Early Cardiac Progenitors

早期心脏祖细胞

基本信息

批准号：
9031132
负责人：
Benoit Gaetan Bruneau
金额：
$ 47.75万
依托单位：
J. DAVID GLADSTONE INSTITUTES
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-07-01 至 2017-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9031132
关键词：
Adult Affect Anterior Biological Assay Cardiac Cardiac Myocytes Cells Congenital Abnormality Congenital Heart Defects Cues Defect Development Embryo Embryonic Development Etiology Gene Transfer Techniques Genetic Health Heart Heart Atrium Heart Block Heart Diseases Human Injury Knowledge Label Lead Left ventricular structure Literature Live Birth Mediating Mesoderm Molecular Mus Myocardial Infarction Myocardium Natural regeneration Nature Nucleic Acid Regulatory Sequences Pathway interactions Plant Roots Population Property Reporter Research Right ventricular structure Signal Pathway Signal Transduction Specific qualifier value Stem cells Testing Transgenic Mice Transgenic Organisms Western World base cardiogenesis cell type embryo tissue embryonic stem cell gastrulation novel postnatal precursor cell progenitor regenerative transcription factor

项目摘要

DESCRIPTION (provided by applicant): The mammalian heart forms early in embryogenesis, and defects in its formation are at the root of congenital heart defects (CHDs), affecting 1-2% of live births. In adults, heart disease is the number one killer in the Western world, resulting in a considerable health burden. Understanding the building blocks of the heart is critical to define the etiology of CHDs and to create novel cell-based regeneration strategies to treat heart disease. Identifying and isolating cardiac precursors from pluripotent cells would allow characterization and expansion of cardiac cells for regenerative strategies. We identified expression of Smarcd3 (also known as Baf60c) as a candidate early marker of a prespecified mesoderm population that gives rise predominantly to cells of the developing heart. Using transgenic reporter assays and inducible Cre-mediated lineage tracing, we showed early expression of Smarcd3 in anterior mesoderm of the mouse is a specific marker of the earliest specified cardiac precursors, preceding expression of any other cardiac precursor marker. We hypothesize that Smarcd3 marks the earliest specific cardiac progenitors in the mouse embryo, and that this specialized mesodermal population has distinct properties that lead to preferential differentiation into cardiomyocytes. We will test this hypothesis in three Specific Aims. Aim 1: To define the early cardiac lineage marked by Smarcd3 expression. Using transgenic reporter lines, we will delineate the relationship between the Smarcd3 lineage and previously characterized cardiac lineages. We will use inducible Cre labeling, combined with multicolor "rainbow" reporter mice to define the early Smarcd3 lineage and the clonal relationships between its descendents. Using fluorescent reporter transgenic mouse lines, we will purify Smarcd3-expressing progenitors Aim 2. To determine the transcriptional and signaling pathways that activate early Smarcd3 expression. In this aim, we will define the genetic and signaling inputs that direct Smarcd3 expression in early cardiac progenitors. We will use transient transgenesis in mouse and differentiating ES cells to define the transcriptional inputs that activate Smarcd3 expression. Using transgenic ES cells expressing EGFP under control of the Smarcd3 regulatory region, we will identify the sets of signaling inputs that direct activation of Smarcd3 in this early population of cardiac precursors. Aim 3: To define signaling pathways that lead to cardiac differentiation of the early cardiac lineage. We will determine the importance of BMP and Wnt signaling in the differentiation of cardiac tissue from embryonic mesoderm, as well as the temporal requirement for these pathways. The results will be critical to understand the inductive cues required for cardiac differentiation. The knowledge generated from this study will be crucial to our understanding of the earliest fate decisions that lead to the formation of te heart.

描述（由申请人提供）：哺乳动物心脏在胚胎发生早期形成，其形成缺陷是先天性心脏缺陷（CHD）的根源，影响1-2%的活产儿。对于成年人来说，心脏病是西方世界的头号杀手，导致相当大的健康负担。了解心脏的组成部分对于确定冠心病的病因和创建新的基于细胞的再生策略来治疗心脏病至关重要。从多能细胞中识别和分离心脏前体细胞将允许对心脏细胞进行表征和扩增，以用于再生策略。我们将 Smarcd3（也称为 Baf60c）的表达确定为预先指定的中胚层群体的候选早期标记物，该中胚层群体主要产生发育中的心脏细胞。使用转基因报告基因检测和诱导型 Cre 介导的谱系追踪，我们发现小鼠前中胚层中 Smarcd3 的早期表达是最早指定的心脏前体标记的特异性标记，先于任何其他心脏前体标记的表达。我们假设 Smarcd3 标记了小鼠胚胎中最早的特定心脏祖细胞，并且这种特殊的中胚层群体具有导致优先分化为心肌细胞的独特特性。我们将在三个具体目标中检验这一假设。目标 1：定义以 Smarcd3 表达为标志的早期心脏谱系。使用转基因报告系，我们将描绘 Smarcd3 谱系和先前表征的心脏谱系之间的关系。我们将使用诱导型 Cre 标记，结合多色“彩虹”报告小鼠来定义早期 Smarcd3 谱系及其后代之间的克隆关系。使用荧光报告基因转基因小鼠系，我们将纯化表达 Smarcd3 的祖细胞。目标 2：确定激活早期 Smarcd3 表达的转录和信号传导途径。为此，我们将定义指导早期心脏祖细胞中 Smarcd3 表达的遗传和信号输入。我们将使用小鼠瞬时转基因和分化 ES 细胞来定义激活 Smarcd3 表达的转录输入。使用在 Smarcd3 调控区控制下表达 EGFP 的转基因 ES 细胞，我们将识别指导激活的信号输入集 Smarcd3 在心脏前体细胞的早期群体中的表达。目标 3：定义导致早期心脏谱系分化的信号通路。我们将确定重要性 BMP 和 Wnt 信号在心脏组织与胚胎中胚层分化过程中的作用，以及这些途径的时间需求。结果对于理解心脏分化所需的诱导线索至关重要。这项研究产生的知识对于我们理解导致心脏形成的最早的命运决定至关重要。