Triplet-repeat oligonucleotide-mediated reversal of RNA toxicity in myotonic dystrophy

SAM Mulders, WJAA van den Broek… - Proceedings of the …, 2009 - National Acad Sciences
SAM Mulders, WJAA van den Broek, TM Wheeler, HJE Croes, P van Kuik-Romeijn…
Proceedings of the National Academy of Sciences, 2009National Acad Sciences
Myotonic dystrophy type 1 (DM1) is caused by toxicity of an expanded, noncoding (CUG) n
tract in DM protein kinase (DMPK) transcripts. According to current evidence the long (CUG)
n segment is involved in entrapment of muscleblind (Mbnl) proteins in ribonuclear
aggregates and stabilized expression of CUG binding protein 1 (CUGBP1), causing
aberrant premRNA splicing and associated pathogenesis in DM1 patients. Here, we report
on the use of antisense oligonucleotides (AONs) in a therapeutic strategy for reversal of …
Myotonic dystrophy type 1 (DM1) is caused by toxicity of an expanded, noncoding (CUG)n tract in DM protein kinase (DMPK) transcripts. According to current evidence the long (CUG)n segment is involved in entrapment of muscleblind (Mbnl) proteins in ribonuclear aggregates and stabilized expression of CUG binding protein 1 (CUGBP1), causing aberrant premRNA splicing and associated pathogenesis in DM1 patients. Here, we report on the use of antisense oligonucleotides (AONs) in a therapeutic strategy for reversal of RNA-gain-of-function toxicity. Using a previously undescribed mouse DM1 myoblast−myotube cell model and DM1 patient cells as screening tools, we have identified a fully 2′-O-methyl-phosphorothioate-modified (CAG)7 AON that silences mutant DMPK RNA expression and reduces the number of ribonuclear aggregates in a selective and (CUG)n-length-dependent manner. Direct administration of this AON in muscle of DM1 mouse models in vivo caused a significant reduction in the level of toxic (CUG)n RNA and a normalizing effect on aberrant premRNA splicing. Our data demonstrate proof of principle for therapeutic use of simple sequence AONs in DM1 and potentially other unstable microsatellite diseases.
National Acad Sciences