Pentatricopeptide repeat protein targeting CUG repeat RNA ameliorates RNA toxicity in a myotonic dystrophy type 1 mouse model

作者：Takayoshi Imai, Maiko Miyai, Joe Nemoto, Takayuki Tamai, Masaru Ohta, Yusuke Yagi, Osamu Nakanishi, Hideki Mochizuki, Masayuki Nakamori · 发表于：Science Translational Medicine · 年份：2025 · DOI：10.1126/scitranslmed.adq2005 · 被引用次数：9 · 研究领域：Genetic Neurodegenerative Diseases、RNA Research and Splicing、CRISPR and Genetic Engineering

Myotonic dystrophy type 1 (DM1) is an autosomal dominant multisystemic disorder caused by the expansion of a CTG-triplet repeat in the 3′ untranslated region of the dystrophia myotonica protein kinase ( DMPK ) gene. It results in the transcription of toxic RNAs that contain expanded CUG repeats (CUG exp ). Splicing factors, such as muscleblind-like 1 (MBNL1), are sequestered by CUG exp , thereby disrupting the normal splicing program that is essential for various cellular functions. Pentatricopeptide repeat (PPR) proteins, originally found in plants, regulate RNA in organelles by binding in a sequence-specific manner. Here, we designed PPR proteins that specifically bind to the hexamer of CUG repeat RNAs (CUG-PPRs) and showed that CUG-PPR1 could ameliorate RNA toxicity induced by CUG exp in cell models of DM1. A single systemic recombinant adeno-associated virus (AAV9) vector–mediated gene delivery of CUG-PPR1 demonstrated long-term therapeutic effects on myotonia and restored splicing activity in a mouse model of DM1. These results highlight the potential of PPR molecules to target pathogenic RNA sequences in DM1 and potentially other RNA-mediated disorders.