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: 7588010
• 负责人: Stephanie M Ware
• 金额: $ 37.5万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7588010
• 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（由申请人提供）：先天性心脏缺陷是最常见的先天缺陷类型，仅在所有LiveBirths的1％中发生。心脏缺陷的一种类别，即杂型，被认为是胚胎发生过程中左右模式异常引起的。以其X连锁形式，异Xy是由ZIC3突变引起的，ZIC3是转录因子的GLI超家族成员。 GLI蛋白是发育过程中刺猬信号传导的介体，ZIC3是该节点处的刺猬信号传导的细胞类型特异性反激活剂的候选者。这项研究的长期目标是定义心脏形态发生所需的L-R模式期间的遗传和分子相互作用。我们已经表明，ZIC3中的突变导致体外的亚细胞定位异常，并且缺乏ZIC3的小鼠概括了患者鉴定的表型。此外，我们已经证明了ZIC3在作用在胚胎节点上的保守信号转导途径上游以控制左右模式。除了ZIC3在围产期细胞中的已知表达外，我们还有最新数据识别节点纤毛中的表达。我们假设ZIC3在淋巴结和围产期冠状细胞中的亚细胞定位对于刺猬信号传导，测定左右图案的测定以及随后的心脏循环形态发生至关重要。所提出的实验旨在确定ZIC3的组织，细胞类型和亚细胞特异性作用，并检查ZIC3表达改变刺猬信号转导的后果。 AIM1将通过有条件的功能方法丧失来测试围围冠冠细胞中ZIC3的细胞自主需求，以进行适当的心脏发育和形态发生。 AIM 2将检验以下假设：ZIC3的亚细胞定位改变改变了节点的净刺猬信号输出，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遗传诊断和治疗干预措施的必要先决条件。这些研究具有鉴定有助于心脏发展的分子和遗传途径的潜力，并将开发出新的工具来剖析先天性心脏病的基础机制。