Factors Regulating Development of Appendicular Skeletal Progenitors

调节附肢骨骼祖细胞发育的因素

基本信息

批准号：
9012780
负责人：
GREGG L DUESTER
金额：
$ 42.9万
依托单位：
SANFORD BURNHAM PREBYS MEDICAL DISCOVERY INSTITUTE
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-02-11 至 2019-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9012780
关键词：
ALDH1A2 gene All-Trans-Retinol Arthritis Binding CRISPR/Cas technology Cartilage DNA Sequence Defect Degenerative polyarthritis Development Elements Embryo Embryo Loss Enzymes Exhibits FGF8 gene Fibroblast Growth Factor Forelimb Foundations Gene Expression Gene Targeting Generations Genes Genetic Genetic Transcription HOX protein Hand Hand Osteoarthritis Health Hindlimb Hip Osteoarthritis Hip region structure Human Indium Introns Knee Osteoarthritis Knowledge LacZ Genes Lateral Ligands Limb Bud Limb structure Link Logic Mediating Mesenchymal Mesoderm Methods Mus Mutagenesis Mutant Strains Mice NRIP1 gene Nuclear PRC1 Protein Pathway interactions Play Recruitment Activity Regenerative Medicine Regulation Repression Retinaldehyde Retinoic Acid Receptor Retinoic Acid Response Element Retinol dehydrogenase Role Signal Transduction Site-Directed Mutagenesis Stem cells Testing Tissues Transgenes Tretinoin Variant Vitamin A Wound Healing articular cartilage base bone chromatin immunoprecipitation design epithelial to mesenchymal transition gene function genetic variant genome wide association study insight loss of function paralogous gene prevent progenitor promoter receptor binding retinaldehyde dehydrogenase skeletal skeletal disorder

项目摘要

DESCRIPTION (provided by applicant): Skeletal disorders such as osteoarthritis and bone/cartilage wounds are currently difficult or impossible to treat. The ability to generate specific skeletal progenitor cells may provide the basis for new treatment therapies using a regenerative medicine approach. In order for this to occur it is essential to understand how skeletal progenitors arise during development. Appendicular skeletal progenitors, in particular, are generated when lateral plate mesoderm undergoes an epithelial-to- mesenchymal transition to generate mesenchymal skeletal progenitors that migrate away from the body axis to form the limb buds. Deciphering the mechanism that stimulates the generation of limb skeletal progenitors is important for understanding and treating appendicular skeletal defects. Recent studies have shown that retinoic acid (RA), an active metabolite of vitamin A, is required specifically for generation of forelimb skeletal progenitors: studies on RA-deficient mutant mouse embryos demonstrated a blockage of forelimb but not hindlimb budding. RA signaling is controlled by RA-synthesizing enzymes, including retinol dehydrogenase 10 (RDH10) that metabolizes retinol (vitamin A) to retinaldehyde, followed by retinaldehyde dehydrogenase 2 (RALDH2; ALDH1A2) that metabolizes retinaldehyde to RA. Interestingly, a forelimb-specific role for RA was shown by a recent genome-wide association study showing that severe osteoarthritis of the hand (the most common form of arthritis), but not hip or knee osteoarthritis, is associated with human ALDH1A2 gene variants that exhibit lower expression in articular cartilage. RA directly regulates gene transcription by functioning as a ligand for nuclear RA receptors that bind RA response elements near target genes. During development, Raldh2-/- embryos (that lack RA activity) fail to induce expression of Tbx5, the earliest known marker of forelimb development, whereas Rdh10-/- embryos (with greatly reduced RA activity) exhibit delayed Tbx5 expression limited to a smaller domain. Preliminary studies suggest that one mode of RA action may be repression of trunk FGF signaling to permit onset of Tbx5 expression. However, alternative mechanisms of RA action may exist including direct RA regulation of Tbx5 or RA regulation of Hox4/5 genes that may be required for induction of Tbx5 in the forelimb field. We will use a genetic loss-of-function approach to uncover the mechanism through which RA interacts with Tbx5, Hox genes, and FGF signaling to stimulate differentiation of lateral plate mesoderm to a forelimb skeletal progenitor fate. This project will generate important basic information on the signaling mechanisms needed for generation of appendicular skeletal progenitors that may aid in the treatment of skeletal disorders.

描述（由适用提供）：目前难以或不可能治疗骨骼疾病，例如骨关节炎和骨/软骨伤口。生成特定骨骼祖细胞的能力可以使用再生医学方法为新的治疗疗法提供基础。为了使情况发生，必须了解在发育过程中骨骼祖细胞的出现。特别是，当侧板中胚层经历上皮到间质跃迁以产生间充质骨骼祖细胞以从体轴迁移以形成肢体芽时，会产生阑尾骨骼祖细胞。破译刺激肢体骨骼祖细胞产生的机制对于理解和治疗阑尾骨骼缺陷很重要。最近的研究表明，维生素A的活性代谢产生的视黄酸（RA）是针对前肢骨骼祖细胞所需的：RA缺乏型突变小鼠胚胎的研究表明，前肢的堵塞，但并非有后肢萌芽。 RA信号通过RA合成酶控制，包括视黄醇脱氢酶10（RDH10），将视网膜葡萄糖（维生素A）代谢为视网膜醛，然后是视网膜脱氢酶2（RaldH2; Aldh1a2; Aldh1a2），以代谢视网膜含量为Ra。有趣的是，近期全基因组关联研究表明，RA的前肢特异性作用表明，手的严重骨关节炎（关节炎的最常见形式），但没有髋关节或膝关节骨关节炎，与关节软骨中表现较低的人类ALDH1A2基因变体有关。 RA通过充当核RA接收器的配体来直接调节基因转录，该核RA接收器结合靶基因附近的RA反应元件。在开发过程中，raldh2 - / - 胚胎（缺乏RA活性）无法诱导TBX5的表达，TBX5是前肢发育的最早已知标志物，而RDH10 - / - 胚胎（大大降低了RA活性）暴露的延迟TBX5 TBX5的TBX5表达限于较小的域。初步研究表明，RA作用的一种模式可能是躯干FGF信号传导的表达，以允许TBX5表达发作。但是，可能存在RA作用的替代机制，包括TBX5的直接RA调节或HOX4/5基因的RA调节，这些基因可能需要在前肢领域诱导TBX5所需的TBX5。我们将使用遗传功能丧失方法来揭示RA与TBX5，HOX基因和FGF信号传导相互作用的机制，以刺激侧板中胚层与前肢骨骼祖细胞命运的分化。该项目将生成有关产生阑尾骨骼祖细胞所需的信号传导机制的重要基本信息，这些信息可能有助于治疗骨骼疾病。