Transcriptional Regulation of Cardiac Morphogenesis

描述(申请人提供)：先天性心脏畸形是最常见的出生缺陷，在儿童和成人人群中会导致晚期心力衰竭。加强对心脏发育过程中指导心脏祖细胞的转录网络的了解，将在基于细胞的治疗和先天性心脏病的治疗方面有重要的应用。此外，一些平行的转录途径或网络已经被提出用于组织的产生和再生，例如心脏。因此，我们预测，心脏前体细胞在发育过程中转录调控机制的定义将增强我们对心脏发生、先天性心脏病和心肌再生的理解。我们最近利用转基因技术从发育中的小鼠心脏中分离和鉴定了心脏祖细胞。我们已经确定Etsrp71是Nkx2-5的潜在下游靶点，并产生了Etsrp71缺陷的胚胎，这些胚胎不能存活，并扰乱了心血管的发育。我们的基本假设是，Nkx2-5调控的网络指导心脏形态发生的不同阶段。我们进一步预测，Etsrp71是Nkx2-5的直接下游靶点，是心内膜/内皮细胞系的主要调节因子。在这些拟议的研究中，我们采取了一种创新的方法来检验这些假说，并利用新兴技术来确定Nkx2-5-Etsrp71级联反应与心血管发育的作用。为了检验这些假设，我们将解决以下具体目标：1)定义从发育中的小鼠心脏分离的心脏前体细胞中的NKX2.5转录调控级联。2)明确Etsrp71在胚胎发育过程中的功能。3)确定Etsrp71是否是心内膜/内皮细胞系的主要调节因子。这些研究将加深我们对转录网络和信号通路的作用的理解，这些转录网络和信号通路机械地调节心脏祖细胞(CPC)群体，以获得发育过程中的心血管命运。此外，这些研究的结果将作为针对先天性心脏病和晚期心力衰竭的治疗策略的平台。与公共卫生相关：先天性心脏病是常见且致命的疾病。增加对心脏发育过程中引导心脏祖细胞和干细胞的网络的了解，将对先天性心脏病的治疗具有重要的治疗应用。由于这些祖细胞的调控在很大程度上尚不清楚，这一提议将破译支配心脏祖细胞的分子通路，最终可能成为增强心脏畸形和晚期心力衰竭患者再生过程的平台。

DESCRIPTION (provided by applicant): Congenital cardiac malformation is the most frequent birth defect and it contributes to advanced heart failure in the pediatric and adult population. An enhanced understanding of the transcriptional networks that direct cardiac progenitors during heart development will have important applications related to cell based therapies and the treatment of congenital heart disease. Furthermore, a number of parallel transcriptional pathways or networks have been proposed for the generation and regeneration of tissues such as the heart. For these reasons, we predict that the definition of the transcriptional regulatory mechanisms of cardiac progenitor cells in the developing heart will enhance our understanding of cardiogenesis, congenital heart disease and myocardial regeneration. We have recently utilized transgenic technology to isolate and characterize cardiac progenitor cells from the developing mouse heart. We have identified Etsrp71 as a potential downstream target of Nkx2-5 and generated Etsrp71 deficient embryos that are nonviable and have perturbed cardiovascular development. Our principle hypothesis is that Nkx2-5 regulated networks direct discrete stages of cardiac morphogenesis. We further predict that the Etsrp71 is a direct downstream target of Nkx2-5 and is a master regulator of the endocardial/endothelial lineages. In these proposed studies, we take an innovative approach to examine these hypotheses and employ emerging technologies to define the role of the Nkx2-5 - Etsrp71 cascade and cardiovascular development. To examine these hypotheses, we will address the following specific aims: 1) To define the Nkx2.5 transcriptional regulatory cascades in cardiac progenitor cells isolated from the developing murine heart. 2) To define the functional role of Etsrp71 during embryogenesis. 3) To determine whether Etsrp71 is a master regulator of the endocardial/endothelial lineage. These studies will enhance our understanding of the role of transcriptional networks and signaling pathways that mechanistically regulate cardiac progenitor cell (CPC) populations to acquire a cardiovascular fate during development. In addition, the results of these studies will serve as a platform for therapeutic strategies directed towards congenital heart disease and advanced heart failure. PUBLIC HEALTH RELEVANCE: Congenital heart disease is common and deadly. An increased understanding of the networks that direct cardiac progenitors and stem cells during heart development will have important therapeutic applications for the treatment of congenital heart disease. As the regulation of these progenitor cells are largely unknown, this proposal will decipher the molecular pathways that govern cardiac progenitors, which may ultimately serve as a platform to enhance the regenerative process in patients with cardiac malformations and advanced heart failure.