Large-Scale Discovery of Enhancers from Human Heart Tissue

Development and function of the human heart depend on the dynamic control of tissue-specific gene expression by distant-acting transcriptional enhancers. While large numbers of heart enhancers have been identified using the mouse as a model system, many of these regulatory sequences are poorly conserved in the human genome. To generate an accurate genome-wide map of human heart enhancers, we used an epigenomic enhancer discovery approach and identified ~6,200 candidate enhancer sequences directly from fetal and adult human heart tissue. Consistent with their predicted function, these elements were markedly enriched near genes implicated in heart development, function and disease. To further validate their in vivo enhancer activity, we tested 65 of these human sequences in a transgenic mouse enhancer assay and observed that 43 (66%) drove reproducible reporter gene expression in the heart. These results support the discovery of a genome-wide set of non-coding sequences highly enriched in human heart enhancers which is likely to facilitate down-stream studies of the role of enhancers in development and pathological conditions of the heart. Examination of AcCBP/p300 binding in human adult heart, human fetal (16wk) heart and mouse postnatal day 2 heart

人类心脏的发育与功能，依赖于远端作用转录增强子（distant-acting transcriptional enhancers）对组织特异性基因表达的动态调控。尽管以小鼠为模型系统已鉴定出大量心脏增强子，但其中多数调控序列在人类基因组中的保守性极差。为构建精准的人类心脏增强子全基因组图谱，本研究采用表观基因组增强子发现策略，直接从胎儿及成人心脏组织中鉴定出约6200个候选增强子序列。与预期功能一致，这些候选序列显著富集于与心脏发育、心脏功能及心脏疾病相关的基因附近。为进一步验证这些序列的体内增强子活性，本研究在转基因小鼠增强子检测实验中对其中65个人类序列开展了验证，结果显示其中43个（占比66%）可在心脏中驱动可重复的报告基因表达。上述结果证实，本研究发现了一组在人类心脏增强子中高度富集的全基因组非编码序列，该序列集有望为探究增强子在心脏发育及心脏病理状态中的作用提供重要助力。本研究同时对成人心脏、人类胎儿（16周龄）心脏以及小鼠出生后第2天心脏中的AcCBP/p300结合情况进行了检测分析。