Early Cardiac Progenitors

早期心脏祖细胞

• 批准号: 8506034
• 负责人: Benoit Gaetan Bruneau
• 金额: $ 45.46万
• 依托单位: J. DAVID GLADSTONE INSTITUTES
• 依托单位国家: 美国
• 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/8506034
• 关键词: Adult; Affect; Anterior; Biological Assay; Cardiac; Cardiac Myocytes; Cells; Commit; 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; public health relevance; regenerative; transcription factor

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育早期形成，其形成缺陷是先天性心脏缺陷（CHD）的根源，影响1-2%的活产婴儿。在成年人中，心脏病是西方世界的头号杀手， 相当大的健康负担。了解心脏的组成部分对于确定CHD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。从多能细胞中鉴定和分离心脏前体细胞将允许表征和扩增心脏细胞用于再生策略。我们确定Smarcd 3（也称为Baf 60 c）的表达是预先指定的中胚层群体的候选早期标志物，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Cre介导的谱系追踪，我们发现Smarcd 3在小鼠前中胚层的早期表达是最早指定的心脏前体的特异性标记，先于任何其他心脏前体标记的表达。我们假设Smarcd 3标志着小鼠胚胎中最早的特异性心脏祖细胞，并且这种专门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Smarcd 3表达为标志的早期心脏谱系。使用转基因报告细胞系，我们将描绘Smarcd 3谱系和先前表征的心脏谱系之间的关系。我们将使用可诱导的Cre标记，结合双“彩虹”报告小鼠来确定早期Smarcd 3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Smarcd 3表达的祖细胞Aim 2。确定激活Smarcd 3早期表达的转录和信号通路。在这个目标中，我们将定义的遗传和信号输入，指导Smarcd 3在早期心脏祖细胞的表达。我们将在小鼠和分化的ES细胞中使用瞬时转基因来定义激活Smarcd 3表达的转录输入。使用在Smarcd 3调控区控制下表达EGFP的转基因ES细胞，我们将鉴定指导激活的信号输入的集合 Smarcd 3在早期心脏前体细胞中的表达。目的3：确定导致早期心脏谱系心脏分化的信号通路。我们将确定 BMP和Wnt信号通路在胚胎中胚层心肌组织分化中的作用，以及这些通路的时间要求。这些结果对于理解心脏分化所需的诱导线索至关重要。从这项研究中产生的知识对于我们理解导致心脏形成的最早命运决定至关重要。