Genetic regulation of cardiac proliferation during development and in regeneration

发育和再生过程中心脏增殖的遗传调控

• 批准号: 9130427
• 负责人: JAU-NIAN CHEN
• 金额: $ 39.93万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-04 至 2017-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9130427
• 关键词: Adult; Animal Model; Automobile Driving; Biochemical; Biochemical Genetics; Cardiac; Cardiac Myocytes; Cardiomegaly; Cell Proliferation; Cell Proliferation Regulation; Cells; Complex; DNA Binding Domain; Data; Development; Embryo; Embryonic Heart; Epigenetic Process; Event; Excision; Fishes; Gene Expression; Genes; Genetic; Genetic Models; Genetic Transcription; Genetic study; Health; Heart; In Vitro; Knockout Mice; Lead; Mammals; Mesoderm; Modeling; Modification; Molecular; Molecular Genetics; Mus; Mutate; Natural regeneration; Neonatal; Organogenesis; Pathway interactions; Polymerase; Population; Proteins; RNA Polymerase II; Regenerative Medicine; Regulation; Regulator Genes; Role; Signal Transduction; Stem cells; Structure; Transcription Elongation; Transcriptional Regulation; Ventricular; Zebrafish; base; cardiac regeneration; cardiogenesis; cell type; design; embryonic stem cell; epigenetic regulation; gain of function; insight; interest; mouse model; novel; overexpression; precursor cell; progenitor; programs; protein complex; stem; success; transcription factor

 DESCRIPTION (provided by applicant): Understanding molecular mechanisms driving a pluripotent progenitor cell to differentiate into a specific cell type is germane to the study of organogenesis and has important significance in regenerative medicine. While the roles of key cardiac-specific transcription factors in heart development have been carefully studied, the importance for protein complexes involved in epigenetic regulation or transcription elongation in cardiac cell formation is just being revealed. In this proposal, we aim to investigate molecular mechanisms by which the RNA Polymerase II- Associated Factor 1 Complex (PAF1C) controls heart development. Biochemical and genetic studies in multiple model organisms suggest that PAF1C functions as a transcription platform required for critical signaling events. However, its roles in heart formation are not known. Our recent genetic studies discovered a novel and essential role for Rtf1, a component of the PAF1C, in the formation and proliferation of cardiomyocytes. We found that zebrafish rtf1 deficient embryos lack the entire population of cardiac progenitor cells, demonstrating that Rtf1 is absolutely required for heart development. Our preliminary data obtained from structure-function analysis and loss- and gain-of- function studies lead us to hypothesize that Rtf1 controls cardiac gene expression by PAF1C- associated epigenetic modification and PAF1C-independent transcription regulation. We will examine this hypothesis in zebrafish and evaluate how these mechanisms influence the formation of cardiac progenitor cells and the proliferation of cardiomyocytes (Aim 1). We showed that Rtf1 promotes cardiac differentiation from embryonic mesoderm in zebrafish. We will examine whether this mechanism is conserved in mammals using mouse ES cells as an in vitro differentiation model. We will also create cardiac-specific conditional knockout mice to assess the role of Rtf1 in mouse heart development (Aim 2). Finally, many developmentally regulated genes are "reutilized" during heart regeneration and Tbx20, an Rtf1 downstream transcription factor, is upregulated after ventricular resection. We thus propose to examine whether the Rtf1-Tbx20 pathway is involved in heart regeneration using both adult zebrafish and neonatal mouse heart regeneration models (Aim 3). Successful completion of the proposed projects will provide new mechanistic insights into the regulation of cardiac progenitor cell formation and cardiomyocyte proliferation during development and in regeneration.

 描述(申请人提供)：了解驱动多能祖细胞分化为特定细胞类型的分子机制与器官发生研究密切相关，在再生医学中具有重要意义。虽然关键的心脏特异转录因子在心脏发育中的作用已经被仔细研究，但参与表观遗传调节或转录延伸的蛋白质复合体在心脏细胞形成中的重要性才刚刚被揭示。在这项提议中，我们旨在研究RNA聚合酶II相关因子1复合体(PAF1C)控制心脏发育的分子机制。多个模式生物的生化和遗传学研究表明，PAF1C作为关键信号事件所需的转录平台发挥作用。然而，它在心脏形成中的作用尚不清楚。我们最近的遗传学研究发现，PAF1C的一个成分Rtf1在心肌细胞的形成和增殖中扮演着一个新的和重要的角色。我们发现，斑马鱼rtf1缺陷的胚胎缺乏心脏祖细胞的整个群体，这表明rtf1是心脏发育所必需的。我们从结构-功能分析和功能丧失和功能获得研究中获得的初步数据使我们假设Rtf1通过PAF1C相关的表观遗传修饰和PAF1C非依赖的转录调控来控制心脏基因的表达。我们将在斑马鱼中检验这一假说，并评估这些机制如何影响心脏前体细胞的形成和心肌细胞的增殖(目标1)。我们发现Rtf1促进了斑马鱼胚胎中胚层的心脏分化。我们将使用小鼠胚胎干细胞作为体外分化模型来检验这一机制在哺乳动物中是否保守。我们还将创建心脏特异的条件性基因敲除小鼠，以评估Rtf1在小鼠心脏发育中的作用(目标2)。最后，在心脏再生过程中，许多发育调节基因被“重新利用”，而Rtf1下游转录因子Tbx20在心脏切除后上调。因此，我们建议使用成年斑马鱼和新生小鼠心脏再生模型来研究Rtf1-Tbx20通路是否参与心脏再生(目标3)。这些拟议项目的成功完成将为心脏前体细胞的形成和心肌细胞在发育和再生过程中的增殖调控提供新的机械见解。