HEMANGIOBLAST DEVELOPMENT AND REGULATION

成血管细胞的发育和调节

基本信息

批准号：
10615772
负责人：
KYUNGHEE CHOI
金额：
$ 71.11万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1996
资助国家：
美国
起止时间：
1996-08-01 至 2025-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10615772
关键词：
ATAC-seq Acetylation Address Applications Grants Bar Codes Basic Science Blood Blood Cells Blood Vessels Cardiac Cardiovascular system Cell Differentiation process Cell Lineage Cell Reprogramming Cells ChIP-seq Chromatin Complex DNA Data Defect Development Embryo Embryonic Development Endothelial Cells Enhancers Epigenetic Process Event Feedback GATA3 gene Generations Genes Genetic Genome Mappings Goals Growth Hematopoietic Hematopoietic System Heterogeneity Human Impairment In Vitro Investigation KDR gene Knock-out Knowledge Maps Mediating Mesoderm Modeling Molecular Mus Outcome Outcome Study Output Pathologic Processes Pathway interactions Play Pluripotent Stem Cells Population Process Regenerative Medicine Regulation Role SMARCA4 gene SMARCC1 gene Signal Transduction Skeletal Muscle Smooth Muscle Smooth Muscle Myocytes Somatic Cell Specific qualifier value System Testing Transgenic Organisms Vascular Endothelial Growth Factors Vascular System Yolk Sac Zebrafish blastomere structure blood vessel development cell type chromatin remodeling cofactor demethylation dosage embryo cell embryonic stem cell epigenetic regulation genome-wide genomic locus in vivo insight overexpression programs promoter recruit single-cell RNA sequencing stem cells transcription factor transcriptome translational potential

项目摘要

Hemangiogenesis, the formation of functional blood and endothelial cells (EC), is requisite for successful embryogenesis. We have so far demonstrated that blood and ECs develop from the PDGFRa-FLK1+ hemangiogenic mesoderm, which originates from the PDGFRa+ nascent mesoderm through a PDGFRa+FLK-1+ intermediary (i.e., PDGFRa+ ® PDGFRa+FLK1+ ® PDGFRa-FLK1+). We recently performed single-cell RNA sequencing and mapped a developmental pathway of the hemangiogenesis. In this process, we discovered that hemangiogenic lineage shares a close molecular ontogeny with the smooth muscle cell (SMC) lineage. Moreover, in vivo, yolk sac SMCs still retained the Flk1+ mesoderm transcriptome signature. Therefore, we proposed that the SMC lineage is the default pathway of the FLK1+ mesoderm. In further delineating mechanisms involved in the hemangiogenesis, we have shown that the transition from PDGFRa+FLK1+ to the PDGFRa-FLK1+ stage is dependent on the ETS transcription factor ETV2, a critical factor for the formation of hematopoietic and endothelial cell lineages. At the molecular level, ETV2 positively activates genes essential for hematopoietic and endothelial cell lineage specification. Two critical events occur in the transition from PDGFRa+FLK1+ to the PDGFRa-FLK1+ stage. First, Etv2 expression becomes higher, suggesting an Etv2 threshold mechanism in hemangiogenesis critical for this transition. Second, ETV2 target gene loci become accessible, suggesting epigenetic and chromatin changes occurring during this transition. We identified BAF155, a subunit of the mammalian SWI/SNF chromatin-remodeling BAF (BRG1/BRM associated factor) complex, as a cofactor of ETV2. This finding suggests that ETV2 utilizes BAF in reconfiguring chromatin accessibility of its target gene loci. A deeper understanding of the lineage relationship among FLK1+ populations and molecular processes occurring during the transition from PDGFRa+FLK1+ to PDGFRa-FLK1+ will be critical for further understanding how the hematopoietic and vascular systems are established in embryogenesis. This proposal's overarching goal is to gain deeper molecular insights into the regulation of Flk1+ lineage allocation concerning Etv2 and Baf155 expression and function. To this end, we will determine if hemangiogenic vs. SMC lineage fate of the FLK1+ mesoderm is controlled by the Etv2 dosage (aim 1), determine if PDGFRa+FLK1+ to the PDGFRa-FLK1+ transition requires ETV2 mediated Flk1 enhancer switching mechanisms (aim 2), and determine the chromatin remodeling requirements in the ETV2 regulation of hemangiogenesis (aim 3). The successful completion of the proposed studies will advance our understanding of how hematopoietic and EC development is regulated. Ultimately, this knowledge will be instrumental for generating hematopoietic and ECs from pluripotent stem cells or somatic cell reprogramming and the function of such cells in a wide range of regenerative medicine applications.

血管生成是功能性血液和内皮细胞（EC）的形成，是成功的必要胚胎发生。到目前为止，我们已经证明了血液和EC从PDGFRA-FLK1+发展血管生成中胚层，起源于PDGFRA+新生中胚层 PDGFRA+ FLK-1+中介（即PDGFRA+®PDGFRA+ FLK1+®PDGFRA-FLK1+）。我们最近进行了单细胞RNA测序，并映射了血管生成的发育途径。在这个过程，我们发现血管谱系与平滑肌细胞（SMC）谱系。此外，在体内，蛋黄囊SMC仍然保留了FLK1+中胚层转录组签名。因此，我们提出SMC谱系是FLK1+的默认途径中胚层。在进一步描述了血管生成涉及的机制中，我们已经表明从PDGFRA+ FLK1+过渡到PDGFRA-FLK1+阶段取决于ETS的转录因子 ETV2，是造血和内皮细胞谱系形成的关键因素。在分子级别，ETV2积极激活对造血和内皮细胞谱系规范必不可少的基因。从PDGFRA+ FLK1+到PDGFRA-FLK1+阶段的过渡中发生了两个关键事件。首先，ETV2 表达变得更高，表明血管生成中的ETV2阈值机制至关重要过渡。其次，ETV2靶基因基因座变得可访问，表明表观遗传和染色质在此过渡期间发生的变化。我们确定了BAF155，这是哺乳动物SWI/SNF的亚基染色质复制BAF（BRG1/BRM相关因子）复合物，作为ETV2的辅因子。这个发现表明ETV2利用BAF重新配置其靶基因基因座的染色质可及性。更深了解FLK1+种群和分子过程之间的谱系关系在从PDGFRA+ FLK1+到PDGFRA-FLK1+的过渡过程中，对于进一步了解如何了解如何造血和血管系统是在胚胎发生中建立的。该提议的总体目标是对FLK1+谱系分配的ETV2和ETV2和 BAF155表达和功能。为此，我们将确定是否血管生成与SMC谱系命运是否 FLK1+中胚层由ETV2剂量控制（AIM 1），确定PDGFRA+ FLK1+是否对 PDGFRA-FLK1+过渡需要ETV2介导的FLK1增强器切换机制（AIM 2），并且确定ETV2调节血管生成的染色质重塑需求（AIM 3）。成功完成拟议的研究将促进我们对造血和如何的理解 EC开发受到监管。最终，这些知识将有助于产生造血以及来自多能干细胞或体细胞重编程的EC以及此类细胞在宽阔的范围内的功能再生医学应用范围。