title: Evaluating the effects of CELF1 deficiency in a mouse model of RNA toxicity.
abstract: Myotonic dystrophy type 1 (DM1), the most common form of adult-onset muscular dystrophy, is caused by an expanded (CTG)n repeat in the 3' untranslated region of the DM protein kinase (DMPK) gene. The toxic RNA transcripts produced from the mutant allele alter the function of RNA-binding proteins leading to the functional depletion of muscleblind-like (MBNL) proteins and an increase in steady state levels of CUG-BP1 (CUGBP-ETR-3 like factor 1, CELF1). The role of increased CELF1 in DM1 pathogenesis is well studied using genetically engineered mouse models. Also, as a potential therapeutic strategy, the benefits of increasing MBNL1 expression have recently been reported. However, the effect of reduction of CELF1 is not yet clear. In this study, we generated CELF1 knockout mice, which also carry an inducible toxic RNA transgene to test the effects of CELF1 reduction in RNA toxicity. We found that the absence of CELF1 did not correct splicing defects. It did however mitigate the increase in translational targets of CELF1 (MEF2A and C/EBPβ). Notably, we found that loss of CELF1 prevented deterioration of muscle function by the toxic RNA, and resulted in better muscle histopathology. These data suggest that while reduction of CELF1 may be of limited benefit with respect to DM1-associated spliceopathy, it may be beneficial to the muscular dystrophy associated with RNA toxicity.
authors.affiliation: Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA.
authors.forename: Yun Kyoung
authors.initials: YK
authors.lastname: Kim
authors.forename: Mahua
authors.initials: M
authors.lastname: Mandal
authors.forename: Ramesh S
authors.initials: RS
authors.lastname: Yadava
authors.forename: Luc
authors.initials: L
authors.lastname: Paillard
authors.forename: Mani S
authors.initials: MS
authors.lastname: Mahadevan
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000235:genetics / Q000378:metabolism; D000067879:CELF1 Protein; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D064326:MEF2 Transcription Factors / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology*; D009223:Myotonic Dystrophy / Q000235:genetics* / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D019076:Transgenes
chemical_list: D022782:CCAAT-Enhancer-Binding Protein-beta; D000067879:CELF1 Protein; C502743:CELF1 protein, mouse; D064326:MEF2 Transcription Factors; C578036:Mef2a protein, mouse; D012333:RNA, Messenger; D016601:RNA-Binding Proteins