Deep Sequencing Analysis of mRNA Isoform Expression Changes in Myotonic Dystrophy

描述（由申请人提供）：肌强直性营养不良症（DM）是成人发病的最常见的肌肉营养不良症，发病率约为1 / 8000。该疾病最常见的形式DM1是由DMPK基因3' UTR中CTG重复扩增引起的，来自该基因的CUG重复rna折叠成发夹，积聚在核病灶中，导致选择性剪接因子Muscleblind （MBNL1）的有效消耗和剪接因子CUG结合蛋白1 （CUGBP1）的过度激活。这些因素对剪接的错误调节是该病的核心。因此，表征糖尿病患者转录组谱的变化是了解疾病发病机制的核心。该项目旨在了解糖尿病的分子基础，并利用基于下一代mRNA测序的方法识别适合治疗干预的基因和mRNA亚型。该项目有以下具体目标：1)生成DM中表达改变的基因、外显子和mRNA亚型的综合目录，并评估这些变化在个体之间的可变性。2)表征小鼠DM模型中基因和mRNA异构体表达变化。3)将基因和异构体变化与DM的临床和病理特征联系起来。实现这些目标将为深入了解DM奠定基础，并将为未来的分子遗传学和筛选研究提供线索，并有可能确定候选治疗靶点。

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.