Regulation of muscle fate specification and cell migration in cardiogenic lineage

心源性谱系中肌肉命运规范和细胞迁移的调节

• 批准号: 8186167
• 负责人: Lionel Christiaen
• 金额: $ 38.34万
• 依托单位: NEW YORK UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2015-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8186167
• 关键词: Bilateral; Biological Assay; Biological Models; Cardiovascular Diseases; Cardiovascular system; Cell Lineage; Cell division; Cells; Chordata; Ciona intestinalis; Development; Dorsal; Embryo; Enhancers; Fluorescence-Activated Cell Sorting; Gene Expression; Genes; Genetic Transcription; Genome; Heart; Heart Atrium; Heart Block; Individual; Invertebrates; Islet Cell; Larva; Lateral; Medicine; Modeling; Molecular; Molecular Analysis; Molecular Target; Muscle; Muscle Development; Pathway interactions; Pattern; Phenotype; Regenerative Medicine; Regulation; Reporter Genes; Role; Series; Side; Signal Transduction; Skeletal Muscle; Stereotyping; Testing; Time; Tissues; Transcript; Urochordata; base; cell motility; heart cell; heart function; induced pluripotent stem cell; insight; islet; notch protein; novel; precursor cell; progenitor; regenerative therapy; transcription factor

DESCRIPTION (provided by applicant): Understanding the mechanisms directing progressive specification of heart cells from multipotent cardiovascular progenitors is essential for the development of regenerative therapies using induced pluripotent stem (iPS) cells. A simple chordate model system, the tunicate Ciona intestinalis, will be used to analyze the cellular and molecular mechanisms that determine muscle-type specification in the cardiogenic lineage. In Ciona embryos, the bilateral pairs of precardiac cells, called trunk ventral cells (TVCs), undergo stereotyped asymmetric cell divisions that distinguish the heart from the atrial siphon muscle (ASM) precursors. The latter then migrate toward the dorso-lateral atrial siphon placode. Following asymmetric divisions of the TVCs, the genes encoding the transcription factors COE and Islet are specifically up- regulated in the ASMs. In addition, COE is necessary and sufficient to block heart specification and promote the ASM fate, including expression of an ASM-specific Islet enhancer and cell migration toward the dorsal side of the larva. Finally, targeted expression of the constitutively active Notch intracellular domain using a TVC-specific enhancer is sufficient to inhibit ASM- specific expression of COE, Islet and cell migration. These observations led to the hypothesis that the initial asymmetric divisions result in heart-specific Notch signaling, which blocks ASM fate specification, possibly by inhibiting the expression of COE. In order to test this hypothesis, the cis-regulatory sequences that control ASM-specific expression of COE will be isolated and characterized, and the function of Notch signaling upstream of COE will be determined. The expression and localization patterns of endogenous regulators and effectors of Notch signaling will be documented in order to gain insight into the mechanisms that polarize the Notch signal during asymmetric TVC divisions. The effects of Notch signaling, COE and Islet on heart vs. ASM fate specification and cell migration will be analyzed using previously established assays in order to begin to characterize the epistatic relationships between these regulators. Finally, whole genome gene expression changes underlying heart vs. ASM fate specification will be documented by obtaining heart and ASM-specific transcription profiles using fluorescence activated cell sorting and microarrays. The results obtained upon completion of this project will characterize the regulation and function of COE, a novel negative regulator of heart fate specification, and illuminate the cellular and molecular mechanisms controlling muscle fate specification and cell migration in the cardiogenic lineage. PUBLIC HEALTH RELEVANCE: Personalized medicine utilizing induced pluripotent stem cells based regenerative medicine represents a novel promising avenue for the treatment of cardiovascular diseases and will require a thorough understanding of the cellular and molecular mechanisms whereby naive cells are determined to form functional heart tissue. While studying these basic mechanisms using a simple invertebrate model, the tunicate Ciona intestinalis, we recently identified the transcription factor COE as a novel negative regulator of heart-fate specification. Here, we propose to conduct an in depth analysis of the molecular and cellular mechanisms that control COE regulation and function and heart-fate specification with potential novel implications for cardiovascular development and medicine.

描述（由申请人提供）：了解指导心脏细胞从多能心血管祖细胞进行性特化的机制对于使用诱导多能干细胞（iPS）开发再生疗法至关重要。一个简单的脊索动物模型系统，被囊玻璃海鞘，将被用来分析细胞和分子机制，确定在心源性谱系的肌肉型规格。在玻璃海鞘胚胎中，两侧成对的心前细胞，称为躯干腹侧细胞（TVC），经历刻板的不对称细胞分裂，将心脏与心房虹吸肌（ASM）前体区分开来。后者然后向背外侧心房虹吸基板迁移。在TVC的不对称分裂之后，编码转录因子COE和Islet的基因在ASM中特异性上调。此外，COE是必要的，足以阻止心脏特化和促进ASM的命运，包括表达的ASM特异性胰岛增强子和细胞迁移到背侧的幼虫。最后，使用TVC特异性增强子靶向表达组成型活性Notch胞内结构域足以抑制COE、胰岛和细胞迁移的ASM特异性表达。这些观察结果导致了这样的假设，即初始不对称分裂导致心脏特异性Notch信号传导，其可能通过抑制COE的表达来阻断ASM命运特化。为了检验这一假设，将分离和表征控制COE的ASM特异性表达的顺式调节序列，并确定COE上游Notch信号传导的功能。Notch信号传导的内源性调节因子和效应因子的表达和定位模式将被记录，以深入了解在不对称TVC分裂期间抑制Notch信号的机制。将使用先前建立的试验分析Notch信号传导、COE和胰岛对心脏与ASM命运特化和细胞迁移的影响，以便开始表征这些调节剂之间的上位关系。最后，将通过使用荧光激活细胞分选和微阵列获得心脏和ASM特异性转录谱，记录心脏与ASM命运规范相关的全基因组基因表达变化。该项目完成后获得的结果将表征COE的调节和功能，COE是一种新的心脏命运规范的负调节剂，并阐明了控制心肌命运规范和细胞迁移的细胞和分子机制。 公共卫生关系：利用基于再生医学的诱导多能干细胞的个性化医学代表了治疗心血管疾病的新的有前途的途径，并且将需要彻底理解幼稚细胞被确定形成功能性心脏组织的细胞和分子机制。在研究这些基本机制，使用一个简单的无脊椎动物模型，被囊玻璃海鞘，我们最近确定了转录因子COE作为一种新的负调节心脏命运的规范。在这里，我们建议进行深入分析的分子和细胞机制，控制COE的调节和功能和心脏的命运规范与心血管发展和医学的潜在新的影响。