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Pharmacotherapy alleviates pathological changes in human direct reprogrammed neuronal cell model of myotonic dystrophy type 1. PLoS One 2022; 17:e0269683. [PMID: 35776705 PMCID: PMC9249217 DOI: 10.1371/journal.pone.0269683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 05/25/2022] [Indexed: 12/02/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a trinucleotide repeat disorder affecting multiple organs. However, most of the research is focused on studying and treating its muscular symptoms. On the other hand, despite the significant impact of the neurological symptoms on patients’ quality of life, no drug therapy was studied due to insufficient reproducibility in DM1 brain-specific animal models. To establish DM1 neuronal model, human skin fibroblasts were directly converted into neurons by using lentivirus expressing small hairpin RNA (shRNA) against poly-pyrimidine tract binding protein (PTBP). We found faster degeneration in DM1 human induced neurons (DM1 hiNeurons) compared to control human induced neurons (ctrl hiNeurons), represented by lower viability from 10 days post viral-infection (DPI) and abnormal axonal growth at 15 DPI. Nuclear RNA foci were present in most of DM1 hiNeurons at 10 DPI. Furthermore, DM1 hiNeurons modelled aberrant splicing of MBNL1 and 2, MAPT, CSNK1D and MPRIP at 10 DPI. We tested two drugs that were shown to be effective for DM1 in non-neuronal model and found that treatment of DM1 hiNeurons with 100 nM or 200 nM actinomycin D (ACT) for 24 h resulted in more than 50% reduction in the number of RNA foci per nucleus in a dose dependent manner, with 16.5% reduction in the number of nuclei containing RNA foci at 200 nM and treatment with erythromycin at 35 μM or 65 μM for 48 h rescued mis-splicing of MBNL1 exon 5 and MBNL 2 exons 5 and 8 up to 17.5%, 10% and 8.5%, respectively. Moreover, erythromycin rescued the aberrant splicing of MAPT exon 2, CSNK1D exon 9 and MPRIP exon 9 to a maximum of 46.4%, 30.7% and 19.9%, respectively. These results prove that our model is a promising tool for detailed pathogenetic examination and novel drug screening for the nervous system.
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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.
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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
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Degener MJF, van Cruchten RTP, Otero BA, Wang E, Wansink DG, ‘t Hoen PAC. A comprehensive atlas of fetal splicing patterns in the brain of adult myotonic dystrophy type 1 patients. NAR Genom Bioinform 2022; 4:lqac016. [PMID: 35274098 PMCID: PMC8903011 DOI: 10.1093/nargab/lqac016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 01/28/2022] [Accepted: 02/13/2022] [Indexed: 11/14/2022] Open
Abstract
In 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.
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Affiliation(s)
- Max J F Degener
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Remco T P van Cruchten
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Brittney A Otero
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics, Genetics Institute, University of Florida, FL 32610-0266 Gainesville, FL, USA
| | - Eric T Wang
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics, Genetics Institute, University of Florida, FL 32610-0266 Gainesville, FL, USA
| | - Derick G Wansink
- Department of Cell Biology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Peter A C ‘t Hoen
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
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Liu J, Guo ZN, Yan XL, Yang Y, Huang S. Brain Pathogenesis and Potential Therapeutic Strategies in Myotonic Dystrophy Type 1. Front Aging Neurosci 2021; 13:755392. [PMID: 34867280 PMCID: PMC8634727 DOI: 10.3389/fnagi.2021.755392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Accepted: 10/20/2021] [Indexed: 12/17/2022] Open
Abstract
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.
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Affiliation(s)
- Jie Liu
- Department of Neurology, Stroke Center & Clinical Trial and Research Center for Stroke, The First Hospital of Jilin University, Changchun, China
- China National Comprehensive Stroke Center, Changchun, China
- Jilin Provincial Key Laboratory of Cerebrovascular Disease, Changchun, China
| | - Zhen-Ni Guo
- Department of Neurology, Stroke Center & Clinical Trial and Research Center for Stroke, The First Hospital of Jilin University, Changchun, China
- China National Comprehensive Stroke Center, Changchun, China
- Jilin Provincial Key Laboratory of Cerebrovascular Disease, Changchun, China
| | - Xiu-Li Yan
- Department of Neurology, Stroke Center & Clinical Trial and Research Center for Stroke, The First Hospital of Jilin University, Changchun, China
| | - Yi Yang
- Department of Neurology, Stroke Center & Clinical Trial and Research Center for Stroke, The First Hospital of Jilin University, Changchun, China
- China National Comprehensive Stroke Center, Changchun, China
- Jilin Provincial Key Laboratory of Cerebrovascular Disease, Changchun, China
| | - Shuo Huang
- Department of Neurology, Stroke Center & Clinical Trial and Research Center for Stroke, The First Hospital of Jilin University, Changchun, China
- China National Comprehensive Stroke Center, Changchun, China
- Jilin Provincial Key Laboratory of Cerebrovascular Disease, Changchun, China
- *Correspondence: Shuo Huang,
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De Serres-Bérard T, Pierre M, Chahine M, Puymirat J. Deciphering the mechanisms underlying brain alterations and cognitive impairment in congenital myotonic dystrophy. Neurobiol Dis 2021; 160:105532. [PMID: 34655747 DOI: 10.1016/j.nbd.2021.105532] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 09/24/2021] [Accepted: 10/11/2021] [Indexed: 12/13/2022] Open
Abstract
Myotonic dystrophy type 1 (DM1) is a multisystemic and heterogeneous disorder caused by the expansion of CTG repeats in the 3' UTR of the myotonic dystrophy protein kinase (DMPK) gene. There is a congenital form (CDM1) of the disease characterized by severe hypotonia, respiratory insufficiency as well as developmental delays and intellectual disabilities. CDM1 infants manifest important brain structure abnormalities present from birth while, in contrast, older patients with adult-onset DM1 often present neurodegenerative features and milder progressive cognitive deficits. Promising therapies targeting central molecular mechanisms contributing to the symptoms of adult-onset DM1 are currently in development, but their relevance for treating cognitive impairment in CDM1, which seems to be a partially distinct neurodevelopmental disorder, remain to be elucidated. Here, we provide an update on the clinical presentation of CDM1 and review recent in vitro and in vivo models that have provided meaningful insights on its consequences in development, with a particular focus on the brain. We discuss how enhanced toxic gain-of-function of the mutated DMPK transcripts with larger CUG repeats and the resulting dysregulation of RNA-binding proteins may affect the developing cortex in utero. Because the methylation of CpG islets flanking the trinucleotide repeats has emerged as a strong biomarker of CDM1, we highlight the need to investigate the tissue-specific impacts of these chromatin modifications in the brain. Finally, we outline promising potential therapeutic treatments for CDM1 and propose future in vitro and in vivo models with great potential to shed light on this disease.
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Affiliation(s)
- Thiéry De Serres-Bérard
- LOEX, CHU de Québec-Université Laval Research Center, Quebec City, Canada; CERVO Brain Research Center, Institut universitaire en santé mentale de Québec, Quebec City, Canada
| | - Marion Pierre
- CERVO Brain Research Center, Institut universitaire en santé mentale de Québec, Quebec City, Canada
| | - Mohamed Chahine
- CERVO Brain Research Center, Institut universitaire en santé mentale de Québec, Quebec City, Canada; Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, Canada.
| | - Jack Puymirat
- LOEX, CHU de Québec-Université Laval Research Center, Quebec City, Canada; Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, Canada
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Otero BA, Poukalov K, Hildebrandt RP, Thornton CA, Jinnai K, Fujimura H, Kimura T, Hagerman KA, Sampson JB, Day JW, Wang ET. Transcriptome alterations in myotonic dystrophy frontal cortex. Cell Rep 2021; 34:108634. [PMID: 33472074 PMCID: PMC9272850 DOI: 10.1016/j.celrep.2020.108634] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/16/2020] [Accepted: 12/21/2020] [Indexed: 12/13/2022] Open
Abstract
Myotonic dystrophy (DM) is caused by expanded CTG/CCTG repeats, causing symptoms in skeletal muscle, heart, and central nervous system (CNS). CNS issues are debilitating and include hypersomnolence, executive dysfunction, white matter atrophy, and neurofibrillary tangles. Here, we generate RNA-seq transcriptomes from DM and unaffected frontal cortex and identify 130 high-confidence splicing changes, most occurring only in cortex, not skeletal muscle or heart. Mis-spliced exons occur in neurotransmitter receptors, ion channels, and synaptic scaffolds, and GRIP1 mis-splicing modulates kinesin association. Optical mapping of expanded CTG repeats reveals extreme mosaicism, with some alleles showing >1,000 CTGs. Mis-splicing severity correlates with CTG repeat length across individuals. Upregulated genes tend to be microglial and endothelial, suggesting neuroinflammation, and downregulated genes tend to be neuronal. Many gene expression changes strongly correlate with mis-splicing, suggesting candidate biomarkers of disease. These findings provide a framework for mechanistic and therapeutic studies of the DM CNS. Otero et al. characterize DM1 frontal cortex transcriptomes and observe extreme CTG repeat lengths even in individuals showing modest mis-splicing. Mis-splicing is enriched in ion channels, neurotransmitter receptors, and synaptic scaffolds, in some cases potentially altering synaptic trafficking. Inferred expression signatures from microglia and endothelial cells suggest neuroinflammation.
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Affiliation(s)
- Brittney A Otero
- Department of Molecular Genetics & Microbiology, Center for NeuroGenetics, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Kiril Poukalov
- Department of Molecular Genetics & Microbiology, Center for NeuroGenetics, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Ryan P Hildebrandt
- Department of Molecular Genetics & Microbiology, Center for NeuroGenetics, Genetics Institute, University of Florida, Gainesville, FL, USA
| | - Charles A Thornton
- Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA
| | - Kenji Jinnai
- Department of Neurology, National Hospital Organization Hyogo-Chuo Hospital, Sanda, Japan
| | - Harutoshi Fujimura
- Department of Neurology, National Hospital Organization Toneyama Hospital, Osaka, Japan
| | - Takashi Kimura
- Department of Neurology, Hyogo College of Medicine, Nichinomiya, Japan
| | | | | | - John W Day
- Department of Neurology, Stanford University, Palo Alto, CA, USA
| | - Eric T Wang
- Department of Molecular Genetics & Microbiology, Center for NeuroGenetics, Genetics Institute, University of Florida, Gainesville, FL, USA.
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