Expanded CTG repeats within the DMPK 3' UTR causes severe skeletal muscle wasting in an inducible mouse model for myotonic dystrophy.
Fiche publication
Date publication
février 2008
Auteurs
Membres identifiés du Cancéropôle Est :
Pr CHAMBON Pierre, Dr METZGER Daniel
Tous les auteurs :
Orengo JP, Chambon P, Metzger D, Mosier DR, Snipes GJ, Cooper TA
Lien Pubmed
Résumé
Severe skeletal muscle wasting is the most debilitating symptom experienced by individuals with myotonic dystrophy type 1 (DM1). We present a DM1 mouse model with inducible and skeletal muscle-specific expression of large tracts of CTG repeats in the context of DMPK exon 15. These mice recapitulate many findings associated with DM1 skeletal muscle, such as CUG RNA foci with Muscleblind-like 1 (MBNL1) protein colocalization, misregulation of developmentally regulated alternative splicing events, myotonia, characteristic histological abnormalities, and increased CUGBP1 protein levels. Importantly, this DM1 mouse model recapitulates severe muscle wasting, which has not been reported in models in which depletion of MBNL1 is the main feature. Using these mice, we discovered previously undescribed alternative splicing events that are responsive to CUGBP1 and not MBNL, and these events were found to be misregulated in individuals with DM1. Our results indicate that increased CUGBP1 protein levels are associated with DMPK-CUG RNA expression, suggesting a role for CUGBP1-specific splicing or cytoplasmic functions in muscle wasting.
Référence
Proc Natl Acad Sci U S A. 2008 Feb 19;105(7):2646-51