Epigenetic Determinants of Lipid Response to Dietary Fat and Fenofibrate

描述（由申请人提供）：血脂异常在心血管疾病的发生中发挥着重要作用，这激发了人们对更好地了解导致血脂异常（尤其是高甘油三酯血症）的环境因素的兴趣。表观遗传变异可能影响甘油三酯（TG）代谢和对环境挑战的反应。我们的目标是进行第一个实验，全面扫描表观基因组的决定因素TG和其他血脂异常的反应，两个“环境”干预，一个提高TG（高脂肪餐），一个降低TG（3周非诺贝特治疗）。这些实验将在基因-环境相互作用网络的NHLBI项目“降脂和饮食遗传学”（GOLDN）研究中进行。GOLDN从明尼苏达州和犹他州的野外中心招募了家庭成员，并对他们进行了酶和NMR脂质和炎症标志物的表型分析，以应对这两种干预措施。拟议的研究将利用这一独特的资源，利用以前收集的样本，实现以下目标：（1）使用下一代测序方法，具体地说，在来自184个家族的1，048个个体中进行全基因组CpG甲基化分析，以鉴定有助于TG和TG相关表型对脂肪餐、非诺贝特、和非诺贝特治疗背景下的脂肪餐。从这些结果中，我们将选择20个具有最佳证据的候选基因用于目标2中的进一步表征。(2)使用启动子和所有1，048个家族成员中其他感兴趣区域的亚硫酸氢盐测序来表征这20个基因的甲基化状态。(3)在外部队列中重复目标1和2的显著结果。(4)进行基因表达研究，以确定目标1-3中甲基化结果的功能影响，因为DNA甲基化可能以多种方式影响附近基因的表达，包括转录率、选择性剪接、微小RNA抑制或等位基因特异性表达。我们将使用称为RNAseq的方法对来自150名受试者的mRNA和microRNA进行下一代测序。如果成功，我们将确定新的表观遗传变异，预测对膳食脂肪反应不良或对非诺贝特反应良好的个体，这将导致开发有针对性的干预措施，以更有效地预防和治疗高脂血症。

DESCRIPTION (provided by applicant): Dyslipidemias play a large role in the occurrence of cardiovascular disease, which has fueled interest to better understand environmental factors responsible for dyslipidemias, especially hypertriglyceridemia. Epigenetic variations may affect triglyceride (TG) metabolism and response to environmental challenges. Our goal is to conduct the first experiments that will comprehensively scan the epigenome for determinants of TG and other dyslipidemic responses to two "environmental" interventions, one to raise TGs (a high-fat meal), and one to lower TGs (3-week fenofibrate treatment). These experiments will be conducted in the NHLBI Program in Gene-Environment Interaction Network's "Genetics of Lipid Lowering and Diet" (GOLDN) study. GOLDN recruited family members from field centers in Minnesota and Utah and phenotyped them extensively for enzymatic and NMR lipids and inflammatory markers in response to the two interventions. The proposed study will build upon this unique resource using previously collected samples to implement the following aims: (1) Conduct genome-wide CpG methylation analysis, using next generation sequencing method, specifically, Reduced Representation Bisulfite Sequencing, in 1,048 individuals from 184 families to identify epigenetic variation contributing to the response of TGs and TG-related phenotypes to a fat meal, fenofibrate, and a fat meal in the context of fenofibrate treatment. From these results, we will select 20 candidate genes with the best evidence for further characterization in Aim 2. (2) Characterize the methylation state of these 20 genes using bisulfite sequencing of promoters and other regions of interest in all 1,048 family members. (3) Replicate significant findings from Aims 1 and 2 in external cohorts. (4) Conduct gene expression studies to identify the functional impact of methylation findings from Aims 1-3 since DNA methylation may affect the expression of nearby genes in a variety of ways, including transcription rates, alternative splicing, microRNA inhibition, or allele specific expression. We will apply next-generation sequencing to both mRNA and microRNA from 150 subjects using a method called RNAseq. If successful, we will identify novel epigenetic variations that predict individuals who respond poorly to dietary fat or favorably to fenofibrate which will lead to the development of targeted interventions to more effectively prevent and treat hypertriglyceridemia.