Pathogenic mechanisms and therapeutics for the cardiac manifestations of myotonic dystrophy type 1

1型强直性肌营养不良心脏表现的发病机制和治疗

• 批准号: 10375515
• 负责人: Thomas A Cooper
• 金额: $ 43.16万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-15 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10375515
• 关键词: 3' Untranslated Regions; Adult; Affect; Alleles; Alternative Splicing; Arrhythmia; Binding; CUG repeat; Cardiac; Cardiac Myocytes; Cause of Death; Cell Culture Techniques; Cessation of life; Chimeric Proteins; DNA; Data Set; Disease; Down-Regulation; Doxycycline; Electrophysiology (science); Event; Exhibits; Exons; Fetal Proteins; Gastrointestinal tract structure; Gene Expression; Genes; Genetic; Genetic Transcription; Genomic Segment; Goals; Guide RNA; Heart; Human; Incidence; Individual; Interruption; Investigation; Knock-out; Life; Link; Mediating; Messenger RNA; MicroRNAs; Modeling; Molecular; Molecular Analysis; Mus; Muscular Dystrophies; Mutate; Myocardial dysfunction; Myotonic Dystrophy; Myotonic dystrophy type 1; Neuraxis; Nuclear RNA; Pathogenesis; Pathogenicity; Pathway interactions; Patients; Phenocopy; Phenotype; Physiological; Protein Isoforms; Protein Kinase C; Publishing; RNA; RNA Degradation; RNA Polymerase II; RNA Processing; RNA Splicing; RNA Transcription Inhibition; RNA-Binding Proteins; Regulation; Signal Pathway; Signal Transduction; Skeletal Muscle; Sodium Channel; Subcellular structure; System; Testing; Tetracyclines; Therapeutic; Tissue Sample; Tissues; Toxic effect; Trans-Activators; Transgenes; Transgenic Mice; Up-Regulation; Validation; Ventricular Dysfunction; Withdrawal; base; efficacy testing; endonuclease; expectation; heart function; in vivo; inducible gene expression; loss of function; mortality; mouse model; mutant; novel; novel therapeutic intervention; protein activation; skeletal muscle wasting; small molecule; sudden cardiac death; therapeutic evaluation; transcriptome; transcriptome sequencing; vector; voltage; 3' Untranslated Regions; Adult; Affect; Alleles; Alternative Splicing; Arrhythmia; Binding; CUG repeat; Cardiac; Cardiac Myocytes; Cause of Death; Cell Culture Techniques; Cessation of life; Chimeric Proteins; DNA; Data Set; Disease; Down-Regulation; Doxycycline; Electrophysiology (science); Event; Exhibits; Exons; Fetal Proteins; Gastrointestinal tract structure; Gene Expression; Genes; Genetic; Genetic Transcription; Genomic Segment; Goals; Guide RNA; Heart; Human; Incidence; Individual; Interruption; Investigation; Knock-out; Life; Link; Mediating; Messenger RNA; MicroRNAs; Modeling; Molecular; Molecular Analysis; Mus; Muscular Dystrophies; Mutate; Myocardial dysfunction; Myotonic Dystrophy; Myotonic dystrophy type 1; Neuraxis; Nuclear RNA; Pathogenesis; Pathogenicity; Pathway interactions; Patients; Phenocopy; Phenotype; Physiological; Protein Isoforms; Protein Kinase C; Publishing; RNA; RNA Degradation; RNA Polymerase II; RNA Processing; RNA Splicing; RNA Transcription Inhibition; RNA-Binding Proteins; Regulation; Signal Pathway; Signal Transduction; Skeletal Muscle; Sodium Channel; Subcellular structure; System; Testing; Tetracyclines; Therapeutic; Tissue Sample; Tissues; Toxic effect; Trans-Activators; Transgenes; Transgenic Mice; Up-Regulation; Validation; Ventricular Dysfunction; Withdrawal; base; efficacy testing; endonuclease; expectation; heart function; in vivo; inducible gene expression; loss of function; mortality; mouse model; mutant; novel; novel therapeutic intervention; protein activation; skeletal muscle wasting; small molecule; sudden cardiac death; therapeutic evaluation; transcriptome; transcriptome sequencing; vector; voltage

Project Summary / Abstract Myotonic dystrophy (DM) is the most common cause of adult onset muscular dystrophy and the second most common cause of muscular dystrophy overall. At least 50% of individuals affected by DM type 1 (DM1) have cardiac involvement, primarily conduction abnormalities and life threatening arrhythmias. Cardiac involvement is the second leading cause of mortality in DM1 responsible for 25% of disease-related deaths. The pathogenic cause of DM1 is well established to be toxicity of the expanded CUG repeat- containing (CUGexp) RNA expressed from the expanded DMPK allele. The CUGexp RNA disrupts RNA processing, signaling pathways and microRNA regulation. However the specific molecular mechanisms by which expression of CUGexp RNA in heart tissue causes conduction abnormalities, arrhythmias and ventricular dysfunction are unknown. Therapeutic approaches applied to DM1 have focused on skeletal muscle and heart presents a separate set of issues with regard to both the details of disease mechanisms and therapeutic approaches. We developed a mouse model for tetracycline (tet)-inducible expression of CUGexp RNA specifically in cardiomyocytes. The tet-inducible transgene expresses 960 interrupted CUG repeats in the context of a human DMPK genomic segment containing exons 11-15. Expression of CUG960 RNA produces most of the cardiac conduction abnormalities and propensity for the arrhythmias that are likely to be responsible for cardiac sudden death in DM1. The mice also show robust splicing changes as observed in DM1 heart tissue. Importantly molecular and electrophysiological abnormalities are reversible upon shutting off expression of CUG960 RNA. In this project we will use the mouse model to identify and test hypotheses for the molecular basis for heart pathogenesis in DM1 and apply novel therapeutic approaches. The goal of the first aim is to use in vivo and ex vivo electrophysiological analyses in combination with detailed analyses of intracellular structure, transcriptome and signaling changes to identify the basis for the cardiac manifestations induced by CUG960 RNA. The key results will be tested in DM1 tissue samples for validation. The second aim is to use genetic rescue of the cardiac features to test hypothesized disease mechanisms, and with the expectation that multiple mechanisms contribute to pathogenesis, to determine the contributions of different mechanisms. The third aim is to apply approaches using deactivated Cas9 to target CUG960 RNA for transcriptional or post-transcriptional downregulation. Upon completion of this project we anticipate having an understanding of the molecular and physiological pathways linking CUGexp RNA to cardiac dysfunction and to have optimized a therapeutic approach to reverse DM1 cardiac features.

项目摘要 /摘要 肌营养不良症（DM）是成人发作肌肉营养不良的最常见原因，第二个 总体上肌营养不良的最常见原因。受DM 1型影响的个体中至少有50％ （DM1）具有心脏参与，主要是传导异常和威胁性心律失常。 心脏参与是导致25％与疾病有关的DM1死亡率的第二大原因 死亡人数。 DM1的致病原因已被良好确定为扩展的CUG重复的毒性 包含从扩展的DMPK等位基因表达的（CugeXP）RNA。 CugeXP RNA破坏RNA 处理，信号通路和microRNA调节。但是，特定的分子机制是 心脏组织中CugeXP RNA的表达导致传导异常，心律不齐和 心室功能障碍未知。适用于DM1的治疗方法专注于骨骼 关于疾病机制的两个细节，肌肉和心脏提出了一组单独的问题 和治疗方法。我们开发了一种用于四环素的小鼠模型（TET） CugeXP RNA专门在心肌细胞中。 TET诱导的转基因表达960个中断的CUG 在包含外显子11-15的人类DMPK基因组段的背景下重复。 CUG960的表达 RNA产生大多数心脏传导异常和心律不齐的倾向 DM1中可能导致心脏突然死亡。老鼠还显示出强大的剪接变化 在DM1心脏组织中观察到。重要的是分子和电生理异常是可逆的 关闭CUG960 RNA的表达后。在此项目中，我们将使用鼠标模型识别和测试 假设DM1中心脏发病机理的分子基础并采用新型治疗方法。 第一个目的的目的是在体内和体内电生理分析中结合使用 细胞内结构，转录组和信号传导变化的详细分析，以识别 CUG960 RNA诱导的心脏表现。关键结果将在DM1组织样品中测试 验证。第二个目的是利用心脏特征的遗传营救来检验假设的疾病 机制，并期望多种机制有助于发病机理，以确定 不同机制的贡献。第三个目的是使用停用的cas9应用方法 目标CUG960 RNA用于转录或转录后下调。完成该项目后 我们预计将了解将CugeXP RNA连接到的分子和生理途径 心脏功能障碍并优化了一种逆转DM1心脏特征的治疗方法。