Integrating functional genomics in primary human adipocytes to investigate gene regulatory circuitry for obesogenic cardiovascular traits

将功能基因组学整合到原代人类脂肪细胞中，研究肥胖心血管特征的基因调控电路

• 批准号: 9908159
• 负责人: Kristina Marie Garske
• 金额: $ 3.71万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-12 至 2021-04-11
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9908159
• 关键词: Address; Adipocytes; Adipose tissue; Affect; Animal Model; Architecture; Biological Assay; Blood Circulation; Body mass index; Cardiovascular Diseases; Cardiovascular system; Caring; Cause of Death; Chromatin; Chromosome 11; Clinical; Complex; Data; Defect; Detection; Diagnosis; Disease; Dyslipidemias; Economic Burden; Elements; Endocrine; Endocrine Glands; Energy Intake; Energy Metabolism; Environment; Etiology; Exhibits; Gene Expression; Genes; Genetic; Genetic Variation; Genomic approach; Genomics; Genotype; Goals; Haplotypes; Heritability; Homeostasis; Human; Human Genetics; Hypertriglyceridemia; Impairment; In Vitro; Individual; Knowledge; Laboratories; Lead; Link; Lipids; Measurement; Measures; Mediating; Medical; Medical Economics; Metabolic; Metabolic syndrome; Mexican; Mission; Molecular; Molecular Genetics; Monounsaturated Fatty Acids; National Heart, Lung, and Blood Institute; Nonesterified Fatty Acids; Nucleic Acid Regulatory Sequences; Obesity; Outcome; Overweight; Pathway interactions; Phenotype; Physiological; Population; Population Heterogeneity; Prevention strategy; Quantitative Trait Loci; RNA Sequences; Regulator Genes; Regulatory Element; Risk; Risk Factors; Serum; Signal Transduction; Single Nucleotide Polymorphism; Stimulus; System; Testing; Transposase; Triglycerides; Variant; biobank; cardiovascular disorder risk; cardiovascular risk factor; clinical phenotype; clinically significant; cohort; differential expression; functional genomics; gene function; gene interaction; genome wide association study; genomic data; human subject; improved; lipid disorder; lipid metabolism; man; men; metabolic phenotype; obesogenic; phenotypic data; prevent; promoter; response; subcutaneous; trait; transcriptome sequencing; transcriptomics; uptake

ABSTRACT Abnormal serum lipid levels, or dyslipidemias, are risk factors for cardiovascular disease (CVD), the leading cause of death worldwide. The genetic factors underlying serum triglyceride (TG) levels are not well understood, despite this trait exhibiting ~50% heritability. Adipose tissue is an important endocrine organ for lipid homeostasis, and adipocytes are key players in energy intake and expenditure mediated through free fatty acid uptake and TG storage and mobilization. The goal of this project is to improve the current understanding of genomic regulatory mechanisms in gene expression and lipid processing pathways in adipocytes. Aim 1 is targeted to identify serum TG-correlated, adipose-expressed genes that are under local genetic control by expression quantitative trait loci (cis-eQTLs) in the Finnish METabolic Syndrome In Men (METSIM) cohort. We will use promoter Capture Hi-C (pCHi-C) in primary human white adipocytes (HWA) to identify which adipose cis-eQTLs interact with the target gene promoter, as promoter-interacting regions are enriched for regulatory elements. Our preliminary data support this, showing that SNPs in open chromatin within promoter-interacting regions in HWA contribute significantly to the heritability of adipose gene expression and serum TG levels in the METSIM cohort. By further integrating lipid genome-wide association study (GWAS) loci into our analysis, we can find a target gene and underlying mechanism of the GWAS signal. In Aim 2 we will perform RNA- sequencing, pCHi-C, and Assay for Transposase-Accessible Chromatin (ATAC)-seq in primary HWA after treating them with saturated or monounsaturated fatty acids, to investigate the genomic regulatory mechanisms altered in response to lipid challenge. This will facilitate detection of elements mediating gene expression changes, assayed through both pCHi-C and ATAC-seq. We hypothesize that genomic regulatory architecture uncovered in this system can be used across populations. We will thus use our data to examine Mexican-specific regions found to be associated with high serum TGs in our laboratory. One locus on chromosome 11 contains a risk haplotype for both high TGs and increased post-prandial TG levels after a fatty meal. The regulatory circuitry, identified in HWA both before and after lipid challenge, can be highly valuable for understanding how Mexican-specific variation might lead to genetic dysregulation at this locus. Aim 2 will also use the UK Biobank (UKBB) for genotype-by-environment interaction analyses. Many systemic metabolic disturbances that are more likely to be present in obese and overweight individuals involve adipocyte function. The UKBB has so far collected genotypes and deep clinical phenotypes for ~150,000 humans, with measures including BMI, lipids, and other CVD risk factors. We will use BMI as an interaction term to test whether the variants within lipid challenge-responsive regions in primary HWA are more likely to affect TGs in the context of this common obesity measurement. Aims 1 and 2 align with the mission of NHLBI to improve medical care for CVD and dyslipidemia through identification of mechanisms of trait-associated variants in diverse populations.

抽象的 血清脂质水平异常或血脂异常是心血管疾病（CVD）的危险因素，领先 全球死亡原因。血清甘油三酸酯（TG）水平不好的遗传因素 理解，尽管这种特征表现出约50％的遗传力。脂肪组织是重要的内分泌器官 脂质稳态和脂肪细胞是通过自由脂肪介导的能量摄入和支出的关键参与者 酸吸收和TG存储和动员。该项目的目的是提高当前的理解 脂肪细胞中基因表达和脂质加工途径中的基因组调节机制。目标1是 旨在识别血清TG相关的脂肪表达的基因，这些基因受到局部遗传控制 男性（METSIM）队列中芬兰代谢综合征中的表达定量性状基因座（顺式EQTL）。我们 将使用启动子Capture Hi-C（PCHI-C）中的主要人类白色脂肪细胞（HWA）来识别哪种脂肪 顺式EQTL与靶基因启动子相互作用，因为启动子相互作用区域富含调节性 元素。我们的初步数据支持这一点，表明启动子中的开放染色质中的SNP HWA区域对脂肪基因表达和血清TG水平的遗传力显着贡献 Metsim队列。通过进一步将脂质基因组关联研究（GWAS）基因座整合到我们的分析中 我们可以找到GWAS信号的靶基因和基础机制。在AIM 2中，我们将执行RNA- 对转座酶可访问的染色质（ATAC）-Seq的测序，PCHI-C和测定在原代HWA之后 用饱和或单不饱和脂肪酸处理它们，以研究基因组调节 响应脂质挑战时的机制改变了。这将有助于检测介导基因的元素 表达变化，通过PCHI-C和ATAC-SEQ进行测定。我们假设基因组调节 该系统中发现的建筑可以在人群中使用。因此，我们将使用我们的数据检查 墨西哥特异性地区发现我们的实验室中与高血清TG有关。一个基因座 11号染色体均包含高TG的风险单倍型，并在脂肪之后提高了餐后TG水平 一顿饭。在脂质挑战之前和之后，在HWA中确定的监管电路可能是高度有价值的 为了了解墨西哥特异性变异如何导致该基因座的遗传失调。 AIM 2意志 还使用英国生物库（UKBB）进行逐个环境的相互作用分析。许多全身代谢 肥胖和超重个体中更可能出现的干扰涉及脂肪细胞功能。 到目前为止，UKBB收集了约15万人的基因型和深层临床表型 包括BMI，脂质和其他CVD风险因素。我们将使用BMI作为互动术语来测试是否 脂质挑战响应区域内主要HWA中的变体更有可能在背景下影响TGS 这种常见的肥胖测量。目标1和2与NHLBI的任务保持一致，以改善医疗服务 CVD和血脂血症通过鉴定不同人群中与性状相关变体的机制。