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

• Published in: Proceedings of the National Academy of Sciences - PNAS 2009-08, Vol.106 (33), p.13915-13920
• Main Authors: Mulders, Susan A.M, van den Broek, Walther J.A.A, Wheeler, Thurman M, Croes, Huib J.E, van Kuik-Romeijn, Petra, de Kimpe, Sjef J, Furling, Denis, Platenburg, Gerard J, Gourdon, Geneviève, Thornton, Charles A, Wieringa, Bé, Wansink, Derick G
• Format: Article
• Language: English
• Subjects: Alleles; Animals; Biological Sciences; CELF1 Protein; Cell nucleus; Cells; Gene expression; Gene Silencing; Kinases; Life Sciences; Messenger RNA; Mice; Models, Genetic; Muscle fibers; Muscle, Skeletal - metabolism; Muscles; Musculoskeletal diseases; Mutation; Myoblasts; Myoblasts - metabolism; Myotonic dystrophy; Myotonic Dystrophy - genetics; Myotonic Dystrophy - therapy; Oligonucleotides - chemistry; Oligonucleotides - genetics; Oligonucleotides, Antisense - genetics; Reverse transcriptase polymerase chain reaction; Ribonucleic acid; RNA; RNA - genetics; RNA Interference; RNA Splicing; RNA-Binding Proteins - genetics; Rodents; Splicing; Toxicity
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0905780106

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.