title: Abnormal splicing of NEDD4 in myotonic dystrophy type 2: possible link to statin adverse reactions.
abstract: Myotonic dystrophy type 2 (DM2) is a multisystemic disorder caused by a (CCTG)n repeat expansion in intron 1 of CNBP. Transcription of the repeats causes a toxic RNA gain of function involving their accumulation in ribonuclear foci. This leads to sequestration of splicing factors and alters pre-mRNA splicing in a range of downstream effector genes, which is thought to contribute to the diverse DM2 clinical features. Hyperlipidemia is frequent in DM2 patients, but the treatment is problematic because of an increased risk of statin-induced adverse reactions. Hypothesizing that shared pathways lead to the increased risk, we compared the skeletal muscle expression profiles of DM2 patients and controls with patients with hyperlipidemia on statin therapy. Neural precursor cell expressed, developmentally downregulated-4 (NEDD4), an ubiquitin ligase, was one of the dysregulated genes identified in DM2 patients and patients with statin-treated hyperlipidemia. In DM2 muscle, NEDD4 mRNA was abnormally spliced, leading to aberrant NEDD4 proteins. NEDD4 was down-regulated in persons taking statins, and simvastatin treatment of C2C12 cells suppressed NEDD4 transcription. Phosphatase and tensin homologue (PTEN), an established NEDD4 target, was increased and accumulated in highly atrophic DM2 muscle fibers. PTEN ubiquitination was reduced in DM2 myofibers, suggesting that the NEDD4-PTEN pathway is dysregulated in DM2 skeletal muscle. Thus, this pathway may contribute to the increased risk of statin-adverse reactions in patients with DM2.
authors.affiliation: Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland.
authors.forename: Mark
authors.initials: M
authors.lastname: Screen
authors.affiliation: Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland.
authors.forename: Per Harald
authors.initials: PH
authors.lastname: Jonson
authors.affiliation: Neuromuscular Research Centre, Department of Neurology, University Hospital and University of Tampere, Tampere, Finland.
authors.forename: Olayinka
authors.initials: O
authors.lastname: Raheem
authors.affiliation: Neuromuscular Research Centre, Department of Neurology, University Hospital and University of Tampere, Tampere, Finland.
authors.forename: Johanna
authors.initials: J
authors.lastname: Palmio
authors.affiliation: Department of Clinical Chemistry, Fimlab Laboratories, and School of Medicine, University of Tampere, Tampere, Finland.
authors.forename: Reijo
authors.initials: R
authors.lastname: Laaksonen
authors.affiliation: Department of Clinical Chemistry, Fimlab Laboratories, and School of Medicine, University of Tampere, Tampere, Finland.
authors.forename: Terho
authors.initials: T
authors.lastname: Lehtimäki
authors.affiliation: Department of Genetics, the University of Texas MD Anderson Cancer Center, Houston, Texas.
authors.forename: Mario
authors.initials: M
authors.lastname: Sirito
authors.affiliation: Department of Genetics, the University of Texas MD Anderson Cancer Center, Houston, Texas; Human & Molecular Genetics, Graduate School of Biomedical Sciences, University of Texas at Houston, Houston, Texas; Genes & Development Programs, Graduate School of Biomedical Sciences, University of Texas at Houston, Houston, Texas.
authors.forename: Ralf
authors.initials: R
authors.lastname: Krahe
authors.affiliation: Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland.
authors.forename: Peter
authors.initials: P
authors.lastname: Hackman
authors.affiliation: Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland; Neuromuscular Research Centre, Department of Neurology, University Hospital and University of Tampere, Tampere, Finland; Department of Neurology, Vaasa Central Hospital, Vaasa, Finland. Electronic address: bjarne.udd@netikka.fi.
authors.forename: Bjarne
authors.initials: B
authors.lastname: Udd
mesh_terms: D000328:Adult; D015153:Blotting, Western; D056827:Endosomal Sorting Complexes Required for Transport / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005455:Fluorescent Antibody Technique; D005838:Genotype; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000009:adverse effects*; D006949:Hyperlipidemias / Q000188:drug therapy / Q000209:etiology; D007150:Immunohistochemistry; D027381:Liver-Specific Organic Anion Transporter 1; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism*; D009223:Myotonic Dystrophy / Q000150:complications / Q000235:genetics / Q000378:metabolism*; D000075702:Nedd4 Ubiquitin Protein Ligases; D020411:Oligonucleotide Array Sequence Analysis; D027361:Organic Anion Transporters / Q000235:genetics; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D012326:RNA Splicing; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D059467:Transcriptome; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*
chemical_list: D056827:Endosomal Sorting Complexes Required for Transport; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D027381:Liver-Specific Organic Anion Transporter 1; D027361:Organic Anion Transporters; C503999:SLCO1B1 protein, human; D000075702:Nedd4 Ubiquitin Protein Ligases; C000618483:Nedd4 protein, human; D044767:Ubiquitin-Protein Ligases; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human