差异甲基化和表达的基因，然后使用 qRT-PCR 和单基因验证所选基因甲基化分析。最后，转录因子募集和转录速率之间的机制关系将通过染色质免疫沉淀和核连续确定。该项目有可能提供有关肥胖表观遗传学的突破性信息。 公共卫生相关性：肥胖及其相关疾病、代谢综合征和心血管疾病通常具有潜在的遗传因素，只有在营养过剩和/或久坐的生活方式后才会变得明显。这表明环境在肥胖的发生中发挥着重要作用，从生物学角度来看，这可能表现为一种表观遗传现象；即，基因在 DNA 序列以外的水平上受到影响。我们建议检验以下假设：成年期肥胖的发生至少部分通过 DNA 甲基化的变化改变肝脏中的基因表达和能量代谢。高脂肪饮食后，将在整个基因组水平上以高分辨率测量 DNA 甲基化和基因表达。使用最先进的生物信息学方法和复杂的分子测定，我们将识别和验证高脂肪饮食后甲基化和表达发生变化的单个基因，并确定 DNA 甲基化如何改变转录因子的招募和速率的转录。该项目有可能提供有关环境（在本例中为高脂肪饮食）如何影响肥胖遗传学的突破性信息。