1
|
Nakamori M, Shimizu H, Ogawa K, Hasuike Y, Nakajima T, Sakurai H, Araki T, Okada Y, Kakita A, Mochizuki H. Cell type-specific abnormalities of central nervous system in myotonic dystrophy type 1. Brain Commun 2022; 4:fcac154. [PMID: 35770133 PMCID: PMC9218787 DOI: 10.1093/braincomms/fcac154] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 03/13/2022] [Accepted: 06/09/2022] [Indexed: 11/17/2022] Open
Abstract
Myotonic dystrophy type 1 is a multisystem genetic disorder involving the muscle, heart and CNS. It is caused by toxic RNA transcription from expanded CTG repeats in the 3′-untranslated region of DMPK, leading to dysregulated splicing of various genes and multisystemic symptoms. Although aberrant splicing of several genes has been identified as the cause of some muscular symptoms, the pathogenesis of CNS symptoms prevalent in patients with myotonic dystrophy type 1 remains unelucidated, possibly due to a limitation in studying a diverse mixture of different cell types, including neuronal cells and glial cells. Previous studies revealed neuronal loss in the cortex, myelin loss in the white matter and the presence of axonal neuropathy in patients with myotonic dystrophy type 1. To elucidate the CNS pathogenesis, we investigated cell type-specific abnormalities in cortical neurons, white matter glial cells and spinal motor neurons via laser-capture microdissection. We observed that the CTG repeat instability and cytosine–phosphate–guanine (CpG) methylation status varied among the CNS cell lineages; cortical neurons had more unstable and longer repeats with higher CpG methylation than white matter glial cells, and spinal motor neurons had more stable repeats with lower methylation status. We also identified splicing abnormalities in each CNS cell lineage, such as DLGAP1 in white matter glial cells and CAMKK2 in spinal motor neurons. Furthermore, we demonstrated that aberrant splicing of CAMKK2 is associated with abnormal neurite morphology in myotonic dystrophy type 1 motor neurons. Our laser-capture microdissection-based study revealed cell type-dependent genetic, epigenetic and splicing abnormalities in myotonic dystrophy type 1 CNS, indicating the significant potential of cell type-specific analysis in elucidating the CNS pathogenesis.
Collapse
Affiliation(s)
- Masayuki Nakamori
- Department of Neurology, Osaka University Graduate School of Medicine , 2-2 Yamadaoka, Suita, Osaka 565-0871 , Japan
- Institute for Open and Transdisciplinary Research Initiatives (OTRI), Osaka University , 1-1 Yamadaoka, Suita, Osaka 565-0871 , Japan
| | - Hiroshi Shimizu
- Department of Pathology, Brain Research Institute, Niigata University , 1-757 Asahimachi, Chuo-ku, Niigata 951-8585 , Japan
| | - Kotaro Ogawa
- Department of Neurology, Osaka University Graduate School of Medicine , 2-2 Yamadaoka, Suita, Osaka 565-0871 , Japan
- Department of Statistical Genetics, Osaka University Graduate School of Medicine , 2-2 Yamadaoka, Suita, Osaka 565-0871 , Japan
| | - Yuhei Hasuike
- Department of Neurology, Osaka University Graduate School of Medicine , 2-2 Yamadaoka, Suita, Osaka 565-0871 , Japan
| | - Takashi Nakajima
- Department of Neurology, National Hospital Organization Niigata National Hospital , 3-52 Akasakamachi, Kashiwazaki, Niigata 945-8585 , Japan
| | - Hidetoshi Sakurai
- Center for iPS Cell Research and Application (CiRA), Kyoto University , 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507 , Japan
| | - Toshiyuki Araki
- Department of Peripheral Nervous System Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry , 4-1-1 Ogawahigashimachi, Kodaira, Tokyo 187-8502 , Japan
| | - Yukinori Okada
- Department of Statistical Genetics, Osaka University Graduate School of Medicine , 2-2 Yamadaoka, Suita, Osaka 565-0871 , Japan
| | - Akiyoshi Kakita
- Department of Pathology, Brain Research Institute, Niigata University , 1-757 Asahimachi, Chuo-ku, Niigata 951-8585 , Japan
| | - Hideki Mochizuki
- Department of Neurology, Osaka University Graduate School of Medicine , 2-2 Yamadaoka, Suita, Osaka 565-0871 , Japan
| |
Collapse
|
2
|
Cellular Senescence and Aging in Myotonic Dystrophy. Int J Mol Sci 2022; 23:ijms23042339. [PMID: 35216455 PMCID: PMC8877951 DOI: 10.3390/ijms23042339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/06/2022] [Accepted: 02/12/2022] [Indexed: 01/10/2023] Open
Abstract
Myotonic dystrophy (DM) is a dominantly inherited multisystemic disorder affecting various organs, such as skeletal muscle, heart, the nervous system, and the eye. Myotonic dystrophy type 1 (DM1) and type 2 (DM2) are caused by expanded CTG and CCTG repeats, respectively. In both forms, the mutant transcripts containing expanded repeats aggregate as nuclear foci and sequester several RNA-binding proteins, resulting in alternative splicing dysregulation. Although certain alternative splicing events are linked to the clinical DM phenotypes, the molecular mechanisms underlying multiple DM symptoms remain unclear. Interestingly, multi-systemic DM manifestations, including muscle weakness, cognitive impairment, cataract, and frontal baldness, resemble premature aging. Furthermore, cellular senescence, a critical contributor to aging, is suggested to play a key role in DM cellular pathophysiology. In particular, several senescence inducers including telomere shortening, mitochondrial dysfunction, and oxidative stress and senescence biomarkers such as cell cycle inhibitors, senescence-associated secretory phenotype, chromatin reorganization, and microRNA have been implicated in DM pathogenesis. In this review, we focus on the clinical similarities between DM and aging, and summarize the involvement of cellular senescence in DM and the potential application of anti-aging DM therapies.
Collapse
|
3
|
Fralish Z, Lotz EM, Chavez T, Khodabukus A, Bursac N. Neuromuscular Development and Disease: Learning From in vitro and in vivo Models. Front Cell Dev Biol 2021; 9:764732. [PMID: 34778273 PMCID: PMC8579029 DOI: 10.3389/fcell.2021.764732] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/06/2021] [Indexed: 01/02/2023] Open
Abstract
The neuromuscular junction (NMJ) is a specialized cholinergic synaptic interface between a motor neuron and a skeletal muscle fiber that translates presynaptic electrical impulses into motor function. NMJ formation and maintenance require tightly regulated signaling and cellular communication among motor neurons, myogenic cells, and Schwann cells. Neuromuscular diseases (NMDs) can result in loss of NMJ function and motor input leading to paralysis or even death. Although small animal models have been instrumental in advancing our understanding of the NMJ structure and function, the complexities of studying this multi-tissue system in vivo and poor clinical outcomes of candidate therapies developed in small animal models has driven the need for in vitro models of functional human NMJ to complement animal studies. In this review, we discuss prevailing models of NMDs and highlight the current progress and ongoing challenges in developing human iPSC-derived (hiPSC) 3D cell culture models of functional NMJs. We first review in vivo development of motor neurons, skeletal muscle, Schwann cells, and the NMJ alongside current methods for directing the differentiation of relevant cell types from hiPSCs. We further compare the efficacy of modeling NMDs in animals and human cell culture systems in the context of five NMDs: amyotrophic lateral sclerosis, myasthenia gravis, Duchenne muscular dystrophy, myotonic dystrophy, and Pompe disease. Finally, we discuss further work necessary for hiPSC-derived NMJ models to function as effective personalized NMD platforms.
Collapse
Affiliation(s)
- Zachary Fralish
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Ethan M Lotz
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Taylor Chavez
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Alastair Khodabukus
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Nenad Bursac
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| |
Collapse
|
4
|
Mérien A, Tahraoui-Bories J, Cailleret M, Dupont JB, Leteur C, Polentes J, Carteron A, Polvèche H, Concordet JP, Pinset C, Jarrige M, Furling D, Martinat C. CRISPR gene editing in pluripotent stem cells reveals the function of MBNL proteins during human in vitro myogenesis. Hum Mol Genet 2021; 31:41-56. [PMID: 34312665 PMCID: PMC8682758 DOI: 10.1093/hmg/ddab218] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/10/2021] [Accepted: 07/21/2021] [Indexed: 11/14/2022] Open
Abstract
Alternative splicing has emerged as a fundamental mechanism for the spatiotemporal control of development. A better understanding of how this mechanism is regulated has the potential not only to elucidate fundamental biological principles, but also to decipher pathological mechanisms implicated in diseases where normal splicing networks are misregulated. Here, we took advantage of human pluripotent stem cells to decipher during human myogenesis the role of muscleblind-like (MBNL) proteins, a family of tissue-specific splicing regulators whose loss of function is associated with myotonic dystrophy type 1 (DM1), an inherited neuromuscular disease. Thanks to the CRISPR/Cas9 technology, we generated human-induced pluripotent stem cells (hiPSCs) depleted in MBNL proteins and evaluated the consequences of their losses on the generation of skeletal muscle cells. Our results suggested that MBNL proteins are required for the late myogenic maturation. In addition, loss of MBNL1 and MBNL2 recapitulated the main features of DM1 observed in hiPSC-derived skeletal muscle cells. Comparative transcriptomic analyses also revealed the muscle-related processes regulated by these proteins that are commonly misregulated in DM1. Together, our study reveals the temporal requirement of MBNL proteins in human myogenesis and should facilitate the identification of new therapeutic strategies capable to cope with the loss of function of these MBNL proteins.
Collapse
Affiliation(s)
- Antoine Mérien
- INSERM/UEPS UMR 861, Paris Saclay University, I-STEM, 91100 Corbeil-Essonnes, France
| | - Julie Tahraoui-Bories
- INSERM/UEPS UMR 861, Paris Saclay University, I-STEM, 91100 Corbeil-Essonnes, France
| | - Michel Cailleret
- INSERM/UEPS UMR 861, Paris Saclay University, I-STEM, 91100 Corbeil-Essonnes, France
| | - Jean-Baptiste Dupont
- INSERM/UEPS UMR 861, Paris Saclay University, I-STEM, 91100 Corbeil-Essonnes, France
| | | | | | | | | | | | | | | | - Denis Furling
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de recherche en myologie, Paris, France
| | - Cécile Martinat
- INSERM/UEPS UMR 861, Paris Saclay University, I-STEM, 91100 Corbeil-Essonnes, France
| |
Collapse
|
5
|
Alexander MS, Hightower RM, Reid AL, Bennett AH, Iyer L, Slonim DK, Saha M, Kawahara G, Kunkel LM, Kopin AS, Gupta VA, Kang PB, Draper I. hnRNP L is essential for myogenic differentiation and modulates myotonic dystrophy pathologies. Muscle Nerve 2021; 63:928-940. [PMID: 33651408 DOI: 10.1002/mus.27216] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 02/25/2021] [Accepted: 02/28/2021] [Indexed: 12/12/2022]
Abstract
INTRODUCTION RNA-binding proteins (RBPs) play an important role in skeletal muscle development and disease by regulating RNA splicing. In myotonic dystrophy type 1 (DM1), the RBP MBNL1 (muscleblind-like) is sequestered by toxic CUG repeats, leading to missplicing of MBNL1 targets. Mounting evidence from the literature has implicated other factors in the pathogenesis of DM1. Herein we sought to evaluate the functional role of the splicing factor hnRNP L in normal and DM1 muscle cells. METHODS Co-immunoprecipitation assays using hnRNPL and MBNL1 expression constructs and splicing profiling in normal and DM1 muscle cell lines were performed. Zebrafish morpholinos targeting hnrpl and hnrnpl2 were injected into one-cell zebrafish for developmental and muscle analysis. In human myoblasts downregulation of hnRNP L was achieved with shRNAi. Ascochlorin administration to DM1 myoblasts was performed and expression of the CUG repeats, DM1 splicing biomarkers, and hnRNP L expression levels were evaluated. RESULTS Using DM1 patient myoblast cell lines we observed the formation of abnormal hnRNP L nuclear foci within and outside the expanded CUG repeats, suggesting a role for this factor in DM1 pathology. We showed that the antiviral and antitumorigenic isoprenoid compound ascochlorin increased MBNL1 and hnRNP L expression levels. Drug treatment of DM1 muscle cells with ascochlorin partially rescued missplicing of established early biomarkers of DM1 and improved the defective myotube formation displayed by DM1 muscle cells. DISCUSSION Together, these studies revealed that hnRNP L can modulate DM1 pathologies and is a potential therapeutic target.
Collapse
Affiliation(s)
- Matthew S Alexander
- Division of Neurology, Department of Pediatrics, University of Alabama at Birmingham and Children's of Alabama, Birmingham, Alabama, USA.,Center for Exercise Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA.,Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA.,Civitan International Research Center, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Rylie M Hightower
- Division of Neurology, Department of Pediatrics, University of Alabama at Birmingham and Children's of Alabama, Birmingham, Alabama, USA.,Center for Exercise Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Andrea L Reid
- Division of Neurology, Department of Pediatrics, University of Alabama at Birmingham and Children's of Alabama, Birmingham, Alabama, USA
| | - Alexis H Bennett
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Lakshmanan Iyer
- Department of Neuroscience, Tufts University, Boston, Massachusetts, USA
| | - Donna K Slonim
- Department of Computer Science, Tufts University, Medford, Massachusetts, USA
| | - Madhurima Saha
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Genri Kawahara
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Louis M Kunkel
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA.,Harvard Stem Cell Institute, Cambridge, Massachusetts, USA.,The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Alan S Kopin
- Department of Medicine, Molecular Cardiology Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
| | - Vandana A Gupta
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida, USA.,Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida, USA.,Department of Neurology, University of Florida College of Medicine, Gainesville, Florida, USA.,Genetics Institute and Myology Institute, University of Florida, Gainesville, Florida, USA.,Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, Minneapolis, Minnesota, USA.,Neurology Department, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Isabelle Draper
- Department of Medicine, Molecular Cardiology Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
| |
Collapse
|
6
|
First Identification of RNA-Binding Proteins That Regulate Alternative Exons in the Dystrophin Gene. Int J Mol Sci 2020; 21:ijms21207803. [PMID: 33096920 PMCID: PMC7589424 DOI: 10.3390/ijms21207803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/16/2020] [Accepted: 10/19/2020] [Indexed: 12/29/2022] Open
Abstract
The Duchenne muscular dystrophy (DMD) gene has a complex expression pattern regulated by multiple tissue-specific promoters and by alternative splicing (AS) of the resulting transcripts. Here, we used an RNAi-based approach coupled with DMD-targeted RNA-seq to identify RNA-binding proteins (RBPs) that regulate splicing of its skeletal muscle isoform (Dp427m) in a human muscular cell line. A total of 16 RBPs comprising the major regulators of muscle-specific splicing events were tested. We show that distinct combinations of RBPs maintain the correct inclusion in the Dp427m of exons that undergo spatio-temporal AS in other dystrophin isoforms. In particular, our findings revealed the complex networks of RBPs contributing to the splicing of the two short DMD exons 71 and 78, the inclusion of exon 78 in the adult Dp427m isoform being crucial for muscle function. Among the RBPs tested, QKI and DDX5/DDX17 proteins are important determinants of DMD exon inclusion. This is the first large-scale study to determine which RBP proteins act on the physiological splicing of the DMD gene. Our data shed light on molecular mechanisms contributing to the expression of the different dystrophin isoforms, which could be influenced by a change in the function or expression level of the identified RBPs.
Collapse
|
7
|
Bosè F, Renna LV, Fossati B, Arpa G, Labate V, Milani V, Botta A, Micaglio E, Meola G, Cardani R. TNNT2 Missplicing in Skeletal Muscle as a Cardiac Biomarker in Myotonic Dystrophy Type 1 but Not in Myotonic Dystrophy Type 2. Front Neurol 2019; 10:992. [PMID: 31611837 PMCID: PMC6776629 DOI: 10.3389/fneur.2019.00992] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 09/02/2019] [Indexed: 12/31/2022] Open
Abstract
Cardiac involvement is one of the most important manifestations of the multisystemic phenotype of patients affected by myotonic dystrophy (DM) and represents the second cause of premature death. Molecular mechanisms responsible for DM cardiac defects are still unclear; however, missplicing of the cardiac isoform of troponin T (TNNT2) and of the cardiac sodium channel (SCN5A) genes might contribute to the reduced myocardial function and conduction abnormalities seen in DM patients. Since, in DM skeletal muscle, the TNNT2 gene shows the same aberrant splicing pattern observed in cardiac muscle, the principal aim of this work was to verify if the TNNT2 aberrant fetal isoform expression could be secondary to myopathic changes or could reflect the DM cardiac phenotype. Analysis of alternative splicing of TNNT2 and of several genes involved in DM pathology has been performed on muscle biopsies from patients affected by DM type 1 (DM1) or type 2 (DM2) with or without cardiac involvement. Our analysis shows that missplicing of muscle-specific genes is higher in DM1 and DM2 than in regenerating control muscles, indicating that these missplicing could be effectively important in DM skeletal muscle pathology. When considering the TNNT2 gene, missplicing appears to be more evident in DM1 than in DM2 muscles since, in DM2, the TNNT2 fetal isoform appears to be less expressed than the adult isoform. This evidence does not seem to be related to less severe muscle histopathological alterations that appear to be similar in DM1 and DM2 muscles. These results seem to indicate that the more severe TNNT2 missplicing observed in DM1 could not be related only to myopathic changes but could reflect the more severe general phenotype compared to DM2, including cardiac problems that appear to be more severe and frequent in DM1 than in DM2 patients. Moreover, TNNT2 missplicing significantly correlates with the QRS cardiac parameter in DM1 but not in DM2 patients, indicating that this splicing event has good potential to function as a biomarker of DM1 severity and it should be considered in pharmacological clinical trials to monitor the possible effects of different therapeutic approaches on skeletal muscle tissues.
Collapse
Affiliation(s)
- Francesca Bosè
- Laboratory of Muscle Histopathology and Molecular Biology, IRCCS-Policlinico San Donato, Milan, Italy
| | - Laura Valentina Renna
- Laboratory of Muscle Histopathology and Molecular Biology, IRCCS-Policlinico San Donato, Milan, Italy
| | - Barbara Fossati
- Department of Neurology, IRCCS-Policlinico San Donato, Milan, Italy.,Department of Neurorehabilitation Sciences, Casa Cura Policlinico (CCP), Milan, Italy
| | - Giovanni Arpa
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Valentina Labate
- University Cardiology Unit, IRCCS-Policlinico San Donato, Milan, Italy
| | - Valentina Milani
- Scientific Directorate, IRCCS Policlinico San Donato, Milan, Italy
| | - Annalisa Botta
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Emanuele Micaglio
- Department of Arrhythmology, IRCCS Policlinico San Donato, Milan, Italy
| | - Giovanni Meola
- Department of Neurology, IRCCS-Policlinico San Donato, Milan, Italy.,Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Rosanna Cardani
- Laboratory of Muscle Histopathology and Molecular Biology, IRCCS-Policlinico San Donato, Milan, Italy
| |
Collapse
|
8
|
Abstract
Myotonic dystrophy is an autosomal dominant muscular dystrophy not only associated with muscle weakness, atrophy, and myotonia but also prominent multisystem involvement. There are 2 similar, but distinct, forms of myotonic dystrophy; type 1 is caused by a CTG repeat expansion in the DMPK gene, and type 2 is caused by a CCTG repeat expansion in the CNBP gene. Type 1 is associated with distal limb, neck flexor, and bulbar weakness and results in different phenotypic subtypes with variable onset from congenital to very late-onset as well as variable signs and symptoms. The classically described adult-onset form is the most common. In contrast, myotonic dystrophy type 2 is adult-onset or late-onset, has proximal predominant muscle weakness, and generally has less severe multisystem involvement. In both forms of myotonic dystrophy, the best characterized disease mechanism is a RNA toxic gain-of-function during which RNA repeats form nuclear foci resulting in sequestration of RNA-binding proteins and, therefore, dysregulated splicing of premessenger RNA. There are currently no disease-modifying therapies, but clinical surveillance, preventative measures, and supportive treatments are used to reduce the impact of muscular impairment and other systemic involvement including cataracts, cardiac conduction abnormalities, fatigue, central nervous system dysfunction, respiratory weakness, dysphagia, and endocrine dysfunction. Exciting preclinical progress has been made in identifying a number of potential strategies including genome editing, small molecule therapeutics, and antisense oligonucleotide-based therapies to target the pathogenesis of type 1 and type 2 myotonic dystrophies at the DNA, RNA, or downstream target level.
Collapse
Affiliation(s)
- Samantha LoRusso
- Department of Neurology, The Ohio State University, 395 West 12th Avenue, Columbus, OH, 43210, USA
| | - Benjamin Weiner
- The Ohio State University College of Medicine, The Ohio State University, 370 West 9th Avenue, Columbus, OH, 43210, USA
| | - W David Arnold
- Department of Neurology, The Ohio State University, 395 West 12th Avenue, Columbus, OH, 43210, USA.
| |
Collapse
|
9
|
Matloka M, Klein AF, Rau F, Furling D. Cells of Matter- In Vitro Models for Myotonic Dystrophy. Front Neurol 2018; 9:361. [PMID: 29875732 PMCID: PMC5974047 DOI: 10.3389/fneur.2018.00361] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 05/03/2018] [Indexed: 12/17/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1 also known as Steinert disease) is a multisystemic disorder mainly characterized by myotonia, progressive muscle weakness and wasting, cognitive impairments, and cardiac defects. This autosomal dominant disease is caused by the expression of nuclear retained RNAs containing pathologic expanded CUG repeats that alter the function of RNA-binding proteins in a tissue-specific manner, leading ultimately to neuromuscular dysfunction and clinical symptoms. Although considerable knowledge has been gathered on myotonic dystrophy since its first description, the development of novel relevant disease models remains of high importance to investigate pathophysiologic mechanisms and to assess new therapeutic approaches. In addition to animal models, in vitro cell cultures provide a unique resource for both fundamental and translational research. This review discusses how cellular models broke ground to decipher molecular basis of DM1 and describes currently available cell models, ranging from exogenous expression of the CTG tracts to variable patients' derived cells.
Collapse
Affiliation(s)
| | | | | | - Denis Furling
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, Paris, France
| |
Collapse
|
10
|
Thomas JD, Oliveira R, Sznajder ŁJ, Swanson MS. Myotonic Dystrophy and Developmental Regulation of RNA Processing. Compr Physiol 2018; 8:509-553. [PMID: 29687899 PMCID: PMC11323716 DOI: 10.1002/cphy.c170002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Myotonic dystrophy (DM) is a multisystemic disorder caused by microsatellite expansion mutations in two unrelated genes leading to similar, yet distinct, diseases. DM disease presentation is highly variable and distinguished by differences in age-of-onset and symptom severity. In the most severe form, DM presents with congenital onset and profound developmental defects. At the molecular level, DM pathogenesis is characterized by a toxic RNA gain-of-function mechanism that involves the transcription of noncoding microsatellite expansions. These mutant RNAs disrupt key cellular pathways, including RNA processing, localization, and translation. In DM, these toxic RNA effects are predominantly mediated through the modulation of the muscleblind-like and CUGBP and ETR-3-like factor families of RNA binding proteins (RBPs). Dysfunction of these RBPs results in widespread RNA processing defects culminating in the expression of developmentally inappropriate protein isoforms in adult tissues. The tissue that is the focus of this review, skeletal muscle, is particularly sensitive to mutant RNA-responsive perturbations, as patients display a variety of developmental, structural, and functional defects in muscle. Here, we provide a comprehensive overview of DM1 and DM2 clinical presentation and pathology as well as the underlying cellular and molecular defects associated with DM disease onset and progression. Additionally, fundamental aspects of skeletal muscle development altered in DM are highlighted together with ongoing and potential therapeutic avenues to treat this muscular dystrophy. © 2018 American Physiological Society. Compr Physiol 8:509-553, 2018.
Collapse
Affiliation(s)
- James D. Thomas
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, Florida, USA
| | - Ruan Oliveira
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, Florida, USA
| | - Łukasz J. Sznajder
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, Florida, USA
| | - Maurice S. Swanson
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, Florida, USA
| |
Collapse
|
11
|
Nakamori M, Hamanaka K, Thomas JD, Wang ET, Hayashi YK, Takahashi MP, Swanson MS, Nishino I, Mochizuki H. Aberrant Myokine Signaling in Congenital Myotonic Dystrophy. Cell Rep 2017; 21:1240-1252. [PMID: 29091763 PMCID: PMC5689469 DOI: 10.1016/j.celrep.2017.10.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 09/02/2017] [Accepted: 10/04/2017] [Indexed: 02/07/2023] Open
Abstract
Myotonic dystrophy types 1 (DM1) and 2 (DM2) are dominantly inherited neuromuscular disorders caused by a toxic gain of function of expanded CUG and CCUG repeats, respectively. Although both disorders are clinically similar, congenital myotonic dystrophy (CDM), a severe DM form, is found only in DM1. CDM is also characterized by muscle fiber immaturity not observed in adult DM, suggesting specific pathological mechanisms. Here, we revealed upregulation of the interleukin-6 (IL-6) myokine signaling pathway in CDM muscles. We also found a correlation between muscle immaturity and not only IL-6 expression but also expanded CTG repeat length and CpG methylation status upstream of the repeats. Aberrant CpG methylation was associated with transcriptional dysregulation at the repeat locus, increasing the toxic RNA burden that upregulates IL-6. Because the IL-6 pathway is involved in myocyte maturation and muscle atrophy, our results indicate that enhanced RNA toxicity contributes to severe CDM phenotypes through aberrant IL-6 signaling.
Collapse
Affiliation(s)
- Masayuki Nakamori
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.
| | - Kohei Hamanaka
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8502, Japan
| | - James D Thomas
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL 32610, USA
| | - Eric T Wang
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL 32610, USA
| | - Yukiko K Hayashi
- Department of Pathophysiology, Tokyo Medical University, Shinjuku, Tokyo 160-0022, Japan
| | - Masanori P Takahashi
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan; Department of Functional Diagnostic Science, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Maurice S Swanson
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL 32610, USA
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo 187-8502, Japan
| | - Hideki Mochizuki
- Department of Neurology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| |
Collapse
|
12
|
Splicing misregulation of SCN5A contributes to cardiac-conduction delay and heart arrhythmia in myotonic dystrophy. Nat Commun 2016; 7:11067. [PMID: 27063795 PMCID: PMC4831019 DOI: 10.1038/ncomms11067] [Citation(s) in RCA: 126] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 02/16/2016] [Indexed: 12/11/2022] Open
Abstract
Myotonic dystrophy (DM) is caused by the expression of mutant RNAs containing expanded CUG repeats that sequester muscleblind-like (MBNL) proteins, leading to alternative splicing changes. Cardiac alterations, characterized by conduction delays and arrhythmia, are the second most common cause of death in DM. Using RNA sequencing, here we identify novel splicing alterations in DM heart samples, including a switch from adult exon 6B towards fetal exon 6A in the cardiac sodium channel, SCN5A. We find that MBNL1 regulates alternative splicing of SCN5A mRNA and that the splicing variant of SCN5A produced in DM presents a reduced excitability compared with the control adult isoform. Importantly, reproducing splicing alteration of Scn5a in mice is sufficient to promote heart arrhythmia and cardiac-conduction delay, two predominant features of myotonic dystrophy. In conclusion, misregulation of the alternative splicing of SCN5A may contribute to a subset of the cardiac dysfunctions observed in myotonic dystrophy. Patients with myotonic dystrophy (MD) suffer from severe cardiac issues of unknown aetiology. Freyermuth et al. show that fatal changes in cardiac electrophysiological properties in humans and mice with MD may arise from misregulation of the alternative splicing of the cardiac Na+ channel SCN5A transcript, resulting in expression of its fetal form.
Collapse
|
13
|
Laustriat D, Gide J, Barrault L, Chautard E, Benoit C, Auboeuf D, Boland A, Battail C, Artiguenave F, Deleuze JF, Bénit P, Rustin P, Franc S, Charpentier G, Furling D, Bassez G, Nissan X, Martinat C, Peschanski M, Baghdoyan S. In Vitro and In Vivo Modulation of Alternative Splicing by the Biguanide Metformin. MOLECULAR THERAPY-NUCLEIC ACIDS 2015; 4:e262. [PMID: 26528939 PMCID: PMC4877444 DOI: 10.1038/mtna.2015.35] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 09/22/2015] [Indexed: 01/02/2023]
Abstract
Major physiological changes are governed by alternative splicing of RNA, and its misregulation may lead to specific diseases. With the use of a genome-wide approach, we show here that this splicing step can be modified by medication and demonstrate the effects of the biguanide metformin, on alternative splicing. The mechanism of action involves AMPK activation and downregulation of the RBM3 RNA-binding protein. The effects of metformin treatment were tested on myotonic dystrophy type I (DM1), a multisystemic disease considered to be a spliceopathy. We show that this drug promotes a corrective effect on several splicing defects associated with DM1 in derivatives of human embryonic stem cells carrying the causal mutation of DM1 as well as in primary myoblasts derived from patients. The biological effects of metformin were shown to be compatible with typical therapeutic dosages in a clinical investigation involving diabetic patients. The drug appears to act as a modifier of alternative splicing of a subset of genes and may therefore have novel therapeutic potential for many more diseases besides those directly linked to defective alternative splicing.
Collapse
Affiliation(s)
| | | | | | - Emilie Chautard
- Centre de Recherche en Cancérologie de Lyon, INSERM U1052, Centre Léon Bérard, Lyon, France.,Université Lyon 1, CNRS, UMR 5558, INRIA Bamboo, Villeurbanne, France
| | - Clara Benoit
- Centre de Recherche en Cancérologie de Lyon, INSERM U1052, Centre Léon Bérard, Lyon, France
| | - Didier Auboeuf
- Centre de Recherche en Cancérologie de Lyon, INSERM U1052, Centre Léon Bérard, Lyon, France
| | - Anne Boland
- Centre National de Génotypage, Institut de Génomique, CEA, Evry, France
| | | | | | | | - Paule Bénit
- INSERM UMR 1141, Hôpital Robert Debré, Paris, France.,Université Paris 7, Faculté de Médecine Denis Diderot, Paris, France
| | - Pierre Rustin
- INSERM UMR 1141, Hôpital Robert Debré, Paris, France.,Université Paris 7, Faculté de Médecine Denis Diderot, Paris, France
| | - Sylvia Franc
- Centre Hospitalier Sud Francilien and CERITD, Evry Cedex, France
| | | | - Denis Furling
- Sorbonne Universités, UPMC Université Paris 06, Centre de Recherche en Myologie, INSERM UMRS974, CNRS FRE3617, Institut de Myologie, Paris 75013, France
| | - Guillaume Bassez
- GH Henri Mondor, Inserm U955, Université Paris Est, Créteil, France
| | | | | | | | | |
Collapse
|
14
|
Rau F, Lainé J, Ramanoudjame L, Ferry A, Arandel L, Delalande O, Jollet A, Dingli F, Lee KY, Peccate C, Lorain S, Kabashi E, Athanasopoulos T, Koo T, Loew D, Swanson MS, Le Rumeur E, Dickson G, Allamand V, Marie J, Furling D. Abnormal splicing switch of DMD's penultimate exon compromises muscle fibre maintenance in myotonic dystrophy. Nat Commun 2015; 6:7205. [PMID: 26018658 PMCID: PMC4458869 DOI: 10.1038/ncomms8205] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/16/2015] [Indexed: 02/06/2023] Open
Abstract
Myotonic Dystrophy type 1 (DM1) is a dominant neuromuscular disease caused by nuclear-retained RNAs containing expanded CUG repeats. These toxic RNAs alter the activities of RNA splicing factors resulting in alternative splicing misregulation and muscular dysfunction. Here we show that the abnormal splicing of DMD exon 78 found in dystrophic muscles of DM1 patients is due to the functional loss of MBNL1 and leads to the re-expression of an embryonic dystrophin in place of the adult isoform. Forced expression of embryonic dystrophin in zebrafish using an exon-skipping approach severely impairs the mobility and muscle architecture. Moreover, reproducing Dmd exon 78 missplicing switch in mice induces muscle fibre remodelling and ultrastructural abnormalities including ringed fibres, sarcoplasmic masses or Z-band disorganization, which are characteristic features of dystrophic DM1 skeletal muscles. Thus, we propose that splicing misregulation of DMD exon 78 compromises muscle fibre maintenance and contributes to the progressive dystrophic process in DM1.
Collapse
Affiliation(s)
- Frédérique Rau
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Institut de Myologie, GH Pitié-Salpêtrière, F-75013 Paris, France
| | - Jeanne Lainé
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Institut de Myologie, GH Pitié-Salpêtrière, F-75013 Paris, France.,Sorbonne Universités, UPMC Paris 06, Département de Physiologie, Site Pitié-Salpêtrière, F-75013 Paris, France
| | - Laetitita Ramanoudjame
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Institut de Myologie, GH Pitié-Salpêtrière, F-75013 Paris, France
| | - Arnaud Ferry
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Institut de Myologie, GH Pitié-Salpêtrière, F-75013 Paris, France
| | - Ludovic Arandel
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Institut de Myologie, GH Pitié-Salpêtrière, F-75013 Paris, France
| | - Olivier Delalande
- Université de Rennes 1, Institut de Génétique et Développement de Rennes, F-35043 Rennes, France
| | - Arnaud Jollet
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Institut de Myologie, GH Pitié-Salpêtrière, F-75013 Paris, France
| | - Florent Dingli
- Institut Curie, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, F-75005 Paris, France
| | - Kuang-Yung Lee
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, Florida 32610, USA.,Department of Neurology, Chang Gung Memorial Hospital, Keelung 204, Taiwan
| | - Cécile Peccate
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Institut de Myologie, GH Pitié-Salpêtrière, F-75013 Paris, France
| | - Stéphanie Lorain
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Institut de Myologie, GH Pitié-Salpêtrière, F-75013 Paris, France
| | - Edor Kabashi
- Sorbonne Université, UPMC Univ Paris 06, UM 75, INSERM U1127, CNRS UMR7225, ICM, Paris, F-75013 Paris, France
| | - Takis Athanasopoulos
- School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey, TW20 0EX, UK
| | - Taeyoung Koo
- School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey, TW20 0EX, UK
| | - Damarys Loew
- Institut Curie, Centre de Recherche, Laboratoire de Spectrométrie de Masse Protéomique, F-75005 Paris, France
| | - Maurice S Swanson
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, Florida 32610, USA
| | - Elisabeth Le Rumeur
- Université de Rennes 1, Institut de Génétique et Développement de Rennes, F-35043 Rennes, France
| | - George Dickson
- School of Biological Sciences, Royal Holloway-University of London, Egham, Surrey, TW20 0EX, UK
| | - Valérie Allamand
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Institut de Myologie, GH Pitié-Salpêtrière, F-75013 Paris, France
| | - Joëlle Marie
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Institut de Myologie, GH Pitié-Salpêtrière, F-75013 Paris, France
| | - Denis Furling
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Center for Research in Myology, Institut de Myologie, GH Pitié-Salpêtrière, F-75013 Paris, France
| |
Collapse
|
15
|
González-Barriga A, Kranzen J, Croes HJE, Bijl S, van den Broek WJAA, van Kessel IDG, van Engelen BGM, van Deutekom JCT, Wieringa B, Mulders SAM, Wansink DG. Cell membrane integrity in myotonic dystrophy type 1: implications for therapy. PLoS One 2015; 10:e0121556. [PMID: 25799359 PMCID: PMC4370802 DOI: 10.1371/journal.pone.0121556] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 02/15/2015] [Indexed: 01/04/2023] Open
Abstract
Myotonic Dystrophy type 1 (DM1) is a multisystemic disease caused by toxic RNA from a DMPK gene carrying an expanded (CTG•CAG)n repeat. Promising strategies for treatment of DM1 patients are currently being tested. These include antisense oligonucleotides and drugs for elimination of expanded RNA or prevention of aberrant binding to RNP proteins. A significant hurdle for preclinical development along these lines is efficient systemic delivery of compounds across endothelial and target cell membranes. It has been reported that DM1 patients show elevated levels of markers of muscle damage or loss of sarcolemmal integrity in their serum and that splicing of dystrophin, an essential protein for muscle membrane structure, is abnormal. Therefore, we studied cell membrane integrity in DM1 mouse models commonly used for preclinical testing. We found that membranes in skeletal muscle, heart and brain were impermeable to Evans Blue Dye. Creatine kinase levels in serum were similar to those in wild type mice and expression of dystrophin protein was unaffected. Also in patient muscle biopsies cell surface expression of dystrophin was normal and calcium-positive fibers, indicating elevated intracellular calcium levels, were only rarely seen. Combined, our findings indicate that cells in DM1 tissues do not display compromised membrane integrity. Hence, the cell membrane is a barrier that must be overcome in future work towards effective drug delivery in DM1 therapy.
Collapse
Affiliation(s)
- Anchel González-Barriga
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
- Prosensa Therapeutics B.V., Leiden, The Netherlands
| | - Julia Kranzen
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Huib J. E. Croes
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Suzanne Bijl
- Prosensa Therapeutics B.V., Leiden, The Netherlands
| | - Walther J. A. A. van den Broek
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Ingeborg D. G. van Kessel
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Baziel G. M. van Engelen
- Department of Neurology, Donders Centre for Neuroscience, Radboud university medical center, Nijmegen, The Netherlands
| | | | - Bé Wieringa
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
| | - Susan A. M. Mulders
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
- Prosensa Therapeutics B.V., Leiden, The Netherlands
| | - Derick G. Wansink
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud university medical center, Nijmegen, The Netherlands
- * E-mail:
| |
Collapse
|
16
|
Yamashita Y, Matsuura T, Kurosaki T, Amakusa Y, Kinoshita M, Ibi T, Sahashi K, Ohno K. LDB3 splicing abnormalities are specific to skeletal muscles of patients with myotonic dystrophy type 1 and alter its PKC binding affinity. Neurobiol Dis 2014; 69:200-5. [PMID: 24878509 DOI: 10.1016/j.nbd.2014.05.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 05/06/2014] [Accepted: 05/19/2014] [Indexed: 01/20/2023] Open
Abstract
Myotonic dystrophy type 1 (DM1) is caused by transcription of CUG repeat RNA, which causes sequestration of muscleblind-like 1 (MBNL1) and upregulation of CUG triplet repeat RNA-binding protein (CUG-BP1). In DM1, dysregulation of these proteins contributes to many aberrant splicing events, causing various symptoms of the disorder. Here, we demonstrate the occurrence of aberrant splicing of LIM domain binding 3 (LDB3) exon 11 in DM1 skeletal muscle. Exon array surveys, RT-PCR, and western blotting studies demonstrated that exon 11 inclusion was DM1 specific and could be reproduced by transfection of a minigene containing the CTG repeat expansion. Moreover, we found that the LDB3 exon 11-positive isoform had reduced affinity for PKC compared to the exon 11-negative isoform. Since PKC exhibits hyperactivation in DM1 and stabilizes CUG-BP1 by phosphorylation, aberrant splicing of LDB3 may contribute to CUG-BP1 upregulation through changes in its affinity for PKC.
Collapse
Affiliation(s)
- Yoshihiro Yamashita
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tohru Matsuura
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan; Division of Neurology, Department of Medicine, Jichi Medical University, Shomotsuke, Japan.
| | - Tatsuaki Kurosaki
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yoshinobu Amakusa
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masanobu Kinoshita
- Department of Frontier Health Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, Tokyo, Japan
| | - Tohru Ibi
- Department of Neurology, Aichi Medical University School of Medicine, Aichi, Japan
| | - Ko Sahashi
- Department of Neurology, Aichi Medical University School of Medicine, Aichi, Japan
| | - Kinji Ohno
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
| |
Collapse
|
17
|
Brugada syndrome and abnormal splicing of SCN5A in myotonic dystrophy type 1. Arch Cardiovasc Dis 2013; 106:635-43. [DOI: 10.1016/j.acvd.2013.08.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 08/16/2013] [Accepted: 08/29/2013] [Indexed: 01/22/2023]
|
18
|
Nakamori M, Sobczak K, Puwanant A, Welle S, Eichinger K, Pandya S, Dekdebrun J, Heatwole CR, McDermott MP, Chen T, Cline M, Tawil R, Osborne RJ, Wheeler TM, Swanson M, Moxley RT, Thornton CA. Splicing biomarkers of disease severity in myotonic dystrophy. Ann Neurol 2013; 74:862-72. [PMID: 23929620 PMCID: PMC4099006 DOI: 10.1002/ana.23992] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 06/25/2013] [Accepted: 07/27/2013] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To develop RNA splicing biomarkers of disease severity and therapeutic response in myotonic dystrophy type 1 (DM1) and type 2 (DM2). METHODS In a discovery cohort, we used microarrays to perform global analysis of alternative splicing in DM1 and DM2. The newly identified splicing changes were combined with previous data to create a panel of 50 putative splicing defects. In a validation cohort of 50 DM1 subjects, we measured the strength of ankle dorsiflexion (ADF) and then obtained a needle biopsy of tibialis anterior (TA) to analyze splice events in muscle RNA. The specificity of DM-associated splicing defects was assessed in disease controls. The CTG expansion size in muscle tissue was determined by Southern blot. The reversibility of splicing defects was assessed in transgenic mice by using antisense oligonucleotides to reduce levels of toxic RNA. RESULTS Forty-two splicing defects were confirmed in TA muscle in the validation cohort. Among these, 20 events showed graded changes that correlated with ADF weakness. Five other splice events were strongly affected in DM1 subjects with normal ADF strength. Comparison to disease controls and mouse models indicated that splicing changes were DM-specific, mainly attributable to MBNL1 sequestration, and reversible in mice by targeted knockdown of toxic RNA. Splicing defects and weakness were not correlated with CTG expansion size in muscle tissue. INTERPRETATION Alternative splicing changes in skeletal muscle may serve as biomarkers of disease severity and therapeutic response in myotonic dystrophy.
Collapse
Affiliation(s)
- Masayuki Nakamori
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Krzysztof Sobczak
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Araya Puwanant
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Steve Welle
- Department of Medicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Katy Eichinger
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Shree Pandya
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Jeannne Dekdebrun
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Chad R. Heatwole
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Michael P. McDermott
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
- Department of Biostatistics and Computational Biology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Tian Chen
- Department of Biostatistics and Computational Biology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Melissa Cline
- RNA Center, Department of Molecular, Cell and Developmental Biology, Sinsheimer Labs, University of California, Santa Cruz, California 95064 USA
| | - Rabi Tawil
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Robert J. Osborne
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Thurman M. Wheeler
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
- Center for Neural Development and Disease, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Maurice Swanson
- Department of Molecular Genetics & Microbiology, University of Florida, College of Medicine, Gainesville, FL 32610 USA
| | - Richard T. Moxley
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Charles A. Thornton
- Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA
- Center for Neural Development and Disease, University of Rochester Medical Center, Rochester, NY 14642, USA
- Center for RNA Biology, University of Rochester Medical Center, Rochester, NY 14642, USA
| |
Collapse
|
19
|
Bachinski LL, Baggerly KA, Neubauer VL, Nixon TJ, Raheem O, Sirito M, Unruh AK, Zhang J, Nagarajan L, Timchenko LT, Bassez G, Eymard B, Gamez J, Ashizawa T, Mendell JR, Udd B, Krahe R. Most expression and splicing changes in myotonic dystrophy type 1 and type 2 skeletal muscle are shared with other muscular dystrophies. Neuromuscul Disord 2013; 24:227-40. [PMID: 24332166 DOI: 10.1016/j.nmd.2013.11.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 10/30/2013] [Accepted: 11/07/2013] [Indexed: 12/20/2022]
Abstract
The prevailing pathomechanistic paradigm for myotonic dystrophy (DM) is that aberrant expression of embryonic/fetal mRNA/protein isoforms accounts for most aspects of the pleiotropic phenotype. To identify aberrant isoforms in skeletal muscle of DM1 and DM2 patients, we performed exon-array profiling and RT-PCR validation on the largest DM sample set to date, including Duchenne, Becker and tibial muscular dystrophy (NMD) patients as disease controls, and non-disease controls. Strikingly, most expression and splicing changes in DM patients were shared with NMD controls. Comparison between DM and NMD identified almost no significant differences. We conclude that DM1 and DM2 are essentially identical for dysregulation of gene expression, and DM expression changes represent a subset of broader spectrum dystrophic changes. We found no evidence for qualitative splicing differences between DM1 and DM2. While some DM-specific splicing differences exist, most of the DM splicing differences were also seen in NMD controls. SSBP3 exon 6 missplicing was observed in all diseased muscle and led to reduced protein. We conclude there is no widespread DM-specific spliceopathy in skeletal muscle and suggest that missplicing in DM (and NMD) may not be the driving mechanism for the muscle pathology, since the same pathways show expression changes unrelated to splicing.
Collapse
Affiliation(s)
- Linda L Bachinski
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Keith A Baggerly
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Valerie L Neubauer
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Tamara J Nixon
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Olayinka Raheem
- Department of Neurology, Tampere University Hospital and Medical School, Tampere, Finland
| | - Mario Sirito
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Anna K Unruh
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jiexin Zhang
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Lalitha Nagarajan
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Lubov T Timchenko
- Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, TX, USA
| | - Guillaume Bassez
- Neuromuscular Reference Center, Henri Mondor University Hospital, INSERM U955, East-Paris University, Créteil, France
| | - Bruno Eymard
- Reference Center for Neuromuscular Diseases, Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France
| | - Josep Gamez
- Neuromuscular Disorders Clinic, Neurology Department, Hospital General Vall d'Hebron, Barcelona, Spain
| | - Tetsuo Ashizawa
- Department of Neurology, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Jerry R Mendell
- Division of Child Neurology, Nationwide Childrens Hospital, Ohio State University College of Medicine, Columbus, OH, USA
| | - Bjarne Udd
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX, USA; Folkhälsan Institute of Genetics and Department of Medical Genetics, University of Helsinki, Finland; Department of Neurology, Vasa Central Hospital, Finland
| | - Ralf Krahe
- Department of Genetics, University of Texas MD Anderson Cancer Center, Houston, TX, USA; Graduate Programs in Human & Molecular Genetics, University of Texas at Houston Graduate School in Biomedical Sciences, Houston, TX, USA; Graduate Programs in Genes & Development, University of Texas at Houston Graduate School in Biomedical Sciences, Houston, TX, USA.
| |
Collapse
|
20
|
Vihola A, Sirito M, Bachinski LL, Raheem O, Screen M, Suominen T, Krahe R, Udd B. Altered expression and splicing of Ca(2+) metabolism genes in myotonic dystrophies DM1 and DM2. Neuropathol Appl Neurobiol 2013; 39:390-405. [PMID: 22758909 DOI: 10.1111/j.1365-2990.2012.01289.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
AIMS Myotonic dystrophy types 1 and 2 (DM1 and DM2) are multisystem disorders caused by similar repeat expansion mutations, with similar yet distinct clinical features. Aberrant splicing of multiple effector genes, as well as dysregulation of transcription and translation, has been suggested to underlie different aspects of the complex phenotypes in DM1 and DM2. Ca(2+) plays a central role in both muscle contraction and control of gene expression, and recent expression profiling studies have indicated major perturbations of the Ca(2+) signalling pathways in DM. Here we have further investigated the expression of genes and proteins involved in Ca(2+) metabolism in DM patients, including Ca(2+) channels and Ca(2+) binding proteins. METHODS We used patient muscle biopsies to analyse mRNA expression and splicing of genes by microarray expression profiling and RT-PCR. We studied protein expression by immunohistochemistry and immunoblotting. RESULTS Most of the genes studied showed mRNA up-regulation in expression profiling. When analysed by immunohistochemistry the Ca(2+) release channel ryanodine receptor was reduced in DM1 and DM2, as was calsequestrin 2, a sarcoplasmic reticulum lumen Ca(2+) storage protein. Abnormal splicing of ATP2A1 was more pronounced in DM2 than DM1. CONCLUSIONS We observed abnormal mRNA and protein expression in DM affecting several proteins involved in Ca(2+) metabolism, with some differences between DM1 and DM2. Our protein expression studies are suggestive of a post-transcriptional defect(s) in the myotonic dystrophies.
Collapse
Affiliation(s)
- A Vihola
- Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland.
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Nakamori M, Takahashi MP. The role of α-dystrobrevin in striated muscle. Int J Mol Sci 2011; 12:1660-71. [PMID: 21673914 PMCID: PMC3111625 DOI: 10.3390/ijms12031660] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 01/29/2011] [Accepted: 02/23/2011] [Indexed: 12/29/2022] Open
Abstract
Muscular dystrophies are a group of diseases that primarily affect striated muscle and are characterized by the progressive loss of muscle strength and integrity. Major forms of muscular dystrophies are caused by the abnormalities of the dystrophin glycoprotein complex (DGC) that plays crucial roles as a structural unit and scaffolds for signaling molecules at the sarcolemma. α-Dystrobrevin is a component of the DGC and directly associates with dystrophin. α-Dystrobrevin also binds to intermediate filaments as well as syntrophin, a modular adaptor protein thought to be involved in signaling. Although no muscular dystrophy has been associated within mutations of the α-dystrobrevin gene, emerging findings suggest potential significance of α-dystrobrevin in striated muscle. This review addresses the functional role of α-dystrobrevin in muscle as well as its possible implication for muscular dystrophy.
Collapse
Affiliation(s)
- Masayuki Nakamori
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2, D-4, Yamadaoka, Suita, Osaka 565-0871, Japan; E-Mail:
- Department of Neurology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 645 URMC, Rochester, NY 14642, USA
| | - Masanori P. Takahashi
- Department of Neurology, Osaka University Graduate School of Medicine, 2-2, D-4, Yamadaoka, Suita, Osaka 565-0871, Japan; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +81-6-6879-3571; Fax: +81-6-6879-3579
| |
Collapse
|
22
|
Abstract
DM1 (myotonic dystrophy type I) is a common form of muscular dystrophy that affects mainly adults. It is a disease that belongs to the group of defective RNA export diseases, since a major part of the pathogenic mechanism of the disease is the retention of the mutant transcripts in the cell nucleus. The presence of an expanded CUG trinucleotide repeat in the 3'-UTR (3'-untranslated region) of the DMPK (myotonic dystrophy protein kinase) gene causes the attraction of RNA-binding proteins by the nuclear-located mutant transcripts. As a result of the occupation of the RNA-binding proteins, there is defective mis-splicing of several cellular transcripts. This is believed to be a major pathogenic mechanism of the disease and any attempt to repair the activities of the RNA-binding proteins or target the mutant transcripts should be beneficial for the patients. Certain approaches have been described in the literature and they demonstrate progress in various directions. The purpose of the present review is to summarize the successful attempts to tackle the pathogenesis caused by nuclear retention of mutant transcripts in myotonic dystrophy and to discuss the possible gains from such approaches.
Collapse
|
23
|
Ward AJ, Rimer M, Killian JM, Dowling JJ, Cooper TA. CUGBP1 overexpression in mouse skeletal muscle reproduces features of myotonic dystrophy type 1. Hum Mol Genet 2010; 19:3614-22. [PMID: 20603324 DOI: 10.1093/hmg/ddq277] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The neuromuscular disease myotonic dystrophy type I (DM1) affects multiple organ systems with the major symptoms being severe muscle weakness, progressive muscle wasting and myotonia. The causative mutation in DM1 is a CTG repeat expansion in the 3'-untranslated region of the DM protein kinase (DMPK) gene. RNA transcribed from the expanded allele contains the expanded CUG repeats and leads to the nuclear depletion of Muscleblind-like 1 (MBNL1) and to the increased steady-state levels of CUG-binding protein 1 (CUGBP1). The pathogenic effects of MBNL1 depletion have previously been tested by the generation of MBNL1 knockout mice, but the consequence of CUGBP1 overexpression in adult muscle is not known. In a DM1 mouse model expressing RNA containing 960 CUG repeats in skeletal muscle, CUGBP1 up-regulation is temporally correlated with severe muscle wasting. In this study, we generated transgenic mice with doxycycline-inducible and skeletal muscle-specific expression of CUGBP1. Adult mouse skeletal muscle overexpressing CUGBP1 reproduces molecular and physiological defects of DM1 tissue. The results from this study strongly suggest that CUGBP1 has a major role in DM1 skeletal muscle pathogenesis.
Collapse
Affiliation(s)
- Amanda J Ward
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | | | | | | | | |
Collapse
|
24
|
Ribonuclear inclusions and MBNL1 nuclear sequestration do not affect myoblast differentiation but alter gene splicing in myotonic dystrophy type 2. Neuromuscul Disord 2009; 19:335-43. [PMID: 19345584 DOI: 10.1016/j.nmd.2009.03.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2009] [Revised: 02/25/2009] [Accepted: 03/03/2009] [Indexed: 12/22/2022]
Abstract
Myotonic dystrophy type 2 (DM2) is an autosomal dominant multisystemic disorder caused by a CCTG expansion in intron 1 of the zinc finger protein 9 gene on chromosome 3. Mutant transcripts are retained in muscle nuclei producing ribonuclear inclusions, which can bind specific RNA-binding proteins leading to a reduction in their activity. The nuclear sequestration of muscleblind-like proteins appears to be involved in splicing defects of genes directly related to the myotonic dystrophy phenotypes. Experimental evidence suggests that ribonuclear inclusions and muscleblind-like protein 1 (MBNL1) sequestration are strongly involved in DM2 pathogenesis. By using fluorescence in situ hybridization in combination with MBNL1-immunofluorescence, we have observed the presence of ribonuclear inclusions and MBNL1 nuclear sequestration at different time points of in vitro myoblast differentiation in each DM2 patient examined. Immunofluorescence and Western blot analysis of several markers of skeletal muscle differentiation reveal that the degree of differentiation of DM2 myoblasts is comparable to that observed in controls. Nevertheless the splicing pattern of the insulin receptor and MBNL1 transcripts, directly related to the DM2 phenotype, appears to be altered in in vitro differentiated DM2 myotubes. Our data seem indicate that the presence of ribonuclear inclusions and MBNL1 nuclear foci are involved in alteration of alternative splicing but do not impair DM2 myogenic differentiation.
Collapse
|
25
|
Friedberg F. Alternative splicing for members of human mosaic domain superfamilies. I. The CH and LIM domains containing group of proteins. Mol Biol Rep 2008; 36:1059-81. [DOI: 10.1007/s11033-008-9281-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Accepted: 05/28/2008] [Indexed: 11/29/2022]
|