Towards a Mechanistic Undestanding of Adolscent Idiopathic Scoliosis

项目摘要：在这里，我们试图了解常见的儿科疾病的细胞和分子原因。 肌肉骨骼疾病，青少年特发性脊柱侧凸（AIS）。AIS的人群研究正在开始 揭示这种疾病的重要危险位点，但在了解病因方面进展有限。 的AIS。在某种程度上，这是由于缺乏良好的，遗传上易于处理的脊柱侧凸疾病动物模型。我们将 我们的努力集中在功能分析的一些明确的动物模型的AIS，我们产生的两个 小鼠和斑马鱼模型系统。与此同时，我们将推进该领域的基因发现， 应用现代遗传学方法来表征导致AIS样脊柱畸形的新突变， 现有的斑马鱼突变体的集合。该项目将测试以下假设：首先， 在我们的Gpr 126小鼠模型中，迟发性脊柱侧凸是椎间融合器胚胎缺陷的结果。 光盘。第二，软骨和椎间盘中Gpr 126信号传导的功能分析将提供一种新的方法， 对人类AIS病理生理学的机械理解，以及，有助于强调新的基因 和导致AIS的途径。第三，我们在斑马鱼模型中发现基因的计划， 在斑马鱼和小鼠模型中对AIS样脊柱侧凸的功能分析将为 对人类AIS病因的更多机械理解。这些假设将在三个条件下进行检验。 具体目标： I.确定AIS何时何地需要Gpr 126。共同祖细胞中Gpr 126功能的丧失 的软骨和骨组织模型AIS在小鼠。在小鼠中使用条件遗传方法， 我们将进一步研究这些组织中Gpr 126的缺失如何导致脊柱侧凸的发生和发展， 我们将定义Gpr 126在脊柱发育中功能的时间窗。二.什么是分子 Gpr 126在椎间盘和软骨中的作用在这里，我们将调查的机制， GPR 126控制软骨细胞外基质的成熟和沉积以及软骨细胞外基质的发育。 椎间盘以及这与小鼠脊柱侧凸发病的关系。三.分子表征 脊柱畸形的遗传学和病因学。确定对正常脊柱重要的基因和途径 为了进一步发展，我们利用正向遗传学方法分离了一组成年可行的脊柱畸形， 突变斑马鱼我们将应用大规模平行测序来鉴定新的脊柱畸形疾病基因 在这些现有的突变株系中。为了获得对脊柱侧凸的机械理解，我们将：a）进行 对这些新的突变斑马鱼品系中的两种进行功能分析，影响细胞外基质修饰基因; 和B）在已知的人类AIS风险基因座的明确斑马鱼模型中研究脊柱侧凸的病因。 这些结果有望揭示以前未知的机制和正常脊柱所必需的途径 发展

Project Summary: Here we seek to understand the cellular and molecular causes of a common pediatric musculoskeletal disease, adolescent idiopathic scoliosis (AIS). Human population studies of AIS are beginning to uncover important risk loci for this disease, but there has been limited progress in understanding the etiology of AIS. In part, this is due to a lack of good, genetically tractable animal models of scoliotic diseases. We will focus our efforts on the functional analysis of a few explicit animal models of AIS which we generated in both mouse and zebrafish model systems. At the same time, we will advance gene discovery in this field, by applying modern genetic approaches to characterize novel mutations that cause AIS-like spine deformity in an existing collection of zebrafish mutants we generated. The project will test the following hypotheses: First, that late-onset scoliosis in our Gpr126 mouse model is a consequence of embryonic defects of the intervertebral discs. Second, that functional analysis of Gpr126 signaling in cartilage and the intervertebral disc will provide a mechanistic understanding of the pathophysiology of AIS in humans, as well as, help to emphasize new genes and pathways that contribute to AIS. Third, that our plan for gene discovery in the zebrafish model and functional analysis of AIS-like scoliosis in zebrafish and mouse models will provide a synergistic framework for more mechanistic understanding of the causes of AIS in humans. These hypotheses will be tested under three Specific Aims: I. Determine when and where Gpr126 is required for AIS. Loss of Gpr126 function in a common progenitor cell of cartilage and bone tissues models AIS in the mouse. Using conditional genetic approaches in the mouse, we will refine how the loss of Gpr126 in these tissues contribute to the onset and progression of scoliosis and we will define the temporal window for Gpr126 function in spine development. II. What is the molecular function of Gpr126 in the intervertebral disc and cartilage? Here we will investigate the mechanism by which Gpr126 controls the maturation and deposition of the cartialge extracellular matrix and the development of the interverterbal disc and how this relates to onset of scoliosis in the mouse. III. Characterization of the molecular genetics and etiologies of spine deformity. To identify genes and pathways important for normal spine development, we utilized a forward genetics approach to isolate a collection of adult-viable spine deformity mutant zebrafish. We will apply massively parallel sequencing to identify novel spine deformity disease genes in these existing mutant lines. In order to gain a mechanistic understanding of scoliosis we will: a) undertake functional analysis of two of these novel mutant zebrafish lines, affecting extracellular matrix modifying genes; and b) investigate the etiology of scoliosis in an explicit zebrafish model of a well-known human AIS risk locus. The results are excepted to reveal previously unknown mechanisms and pathways essential for normal spine development.