Preclinical models and therapies for myotonic dystrophy type 2

2 型强直性肌营养不良的临床前模型和治疗

基本信息

批准号：
10237269
负责人：
CHARLES A THORNTON
金额：
$ 23.08万
依托单位：
UNIVERSITY OF ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-09-30 至 2023-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10237269
关键词：
3&apos Untranslated Regions ACTA1 gene Actins Address Adult Aging Animal Model Antisense Oligonucleotides Biology Brain C9ORF72 CUG repeat Cell Nucleus Characteristics Clinical Clinical Trials Consensus Sequence Cornea Data Development Disease Electroporation Exons Family Frontotemporal Dementia Fuchs&apos Endothelial Dystrophy Genes Genetic Genetic Transcription Human Infant Inflammation Injury Introns Location Methods Modeling Mus Muscle Muscular Dystrophies Mutation Myopathy Myotonia Myotonic dystrophy type 1 Myotonic dystrophy type 2 Nerve Degeneration Neuraxis Nuclear Pathogenicity Pathology Patients Pattern Peptides Pharmaceutical Preparations Phenotype Poly A Population Pre-Clinical Model Process Production Property Proteins RNA RNA-Binding Proteins Research Site Skeletal Muscle TCF7L2 gene Testing Therapeutic Therapeutic Effect Therapeutic Studies Toxic effect Transgenes Transgenic Mice Translation Initiation Translational Research Translations Untranslated RNA congenital myopathy design effective therapy familial amyotrophic lateral sclerosis follow-up in vivo knock-down metabolic abnormality assessment mouse model muscle stress nucleic acid binding protein pre-clinical therapy process repeatability skeletal small molecule small molecule therapeutics targeted therapy trials targeted treatment therapeutic development transcriptome transcriptomics

项目摘要

Myotonic dystrophy type 2 (DM2) is an autosomal dominant form of muscular dystrophy, resulting from expansion of a CCTG repeat in CNBP, the gene encoding Cellular Nucleic Acid Binding Protein. The discovery of the DM2 mutation provided critical support for the concept that expanded repeats in non-coding regions give rise to dominant acting RNAs. A unifying model for RNA toxicity in myotonic dystrophy type 1 (DM1), DM2, and potentially other repeat expansion diseases is that RNA binding proteins are sequestered by expanded RNA repeats, giving rise to pervasive changes in the transcriptome when the functions of RNA binding proteins are lost. However, 3 of the 4 commonest RNA dominant diseases result from repeat expansions in introns. Once transcribed, introns are rapidly excised and degraded, therefore the concept that intronic repeats act as a sink for RNA binding proteins seems implausible. More surprisingly, recent studies also indicate that intronic expanded repeats in patients with DM2 or familial ALS undergo translation in the central nervous system, through a process of Repeat Associated Non-AUG (RAN) translation, resulting in production of deleterious tetra- or di-peptide repeat proteins. Whether this occurs in skeletal muscle has not been determined. Therapeutic development for DM1 has advanced rapidly, but has hardly begun for DM2, partly due to the lack of animal models. DM1 and DM2 many share many clinical features, but also have important differences. For example, DM1 often effects skeletal muscle in infants, leading to congenital myopathy, but this does not occur in DM2. In Aim 1 of this proposal we have developed transgenic mouse models of DM2, that express expanded CCUG repeat (CCUGexp) RNA in an intron or in the 3′ untranslated region. To better understand differences between DM1 and DM2, we will use these models, and previous models for DM1, to compare toxicities and transcriptomic effects of expanded RNA repeats in introns versus exons, and the relative toxicities of CCUG versus CUG repeats. We will also study the metabolism of intronic RNA repeats. In particular, we will follow up on preliminary data suggesting that processing of an intron containing expanded CCUG repeats is altered, leading to intron retention. In Aim 2 we will determine the conditions under which RAN translation of intronic CCUGexp RNA occurs in skeletal muscle in vivo. Using transgenic mice, and an electroporation model for transient expression of CCUGexp RNA, we will quantify RAN translation, and test the hypothesis that RAN translation is promoted or pre-conditioned by muscle stress. Finally in Aim 3 we will study therapeutic effects in the new mouse models, using antisense oligonucleotide and small molecule drugs. Overall, this project will clarify mechanisms important to DMpathogenesis and initiate the process of therapeutic development for DM2.

肌发育症2型（DM2）是肌肉营养不良的一种常染色体显性形式，由 CNBP中CCTG重复的扩展，CNBP是编码细胞核酸结合蛋白的基因。发现 DM2突变的关键支持为扩大非编码区域的重复序列的概念提供了重要支持引起主导性RNA。肌发育症1型（DM1）中RNA毒性的统一模型， DM2以及可能其他重复膨胀疾病是RNA结合蛋白被隔离 RNA的扩展RNA重复序列，当RNA功能时会导致转录组的普遍变化结合蛋白会丢失。但是，重复的四种最常见的RNA主要疾病中有3种引起内含子的扩展。转录后，内含子将迅速超过和退化，因此内含子重复作为RNA结合蛋白的下水道似乎难以置信。更令人惊讶的，最近的研究还表明，内含子的DM2患者或家族ALS患者的内含子扩展重复序列在中枢神经系统，通过重复相关的非aug（ran）翻译的过程，导致产生有害的四肽重复蛋白。这是否发生在骨骼肌中被确定。 DM1的治疗开发已经迅速发展，但几乎没有开始DM2，部分是由于缺乏动物模型。 DM1和DM2许多具有许多临床特征，但也有重要差异。例如，DM1通常会影响婴儿的骨骼肌，导致先天性肌病，但这在DM2中没有发生。在此提案的目标1中，我们开发了转基因鼠标 DM2的模型，即在内含子或3'未翻译中扩展CCUG重复（CCUGEXP）RNA 地区。为了更好地理解DM1和DM2之间的差异，我们将使用这些模型，并以前 DM1的模型，比较内含子中扩展的RNA重复序列的战术和转录组效应外显子，以及CCUG与CUG重复的相对毒性。我们还将研究内含子的代谢 RNA重复。特别是，我们将跟进初步数据，表明加工内含子包含扩展的CCUG重复序列会改变，从而导致内含子保留。在AIM 2中，我们将确定在体内骨骼肌中，内含子ccugexp RNA转换的条件。使用转基因小鼠和用于CCUGEXP RNA瞬时表达的电穿孔模型，我们将定量运行翻译，并检验肌肉促进或预先提倡翻译的假设压力。最后，在AIM 3中，我们将使用反义研究新小鼠模型中的治疗效果寡核苷酸和小分子药物。总体而言，该项目将阐明对机制至关重要的机制 DMPatheresogeny并启动DM2理论发展的过程。