Epigenetics of energy homeostasis, bioenergetics and obesity

项目总结 肥胖是一种慢性疾病，定义为体内多余脂肪的积累，并与高 发病率和死亡率。在美国，肥胖影响了超过三分之一的成年人口， 更令人担忧的是，它影响了大约五分之一的儿童和青少年。此外，中国的种族差异 肥胖率很明显，西班牙裔儿童的肥胖率远远高于高加索儿童。肥胖症 表型本质上是由能量平衡决定的--能量摄入量、能量 支出和储能。导致肥胖的遗传和环境侮辱的复杂相互作用 很可能是通过这种能量联系来调节的。这个项目的最终目标是识别表观遗传标记。 这可能有助于能量动态平衡和细胞生物能量学，最终导致肥胖风险。 使用最先进的下一代测序技术，我们将在 包括数百个合理的候选基因和100多个候选基因的靶向设计分析 基因组中有1000个具有代表性的CpG基因座。这个应用程序利用了家庭万岁研究， 旨在评估导致西班牙裔儿童肥胖的遗传和环境风险因素。它 提供独特的表型集合，包括人体测量和身体成分、饮食和体格 健身，24小时热量测量数据，以评估能量消耗、饮食行为和血液生化。916 这项研究中的西班牙裔儿童将接受基于血液的DNA甲基化分析，以确定与 与能量摄入和消耗有关的表型，以及肥胖。我们将检查DNA甲基化的相关性 在三组配对的血液-肌肉样本中，确定基因的优先顺序，以进行功能分析。要了解如何 与能量表型和肥胖相关的DNA甲基化变化可能会影响能量利用 在细胞层面，我们将采用IPSC衍生的骨骼肌细胞系统。对于三个非常重要的能量- 和/或肥胖相关的CpG位点或差异甲基化区域，我们将研究CRISPR- 基因表达和生物能量学的介导性表观遗传修饰。我们将研究对细胞 基础呼吸和最大呼吸、三磷酸腺苷相关呼吸、质子泄漏、脂肪酸利用和糖酵解。 通过研究DNA甲基化在能量相关表型和细胞生物能量学中的作用，我们希望 以进一步阐明导致肥胖的表观遗传机制。表观基因组处于一个恒定的状态 通量，不仅可以被外部环境刺激改变，而且可以通过表观遗传工程进行编辑。 识别与能量平衡和肥胖有关的基因可以为肥胖的发生发展提供依据。 靶向治疗旨在了解基因功能，并最终治疗肥胖症。

PROJECT SUMMARY Obesity is a chronic medical condition, defined by the accumulation of excess body fat and associated with high rates of morbidity and mortality. In the United States, obesity affects more than one-third of the adult population, and even more alarming, it affects about one-fifth of children and adolescents. Moreover, ethnic variations in obesity prevalence are evident, with rates in Hispanic children much higher than that of Caucasians. The obesity phenotype is essentially governed by energy homeostasis – the intricate balance between energy intake, energy expenditure and energy storage. The complex interplay of genetic and environmental insults leading to obesity are likely mediated through this energy nexus. The ultimate goal of this project is to identify epigenetic marks that might contribute to energy homeostasis and cellular bioenergetics, which culminate in obesity risk. Using state-of-the-art next-generation sequencing technologies we will examine DNA methylation profiles in a targeted-design assay that includes several hundred well justified candidate genes and more than a hundred thousand representative CpG loci across the genome. This application makes use of the Viva la Familia Study, designed to assess genetic and environmental risk factors for obesity development in Hispanic children. It provides a unique collection of phenotypes, including anthropometry and body composition, diet and physical fitness, 24-hour calorimetry data to assess energy expenditure, eating behavior, and blood biochemistries. 916 Hispanic children from this study will undergo blood-based DNA methylation profiling to identify associations with phenotypes related to energy intake and expenditure, and obesity. We will examine DNA methylation correlations in three cohorts of paired blood-muscle samples to prioritize genes for functional analysis. To understand how DNA methylation changes associated with energy phenotypes and obesity might influence energy utilization at a cellular level, we will employ an iPSC-derived skeletal muscle cell system. For three highly significant energy- and/or obesity-associated CpG sites or differentially methylated regions, we will investigate the effect of CRISPR- mediated epigenetic modifications on gene expression and bioenergetics. We will investigate effects on cellular basal and maximal respiration, ATP-linked respiration, proton leak, fatty acid utilization and glycolysis. By investigating the role of DNA methylation in energy-related phenotypes and cellular bioenergetics, we hope to further elucidate the epigenetic mechanisms contributing to obesity. The epigenome is in a constant state of flux and is not only modified by external environmental stimuli but can be edited through epigenetic engineering. The identification of genes involved in energy balance and obesity can provide a basis for the development of targeted therapies aimed at understanding gene function, and ultimately the treatment of obesity.