scholarly journals Staufen1 impairs stress granule formation in skeletal muscle cells from myotonic dystrophy type 1 patients

2016 ◽  
Vol 27 (11) ◽  
pp. 1728-1739 ◽  
Author(s):  
Aymeric Ravel-Chapuis ◽  
Amanda Klein Gunnewiek ◽  
Guy Bélanger ◽  
Tara E. Crawford Parks ◽  
Jocelyn Côté ◽  
...  
Keyword(s):  
Myotonic Dystrophy ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Muscle Cells ◽  
Cellular Stress Response ◽  
Granule Formation ◽  
A Cell ◽  
Cell Type Specific ◽  
Cug Repeats

Myotonic dystrophy (DM1) is caused by an expansion of CUG repeats (CUGexp) in the DMPK mRNA 3′UTR. CUGexp-containing mRNAs become toxic to cells by misregulating RNA-binding proteins. Here we investigated the consequence of this RNA toxicity on the cellular stress response. We report that cell stress efficiently triggers formation of stress granules (SGs) in proliferating, quiescent, and differentiated muscle cells, as shown by the appearance of distinct cytoplasmic TIA-1– and DDX3-containing foci. We show that Staufen1 is also dynamically recruited into these granules. Moreover, we discovered that DM1 myoblasts fail to properly form SGs in response to arsenite. This blockage was not observed in DM1 fibroblasts, demonstrating a cell type–specific defect. DM1 myoblasts display increased expression and sequestration of toxic CUGexp mRNAs compared with fibroblasts. Of importance, down-regulation of Staufen1 in DM1 myoblasts rescues SG formation. Together our data show that Staufen1 participates in the inhibition of SG formation in DM1 myoblasts. These results reveal that DM1 muscle cells fail to properly respond to stress, thereby likely contributing to the complex pathogenesis of DM1.

scholarly journals Brain Pathogenesis and Potential Therapeutic Strategies in Myotonic Dystrophy Type 1

2021 ◽  
Vol 13 ◽  
Author(s):  
Jie Liu ◽  
Zhen-Ni Guo ◽  
Xiu-Li Yan ◽  
Yi Yang ◽  
Shuo Huang
Keyword(s):  
Myotonic Dystrophy ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Brain Diseases ◽  
Myotonic Dystrophy Type 1 ◽  
Myotonic Dystrophy Type ◽  
Multiple Systems ◽  
Intervention Measures ◽  
Therapeutic Tools

Myotonic dystrophy type 1 (DM1) is the most common muscular dystrophy that affects multiple systems including the muscle and heart. The mutant CTG expansion at the 3′-UTR of the DMPK gene causes the expression of toxic RNA that aggregate as nuclear foci. The foci then interfere with RNA-binding proteins, affecting hundreds of mis-spliced effector genes, leading to aberrant alternative splicing and loss of effector gene product functions, ultimately resulting in systemic disorders. In recent years, increasing clinical, imaging, and pathological evidence have indicated that DM1, though to a lesser extent, could also be recognized as true brain diseases, with more and more researchers dedicating to develop novel therapeutic tools dealing with it. In this review, we summarize the current advances in the pathogenesis and pathology of central nervous system (CNS) deficits in DM1, intervention measures currently being investigated are also highlighted, aiming to promote novel and cutting-edge therapeutic investigations.

scholarly journals Increased Muscleblind levels by chloroquine treatment improve myotonic dystrophy type 1 phenotypes in in vitro and in vivo models

2019 ◽  
Vol 116 (50) ◽  
pp. 25203-25213 ◽  
Author(s):  
Ariadna Bargiela ◽  
Maria Sabater-Arcis ◽  
Jorge Espinosa-Espinosa ◽  
Miren Zulaica ◽  
Adolfo Lopez de Munain ◽  
...  
Keyword(s):  
Myotonic Dystrophy ◽  
Rna Binding ◽  
Trinucleotide Repeat ◽  
Rna Binding Proteins ◽  
Myotonic Dystrophy Type 1 ◽  
Myotonic Dystrophy Type ◽  
Muscle Area ◽  
In Vivo Models

Myotonic dystrophy type 1 (DM1) is a life-threatening and chronically debilitating neuromuscular disease caused by the expansion of a CTG trinucleotide repeat in the 3′ UTR of the DMPK gene. The mutant RNA forms insoluble structures capable of sequestering RNA binding proteins of the Muscleblind-like (MBNL) family, which ultimately leads to phenotypes. In this work, we demonstrate that treatment with the antiautophagic drug chloroquine was sufficient to up-regulate MBNL1 and 2 proteins in Drosophila and mouse (HSALR) models and patient-derived myoblasts. Extra Muscleblind was functional at the molecular level and improved splicing events regulated by MBNLs in all disease models. In vivo, chloroquine restored locomotion, rescued average cross-sectional muscle area, and extended median survival in DM1 flies. In HSALR mice, the drug restored muscular strength and histopathology signs and reduced the grade of myotonia. Taken together, these results offer a means to replenish critically low MBNL levels in DM1.

scholarly journals High-throughput kinome-RNAi screen identifies protein kinase R activator (PACT) as a novel genetic modifier of CUG foci integrity in myotonic dystrophy type 1 (DM1)

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0256276
Author(s):  
Nafisa Neault ◽  
Sean O’Reilly ◽  
Aiman Tariq Baig ◽  
Julio Plaza-Diaz ◽  
Mehrdad Azimi ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Myotonic Dystrophy ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Genetic Modifier ◽  
Myotonic Dystrophy Type 1 ◽  
Myotonic Dystrophy Type ◽  
Aberrant Expression ◽  
Significant Correction

Myotonic Dystrophy Type 1 (DM1) is the most common form of adult muscular dystrophy (~1:8000). In DM1, expansion of CTG trinucleotide repeats in the 3’ untranslated region of the dystrophia myotonica protein kinase (DMPK) gene results in DMPK mRNA hairpin structures which aggregate as insoluble ribonuclear foci and sequester several RNA-binding proteins. The resulting sequestration and misregulation of important splicing factors, such as muscleblind-like 1 (MBNL1), causes the aberrant expression of fetal transcripts for several genes that contribute to the disease phenotype. Previous work has shown that antisense oligonucleotide-mediated disaggregation of the intranuclear foci has the potential to reverse downstream anomalies. To explore whether the nuclear foci are, to some extent, controlled by cell signalling pathways, we have performed a screen using a small interfering RNA (siRNA) library targeting 518 protein kinases to look at kinomic modulation of foci integrity. RNA foci were visualized by in situ hybridization of a fluorescent-tagged (CAG)10 probe directed towards the expanded DMPK mRNA and the cross-sectional area and number of foci per nuclei were recorded. From our screen, we have identified PACT (protein kinase R (PKR) activator) as a novel modulator of foci integrity and have shown that PACT knockdown can both increase MBNL1 protein levels; however, these changes are not suffcient for significant correction of downstream spliceopathies.

scholarly journals A comprehensive atlas of fetal splicing patterns in the brain of adult myotonic dystrophy type 1 patients

2021 ◽  
Author(s):  
Max J. F. Degener ◽  
Remco T.P. van Cruchten ◽  
Brittney A. Otero ◽  
Eric T. Wang ◽  
Derick G. Wansink ◽  
...  
Keyword(s):  
Myotonic Dystrophy ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Myotonic Dystrophy Type 1 ◽  
Myotonic Dystrophy Type ◽  
Healthy Individuals ◽  
Developmentally Regulated ◽  
The Central Nervous System ◽  
Splicing Patterns

ABSTRACTIn patients with myotonic dystrophy type 1 (DM1), dysregulation of RNA-binding proteins like MBNL and CELF1 leads to alternative splicing of exons and is thought to induce a return to fetal splicing patterns in adult tissues, including the central nervous system (CNS). To comprehensively evaluate this, we created an atlas of developmentally regulated splicing patterns in the frontal cortex of healthy individuals and DM1 patients by combining RNA-seq data from BrainSpan, GTEx and DM1 patients. Thirty four splice events displayed an inclusion pattern in DM1 patients that is typical for the fetal situation in healthy individuals. The regulation of DM1-relevant splicing patterns could partly be explained by changes in mRNA expression of the splice regulators MBNL1, MBNL2 and CELF1. On the contrary, interindividual differences in splicing patterns between healthy adults could not be explained by differential expression of these splice regulators. Our findings lend transcriptome-wide evidence to the previously noted shift to fetal splicing patterns in the adult DM1 brain as a consequence of an imbalance in antagonistic MBNL and CELF1 activities. Our atlas serves as a solid foundation for further study and understanding of the cognitive phenotype in patients.

scholarly journals An Overview of Circular RNAs and Their Implications in Myotonic Dystrophy

2019 ◽  
Vol 20 (18) ◽  
pp. 4385 ◽  
Author(s):  
Karol Czubak ◽  
Saam Sedehizadeh ◽  
Piotr Kozlowski ◽  
Marzena Wojciechowska
Keyword(s):  
Myotonic Dystrophy ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Current Knowledge ◽  
Circular Rnas ◽  
Contributing Factors ◽  
Aberrant Expression ◽  
New Members ◽  
Human Disorders

Circular RNAs (circRNAs) are a class of single-stranded covalently closed RNA rings. Biogenesis of circRNAs, which may occur co-transcriptionally and post-transcriptionally via a back-splicing mechanism, requires the presence of complementary and/or inverted repeat sequences in introns flanking back-spliced exons and is facilitated by RNA-binding proteins. CircRNAs are abundant across eukaryotes; however, their biological functions remain largely speculative. Recently, they have been emerging as new members of a gene regulatory network and contributing factors in various human diseases including cancer, neurological, muscular and cardiovascular disorders. In this review, we present an overview of the current knowledge about circRNAs biogenesis and their aberrant expression in various human disorders. In particular, we focus on the latest discovery of circRNAs global upregulation in myotonic dystrophy type 1 (DM1) skeletal muscles and the role these prospective biomarkers might have for prognosis and therapeutic response in DM1.

scholarly journals Dysregulation of GSK3β-Target Proteins in Skin Fibroblasts of Myotonic Dystrophy Type 1 (DM1) Patients

2021 ◽  
pp. 1-17
Author(s):  
Valentina Grande ◽  
Denisa Hathazi ◽  
Emily O′Connor ◽  
Theo Marteau ◽  
Ulrike Schara-Schmidt ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Myotonic Dystrophy ◽  
Rna Binding ◽  
Glycogen Synthase ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Myotonic Dystrophy Type 1 ◽  
Myotonic Dystrophy Type ◽  
Treatment Responses

Myotonic dystrophy type 1 (DM1) is the most common monogenetic muscular disorder of adulthood. This multisystemic disease is caused by CTG repeat expansion in the 3′-untranslated region of the DM1 protein kinase gene called DMPK. DMPK encodes a myosin kinase expressed in skeletal muscle cells and other cellular populations such as smooth muscle cells, neurons and fibroblasts. The resultant expanded (CUG)n RNA transcripts sequester RNA binding factors leading to ubiquitous and persistent splicing deregulation. The accumulation of mutant CUG repeats is linked to increased activity of glycogen synthase kinase 3 beta (GSK3β), a highly conserved and ubiquitous serine/threonine kinase with functions in pathways regulating inflammation, metabolism, oncogenesis, neurogenesis and myogenesis. As GSK3β-inhibition ameliorates defects in myogenesis, muscle strength and myotonia in a DM1 mouse model, this kinase represents a key player of DM1 pathobiochemistry and constitutes a promising therapeutic target. To better characterise DM1 patients, and monitor treatment responses, we aimed to define a set of robust disease and severity markers linked to GSK3βby unbiased proteomic profiling utilizing fibroblasts derived from DM1 patients with low (80– 150) and high (2600– 3600) CTG-repeats. Apart from GSK3β increase, we identified dysregulation of nine proteins (CAPN1, CTNNB1, CTPS1, DNMT1, HDAC2, HNRNPH3, MAP2K2, NR3C1, VDAC2) modulated by GSK3β. In silico-based expression studies confirmed expression in neuronal and skeletal muscle cells and revealed a relatively elevated abundance in fibroblasts. The potential impact of each marker in the myopathology of DM1 is discussed based on respective function to inform potential uses as severity markers or for monitoring GSK3β inhibitor treatment responses.

scholarly journals Defined d-hexapeptides bind CUG repeats and rescue phenotypes of myotonic dystrophy myotubes in a Drosophila model of the disease

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna Rapisarda ◽  
Ariadna Bargiela ◽  
Beatriz Llamusi ◽  
Isabel Pont ◽  
Roger Estrada-Tejedor ◽  
...  
Keyword(s):  
Myotonic Dystrophy ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Ctg Repeats ◽  
Rna Hairpins ◽  
Drosophila Model ◽  
Toxic Rna ◽  
Rna Complexes ◽  
Cug Repeats

AbstractIn Myotonic Dystrophy type 1 (DM1), a non-coding CTG repeats rare expansion disease; toxic double-stranded RNA hairpins sequester the RNA-binding proteins Muscleblind-like 1 and 2 (MBNL1 and 2) and trigger other DM1-related pathogenesis pathway defects. In this paper, we characterize four d-amino acid hexapeptides identified together with abp1, a peptide previously shown to stabilize CUG RNA in its single-stranded conformation. With the generalized sequence cpy(a/t)(q/w)e, these related peptides improved three MBNL-regulated exon inclusions in DM1-derived cells. Subsequent experiments showed that these compounds generally increased the relative expression of MBNL1 and its nuclear-cytoplasmic distribution, reduced hyperactivated autophagy, and increased the percentage of differentiated (Desmin-positive) cells in vitro. All peptides rescued atrophy of indirect flight muscles in a Drosophila model of the disease, and partially rescued muscle function according to climbing and flight tests. Investigation of their mechanism of action supports that all four compounds can bind to CUG repeats with slightly different association constant, but binding did not strongly influence the secondary structure of the toxic RNA in contrast to abp1. Finally, molecular modeling suggests a detailed view of the interactions of peptide-CUG RNA complexes useful in the chemical optimization of compounds.

scholarly journals Cpy(a/t)(q/w)e D-Hexapeptides Bind CUG Repeats and Rescue Phenotypes of Myotonic Dystrophy Myoblasts and A Drosophila Model of the Disease

2020 ◽  
Author(s):  
Ariadna Bargiela ◽  
Ruben Artero ◽  
Roger Estrada-Tejedor ◽  
Anna Rapisarda ◽  
Enrique Garcia-España ◽  
...  
Keyword(s):  
Myotonic Dystrophy ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Ctg Repeats ◽  
Rna Hairpins ◽  
Drosophila Model ◽  
Toxic Rna ◽  
Rna Complexes ◽  
Cug Repeats

Abstract In Myotonic Dystrophy type 1 (DM1), a non-coding CTG repeats rare expansion disease; toxic double-stranded RNA hairpins sequester the RNA-binding proteins Muscleblind-like 1 and 2 (MBNL1 and 2) and trigger other DM1-related pathogenesis pathway defects. In this paper, we characterize four D-amino acid hexapeptides identified together with abp1, a peptide previously shown to stabilize CUG RNA in its single-stranded conformation. With the generalized sequence cpy(a/t)(q/w)e, these related peptides improved three MBNL-regulated exon inclusions in DM1-derived cells. Subsequent experiments showed that these compounds generally increased the relative expression of MBNL1 and its nuclear-cytoplasmic distribution, reduced hyperactivated autophagy, and increased the percentage of differentiated (Desmin-positive) cells in vitro. All peptides rescued atrophy of indirect flight muscles in a Drosophila model of the disease, and partially rescued muscle function according to climbing and flight tests. Investigation of their mechanism of action supports that all four compounds can bind to CUG repeats with slightly different constant affinities, but binding did not strongly influence the secondary structure of the toxic RNA in contrast to abp1. Finally, molecular modeling suggests a detailed view of the interactions of peptide-CUG RNA complexes useful in the chemical optimization of compounds.

scholarly journals RNA m6A modification orchestrates a LINE-1–host interaction that facilitates retrotransposition and contributes to long gene vulnerability

Cell Research ◽  
2021 ◽  
Author(s):  
Feng Xiong ◽  
Ruoyu Wang ◽  
Joo-Hyung Lee ◽  
Shenglan Li ◽  
Shin-Fu Chen ◽  
...  
Keyword(s):  
Matrix Protein ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Regulatory Elements ◽  
Host Interaction ◽  
Damage Repair ◽  
Novel Host ◽  
Cell Type Specific ◽  
Human Fetal Tissues ◽  
Long Genes

AbstractThe molecular basis underlying the interaction between retrotransposable elements (RTEs) and the human genome remains poorly understood. Here, we profiled N6-methyladenosine (m6A) deposition on nascent RNAs in human cells by developing a new method MINT-Seq, which revealed that many classes of RTE RNAs, particularly intronic LINE-1s (L1s), are strongly methylated. These m6A-marked intronic L1s (MILs) are evolutionarily young, sense-oriented to hosting genes, and are bound by a dozen RNA binding proteins (RBPs) that are putative novel readers of m6A-modified RNAs, including a nuclear matrix protein SAFB. Notably, m6A positively controls the expression of both autonomous L1s and co-transcribed L1 relics, promoting L1 retrotransposition. We showed that MILs preferentially reside in long genes with critical roles in DNA damage repair and sometimes in L1 suppression per se, where they act as transcriptional “roadblocks” to impede the hosting gene expression, revealing a novel host-weakening strategy by the L1s. In counteraction, the host uses the SAFB reader complex to bind m6A-L1s to reduce their levels, and to safeguard hosting gene transcription. Remarkably, our analysis identified thousands of MILs in multiple human fetal tissues, enlisting them as a novel category of cell-type-specific regulatory elements that often compromise transcription of long genes and confer their vulnerability in neurodevelopmental disorders. We propose that this m6A-orchestrated L1–host interaction plays widespread roles in gene regulation, genome integrity, human development and diseases.

Abstract P104: Reactivation of Embryonic Gene Program due to CUG Repeat RNA Expression in Myotonic Dystrophy

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Auinash Kalsotra ◽  
Ravi Singh ◽  
Chad Creighton ◽  
Thomas Cooper
Keyword(s):  
Gene Expression ◽  
Myotonic Dystrophy ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Expression Patterns ◽  
Causative Mutation ◽  
Inherited Disease ◽  
Aberrant Expression ◽  
Organ Systems ◽  
General Response

Myotonic dystrophy type 1 (DM1) is a dominantly inherited disease that affects multiple organ systems. Cardiac involvement, which is characterized by conduction defects and arrhythmias, is the second leading cause of death in DM1 patients. The causative mutation is a CTG expansion in the 3' untranslated region of DMPK gene resulting in aberrant expression of CUG repeat RNA that accumulates into nuclear foci and causes misregulation in alternative splicing. Here we show that heart-specific and inducible expression of CUG repeat RNA in a DM1 mouse model results in global reactivation of embryonic gene expression program in adult heart that is distinct from a general hypertrophic stress response. Using q-PCR TaqMan arrays, we identified 54 miRNAs that were differentially expressed in DM1 mouse hearts one week following induction of CUG repeat RNA. Interestingly, 83% (45/54) of them exhibited a developmental shift in expression towards the embryonic pattern. Because over 90% (41/45) of them were down regulated within 72 hr after induction of repeat RNA and only 2/22 examined decreased in two unrelated mouse models of heart disease, we conclude their reduced expression is specific to DM1 and not simply a general response to cardiac injury. Microarray studies revealed a developmental switch not only in the miRNA expression patterns but also a pervasive shift in mRNA steady state levels of a number of genes to embryonic stage. Intriguingly, we found that loss of MBNL1 or gain of CELF1 activity, two major RNA binding proteins disrupted in DM1, are not driving the miRNA misregulation since their expression is indistinguishable between wild type, MBNL1 knock out and CELF1 over expressing mice. Moreover, comparable decrease in ten out of ten primary miRNA transcripts examined suggests loss of expression is not due to a processing defect. Instead, we discovered that adult-to-embryonic shift in expression of select micro- and messenger RNAs in DM1 heart occurs due to specific inactivation of a Mef2 transcriptional program. We are currently determining causal contributions of this Mef2-miRNA circuitry in the developmental reprogramming of gene expression in DM1 as well as its direct role in cardiac manifestations of this disease.

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