Proof of concept of blockmiR induced MBNL rescue in Myotonic dystrophy muscle cells

The symptoms of Myotonic Dystrophy Type 1 (DM1) are multi-systemic and life-threatening. The neuromuscular disorder is rooted in a non-coding CTG microsatellite expansion in the DMPK gene that is correctly transcribed and physically sequesters the MBNL family of proteins. The high-affinity binding occurring between the proteins and the repetitions disallows MBNL proteins from performing their post-transcriptional splicing regulation leading to downstream molecular effects directly related to disease symptoms such as myotonia and muscle weakness. In this study, we build off of previously demonstrated evidence showing that the silencing of miR-23b and miR-218 can increase MBNL1 and 2 protein in DM1 cells. Here we use blockmiR antisense technology to block the binding sites of these miRNAs in order to increase MBNL translation into protein without binding to the microRNAs in DM1 muscle cells. The blockmiRs show therapeutic effects with the rescue of mis-splicing, MBNL subcellular localization, and transcriptomic expression proving that this novel and highly specific strategy could be a potentially viable therapy in Vivo. Overall design: We have 3 replicas of: Control, DM1, DM1 + antagomiR23b, DM1 + BlockmiR.