Shox2 and temporomandibular joint formation

Shox2 与颞下颌关节形成

基本信息

批准号：
8204861
负责人：
Yiping Chen
金额：
$ 34.68万
依托单位：
TULANE UNIVERSITY OF LOUISIANA
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-01-01 至 2013-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8204861
关键词：
Ablation Accounting Adhesions Affect Alleles Animal Model Ankylosis Applications Grants Biological Assay Biological Models Breathing Cause of Death Cells Cephalic Chondrocytes Deglutition Deposition Development Disease Dyschondrosteosis Dysplasia EMSA Embryonic Development Enzymes Exhibits Fibrocartilages Genes Genetic Genetic Transcription Glenoid structure Goals Growth Head Heart Histones Homeobox Genes Human Hyaline Cartilage In Vitro Individual Joints Limb structure Link Mandible Mandibular Condyle Maxilla Mesenchymal Modification Molecular Morphogenesis Mus Mutant Strains Mice Mutate Mutation Neural Crest Oral cavity Osteogenesis Pattern Phenotype Phosphorylation Play Post-Translational Protein Processing Protein Dephosphorylation Protein Isoforms Proteins Relative (related person)Reporter Reporting Role Site Stem cells Surface Symptoms Syndrome Temporal bone structure Temporomandibular Joint Temporomandibular Joint Disorders Testing Transactivation Trauma Turner&apos s Syndrome Ubiquitin Undifferentiated United States Variant Wasting Syndrome capsule congenital infection feeding in vivo jaw movement mutant postnatal

项目摘要

The temporomandibular joint (TMJ) ankylosis is clinically defined as limited mouth opening due to either a fibrous or bony union between the head of the condyle and the glenoid fossa. Although most incidents of TMJ ankylosis occur after trauma or an infection, congenital cases have been reported. Currently little is known about the TMJ morphogenesis and the underlying genetic, cellular and molecular mechanisms. Particularly, nothing is known about genetic alteractions that cause congenital TMJ ankylosis. The homeobox gene Shox2 is expressed specifically in the mesenchymal cells of the maxilla-mandibular junction and later in the immatured chondrocytes of the condyle of the TMJ. A conditional inactivation of Shox2 in cranial neural crest derived cells leads to dysplasia and ankylosis of the TMJ. Thus, Shox2 mutant mice serve as a unique model system for the studies of the mammalian TMJ development and its underlying mechanisms. We hypothesize that Shox2 plays a crucial role in TMJ development by regulating Runx2 expression directly. We also hypothesize that SUMO modification of Shox2a is essential for the TMJ formation. Four specific aims are proposed to test these hypotheses. In Aim 1, we will determine if Runx2 is a direct downstream target of Shox2 by reporter assay, EMSA and ChIP assay. We will also determine if phosphorylation impairs Shox2a's transactivating potency by creating mutant forms of Shox2a mimicking constitutively phosphorylation state or constitutively dephosphorylation state. In Aim 2, we will define SUMO modification of Shox2a and its consequences on the modulation of the Shox2a's transcriptional capacity. In this aim, we will further define the interaction between Shox2a and Histone 3.3, which may enhance the transcription capacity of Shox2a. The human SHOXa will be included in parallel in the proposed studies. In Aim 3, we will determine the role of SUMO modifcation of Shox2a in the TMJ development by expressing the mutated forms of Shox2a that either can not be sumoylated or mimic constitutively sumoylated status in the endogenous Shox2-expressing domains. In the last aim, we will test if human SHOX and SHOX2 are functionally redundant in embryonic development through targeted insertion of the human SHOX gene into the mouse Shox2 allele.

颞下颌关节（TMJ）强直在临床上被定义为受限的口腔由于髁头和骨之间的纤维或骨结合而导致的开口关节窝。尽管大多数颞下颌关节强直发生在外伤或感染，先天性病例已有报道。目前人们对颞下颌关节知之甚少形态发生及其潜在的遗传、细胞和分子机制。特别是，对于导致先天性颞下颌关节的遗传改变一无所知强直。同源框基因 Shox2 在间充质细胞中特异性表达上颌骨-下颌交界处，后来在未成熟的软骨细胞中 TMJ 髁突。颅神经嵴中 Shox2 的条件失活细胞导致颞下颌关节发育不良和强直。因此，Shox2 突变小鼠可作为研究哺乳动物颞下颌关节发育及其影响的独特模型系统底层机制。我们假设 Shox2 在 TMJ 中起着至关重要的作用通过直接调节 Runx2 表达来开发。我们还假设 SUMO Shox2a 的修饰对于 TMJ 的形成至关重要。四个具体目标是建议检验这些假设。在目标 1 中，我们将确定 Runx2 是否是直接通过报告基因检测、EMSA 和 ChIP 检测确定 Shox2 的下游靶标。我们也会确定磷酸化是否通过产生突变体损害 Shox2a 的反式激活效力 Shox2a 的形式模仿组成型磷酸化状态或组成型去磷酸化状态。在目标 2 中，我们将定义 Shox2a 的 SUMO 修改及其对 Shox2a 转录能力调节的影响。为了这个目标，我们将进一步定义Shox2a和Histone 3.3之间的相互作用，这可能会增强 Shox2a 的转录能力。人类 SHOXa 将同时纳入拟议的研究。在目标 3 中，我们将确定 SUMO 修饰的作用 Shox2a 通过表达 Shox2a 的突变形式参与 TMJ 发育，不能被苏酰化或模拟内源性苏酰化状态 Shox2 表达域。在最后一个目标中，我们将测试人类 SHOX 和 SHOX2 是否通过定向插入，在胚胎发育过程中实现功能冗余将人类 SHOX 基因转化为小鼠 Shox2 等位基因。