Gene Interaction Study of Tbx5, Hh pathway and Osr1 in atrial septation

Tbx5、Hh通路和Osr1在房间隔中的基因相互作用研究

• 批准号: 8574893
• 负责人: Ke Kurt Zhang
• 金额: $ 39.41万
• 依托单位: UNIVERSITY OF NORTH DAKOTA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-05 至 2017-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8574893
• 关键词: Address; Adult; Apoptosis; Atrial Heart Septal Defects; Binding; Bromodeoxyuridine; Cardiac; Cells; Child; Congenital Heart Defects; Data; Defect; Development; Disease; Dorsal; Embryo; Erinaceidae; Event; Failure; Follow-Up Studies; Genetic; Genetic Epistasis; Genetic Techniques; Genetic Transcription; Goals; Growth; Heart; Heart Atrium; Heterozygote; Holt Oram syndrome; Human; Immigration; Immunohistochemistry; In Situ Nick-End Labeling; In Vitro; Incidence; Knock-out; Knockout Mice; Knowledge; Lead; Live Birth; Maps; Methods; Mission; Molecular; Molecular Genetics; Morphology; Mus; Mutation; Nucleic Acid Regulatory Sequences; Pathway interactions; Phenotype; Prevention; Public Health; Publishing; Pulmonary Circulation; Research; Role; Signal Transduction; Staining method; Stains; Stem cells; Techniques; Testing; Venous; Ventricular Septal Defects; Work; base; caspase-3; congenital heart disorder; gene interaction; insight; migration; mouse model; mutant; overexpression; progenitor; public health relevance; smoothened signaling pathway; undergraduate student

DESCRIPTION (provided by applicant): Congenital heart defects (CHD) are common in children, with an incidence of approximately 8 cases per 1000 live births. Atrial septal defects (ASDs) are a prevalent form of CHD. The overall objective of this project is to investigate the molecular signaling network between the odd-skipped related 1 (Osr1; Odd1) and Tbx5-Hedgehog (Hh) pathway in the development of atrial septum. Mutations in Tbx5 cause Holt-Oram syndrome (HOS) in humans, characterized by atrial or ventricular septal defects in the heart. Hegdehog (Hh)-receiving cells in the posterior second heart field (pSHF) have been shown to define a pool of atrial septal progenitors. In preliminary results, we found that Tbx5 was required in the posterior pSHF, specifically in Hh-receiving cells, in order for normal atrial septation to occur. This finding is at least partially due to the role of Tbx5 in regulating the cel cycle progression of the atrial septal progenitors. Also, overexpression of Hh signaling in atrial progenitors rescues ASDs of Tbx5 knockout embryos, suggesting a signaling cascade from Tbx5 down to Hh- pathway. Expression of Osr1 at the dorsal mesocardium overlaps with expression of Tbx5 and Gli1. Importantly, it has been shown that Osr1 knockout mouse embryos fail to form atrial septum. We further demonstrated that Tbx5 directly interact with Osr1 in atrial septation. Thus, there has been a genetic implication of Osr1 in atrial septation, but th mechanistic role of Osr1 in atrial septation remains unknown and is a focus of the proposed research. Our central working hypothesis is that Osr1 interacts with Tbx5 and Hh signaling pathway in the development of atrial septum. To test this hypothesis, we propose to uncover the roles for Osr1 in regulating the migration, proliferation and survival of atrial septum progenitor cells. Furthermore, we will identify the interaction of Osr1 between Hh signaling in atrial septal progenitors during atrial septation. To approach this problem, we will use genetic mosaic and immunohistochemistry techniques to study morphological alterations, and we will use molecular and genetic approaches to identify the mechanisms by which specific atrial septal morphologies are sculpted during development. This proposed research will lay the groundwork for our long-term goal in understanding the molecular network required in the cardiac progenitor specification. This significant research will be performed by undergraduate students and is expected to substantially advance our understanding on cardiac progenitor cell specification, the molecular basis of atrial septation, and the ontogeny of atrial septal defects.

描述（由申请人提供）：先天性心脏病 (CHD) 在儿童中很常见，每 1000 名活产儿中约有 8 例。房间隔缺损 (ASD) 是 CHD 的一种常见形式。该项目的总体目标是研究房间隔发育过程中奇数跳跃相关 1 (Osr1; Odd1) 和 Tbx5-Hedgehog (Hh) 通路之间的分子信号网络。 Tbx5 突变会导致人类发生 Holt-Oram 综合征 (HOS)，其特征是心脏中的房间隔缺损或室间隔缺损。后第二心区 (pSHF) 中的 Hegdehog (Hh) 接收细胞已被证明定义了一组房间隔祖细胞。在初步结果中，我们发现后 pSHF 中需要 Tbx5，特别是 Hh 接受细胞，才能发生正常的房间隔。这一发现至少部分归因于 Tbx5 在调节房间隔祖细胞细胞周期进展中的作用。此外，心房祖细胞中 Hh 信号的过度表达可以挽救 Tbx5 敲除胚胎的 ASD，这表明从 Tbx5 到 Hh 途径的信号级联。 Osr1 在背侧心膜的表达与 Tbx5 和 Gli1 的表达重叠。重要的是，研究表明 Osr1 敲除小鼠胚胎无法形成房间隔。我们进一步证明 Tbx5 在房间隔中直接与 Osr1 相互作用。因此，Osr1 在房间隔中存在遗传意义，但 Osr1 在房间隔中的机制作用仍然未知，也是本研究的重点。我们的中心工作假设是 Osr1 在房间隔发育过程中与 Tbx5 和 Hh 信号通路相互作用。为了检验这一假设，我们建议揭示 Osr1 在调节房间隔祖细胞迁移、增殖和存活中的作用。此外，我们将确定房间隔期间房间隔祖细胞中 Hh 信号传导之间 Osr1 的相互作用。为了解决这个问题，我们将使用遗传镶嵌和免疫组织化学技术来研究形态变化，并且我们将使用分子和遗传学方法来确定发育过程中特定房间隔形态塑造的机制。这项拟议的研究将为我们了解心脏祖细胞规范所需的分子网络的长期目标奠定基础。这项重要的研究将由本科生进行，预计将大大增进我们对心脏祖细胞规范、房间隔的分子基础和房间隔缺损的个体发育的理解。