The Epigenetic Landscape of Heart Development

描述（由申请人提供）： 先天性心脏病（CHD）是人类最常见和最具破坏性的出生缺陷之一。转录因子网络调节心脏细胞的命运和形态发生，转录因子基因的显性突变导致大多数遗传性CHD。这些网络的破坏导致CHD的潜在机制仍有待确定，但在相对狭窄的发育窗口内调控基因表达显然对正常心脏形态发生至关重要。除了转录因子外，通过组蛋白修饰、染色质重塑和非编码RNA的表观遗传调控在调节基因表达程序中具有关键作用。在基因组规模上阐明转录因子和表观遗传调节因子之间的物理和功能相互作用将大大提高我们对心脏发育控制的理解，并对理解CHD的机制基础具有重要意义。我们提出了一个项目，作为NHLBI心脏发育联盟的一部分，为心脏发育提供一个综合的表观遗传景观，重点是CHD相关基因。我们提出三个主要目标。目标1：定义在心脏发育和人类疾病中具有已知作用的转录因子的全基因组占用图，以及在分化心肌细胞中转录的表观遗传调节因子。目的2：明确转录和表观遗传调控在心脏发育和先天性心脏病中的整体功能。我们将研究心脏转录因子功能丧失对表观遗传调控的影响，以及CHD患者疾病特异性诱导多能细胞表观遗传调控的改变。我们还将评估组蛋白修饰在小鼠心脏发育中的整体作用。目的3：将microRNA的表达和功能整合到控制心脏发育的调控网络中。将对来自目标1和2的高分辨率占用图进行miRNA启动子占用的特异性分析，并与分化心肌细胞中miRNA的定量测序相结合。我们将研究高度改变的miRNAs的功能，特别是那些靶向致病心脏转录因子的miRNAs。我们的研究将产生一个重要的和变革性的心脏发育表观遗传图谱，这将首次在一个全面的网络中连接转录和表观遗传调节因子，这将阐明CHD的潜在机制。相关性（参见说明）：该项目将首次允许对先天性心脏病的基因网络进行新的理解。先天性心脏病是最严重的儿童疾病，影响1%的儿童，并导致显着的死亡率和长期疾病。然而，这些疾病的根本原因尚不清楚。我们的项目将把控制基因如何开启或关闭的所谓“表观遗传调节因子”与先天性心脏病联系起来，为这些疾病带来新的重要见解。

DESCRIPTION (provided by applicant): Congenital heart defects (CHDs) are among the most common and most devastating birth defects in humans. Networks of transcription factors regulate cardiac cell fate and morphogenesis, and dominant mutations in transcription factor genes lead to most instances of inherited CHD. The mechanisms underlying CHDs that result from disruption of these networks remain to be identified, but regulation of gene expression within a relatively narrow developmental window is clearly essential for normal cardiac morphogenesis. In addition to transcription factors, epigenetic regulation via histone modifications, chromatin remodeling, and non-coding RNAs have key roles in modulating gene expression programs. Elucidating on a genome scale the physical and functional interactions between transcription factors and epigenetic regulators will considerably enhance our understanding of the control of heart development and will have important implications for understanding the mechanistic basis of CHDs. We propose a project as part of the NHLBI Heart Development consortium to provide an integrated epigenetic landscape for heart development, with a focus on CHD-related genes. We propose three major aims. Aim 1: Define genome-wide occupancy maps of transcription factors with known roles in cardiac development and human disease, and epigenetic regulators of transcription, in differentiating cardiomyocytes. Aim 2: Define the global function of transcriptional and epigenetic regulation in heart development and congenital heart disease. We will examine the effect of loss of function of cardiac transcription factors on epigenetic regulation, and alterations in epigenetic regulation in disease-specific induced pluripotent cells from CHD patients. We will also evaluate the global role of histone modifications in mouse heart development. Aim 3; Integrate microRNA expression and function into the regulatory networks governing cardiac development. High-resolution occupancy maps from Aims 1 and 2 will be analyzed specifically for miRNA promoter occupancy and combined with quantitative sequencing of miRNAs in differentiating cardiomyocytes. We will study the function of highly altered miRNAs, specifically those that target disease-causing cardiac transcription factors. Our studies will yield an important and transformative epigenetic atlas of heart development, which will link for the first time transcriptional and epigenetic regulators in a comprehensive network that will illuminate mechanisms underlying CHDs. RELEVANCE (See instructions): The proposed project will for the first time allow a new understanding of the gene networks that underlie congenital heart disease. Congenital heart disease is the most serious childhood illness, affecting 1% of children, and leading to significant mortality and long-term illness. However the underlying causes of these diseases are not understood. Our project will link the so-called "epigenetic regulators" that control how genes are turned on or off, to congenital heart disease, bringing new important insights into these diseases.