Loss of MBNL1 induces RNA mis-processing in the thymus and peripheral blood.
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus Homo sapiens
PROVIDER: GSE138691 | GEO | 2020/03/05
REPOSITORIES: GEO
Similar Datasets
Project description:Myotonic dystrophy (dystrophia myotonica, DM) is caused by expansions of CTG (type 1; DM1) or CCTG (type 2; DM2) repeats in the non-coding regions of the DMPK and CNBP genes, and patients with DM1 or DM2 often suffer from sudden cardiac death due to lethal arrhythmia. Specific molecular changes that underlie DM cardiac pathology have been linked to repeat-associated depletion of Muscleblind-like (MBNL) 1 and 2 proteins and upregulation of CUGBP Elav-like family member 1. Aims: We aim to create an Mbnl KO mouse model recapitulating DM cardiogenic death not under anesthesia, since none of the DM mouse models have reached this goal. Besides, it is unclear whether dysfunction of cardiomyocytes, among other cell types in the heart, can solely drive phenotypes. Methods and Results: We generated Myh6-Cre DKO (Mbnl1-/-; Mbnl2cond/cond; Myh6-Cre+/-) mice that completely eliminate Mbnl1/2 expression in cardiomyocytes. In this model, we found increased myocardial fibrosis, dilated cardiomyopathy and various arrhythmias. Importantly, we observed spontaneous lethal arrhythmic events in the context of shortened lifespan. RNA sequencing (RNA-seq) revealed mis-splicing events involving sarcomeric structure, mitochondrial dynamics and vesicular trafficking that mimics DM hearts. Gene expression changes were also noted by RNA-seq, and confirmed by qPCR. Notably, immunoblotting revealed a nearly 6-fold increase of Calsequestrin 1 and 50% reduction of epidermal growth factor proteins. Conclusion: These results showed that complete elimination of MBNL1/2 in mouse cardiomyocytes is sufficient to elicit a full spectrum of DM cardiac phenotypes including cardiac-related sudden death, and therefore these mice could serve as a useful model for studying DM heart pathogenesis and related translational research.
2022-01-01 | GSE184574 | GEO
Project description:For some neurological disorders, disease is primarily RNA-mediated due to expression of non-coding microsatellite expansion RNAs (RNAexp). Toxicity is thought to result from enhanced binding of proteins to these expansions and depletion from their normal cellular targets. However, experimental evidence for this sequestration model is lacking. Here, we use HITS-CLIP and pre-mRNA processing analysis of human control versus myotonic dystrophy (DM) brains to provide compelling evidence for this RNA toxicity model. MBNL2 binds directly to DM repeat expansions in the brain resulting in depletion from its normal RNA targets with downstream effects on alternative splicing and polyadenylation. Similar RNA processing defects were detected in Mbnl compound knockout mice, highlighted by dysregulation of Mapt splicing and fetal tau isoform expression in adults. These results demonstrate that MBNL proteins are directly sequestered by RNAexp in the DM brain and introduce a powerful experimental tool to evaluate RNA-mediated toxicity in other expansion diseases. HITS-CLIP analysis was performed to identify RNA binding sites of MBNL2 in control, DM type 1 (DM1), and DM type 2 (DM2) autopsy-derived brain (n=3). Two regions of the brain selected for the study included the frontal cortex and hippocampus. Libraries were sequenced and wiggle files were generated for each biological replicate as well as three pooled biological replicates (3BRs) per group (control, DM1, and DM2). In addition, differential CLIP analysis (dCLIP) was performed to normalize binding data between groups and identify statistically significant changes in binding. The dCLIP analysis generated bedgraph files representing normalized binding profiles of MBNL2 in each group (control, DM1, and DM2) for visualization and comparative analysis. PolyA-seq was performed on control, DM1, and DM2 autopsy-derived brain samples (hippocampus and frontal cortex, n=3) as well as wild-type (WT) and Mbnl1; Mbnl2 conditional double knockout (Mbnl1-/-; Mbnl2c/c; Nestin-Cre+/- or DKO) brain (n=3). Libraries were sequenced and the resultant files were processed and aligned to the reference genomes (hg19 and mm10). Further computational processing was performed to remove internal oligo(dT) mis-priming events, identify valid polyA sites, and trim to the exact polyA sites. BedGraph files were generated for each group in human (control, DM1, and DM2) and mouse (WT and Mbnl DKO) for comparative visualization.
2015-07-30 | E-GEOD-68890 | biostudies-arrayexpress
Project description:Myotonic dystrophy (DM) is the most common autosomal dominant muscular dystrophy and encompasses both skeletal muscle and cardiac complications. Myotonic dystrophy is nucleotide repeat expansion disorder in which type 1 (DM1) is due to a trinucleotide repeat expansion on chromosome 19 and type 2 (DM2) arises from a tetranucleotide repeat expansion on chromosome 3. Developing representative models of myotonic dystrophy in animals has been challenging due to instability of nucleotide repeat expansions, especially for DM2 which is characterized by nucleotide repeat expansions often greater than 5000 copies. To investigate mechanisms of human DM, we generated cellular models of DM1 and DM2. We used regulated MyoD expression to reprogram urine-derived cells into myotubes. In this cell model, we found impaired dystrophin expression, MBNL foci, and aberrant splicing in DM1 but not in DM2 cells. We generated induced pluripotent stem cells (iPSC) from healthy controls, DM1 and DM2 subjects and differentiated these into cardiomyocytes. DM1 and DM2 cells displayed an increase in RNA foci concomitant with cellular differentiation. IPSC-derived cardiomyocytes from DM1 but not DM2 had aberrant splicing and MBNL sequestration. High resolution imaging revealed tight association between MBNL clusters and RNA FISH foci in DM1. Ca2+ transients differed between DM1 and DM2 IPSC-derived cardiomyocytes and from healthy control cells. RNA-sequencing from DM1 and DM2 iPSC-derived cardiomyocytes both altered gene expression as well as distinct splicing patterns as differential between DM1 and DM2. Together these data support that DM1 and DM2, despite some shared clinical and molecular features, have distinct pathological signatures.
2019-02-12 | GSE125638 | GEO
Project description:Myotonic dystrophy (DM) is a multi-systemic disease that severely impacts cardiac and skeletal muscle functions as well as the central nervous system. DM is unusual because it is RNA-mediated disease due to the expression of C(C)UG expansion RNAs that inhibit the activities of the muscleblind-like (MBNL) proteins. In mice, studies using Mbnl1 and Mbnl2 single knockouts have revealed that Mbnl1 plays a predominant role in skeletal and heart muscle alternative splicing regulation while Mbnl2 performs an analogous splicing function in the brain. However, Mbnl single knockout models fail to recapitulate the full-range of adult-onset DM muscle symptoms. Here, we report that Mbnl1; Mbnl2 double knockouts are embryonic lethal while Mbnl1-/-; Mbnl2+/- mice, which express no Mbnl1 and reduced levels of Mbnl2, are viable but develop cardinal features of adult-onset DM cardiac and skeletal muscle disease including reduced lifespan, heart conduction block, severe myotonia and progressive skeletal muscle weakness. Mbnl2 protein levels are elevated in both Mbnl1-/- and Mbnl1-/-; Mbnl2+/- knockouts where Mbnl2 targets Mbnl1-regulated exons. These findings support the MBNL loss-of-function model for DM and provide novel Mbnl compound knockout models to investigate the molecular pathways disrupted by RNA-mediated disease.
2013-12-01 | GSE47794 | GEO
Project description:Myotonic dystrophy (DM) is a multi-systemic disease that severely impacts cardiac and skeletal muscle functions as well as the central nervous system. DM is unusual because it is RNA-mediated disease due to the expression of C(C)UG expansion RNAs that inhibit the activities of the muscleblind-like (MBNL) proteins. In mice, studies using Mbnl1 and Mbnl2 single knockouts have revealed that Mbnl1 plays a predominant role in skeletal and heart muscle alternative splicing regulation while Mbnl2 performs an analogous splicing function in the brain. However, Mbnl single knockout models fail to recapitulate the full-range of adult-onset DM muscle symptoms. Here, we report that Mbnl1; Mbnl2 double knockouts are embryonic lethal while Mbnl1-/-; Mbnl2+/- mice, which express no Mbnl1 and reduced levels of Mbnl2, are viable but develop cardinal features of adult-onset DM cardiac and skeletal muscle disease including reduced lifespan, heart conduction block, severe myotonia and progressive skeletal muscle weakness. Mbnl2 protein levels are elevated in both Mbnl1-/- and Mbnl1-/-; Mbnl2+/- knockouts where Mbnl2 targets Mbnl1-regulated exons. These findings support the MBNL loss-of-function model for DM and provide novel Mbnl compound knockout models to investigate the molecular pathways disrupted by RNA-mediated disease. Mbnl2 protein-RNA interactions were assessed in 4-month-old WT and Mbnl1-/- quadriceps muscles in triplicates by HITS-CLIP.
2013-12-01 | E-GEOD-47794 | biostudies-arrayexpress
Project description:Myotonic Dystrophy Type-2 (DM2) is an autosomal dominant disease caused by the expansion of a CCTG tetraplet repeat. It is a multisystemic disorder, affecting skeletal muscles, the heart, the eye, the central nervous system and the endocrine system. Whole mRNAs expression was measured in the muscle of DM2 patients and compared it to controls.We identified distinct genes modulated in DM2 patients compared to controls.
2015-04-05 | GSE37084 | GEO
Project description:Myotonic Dystrophy Type-2 (DM2) is an autosomal dominant disease caused by the expansion of a CCTG tetraplet repeat. It is a multisystemic disorder, affecting skeletal muscles, the heart, the eye, the central nervous system and the endocrine system The expression of 365 miRNAs was measured in the muscle of DM2 patients and compared it to controls and were identified distinct miRNAs modulated in DM2 patients compared to controls.
2012-08-27 | GSE37794 | GEO
Project description:Myotonic Dystrophy type 2 (DM2) is an autosomal-dominant, multisystemic disease with a core manifestation of proximal muscle weakness, muscle atrophy, myotonia, and myalgia. The disease-causing CCTG tetranucleotide expansion within the CNBP gene on chromosome 3 leads to an RNA-dominated spliceopathy which is currently untreatable. Research exploring the pathophysiological mechanisms in Myotonic Dystrophy Type 1 resulted in new insights into disease mechanisms and identified mitochondrial dysfunction as promising therapeutic target. It remains unclear whether similar mechanisms underlie DM2 and, if so, whether these might also serve as potential therapeutic targets. In this cross-sectional study, we studied DM2 skeletal muscle biopsy specimens on proteomic, molecular, and morphological including ultrastructural levels in two separate patient cohorts consisting of 8 (explorative cohort) and 40 (confirmatory cohort) patients. Seven muscle biopsy specimens obtained from four female and three male DM2 patients underwent proteomic analysis. We performed immunoblotting of respiratory chain complexes, mitochondrial DNA copy number determination and long-range PCR (LR-PCR) to study mitochondrial deletions on six biopsies. Forty-eight biopsy samples were studied by light and electron microscopy. Proteomic analysis revealed a downregulation of essential mitochondrial proteins, namely of subunits of respiratory chain complexes I, III, and IV (e.g. mt-CO1, mt-ND1, mt-CYB, NDUFB6) and associated translation factors (TACO1). Light microscopy showed an age-inappropriate amount of COX-deficient fibers in most biopsy specimens. Electron microscopy revealed widespread ultrastructural mitochondrial abnormalities including dysmorphic mitochondria with paracrystalline inclusions. Immunoblotting and LR-PCR did not reveal significant differences between patients and controls, while mtDNA-copy number measurement revealed a reduction of mtDNA-copy numbers in the patient group compared to controls. This first multi-level study of DM2 unravels thus far undescribed functional and structural mitochondrial abnormalities. While the molecular link between the tetranucleotide expansion, and mitochondrial dysfunction needs to be further elucidated, these findings may provide an additional route for treatment strategies for DM2.
2024-01-26 | PXD044286 | Pride
Project description:MBNL1 is a known splicing factor and is related to Myotonic Dystrophy (DM). This study examines the tissue specific splicing patterns of MBNL1 using a mutant and wild type mouse across three tissues (heart,brain,quadricep) related publications: Aberrant alternative splicing and extracellular matrix gene expression in mouse models of myotonic dystrophy. Du H, etal Nat Struct Mol Biol. 2010 Feb;17(2):187-93. and Hum Mol Genet. 2006 Jul 1;15(13):2087-97. Failure of MBNL1-dependent post-natal splicing transitions in myotonic dystrophy. Lin X, Miller JW, Mankodi A, Kanadia RN, Yuan Y, Moxley RT, Swanson MS, Thornton CA. We examined quadricep,heart and brain of a mouse MBNL1 mutant to test whether MBNL mutants creates a tissue specific splicing defect. These samples were compared to the tissues of a wild type mouse.
2012-07-30 | E-GEOD-28640 | biostudies-arrayexpress
Project description:Myotonic Dystrophy Type-2 (DM2) is an autosomal dominant disease caused by the expansion of a CCTG tetraplet repeat. It is a multisystemic disorder, affecting skeletal muscles, the heart, the eye, the central nervous system and the endocrine system. Whole mRNAs expression was measured in the muscle of DM2 patients and compared it to controls.We identified distinct genes modulated in DM2 patients compared to controls. Our study included 10 DM2 and 10 control (CTR) muscle biopsies from biceps brachii. DM2 and CTR were age- and sex- matched. Most DM2 patients had myotonia and cataract, two disease hallmarks, while differences in other clinical parameters (muscle strenght, diabetes, CPK, FT3, FT4, TSH, ejection fraction) were not significant. Genes expression was assessed by Affymetrix Gene Chip Human Exon 1.0 ST Array.
2015-04-05 | E-GEOD-37084 | biostudies-arrayexpress