THE ROLE OF TGF-? MODULATORS IN VERTEBRAL DEVELOPMENT

TGF-的作用？

• 批准号: 7959954
• 负责人: Jixiang Ding
• 金额: $ 19.86万
• 依托单位: UNIVERSITY OF LOUISVILLE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7959954
• 关键词: Address; Anatomic structures; Anterior; Area; Binding; Biochemical; Biological Models; Biological Process; Centers of Research Excellence; Complex; Computer Retrieval of Information on Scientific Projects Database; Congenital Abnormality; DNA; Defect; Development; Developmental Biology; Disease; EP300 gene; Embryo; Event; Funding; Genes; Genetic; Grant; Health; Human; In Vitro; Institution; Laboratories; Manuscripts; Mediating; Molecular; Morphogenesis; Mus; Mutant Strains Mice; Neural tube; Pathway interactions; Phenotype; Play; Process; Protein Binding Domain; Protein Family; Proteins; Recruitment Activity; Regulation; Research; Research Personnel; Resources; Role; Signal Pathway; Signal Transduction; Somites; Source; Specificity; Spinal Cord Diseases; System; Tail; Tissues; Transcription Coactivator; United States National Institutes of Health; Zebrafish; Zinc Fingers; developmental genetics; homeodomain; improved; in vivo; intercellular communication; malformation; member; molecular marker; notochord; rib bone structure; somitogenesis; spine bone structure; vertebra body

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Vertebral malformation associates with a large number of distressful human birth defects. Elucidation of the developmental and genetic mechanisms underlying normal vertebral formation will undoubtedly have great impacts on human health. The formation of vertebral system is a complex process involving the morphogenesis of neural tube, notochord, somites and cell  cell signaling events among these tissues. In particular, the formation and differentiation of somites play a critical role in vertebral development and vertebral disorders. Each somite has to establish an anterior-posterior (A-P) polarity and disruption of this A-P polarity during development often leads to the abnormal fusions between vertebrae bodies and ribs resulting in serious vertebral and spinal cord disorders. The development of vertebrate tail provides an excellent model system to study somite formation and differentiation due to its simple anatomic structure compared with the trunk vertebral system. The abnormal fusion between vertebrae bodies usually cause tail bending, kinky tail, that can be easily visualized. The A-P differentiation of somites can be examined by a set of well established molecular markers. In this study, we will focus on the regulation of TGF-b signaling pathway in somitogenesis by exploring the functions of two Smads interacting factors: Zfhx1a and TGIF. Zfhx1a, also called dEF1, encodes a zinc finger protein that contains multiple DNA and protein binding domains including homeodomain and Smad binding domain. In vitro studies showed that members of Zfhx protein family can bind to Smads proteins and recruit transcription activator p300 or repressor CtBP. Depending on the types of recruited co-factors, activators or repressors, Zfhx proteins can either up- or down- regulate TGF-b activity. Biochemical studies have revealed that TGIF antagonizes TGF-b signaling by binding to Smad2. Our recent studies with Zfhx1a and TGIF mutant mice uncovered that loss of Zfhx1a or TGIF function leads to a severe kinky tail phenotype, strongly indicating that these genes play important roles the A-P differentiation of somites. We therefore propose here to examine the functional requirements of Zfhx1a and TGIF during mouse somitogenesis and vertebral development. In addition, we will employ Zebrafish system to determine the specificity of Zfhx1a and TGIF mediated TGF-b suppression in vivo, namely which TGF-b member(s) activity is regulated by Zfhx1a and TGIF in vertebrate somitogenesis. Results from the proposed research will be significant as it address the regulation of an important pathway, TGF-b signaling, in a fundamental biological process, vertebrate body segmentation. In addition, the project features several advantages that fit the purpose of this COBRE application suitably: 1) It is a suitable project for the investigator to enter a new area of birth defect research, vertebral disorders; 2) An additional model system, Zebrafish, will allow the investigator to conduct more mechanistic studies as Zebrafish is more accessible to embryonic and genetic manuscript; 3) Since Zebrafish system is a popular and powerful model system in developmental biology, having a zebrafish model system in the laboratory will improve the research strength to a great extend.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 脊椎畸形与许多严重的出生缺陷有关。阐明正常脊椎形成的发育和遗传机制无疑将对人类健康产生重大影响。脊椎系统的形成是一个复杂的过程，涉及神经管、脊索、体节和细胞的形态发生  这些组织之间的细胞信号事件。特别是体节的形成和分化在脊椎发育和脊椎疾病中起着至关重要的作用。每个体节都必须建立一个前-后（A-P）极性，在发育过程中，这种A-P极性的破坏通常会导致椎体和肋骨之间的异常融合，从而导致严重的脊椎和脊髓疾病。脊椎动物尾部的发育为研究体节的形成和分化提供了一个很好的模型系统。椎体间的异常融合通常会导致尾部弯曲、扭结，易于观察。体节的A-P分化可以通过一组成熟的分子标记来检测。本研究通过探讨两种Smads相互作用因子Zfhx 1a和TGIF的功能，探讨TGF-β信号通路在体节发生中的调控作用。Zfhx 1a也称为dEF 1，编码一种锌指蛋白，其含有多个DNA和蛋白质结合结构域，包括同源结构域和Smad结合结构域。体外研究表明，Zfhx蛋白家族成员可以与Smads蛋白结合，募集转录激活因子p300或抑制因子CtBP。根据募集的辅因子、激活剂或阻遏物的类型，Zfhx蛋白可以上调或下调TGF-β活性。生物化学研究表明，TGIF通过与Smad 2结合来拮抗TGF-β信号传导。我们最近对Zfhx 1a和TGIF突变小鼠的研究发现，Zfhx 1a或TGIF功能的缺失导致严重的扭尾表型，强烈表明这些基因在体节的A-P分化中起重要作用。因此，我们建议在这里检查Zfhx 1a和TGIF在小鼠体节发生和椎骨发育过程中的功能要求。此外，我们将利用斑马鱼系统来确定Zfhx 1a和TGIF介导的体内TGF-b抑制的特异性，即在脊椎动物体节发生中，哪些TGF-b成员的活性受到Zfhx 1a和TGIF的调节。 从拟议的研究结果将是显着的，因为它解决了一个重要的途径，TGF-β信号，在一个基本的生物过程，脊椎动物身体分割的调节。此外，该项目具有几个适合COBRE应用目的的优点：1）这是一个适合研究者进入出生缺陷研究新领域的项目，脊椎疾病; 2）额外的模型系统斑马鱼，将允许研究者进行更多的机制研究，因为斑马鱼更容易获得胚胎和遗传手稿; 3）由于斑马鱼系统是发育生物学中流行的、功能强大的模型系统，在实验室中拥有斑马鱼模型系统将在很大程度上提高研究实力。