CCDC78 and the Pathogenesis of Centronuclear Myopathy

CCDC78 与中心核肌病的发病机制

• 批准号: 8768983
• 负责人: JAMES J DOWLING
• 金额: $ 5.13万
• 依托单位: HOSPITAL FOR SICK CHLDRN (TORONTO)
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8768983
• 关键词: 3' Splice Site; Binding; Biochemical; Biopsy; Cell Nucleus; Centronuclear myopathy; Childhood; Chimeric Proteins; Chromosome Mapping; Co-Immunoprecipitations; Complementary DNA; Coupling; Data; Development; Disease; Dominant-Negative Mutation; Evaluation; Family; Figs - dietary; Future; Gene Expression; Gene Mutation; Genes; Genetic; Goals; Hematoxylin and Eosin Staining Method; Image Analysis; Immunoprecipitation; In Vitro; Knowledge; Life; Mediating; Modeling; Morbidity - disease rate; Motor; Muscle; Muscle Development; Muscle Weakness; Muscle function; Mutate; Mutation; Myopathy; Pathogenesis; Pathologic; Production; Property; Proteins; Proteomics; Role; Sarcoplasmic Reticulum; Skeletal Muscle; Staining method; Stains; Techniques; Testing; Work; Zebrafish; cDNA Expression; combinatorial; disability; effective therapy; exome; exome sequencing; genetic linkage analysis; genetic pedigree; in vivo; loss of function; mortality; muscular structure; mutant; next generation sequencing; novel; proband; protein function; therapy development

DESCRIPTION (provided by applicant): Centronuclear myopathies are a group of childhood onset muscle diseases defined by shared muscle biopsy features and characterized by muscle weakness and severe motor disability. Currently there are 5 known genetic causes for CNM, and recent studies on these gene products have identified abnormal excitation- contraction coupling as a key aspect of disease pathogenesis. Despite these advancements, no treatments current exist for CNMs and much remains to be understood about these clinically severe conditions. Approximately 40% of cases of CNM are genetic unresolved. Determination of additional genetic causes is critical to advance the knowledge of and to develop treatments for this disease. We have used linkage analysis and whole exome sequencing to identify a novel gene mutation in the CCDC78 gene in a family with autosomal dominant CNM. CCDC78 encodes a previously uncharacterized gene product, and the gene mutation is predicted to result in production of a protein with an internal deletion. Our hypotheses are that (a) wild type CCDC78 is required for muscle development and in particular for stabilizing the excitation-contraction coupling machinery and that (b) mutant CCDC78 functions in a dominant negative manner to sequester ECC proteins and thereby impair motor function. These hypotheses will be tested in two aims. Aim 1 will examine the function(s) of wild type CCDC78 and Aim 2 will test the impact of the CCDC78 mutation on muscle development and function. Both aims will utilize a combinatorial approach that includes in vitro studies, biochemical and proteomic techniques, and in vivo experimentation in the zebrafish. In particular, the project will take advantage of the power in the zebrafish for manipulation of gene expression, used to create both loss of function and dominant negative models, and live image analysis, used to dynamically examine specific properties of muscle function. In all, this proposal will determine the function of CCDC78 in muscle development as well as the pathogenic mechanisms underlying its mutation in CNM. These data will be placed in the context of the existing knowledge of CNM, allowing for critical advancements in the understanding of muscle function and the pathogenesis of this devastating disease.

描述（由申请人提供）：中心核肌病是一组儿童期肌肉疾病，这些肌肉疾病由共同的肌肉活检特征定义，并以肌肉无力和严重的运动障碍为特征。当前，有5种CNM的已知遗传原因，并且对这些基因产物的最新研究已经确定异常的激发 - 收缩耦合是疾病发病机理的关键方面。尽管有这些进展，但对于CNM，尚无治疗的目前，并且在这些临床上严重的情况下仍有许多待理解。大约40％的CNM病例未解决。确定额外的遗传原因对于促进对该疾病的知识和发展治疗至关重要。我们已经使用了连锁分析和整个外显子组测序来鉴定常染色体显性CNM家族中CCDC78基因中的新基因突变。 CCDC78编码先前未表征的基因产物，并且预测该基因突变会导致具有内部缺失的蛋白质产生。我们的假设是（a）野生型CCDC78是肌肉发育所必需的，尤其是稳定激发反应偶联机械以及（b）突变型CCDC78以显着的负面方式对隔离ECC蛋白的主要负面功能，从而损害运动功能。这些假设将以两个目的进行检验。 AIM 1将检查野生型CCDC78的功能，AIM 2将测试CCDC78突变对肌肉发育和功能的影响。这两个目标都将利用一种组合方法，其中包括体外研究，生化和蛋白质组学技术以及斑马鱼中的体内实验。特别是，该项目将利用 斑马鱼中的功率来操纵基因表达，用于创造功能丧失和显性阴性模型的丧失，以及实时图像分析，用于动态检查肌肉功能的特定特性。总的来说，该建议将确定CCDC78在肌肉发育中的功能以及CNM中突变的致病机制。这些数据将放置在CNM现有知识的背景下，从而在理解肌肉功能和这种毁灭性疾病的发病机理方面取得了关键的进步。