Deep Sequencing Analysis of mRNA Isoform Expression Changes in Myotonic Dystrophy

描述(申请人提供)：强直性肌营养不良症(DM)是最常见的成人型肌营养不良症，发病率约为每8,000名成年人中就有1名。最常见的疾病DM1是由DMPK基因3‘UTR中扩大的CTG重复序列引起的，该基因中的CUG重复RNA折叠成聚集在核灶中的发夹，导致选择性剪接因子Musclebind1(MBNL1)有效耗尽和剪接因子CUG结合蛋白1(CUGBP1)过度激活。这些因素对剪接的错误调控是该病的核心。因此，表征糖尿病患者转录本的变化谱对于了解疾病的发病机制至关重要。该项目旨在了解糖尿病的分子基础，并利用基于下一代mRNAs测序的方法确定适合于治疗干预的基因和信使核糖核酸亚型。该项目有以下具体目标：1)建立糖尿病中表达改变的基因、外显子和信使核糖核酸亚型的综合目录，并评估这些变化在个体之间的变异性。2)研究糖尿病小鼠模型中基因和mRNA异构体的表达变化。3)探讨DM的基因及亚型改变与临床病理特征的关系。实现这些目标将为更深入地了解糖尿病奠定基础，并将为未来的分子遗传学和筛查研究创造线索，并可能确定候选的治疗靶点。 与公共卫生相关：这项研究项目将全面确定强直性肌营养不良患者肌肉中发生的RNA和蛋白质分子的变化。强直性肌营养不良是肌肉营养不良最常见的成人发病形式，每8000名成年人中就有一人受到影响。了解这些分子变化将有助于确定哪些分子和基因是疾病特定症状的基础，并有助于确定治疗的目标。

DESCRIPTION (provided by applicant): Myotonic dystrophy (DM) is the most common form of adult onset muscular dystrophy, with an incidence of about 1 in 8,000 adults. The most common form of the disease, DM1, is caused by an expanded CTG repeat in the 3' UTR of the DMPK gene, and CUG repeat RNAs from this gene fold into hairpins that accumulate in nuclear foci, resulting in effective depletion of the alternative splicing factor Muscleblind (MBNL1) and hyperactivation of the splicing factor CUG Binding Protein 1 (CUGBP1). Misregulation of splicing by these factors is central in the disease. Thus, characterization of the spectrum of changes in the transcriptomes of DM patients is central to understanding disease pathogenesis. This project seeks to understand the molecular basis of DM and to identify genes and mRNA isoforms suitable for therapeutic intervention using an approach based on next-generation sequencing of mRNAs. The project has the following specific aims: 1) To generate a comprehensive catalog of genes, exons and mRNA isoforms whose expression is altered in DM, and to assess the variability of these changes between individuals. 2) To characterize gene and mRNA isoform expression changes in mouse models of DM. 3) To associate gene and isoform changes with clinical and pathological features in DM. Achieving these aims will lay the foundation for a deeper understanding of DM and will generate leads for future molecular genetics and screening studies and is likely to identify candidate therapeutic targets. PUBLIC HEALTH RELEVANCE: This research project will comprehensively determine the changes in RNA and protein molecules that occur in the muscles of patients affected by myotonic dystrophy, which is the most common adult onset form of muscular dystrophy, affecting 1 in 8,000 adults. Knowledge of these molecular changes will help to identify which molecules and genes underlie specific symptoms of the disease and will aid in identifying targets for therapy.