Project description:Myotonic Dystrophy type 1 (DM1) is a neuromuscular disease associated with toxic RNA containing expanded CUG repeats. Treating mice with the GSK3 inhibitor tideglusib corrected expression of 17% of DM1-related genes. correction of the GSK3β-CUGBP1 pathway in mice expressing long CUG repeats (DMSXL model) is important not only at prenatal and postnatal stage, but also beneficial in adult mice.
Project description:Misregulated alternative splicing appears to be a major factor in the pathogenesis of myotonic dystrophy. The present study was done to further explore alternative splicing in this condition by doing exon-level analysis of mRNA from skeletal muscle of 8 subjects with type 1 myotonic dystrophy, 7 subjects with type 2 myotonic dystrophy, 8 disease controls (subjects with facioscapulohumeral muscular dystrophy), and 8 healthy controls . The ratios of signals from the various exons of a gene provided an index of altered exon inclusion/exclusion that was independent of the overall expression of that gene. There were numerous transcripts for which there was evidence of abnormal alternative splicing in subjects with myotonic dystrophy. For many of these transcripts, the abnormal splicing was confirmed by an independent RT-PCR approach. 31 subjects, one sample per subject, four groups: healthy subjects (n = 8), facioscapulohumeral dystrophy (n = 8), type 1 myotonic dystrophy (n = 8), type 2 myotonic dystrophy (n = 7)
Project description:Autopsy and biopsy muscle and heart tissue was collected from consented human subjects with and without confirmed myotonic dystrophy type 1, myotonic dystrophy type 2, or Duchenne muscular dystrophy. RNA was isolated for preparation of RNAseq libraries and sequenced on the Illumina platform.
Project description:This study examined the effects of antisense oligonucleotides (ASOs) on the muscle transcriptome in a transgenic mouse model of myotonic dystrophy. Two ASOs were tested in HSALR transgenic mice. Both of the ASOs targeted mRNA from a human skeletal actin (hACTA1) transgene. This transgene contains an expanded CTG repeat in the 3M-bM-^@M-^Y untranslated region (UTR) (Mankodi et al M-bM-^@M-^\Myotonic dystrophy in transgenic mice expressing an expanded CUG repeatM-bM-^@M-^] Science 2000; 289:1769-72). ASO 445235 targeted the hACTA1 transcript in the 3M-bM-^@M-^Y UTR, downstream from the expanded repeat. ASO 190401 targeted the hACTA1 transcript in the coding region. The HSALR mice received 4 weeks of biweekly subcutaneous injections of vehicle (saline), ASO 190401, or ASO 445236 (n = 4 per group), at a dose of 25 mg/kg per injection. Wild-type mice of the same strain background received saline injections (n = 4). One week after the final injection, quadriceps muscle was harvested for RNA analysis. Four conditions, four arrays per condition, to compare WT and HSALR trangenic mice without treatment (saline) and to examine the effect of two oligos (vs. saline) in the HSALR transgenic mice.
Project description:In this Study, we used RNA-targeting Cas9 (RCas9) to reverse characteristic Myotonic Dystrophy (DM1) cellular phenotypes such as elimination of RNA foci, MBNL relocalization, and reversal of transcriptome-wide splicing in a mouse model of myotonic Dystrophy (DM1). Furthermore we show that gene expression is not altered with RCas9 treatment in WT mice with or without treatment with immunosuppression
Project description:Misregulated alternative splicing appears to be a major factor in the pathogenesis of myotonic dystrophy. The present study was done to further explore alternative splicing in this condition by doing exon-level analysis of mRNA from skeletal muscle of 8 subjects with type 1 myotonic dystrophy, 7 subjects with type 2 myotonic dystrophy, 8 disease controls (subjects with facioscapulohumeral muscular dystrophy), and 8 healthy controls . The ratios of signals from the various exons of a gene provided an index of altered exon inclusion/exclusion that was independent of the overall expression of that gene. There were numerous transcripts for which there was evidence of abnormal alternative splicing in subjects with myotonic dystrophy. For many of these transcripts, the abnormal splicing was confirmed by an independent RT-PCR approach.
Project description:This study examined the effects of antisense oligonucleotides (ASOs) on the muscle transcriptome in a transgenic mouse model of myotonic dystrophy. Two ASOs were tested in HSALR transgenic mice. Both of the ASOs targeted mRNA from a human skeletal actin (hACTA1) transgene. This transgene contains an expanded CTG repeat in the 3’ untranslated region (UTR) (Mankodi et al “Myotonic dystrophy in transgenic mice expressing an expanded CUG repeat” Science 2000; 289:1769-72). ASO 445235 targeted the hACTA1 transcript in the 3’ UTR, downstream from the expanded repeat. ASO 190401 targeted the hACTA1 transcript in the coding region. The HSALR mice received 4 weeks of biweekly subcutaneous injections of vehicle (saline), ASO 190401, or ASO 445236 (n = 4 per group), at a dose of 25 mg/kg per injection. Wild-type mice of the same strain background received saline injections (n = 4). One week after the final injection, quadriceps muscle was harvested for RNA analysis.
Project description:Myotonic dystrophy type 1 is a dominantly inherited multisystemic disease caused by CTG tandem repeat expansions in the DMPK 3' untranslated region. These expanded repeats are transcribed and produce toxic CUG RNAs that sequester and inhibit activities of the MBNL family of developmental RNA processing factors. Although myotonic dystrophy is classified as a muscular dystrophy, the brain is also severely affected by an unusual cohort of symptoms, including hypersomnia, executive dysfunction, as well as early onsets of tau/MAPT pathology and cerebral atrophy. To address the molecular and cellular events that lead to these pathological outcomes, we recently generated a mouse Dmpk CTG expansion knockin model and identified choroid plexus epithelial cells as particularly affected by the expression of toxic CUG expansion RNAs. To determine if toxic CUG RNAs perturb choroid plexus functions, alternative splicing analysis was performed on lateral and hindbrain choroid plexi from Dmpk CTG knockin mice. Choroid plexus transcriptome-wide changes were evaluated in Mbnl2 knockout mice, a developmental-onset model of myotonic dystrophy brain dysfunction. To determine if transcriptome changes also occurred in the human disease, we obtained post-mortem choroid plexus for RNA-seq from donors without neurologically unaffected (two females, three males; ages 50-70) and myotonic dystrophy type 1 donors (one female, three males; ages 50-70). To test that choroid plexus transcriptome alterations resulted in altered CSF composition, we obtained CSF via lumbar puncture from patients with myotonic dystrophy type 1 (five females, five males; ages 35-55) and non-myotonic dystrophy patients (three females, four males; ages 26-51) and Western blot and osmolarity analyses were used to test CSF alterations predicted by choroid plexus transcriptome analysis. We determined that CUG RNA induced toxicity was more robust in the lateral choroid plexus of Dmpk CTG knockin mice due to comparatively higher Dmpk and lower Mbnl RNA levels. Impaired transitions to adult splicing patterns during choroid plexus development were identified in Mbnl2 knockout mice, including mis-splicing previously found in Dmpk CTG knockin mice. Whole transcriptome analysis of myotonic dystrophy type 1 choroid plexus revealed disease-associated RNA expression and mis-splicing events. Based on these RNA changes, predicted alterations in ion homeostasis, secretory output, and CSF composition were confirmed by analysis of myotonic dystrophy type 1 CSF. Our results implicate choroid plexus spliceopathy and concomitant alterations in CSF homeostasis as an unappreciated contributor to myotonic dystrophy type 1 CNS pathogenesis.
Project description:Myotonic dystrophy type 1 is a dominantly inherited multisystemic disease caused by CTG tandem repeat expansions in the DMPK 3' untranslated region. These expanded repeats are transcribed and produce toxic CUG RNAs that sequester and inhibit activities of the MBNL family of developmental RNA processing factors. Although myotonic dystrophy is classified as a muscular dystrophy, the brain is also severely affected by an unusual cohort of symptoms, including hypersomnia, executive dysfunction, as well as early onsets of tau/MAPT pathology and cerebral atrophy. To address the molecular and cellular events that lead to these pathological outcomes, we recently generated a mouse Dmpk CTG expansion knockin model and identified choroid plexus epithelial cells as particularly affected by the expression of toxic CUG expansion RNAs. To determine if toxic CUG RNAs perturb choroid plexus functions, alternative splicing analysis was performed on lateral and hindbrain choroid plexi from Dmpk CTG knockin mice. Choroid plexus transcriptome-wide changes were evaluated in Mbnl2 knockout mice, a developmental-onset model of myotonic dystrophy brain dysfunction. To determine if transcriptome changes also occurred in the human disease, we obtained post-mortem choroid plexus for RNA-seq from donors without neurologically unaffected (two females, three males; ages 50-70) and myotonic dystrophy type 1 donors (one female, three males; ages 50-70). To test that choroid plexus transcriptome alterations resulted in altered CSF composition, we obtained CSF via lumbar puncture from patients with myotonic dystrophy type 1 (five females, five males; ages 35-55) and non-myotonic dystrophy patients (three females, four males; ages 26-51) and Western blot and osmolarity analyses were used to test CSF alterations predicted by choroid plexus transcriptome analysis. We determined that CUG RNA induced toxicity was more robust in the lateral choroid plexus of Dmpk CTG knockin mice due to comparatively higher Dmpk and lower Mbnl RNA levels. Impaired transitions to adult splicing patterns during choroid plexus development were identified in Mbnl2 knockout mice, including mis-splicing previously found in Dmpk CTG knockin mice. Whole transcriptome analysis of myotonic dystrophy type 1 choroid plexus revealed disease-associated RNA expression and mis-splicing events. Based on these RNA changes, predicted alterations in ion homeostasis, secretory output, and CSF composition were confirmed by analysis of myotonic dystrophy type 1 CSF. Our results implicate choroid plexus spliceopathy and concomitant alterations in CSF homeostasis as an unappreciated contributor to myotonic dystrophy type 1 CNS pathogenesis.