Towards a Mechanistic Undestanding of Adolscent Idiopathic Scoliosis

项目总结：在这里，我们试图了解常见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的人类人口研究正在开始 发现该病的重要危险基因，但对其病因的了解进展有限。 AIS的。在一定程度上，这是由于缺乏良好的、遗传上易处理的脊柱侧弯疾病动物模型。我们会 将我们的精力集中在对AIS的几个显式动物模型的功能分析上，这些模型是我们在 老鼠和斑马鱼模型系统。与此同时，我们将通过以下方式推进这一领域的基因发现 应用现代遗传学方法表征导致AIS样脊柱畸形的新突变 我们产生的斑马鱼变种的现有集合。该项目将检验以下假设：第一， 我们的GPR126小鼠模型中迟发性脊柱侧弯是椎间胚胎缺陷的结果 光盘。其次，对软骨和椎间盘中GPR126信号的功能分析将提供一种 从机制上理解人类AIS的病理生理学，有助于强调新的基因 以及促成AIS的途径。第三，我们在斑马鱼模型中发现基因的计划 斑马鱼和小鼠模型中AIS样脊柱侧弯的功能分析将为 对人类AIS的原因有更机械性的理解。这些假说将在三种情况下进行检验 具体目标： 确定AIS需要GPR126的时间和地点。共同祖细胞中GPR126功能的丧失 在小鼠的软骨和骨组织中建立AIS模型。在小鼠身上使用条件遗传方法， 我们将细化这些组织中GPR126的缺失如何在脊柱侧弯的发生和发展中起作用。 我们将为GPR126在脊柱发育中的作用定义时间窗口。II.分子是什么？ GPR126在椎间盘和软骨中的作用？在这里，我们将研究它的机制 GPR126控制细胞外基质的成熟和沉积，以及细胞外基质的发育 椎间间盘及其与小鼠脊柱侧弯发病的关系。三、分子的表征 脊柱畸形的遗传学和病因。识别对正常脊椎重要的基因和途径 在发育过程中，我们使用了一种正向遗传学方法来分离出一组成人可存活的脊柱畸形 突变的斑马鱼。我们将应用大规模并行测序来识别新的脊柱畸形疾病基因 在这些现有的突变品系中。为了获得对脊柱侧弯的机械性理解，我们将：a) 对两个新的突变斑马鱼品系进行功能分析，影响细胞外基质修饰基因； 以及b)在一个众所周知的人类AIS风险基因座的显式斑马鱼模型中调查脊柱侧弯的病因。 这一结果有望揭示以前未知的对正常脊柱至关重要的机制和途径。 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.