Human hypothalamic neuronal epigenomics and risk for obesity

人类下丘脑神经元表观基因组学和肥胖风险

• 批准号: 10207613
• 负责人: DONNA M LEHMAN
• 金额: $ 25.63万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-15 至 2023-02-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10207613
• 关键词: 18 year old; ATAC-seq; Adult; Age; Alleles; Animals; Autopsy; Benchmarking; Biological Assay; Birth; Body Weight; Body mass index; Body measure procedure; Brain; Brain region; CRISPR/Cas technology; Cell Line; Cells; Chromatin; Chromatin Structure; Chronic Disease; Clinical Pharmacology; Coronary heart disease; DNA Methylation; Data; Databases; Development; Diet; Disease; Enhancers; Ensure; Environmental Exposure; Epigenetic Process; Event; Exons; Family Study; GTP-Binding Proteins; Gene Expression; Gene Expression Profiling; Gene Targeting; General Population; Genes; Genetic; Genetic Predisposition to Disease; Genetic Risk; Genetic Variation; Genome; Genomic Segment; Genotype; Growth; Heritability; Heterogeneity; Heterozygote; Homeostasis; Human; Hypersensitivity; Hypothalamic structure; Imaging Techniques; Individual; Infant; Inherited; Length; Life; Life Style; Link; Malignant Neoplasms; Maps; Mexican Americans; Molecular; Neurons; Non-Insulin-Dependent Diabetes Mellitus; Obesity; Overweight; Pathway interactions; Physiological; Physiology; Population; Positioning Attribute; Predisposition; Prevention; Property; Protocols documentation; Publishing; Quantitative Trait Loci; Regulation; Regulatory Element; Reporter; Research Personnel; Resolution; Risk; Sampling; Signal Transduction; Stroke; Structure of nucleus infundibularis hypothalami; Techniques; Technology; Testing; Therapeutic Intervention; Tissues; Tn5 transposase; Toddler; Translating; United States; Untranslated RNA; Variant; Weight; World Health Organization; Youth; body system; brain tissue; causal variant; diet-induced obesity; energy balance; epigenome; epigenomics; gene product; genetic variant; genome editing; genome wide association study; genome-wide; genomic locus; high throughput screening; human model; human tissue; in vitro Model; in vivo; induced pluripotent stem cell; induced pluripotent stem cell technology; mortality; multidisciplinary; neuron development; next generation sequencing; obesity genetics; obesity risk; obesogenic; promoter; response; risk variant; sex; transcription factor; transcriptome sequencing; transcriptomics; trend

Translating information on genetic risk for body weight regulation into molecular mechanisms can have a significant impact on intervention and therapies. We are seeking to identify genetic variation and their molecular mechanisms that influences obesity through direct effects on the hypothalamus as it is the brain hub that regulates energy homeostasis and there is now considerable evidence for genetic influence to impact this brain region. However, the majority of genetic loci associated with this common, chronic disorder in the general population are located in noncoding regions of the genome, suggesting their influence on energy homeostasis is manifested through changes to the regulome. Thus, pinpointing the causal human variants and connecting them to their downstream targets in brain presents challenges of tissue access for study because much epigenetic control is species-, tissue- and context-specific. To overcome the barrier of limited human tissue access, we have developed a robust protocol for generating human induced pluripotent stem cell (iPSC)- derived neuronal cultures that recapitulate many of the features of hypothalamic neurons from the arcuate nucleus, including by benchmarking this in vitro model to in vivo events that are pivotal in hypothalamic development. We will use this human model and state of the art high throughput assays to map the currently uncharted regulatory landscape of the human hypothalamic neurons across 3 stages in development (early, mid, and late) and under experimental obesogenic conditions. Next, in order to precisely pinpoint the functional variants in BMI GWAS loci that have influence on body weight regulation through hypothalamic epigenomic regulation, we will identify those that influence chromatin accessibility and/or target gene expression by assay in 100 iPSC-derived neuronal lines generated from subjects of the San Antonio Mexican American Family Studies. GWAS variants with both properties have high potential to be causal and manifest effects on body mass index through changes in chromatin structure. Causal determination will be made for a set of these variants using genome editing techniques such as CRISPR/Cas9 to generate isogenic human neuronal cell lines that differ by genotype only at the single locus. Changes in exon-specific target gene expression and chromatin status will be assessed across the 3 developmental stages and under each obesogenic condition. Discovery of epigenetic mechanisms connected to genetic liability will translate the genetic risk information and identify potential underlying factors behind both heritable and diet-induced obesity susceptibility.

将体重调节的遗传风险信息转化为分子机制， 对干预和治疗产生重大影响。我们正在寻求确定遗传变异及其 通过直接作用于下丘脑（大脑中枢）来影响肥胖的分子机制 调节能量平衡，现在有相当多的证据表明遗传影响会影响这一点。 大脑区域。然而，大多数与这种常见的慢性疾病相关的遗传基因座在一般情况下， 种群位于基因组的非编码区，表明它们对能量稳态的影响 是通过调节组的变化表现出来的。因此，精确定位因果人类变异和连接 它们与大脑中下游靶点的相互作用对研究组织的获取提出了挑战，因为 表观遗传控制具有物种特异性、组织特异性和环境特异性。为了克服有限的人体组织 访问，我们已经开发了一个强大的协议，产生人类诱导多能干细胞（iPSC）- 衍生的神经元培养物，其再现了来自弓状核的下丘脑神经元的许多特征， 核，包括通过将该体外模型与在下丘脑中关键的体内事件进行基准测试， 发展我们将使用这种人类模型和最先进的高通量测定来绘制目前的 人类下丘脑神经元在发育的3个阶段（早期， 中期和晚期）和实验性致肥胖条件下。接下来，为了精确地定位功能 通过下丘脑表观基因组影响体重调节的BMI GWAS基因座变异 调控，我们将通过测定来鉴定那些影响染色质可及性和/或靶基因表达的基因。 在从圣安东尼奥墨西哥裔美国人家庭的受试者产生的100个iPSC衍生的神经元系中 问题研究具有这两种特性的GWAS变体具有很高的可能性，对身体有明显的影响。 通过染色质结构的变化来确定质量指数。将对其中一组进行因果关系判定 使用基因组编辑技术如CRISPR/Cas9产生等基因人类神经元细胞 仅在单个基因座上因基因型而不同的品系。外显子特异性靶基因表达的变化， 将在3个发育阶段和每种致肥胖条件下评估染色质状态。 发现与遗传易感性相关的表观遗传机制将转化遗传风险信息， 确定遗传和饮食诱导的肥胖易感性背后的潜在因素。