Myotonic dystrophy type 1 (DM1) leads to altered mRNA expression in heart tissue

Myotonic dystrophy type 1 (DM1) is a dominantly inherited disease that affects multiple organ systems. Cardiac dysfunction is the second leading cause of death in DM1. We quantified gene expression in heart tissue from a heart-specific DM1 mouse model (EpA960/MCM) which inducibly expresses human DMPK exon 15 containing 960 CUG expanded repeats and that reproduced Celf1 up regulation. To assess if, in addition to splicing and miRNA defects, CUGexp RNA also perturbed the steady state mRNA levels of genes, we carried out a microarray study on wildtype E14, adult, MCM controls and DM1 mouse hearts. As anticipated we noted a large number of genes to be developmentally regulated in wildtype hearts, however, within 72h of induction of CUGexp RNA there appeared to be a coordinate adult-to-embryonic shift in steady state levels of many genes. We identified transcripts over-expressed or under-expressed in hearts of wildtype adult mice, wildtype embryonic day 14 (E14), and DM1 mice induced to express CUGexp RNA for 72h and 1wk, when compared to MCM controls. Multiple group comparison.