Role of the Embryonic Node in Cardiac Development and Congenital Heart Disease

胚胎节点在心脏发育和先天性心脏病中的作用

• 批准号: 7837549
• 负责人: Stephanie M Ware
• 金额: $ 17.2万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-15 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7837549
• 关键词: Animal Model; Binding; Biological Assay; Cardiac; Cardiovascular system; Carrier Proteins; Categories; Cell Nucleus; Cells; Cilia; Complex; Congenital Abnormality; Congenital Heart Defects; Cytoplasm; Data; Defect; Dental crowns; Development; Diagnostic; Embryo; Embryonic Development; Erinaceidae; Genetic; Goals; Handedness; Human; In Vitro; Knock-in Mouse; Lateral; Left; Ligands; Limb Bud; Link; Maintenance; Mediating; Mediator of activation protein; Mesoderm; Molecular; Molecular Genetics; Morphogenesis; Morphology; Mus; Mutation; Neural tube; Nodal; Nuclear Localization Signal; Organ; Output; Pathway interactions; Patients; Pattern; Phenotype; Proteins; Randomized; Research Personnel; Role; Side; Signal Transduction; Signal Transduction Pathway; Situs Inversus; Staging; Testing; Therapeutic Intervention; Tissues; Trans-Activators; Transfection; Visceral; Zinc Fingers; base; cell type; chromatin immunoprecipitation; congenital heart disorder; design; fluid flow; gastrulation; hedgehog signal transduction; human SMO protein; in vivo; loss of function; malformation; member; molecular marker; mutant; novel; receptor; research study; response; smoothened signaling pathway; tool; transcription factor

DESCRIPTION (provided by applicant): Congenital heart defects are the most common type of birth defect, occurring in just less than 1% of all livebirths. One category of heart defects, heterotaxy, is thought to result from abnormal left-right patterning during embryogenesis. In its X-linked form, heterotaxy results from mutations in Zic3, a member of the Gli superfamily of transcription factors. Gli proteins are mediators of hedgehog signaling during development, and Zic3 is a candidate for a cell type specific trans-activator of hedgehog signaling at the node. The long term goal of this study is to define genetic and molecular interactions during L-R patterning that are required for cardiac morphogenesis. We have shown that mutations in ZIC3 result in abnormal subcellular localization in vitro, and that mice deficient in Zic3 recapitulate the phenotype identified in patients. Further, we have demonstrated that Zic3 acts upstream of a conserved signal transduction pathway acting at the embryonic node to control left-right patterning. In addition to Zic3's known expression in perinodal cells, we have recent data identifying expression in the cilia of the node. We hypothesize that the subcellular localization of Zic3 in the node and perinodal crown cells is critical for transduction of hedgehog signaling, determination of left- right patterning, and subsequent cardiac looping morphogenesis. The proposed experiments are designed to determine the tissue-, cell-type, and subcellular specific roles of Zic3 and examine the consequences of alteration of Zic3 expression on hedgehog signal transduction. Aim1 will test the cell autonomous requirement for Zic3 in perinodal crown cells for proper cardiac development and looping morphogenesis via a conditional loss of function approach. Aim 2 will test the hypothesis that alteration in the subcellular localization of Zic3 changes the net hedgehog signaling output from the node and lowers the threshold for cardiac and midline developmental defects. An understanding of the molecular hierarchy controlling cardiac looping is a necessary prerequisite for the development of genetic diagnostics and therapeutic interventions. These studies have the potential to identify molecular and genetic pathways contributing to cardiac development and will develop novel tools to dissect mechanisms underlying congenital heart disease.

描述(申请人提供)：先天性心脏缺陷是最常见的出生缺陷类型，仅发生在所有活产的不到1%。心脏缺陷的一种类型，异位畸形，被认为是由于胚胎发育过程中异常的左右模式造成的。在X连锁的形式中，异质性是由转录因子Gli超家族成员Zic3的突变引起的。Gli蛋白是发育过程中Hedgehog信号的介体，而Zic3是Hedgehog信号在节点上的细胞类型特异性反式激活因子。这项研究的长期目标是确定L-R构型期间心脏形态发生所需的遗传和分子相互作用。我们已经证明，ZIC3的突变导致体外异常的亚细胞定位，而ZIC3缺乏的小鼠概括了在患者中发现的表型。此外，我们已经证明Zic3作用于保守的信号转导通路的上游，作用于胚胎结节，控制左右模式。除了已知的ZIC3‘S在结周细胞中的表达外，我们最近的数据也证实了该基因在结节纤毛中的表达。我们推测，Zic3在结节和结周冠状细胞中的亚细胞定位对于Hedgehog信号的转导、左右模式的确定以及随后的心脏环状结构的形成至关重要。拟议的实验旨在确定Zic3在组织、细胞类型和亚细胞中的特定作用，并检查Zic3表达变化对Hedgehog信号转导的影响。AIM1将通过条件功能丧失方法测试结周冠状细胞对Zic3的细胞自主需求，以实现心脏的正常发育和环状形态发生。目的2验证以下假设：Zic3亚细胞定位的改变改变了从结点输出的净刺猬信号，并降低了心脏和中线发育缺陷的阈值。了解控制心脏循环的分子层次结构是发展基因诊断和治疗干预的必要前提。这些研究有可能确定有助于心脏发育的分子和遗传途径，并将开发新的工具来剖析先天性心脏病的潜在机制。