Muscular Dystrophy Specialized Research Center: Project 1

肌营养不良症专业研究中心：项目1

• 批准号: 10652520
• 负责人: KEVIN P. CAMPBELL
• 金额: $ 38.12万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-08 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10652520
• 关键词: Affinity; Binding; Biochemical; Biological Assay; Biopsy; Cells; Clinical; Data; Defect; Development; Diagnosis; Diagnostic; Diagnostic Procedure; Disease; Dystroglycan; ECM receptor; Enzymes; Extracellular Matrix Proteins; Fibroblasts; Functional disorder; Gene Transfer; Genes; Genetic study; Goals; Immunofluorescence Immunologic; Impairment; Laminin; Lead; Length; Limb-Girdle Muscular Dystrophies; Measurement; Measures; Molecular; Monitor; Monoclonal Antibodies; Mus; Muscle; Muscle function; Muscular Dystrophies; Mutation; Pathogenesis; Pathologic; Pathology; Patients; Physiological; Play; Production; Property; Proteins; Regulation; Research; Role; Severities; Stains; Structure; Techniques; Therapeutic; Treatment Efficacy; Validation; alpha Dystroglycan; clinical phenotype; design; dystroglycanopathy; enzyme substrate complex; improved; insight; novel; novel diagnostics; novel therapeutic intervention; rational design; receptor; receptor function; sugar; therapeutic effectiveness; therapy development

Project 1 Project Summary The overall goal of our research is to elucidate the cellular and molecular mechanisms that underly muscular dystrophies in order to facilitate the rational design of novel therapeutic strategies and quantitative assays to assess target engagement and the effectiveness of therapeutic approaches. Our current research focuses on the dystroglycanopathies, a group of congenital/limb-girdle muscular dystrophies caused by defects in post-translational processing of the extracellular matrix (ECM) receptor α-dystroglycan (α-DG). ECM proteins that contain laminin-G-like (LG) domains bind to α-DG via a unique heteropolysaccharide [-GlcA-β1,3-Xyl-α1,3-]n called matriglycan. Genetic studies have shown that mutations in any one of at least eighteen genes encoding enzymes required for α-DG post-translational processing lead to the absence of or a reduction in matriglycan and thus impair α-DG receptor function. Although significant progress has been made in the identification and characterization of dystroglycanopathy genes, we still do not fully understand the biochemical and physiological function of matriglycan, or how its absence or reduction in length causes muscular dystrophy. The overall objective of the proposed research is to provide mechanistic insights into the role matriglycan plays in α-DG receptor function and in the pathophysiology of the dystroglycanopathies. The overarching hypothesis of our research is that a thorough understanding of (a) the shortened matriglycan structure and resulting α-DG receptor dysfunction in dystroglycanopathy patients and (b) the mechanisms underlying the pathophysiology of the dystroglycanopathies, will lead to more reliable diagnostics and novel therapeutic strategies. Specific Aim 1 will establish the relationship between α-DG matriglycan length and laminin-binding properties of matriglycan on α-DG in control and dystroglycanopathy patient fibroblasts and muscle biopsies. These studies will reveal abnormalities in the post-translational processing of α-DG that result in shorter matriglycan with reduced affinity for laminin leading to muscular dystrophy. Specific Aim 2 will define the biochemical regulation of matriglycan synthesis and its role in the receptor function of α-DG. These studies will define the requirements for matriglycan synthesis and how its synthesis is regulated by protein-protein and protein-sugar interactions. Specific Aim 3 will define novel mechanisms underlying the pathophysiology of the dystroglycanopathies and determine the structure and laminin binding properties required to improve muscle function. These studies will use myd mice with established dystrophic muscle pathology that are evaluated before and after LARGE gene transfer. Collectively, these aims will provide an understanding of the pathological mechanisms underlying dystroglycanopathies, which will be needed to develop a rationale for the design of novel diagnostic and therapeutic strategies, as well as approaches to monitoring therapeutic engagement and efficacy.

项目1项目总结 我们研究的总体目标是阐明 以利于合理设计肌营养不良症新的治疗策略和量化 评估目标参与度和治疗方法有效性的分析。我们目前的研究 重点关注血糖营养不良症，一组先天性/四肢带状肌营养不良，由 细胞外基质受体α-Dstroglan(α-DG)的翻译后处理存在缺陷。 含层粘连蛋白-G样结构域的细胞外基质蛋白通过一种独特的杂多糖与α-DG结合 [-GLCA-β1，3-Xyl-α1，3-]n，称为Matriglycan。基因研究表明，至少任何一个基因的突变 18个编码α-DG翻译后处理所需酶的基因导致缺乏 或基质聚糖减少，从而损害α-DG受体功能。尽管取得了重大进展， 在对糖代谢不良症基因的鉴定和表征方面，我们还没有完全做到 了解Matriglycan的生化和生理功能，或者它的缺失或还原是如何在 长度会导致肌肉营养不良。拟议研究的总体目标是提供机械性的 Matriglycan在α-DG受体功能中的作用及其在心脏病理生理中的作用 糖代谢不良症。我们研究的主要假设是，彻底理解(A) 糖代谢不良症患者基质多糖结构缩短及其导致的α-DG受体功能障碍 和(B)血糖异常的病理生理学基础的机制，将导致更多 可靠的诊断和新的治疗策略。具体目标1将建立 对照和对照α-DG上α-DG的片断长度和层粘连蛋白结合特性 糖营养不良症患者成纤维细胞和肌肉活检。这些研究将揭示出 α-DG的翻译后处理导致较短的Matriglycan与层粘连蛋白的亲和力降低 导致肌肉营养不良。特定目标2将定义合成松茸多糖的生化调节 及其在α-DG受体功能中的作用。这些研究将确定对Matriglycan的要求 合成以及蛋白质-蛋白质和蛋白质-糖相互作用如何调节合成。特定目标 3将定义糖尿病营养不良的病理生理学基础上的新机制，并确定 改善肌肉功能所需的结构和层粘连蛋白结合特性。这些研究将使用 对已建立的营养不良肌肉病理的MyD小鼠进行大基因前后的评估 调职。总而言之，这些目标将提供对潜在的病理机制的理解 血糖异常，这将需要为设计新的诊断和治疗方案提供理论基础 治疗战略，以及监测治疗参与度和疗效的方法。