Search results for "MBNL1"
showing 9 items of 19 documents
Design of novel small molecule base-pair recognizers of toxic CUG RNA transcripts characteristics of DM1.
2020
Graphical abstract
Alternative splicing regulation by Muscleblind proteins: from development to disease.
2011
Regulated use of exons in pre-mRNAs, a process known as alternative splicing, strongly contributes to proteome diversity. Alternative splicing is finely regulated by factors that bind specific sequences within the precursor mRNAs. Members of the Muscleblind (Mbl) family of splicing factors control critical exon use changes during the development of specific tissues, particularly heart and skeletal muscle. Muscleblind homologs are only found in metazoans from Nematoda to mammals. Splicing targets and recognition mechanisms are also conserved through evolution. In this recognition, Muscleblind CCCH-type zinc finger domains bind to intronic motifs in pre-mRNA targets in which the protein can e…
Preclinical characterization of antagomiR-218 as a potential treatment for myotonic dystrophy
2021
Myotonic dystrophy type 1 (DM1) is a rare neuromuscular disease caused by expansion of unstable CTG repeats in a non-coding region of the DMPK gene. CUG expansions in mutant DMPK transcripts sequester MBNL1 proteins in ribonuclear foci. Depletion of this protein is a primary contributor to disease symptoms such as muscle weakness and atrophy and myotonia, yet upregulation of endogenous MBNL1 levels may compensate for this sequestration. Having previously demonstrated that antisense oligonucleotides against miR-218 boost MBNL1 expression and rescue phenotypes in disease models, here we provide preclinical characterization of an antagomiR-218 molecule using the HSALR mouse model and patient-d…
Musashi-2 contributes to myotonic dystrophy muscle dysfunction by promoting excessive autophagy through miR-7 biogenesis repression
2021
Skeletal muscle symptoms strongly contribute to mortality of myotonic dystrophy type 1 (DM1) patients. DM1 is a neuromuscular genetic disease caused by CTG repeat expansions that, upon transcription, sequester the Muscleblind-like family of proteins and dysregulate alternative splicing of hundreds of genes. However, mis-splicing does not satisfactorily explain muscle atrophy and wasting, and several other contributing factors have been suggested, including hyperactivated autophagy leading to excessive catabolism. MicroRNA ( miR ) -7 has been demonstrated to be necessary and sufficient to repress the autophagy pathway in cell models of the disease, but the origin of its low levels in DM1 was…
Genetic and Chemical Modifiers Of A CUG Toxicity Model in Drosophila
2007
Non-coding CUG repeat expansions interfere with the activity of human Muscleblind-like (MBNL) proteins contributing to myotonic dystrophy 1 (DM1). To understand this toxic RNA gain-of-function mechanism we developed a Drosophila model expressing 60 pure and 480 interrupted CUG repeats in the context of a non-translatable RNA. These flies reproduced aspects of the DM1 pathology, most notably nuclear accumulation of CUG transcripts, muscle degeneration, splicing misregulation, and diminished Muscleblind function in vivo. Reduced Muscleblind activity was evident from the sensitivity of CUG-induced phenotypes to a decrease in muscleblind genetic dosage and rescue by MBNL1 expression, and furthe…
In vivo discovery of a peptide that prevents CUG-RNA hairpin formation and reverses RNA toxicity in myotonic dystrophy models
2011
6 pages, 5 figures. PMID:21730182[PubMed] PMCID: PMC3141925[Available on 2012/1/19]
miR-7 Restores Phenotypes in Myotonic Dystrophy Muscle Cells by Repressing Hyperactivated Autophagy
2019
International audience; Unstable CTG expansions in the 3' UTR of the DMPK gene are responsible for myotonic dystrophy type 1 (DM1) condition. Muscle dysfunction is one of the main contributors to DM1 mortality and morbidity. Pathways by which mutant DMPK trigger muscle defects, however, are not fully understood. We previously reported that miR-7 was downregulated in a DM1 Drosophila model and in biopsies from patients. Here, using DM1 and normal muscle cells, we investigated whether miR-7 contributes to the muscle phenotype by studying the consequences of replenishing or blocking miR-7, respectively. Restoration of miR-7 with agomiR-7 was sufficient to rescue DM1 myoblast fusion defects and…
Muscleblind, BSF and TBPH are mislocalized in the muscle sarcomere of a Drosophila myotonic dystrophy model
2012
SummaryMyotonic dystrophy type 1 (DM1) is a genetic disease caused by the pathological expansion of a CTG trinucleotide repeat in the 3' UTR of the DMPK gene. In the DMPK transcripts, the CUG expansions sequester RNA-binding proteins into nuclear foci, including transcription factors and alternative splicing regulators such as MBNL1. MBNL1 sequestration has been associated with key features of DM1. However, the basis behind a number of molecular and histological alterations in DM1 remain unclear. To help identify new pathogenic components of the disease, we carried out a genetic screen using a Drosophila model of DM1 that expresses 480 interrupted CTG repeats, i(CTG)480, and a collection of…
Molecular Effects of the CTG Repeats in Mutant Dystrophia Myotonica Protein Kinase Gene
2008
Myotonic Dystrophy type 1 (DM1) is a multi-system disorder characterized by muscle wasting, myotonia, cardiac conduction defects, cataracts, and neuropsychological dysfunction. DM1 is caused by expansion of a CTG repeat in the 3 untranslated region (UTR) of the Dystrophia Myotonica Protein Kinase (DMPK) gene. A body of work demonstrates that DMPK mRNAs containing abnormally expanded CUG repeats are toxic to several cell types. A core mechanism underlying symptoms of DM1 is that mutant DMPK RNA interferes with the developmentally regulated alternative splicing of defined pre-mRNAs. Expanded CUG repeats fold into ds(CUG) hairpins that sequester nuclear proteins including human Muscleblind-lik…