Precise small-molecule cleavage of an r(CUG) repeat expansion in a myotonic dystrophy mouse model
Precise small-molecule cleavage of an r(CUG) repeat expansion in a myotonic dystrophy mouse model
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DOI：
10.1073/pnas.1901484116
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发表时间：
2019-04-16
影响因子：
11.1
通讯作者：
Disney, Matthew D.
中科院分区：
文献类型：
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作者：
Angelbello, Alicia J.;Rzuczek, Suzanne G.;Disney, Matthew D.
强直性肌营养不良1型（DM1）是一种无法治愈的神经肌肉疾病，由转录成r（CUG）（exp）的CTG重复序列扩增引起。RNA重复扩增隔离调节蛋白，如肌盲样蛋白1（MBNL1），其导致前mRNA剪接缺陷。致病的r（CUG）（exp）已被反义寡核苷酸、基于CRISPR的方法和RNA靶向小分子靶向。在本文中，我们描述了一种设计师小分子，Cugamycin，它识别r（CUG）（exp）的结构，并在DM1患者衍生的肌管和DM1小鼠模型中切割它，留下r（CUG）的短重复序列不变。相比之下，识别r（CUG）序列而不是结构的寡核苷酸切割含有长和短r（CUG）的转录物。转录组学、组织学和表型研究表明，Cugamycin广泛且特异性地缓解体内DM1相关缺陷，而没有可检测到的脱靶。因此，结合和切割RNA的小分子具有作为先导化学探针和药物的实用性，并且可以选择性地靶向致病RNA结构，以广泛改善临床前动物模型中的缺陷。
Myotonic dystrophy type 1 (DM1) is an incurable neuromuscular disorder caused by an expanded CTG repeat that is transcribed into r(CUG)(exp). The RNA repeat expansion sequesters regulatory proteins such as Muscleblind-like protein 1 (MBNL1), which causes pre-mRNA splicing defects. The disease-causing r(CUG)(exp) has been targeted by antisense oligonucleotides, CRISPR-based approaches, and RNA-targeting small molecules. Herein, we describe a designer small molecule, Cugamycin, that recognizes the structure of r(CUG)(exp) and cleaves it in both DM1 patient-derived myotubes and a DM1 mouse model, leaving short repeats of r(CUG) untouched. In contrast, oligonucleotides that recognize r(CUG) sequence rather than structure cleave both long and short r(CUG)-containing transcripts. Transcriptomic, histological, and phenotypic studies demonstrate that Cugamycin broadly and specifically relieves DM1-associated defects in vivo without detectable off-targets. Thus, small molecules that bind and cleave RNA have utility as lead chemical probes and medicines and can selectively target disease-causing RNA structures to broadly improve defects in preclinical animal models.