Hand2 Function and Regulation During Craniofacial Development

Hand2 颅面发育过程中的功能和调节

• 批准号: 7896675
• 负责人: David E. Clouthier
• 金额: $ 36.93万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-20 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7896675
• 关键词: Address; BHLH Protein; Biological Models; Branchial arch structure; Cartilage; Cell Death; Cells; Cephalic; Chromosome Mapping; Cleft Palate; Congenital Abnormality; Connective Tissue; Coupling; Data; Defect; Development; Developmental Process; Distal; Down-Regulation; Embryo; Embryonic Development; Endothelin-1; Enhancers; Event; Face; Fibrinogen; First Pharyngeal Arch; Future; Gap Junctions; Gene Expression; Genes; Genetic; Goals; Heart; Human; Human Development; Jaw; Knock-out; Knockout Mice; Knowledge; Lead; Limb Development; Live Birth; Mammals; Mandible; Maps; Micrognathism; Molecular; Molecular Analysis; Morphogenesis; Mouse Strains; Mus; Mutant Strains Mice; Neck; Neural Crest; Neural Crest Cell; Osteogenesis; Pathway interactions; Pattern; Phenotype; Process; Regulation; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Societies; Structure; Syndrome; System; Systems Biology; Testing; Tissue Engineering; Tissues; Transcription Coactivator; Transcription Repressor/Corepressor; Transgenes; Zebrafish; base; bone; craniofacial; daughter cell; developmental genetics; fascinate; gene repression; malformation; middle ear; mutant; novel; prevent; public health relevance; social; transcription factor; Address; BHLH Protein; Biological Models; Branchial arch structure; Cartilage; Cell Death; Cells; Cephalic; Chromosome Mapping; Cleft Palate; Congenital Abnormality; Connective Tissue; Coupling; Data; Defect; Development; Developmental Process; Distal; Down-Regulation; Embryo; Embryonic Development; Endothelin-1; Enhancers; Event; Face; Fibrinogen; First Pharyngeal Arch; Future; Gap Junctions; Gene Expression; Genes; Genetic; Goals; Heart; Human; Human Development; Jaw; Knock-out; Knockout Mice; Knowledge; Lead; Limb Development; Live Birth; Mammals; Mandible; Maps; Micrognathism; Molecular; Molecular Analysis; Morphogenesis; Mouse Strains; Mus; Mutant Strains Mice; Neck; Neural Crest; Neural Crest Cell; Osteogenesis; Pathway interactions; Pattern; Phenotype; Process; Regulation; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Societies; Structure; Syndrome; System; Systems Biology; Testing; Tissue Engineering; Tissues; Transcription Coactivator; Transcription Repressor/Corepressor; Transgenes; Zebrafish; base; bone; craniofacial; daughter cell; developmental genetics; fascinate; gene repression; malformation; middle ear; mutant; novel; prevent; public health relevance; social; transcription factor

DESCRIPTION (provided by applicant): The goal of this project is to define the function of the basic helix-loop-helix transcription factor Hand2 during mammalian lower jaw development. Our hypothesis is that Hand2 contributes to the development of most lower jaw structures by establishing a distal morphogenetic domain in the mandibular arch. Within this boundary, Hand2 confines genes involved in mandibular pharyngeal arch development while also repressing the expression of genes normally observed outside this domain. Further, we hypothesize that Hand2 expression and function is at least partially regulated by Twist1 through both transcriptional repression and genetic interactions. In both mouse and zebrafish, Hand2 is expressed in cranial neural crest cell (NCC)-derived cells within the mandibular pharyngeal arch, from which bone and cartilage of the lower jaw arise. Targeted inactivation of the Hand2 gene in mice results in early embryonic lethality (by E10.5). However, hand2-mutant zebrafish are viable for five days; in these mutants, extensive malformations in craniofacial cartilages are accompanied by positive and negative changes in gene expression. We have shown in term mouse embryos that Hand2-daughter cells compose most structures derived from the mandibular arch. In our Preliminary Data, we show that loss of Hand2 in NCCs resultst in craniofacial defects indicative of NCC mispatterning. In this proposal, we will address the role of Hand2 in facial morphogenesis in three Specific Aims. In Aim 1, we will define the cellular and molecular changes in facial development following conditional inactivation of the Hand2 gene in cranial neural crest cells. In Aim 2, we will use hand2 zebrafish mutants to examine whether Hand2 acts as both a transcriptional activator and repressor and use Hand2 conditional mouse mutants to identify targets of Hand2 action. In Aim 3, we will define the role of Twist1 in the Hand2 mandibular arch domain and determine whether Twist1 and Hand2 interact genetically within this domain. By coupling our cellular and molecular analysis of Hand2 conditional knockout mice with our functional analysis of Hand2 action in mouse and zebrafish, we expect to uncover novel regulatory mechanisms governing fate and identity of NCCs that ultimately lead to facial development and whose disruption can lead to human facial birth defects, including micrognathia. PUBLIC HEALTH RELEVANCE: Craniofacial birth defect syndromes occur in 1 out of every 250 live births and represent a large financial and social burden within our society. While numerous mouse developmental genetics studies have elucidated the basis of some of these syndromes, the cause of many more remains unknown. The phenotype of the hand2 mutant zebrafish indicates that Hand2 may be involved in establishing or maintaining a developmental domain necessary for mandibular arch development, though early lethality prevents analysis of the role of Hand2 in later arch patterning events and bone formation. Our study will directly address the function and regulation of Hand2 during lower jaw development using a combination of model systems. Together, our studies will help define how regional developmental domains necessary for facial development are established and how different domains may antagonize each other to produce a final facial plan. Such knowledge can be subsequently combined using a systems biology approach to build a more comprehensive "gene map" involved in facial formation, which could lead to significant advances in future tissue engineering approaches to treat human craniofacial anomalies.

描述（由申请人提供）：该项目的目的是定义哺乳动物下颌开发过程中基本的螺旋 - 环螺旋转录因子手2的功能。我们的假设是，Hand2通过在下颌拱门中建立一个远端形态发生结构域来促进最低的下颌结构的发展。在这个边界内，Hand2将涉及下颌咽弓发育的基因限制在抑制通常在该域之外观察到的基因的表达。此外，我们假设Hand2表达和功能至少通过转录抑制和遗传相互作用受扭曲1的部分调节。在小鼠和斑马鱼中，Hand2在下颌咽弓内的颅神经Crest细胞（NCC）衍生的细胞中表达，下颌的骨和软骨从中出现。小鼠中手2基因的靶向失活导致早期胚胎致死性（E10.5）。但是，手2突出斑马鱼的可行性五天。在这些突变体中，颅面软骨中的广泛畸形伴随着基因表达的正变化和阴性变化。我们已经在术语小鼠的胚胎中显示了手动2-笑细胞组成源自下颌弓的大多数结构。在我们的初步数据中，我们表明，NCC中的Hand2丢失导致颅面缺陷表明NCC失误。在此提案中，我们将在三个特定目标中解决HAND2在面部形态发生中的作用。在AIM 1中，我们将在颅神经rest细胞中有条件失活后，定义面部发育的细胞和分子变化。在AIM 2中，我们将使用Hand2斑马鱼突变体来检查Hand2是否充当转录激活器和阻遏物，并使用Hand2条件小鼠突变体来识别Hand2动作的靶标。在AIM 3中，我们将定义Twist1在HAND2下颌拱形域中的作用，并确定Twist1和Hand2是否在该域中遗传相互作用。通过将我们对手2条件敲除小鼠的细胞和分子分析与我们对小鼠和斑马鱼中的手动作用的功能分析，我们希望揭示有关NCC命运和NCC身份的新型调节机制，这些机制最终导致面部发育，这些机制最终导致了人的面部出生缺陷，包括人类的面部出生缺陷，包括微观认知。公共卫生相关性：颅面出生缺陷综合征发生在每250个活产中1个，代表我们社会中的巨大财务和社会负担。尽管许多小鼠发育遗传学研究阐明了其中一些综合征的基础，但更多的原因仍然未知。 Hand2突变体斑马鱼的表型表明，Hand2可能参与建立或维持下颌弓发育所需的发育领域，尽管早期致死性阻止了Hand2在后来的拱形图案事件和骨形成中的作用。我们的研究将通过模型系统组合在下颌开发过程中直接解决Hand2的功能和调节。我们的研究共同有助于定义如何建立面部发展所需的区域发展领域，以及不同的领域如何相互拮抗以产生最终的面部计划。随后可以使用系统生物学方法将这些知识结合在一起，以建立面部形成中涉及的更全面的“基因图”，这可能会导致未来的组织工程方法的重大进展，以治疗人类颅面异常。