A Gata456 Pipeline of Discovery

三个高度相关的基因，Gata4，Gata5和Gata6（这里称为Gata456）基本上调控着每一个基因。 心脏生物学方面，从心前中胚层的产生， 心内膜、心外膜和心肌祖细胞，心管形成、生长和形态发生， 隔膜和瓣膜形成、心脏保护和肥大以及再生。这三个基因 调节空间，时间和组织特异性的遗传和表观遗传网络，这些网络是所有这些的基础 对不同的程序了解甚少。此外，每个基因中的突变已经被单独地 与人类心肌病相关，包括心房和心室间隔缺损，法洛四联症， 二叶主动脉瓣综合征和家族性扩张型心肌病。其他转录因子基因，和 已知一些终末分化标记物受Gata456调控，但在理解上存在重大差距 是确定控制中间功能如谱系特化，生长， 形态发生和心脏保护。我们提出了一个新的计划，作为“发现的管道”，以确定 这些下游基因，并探测其在心脏发生和心脏生物学中的功能。总体目标是 确定Gata456基因在各种心脏组织发育和成年期的功能 包括内膜、心肌和心外膜。我们试图破解相对时间 每个基因的表达位置影响细胞命运和存活，以及器官形态发生， 功能互补模型系统利用特定优势并解决物种特异性差异： 斑马鱼用于理解心脏发生，包括形态发生，人类多能干细胞用于 理解人类细胞身份和疾病建模。我们编制了一个斑马鱼和hESC的“工具箱”， 线路和一个调查专家小组，以促进对功能的获得和丧失进行全面分析 表型，具有强大的跟踪记录，这样的分析和发现新的下游目标。一 需要突破性的研究来了解Gata456如何控制心脏发生的各个方面。我们 最后，通过系统地操纵不同发育阶段的每个因素， 和组织环境，导致发现特定的关键下游靶基因，这些基因执行这些不同的功能。 功能协调发展的该项目不会直接开发心脏病的治疗方法，但它可能会提高 细胞疗法的发展。然而，它将突破目前对监管的描述， 在两个领域中的网络：1）定义在特定条件下单个Gata456等位基因的损失或获得的影响。 发育阶段和特定组织，以精确定义发育动物（斑马鱼）的功能 和人细胞（来源于人多能细胞）。2)确定关键下游Gata456目标 负责阶段和组织特异性功能的基因，将其识别为“铅击中”治疗 治疗心脏病的靶点。 !

Three highly related genes, Gata4, Gata5, and Gata6 (referred to here as Gata456) regulate essentially every aspect of cardiac biology, from generation of precardiac mesoderm, specification and differentiation of endocardial, epicardial, and myocardial progenitors, heart tube formation, growth and morphogenesis, septation and valve formation, cardioprotection and hypertrophy, and regeneration. How the three genes regulate the spatial, temporal, and tissue-specific genetic and epigenetic networks that underlie all of these disparate programs is poorly understood. Furthermore, mutations in each of the genes have individually been associated with human cardiomyopathies, including atrial and ventricular septal defects, tetralogy of Fallot, bicuspid aortic valve syndrome, and familial dilated cardiomyopathy. Other transcription factor genes, and some terminal differentiation markers are known to be regulated by Gata456, but a major gap in understanding is the identify of the key target genes that control intermediary functions such as lineage specification, growth, morphogenesis, and cardio-protection. We propose a new program as a “Pipeline of Discovery” to identify these downstream genes and probe their function in cardiogenesis and cardiac biology. The overall goal is to define the function of each Gata456 gene throughout development and adult life in various cardiac tissues including endocardium, myocardium, and epicardium. We seek to break the code for how the relative timing and location of expression for each gene impacts cell fate and survival, and organ morphogenesis and function. Complementary model systems exploit specific advantages and resolve species-specific distinctions: the zebrafish for understanding cardiogenesis including morphogenesis, and human pluripotent stem cells for understanding human cell identity and disease modeling. We have compiled a “toolbox” of zebrafish and hESC lines and an expert team of investigators to facilitate a comprehensive analysis of gain-and loss-of-function phenotypes, with a strong track record for such analyses and discovery of novel downstream targets. A breakthrough is needed to understand how Gata456 controls all the various aspects of cardiogenesis. We are finally in a position to define this code, by a systematic manipulation of each factor in different developmental and tissue contexts, leading to discovery of specific key downstream target genes that carry out these diverse functions. This project will not directly develop therapeutics for cardiac disease, but it will likely enhance development of cellular therapies. Chiefly, it will break ground beyond current descriptions of regulatory networks in two areas: 1) Defining the impact for loss or gain of individual Gata456 alleles at specific developmental stages and in specific tissues to precisely define functions in developing animals (zebrafish) and human cells (derived from human pluripotent cells). 2) Identifying the key downstream Gata456 target genes that are responsible for stage and tissue-specific functions, recognizing these as “lead hit” therapeutic targets for treating cardiac disease. !