1
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Assessment of PABPN1 nuclear inclusions on a large cohort of patients and in a human xenograft model of oculopharyngeal muscular dystrophy. Acta Neuropathol 2022; 144:1157-1170. [PMID: 36197469 PMCID: PMC9637588 DOI: 10.1007/s00401-022-02503-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 08/26/2022] [Accepted: 09/17/2022] [Indexed: 01/26/2023]
Abstract
Oculopharyngeal muscular dystrophy (OPMD) is a rare muscle disease characterized by an onset of weakness in the pharyngeal and eyelid muscles. The disease is caused by the extension of a polyalanine tract in the Poly(A) Binding Protein Nuclear 1 (PABPN1) protein leading to the formation of intranuclear inclusions or aggregates in the muscle of OPMD patients. Despite numerous studies stressing the deleterious role of nuclear inclusions in cellular and animal OPMD models, their exact contribution to human disease is still unclear. In this study, we used a large and unique collection of human muscle biopsy samples to perform an in-depth analysis of PABPN1 aggregates in relation to age, genotype and muscle status with the final aim to improve our understanding of OPMD physiopathology. Here we demonstrate that age and genotype influence PABPN1 aggregates: the percentage of myonuclei containing PABPN1 aggregates increases with age and the chaperone HSP70 co-localize more frequently with PABPN1 aggregates with a larger polyalanine tract. In addition to the previously described PRMT1 and HSP70 co-factors, we identified new components of PABPN1 aggregates including GRP78/BiP, RPL24 and p62. We also observed that myonuclei containing aggregates are larger than myonuclei without. When comparing two muscles from the same patient, a similar amount of aggregates is observed in different muscles, except for the pharyngeal muscle where fewer aggregates are observed. This could be due to the peculiar nature of this muscle which has a low level of PAPBN1 and contains regenerating fibers. To confirm the fate of PABPN1 aggregates in a regenerating muscle, we generated a xenograft model by transplanting human OPMD muscle biopsy samples into the hindlimb of an immunodeficient mouse. Xenografts from subjects with OPMD displayed regeneration of human myofibers and PABPN1 aggregates were rapidly present-although to a lower extent-after muscle fiber regeneration. Our data obtained on human OPMD samples add support to the dual non-exclusive models in OPMD combining toxic PABPN1 intranuclear inclusions together with PABPN1 loss of function which altogether result in this late-onset and muscle selective disease.
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2
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Boulinguiez A, Roth F, Mouigni HR, Butler-Browne G, Mouly V, Trollet C. [Nuclear aggregates in oculopharyngeal muscular dystrophy]. Med Sci (Paris) 2022; 38 Hors série n° 1:13-16. [PMID: 36649629 DOI: 10.1051/medsci/2022175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Oculopharyngeal muscular dystrophy (OPMD) is one of the diseases related to pathological expansions of trinucleotides. Its pathogenesis remains unclear although the presence of aggregates within the nuclei of the muscle fiber seems to play an important role. The basic research studies presented here help understand their composition and their deleterious role. These elements may result in new therapeutic avenues.
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Affiliation(s)
- Alexis Boulinguiez
- Sorbonne Université-Inserm, Centre de Recherche en Myologie, Institut de Myologie, Paris, France
| | - Fany Roth
- Sorbonne Université-Inserm, Centre de Recherche en Myologie, Institut de Myologie, Paris, France
| | - Hadidja Rose Mouigni
- Sorbonne Université-Inserm, Centre de Recherche en Myologie, Institut de Myologie, Paris, France
| | - Gillian Butler-Browne
- Sorbonne Université-Inserm, Centre de Recherche en Myologie, Institut de Myologie, Paris, France
| | - Vincent Mouly
- Sorbonne Université-Inserm, Centre de Recherche en Myologie, Institut de Myologie, Paris, France
| | - Capucine Trollet
- Sorbonne Université-Inserm, Centre de Recherche en Myologie, Institut de Myologie, Paris, France
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3
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Zhang Y, Zeuthen C, Zhu C, Wu F, Mezzell AT, Whitlow TJ, Choo HJ, Vest KE. Pharyngeal pathology in a mouse model of oculopharyngeal muscular dystrophy is associated with impaired basal autophagy in myoblasts. Front Cell Dev Biol 2022; 10:986930. [PMID: 36313551 PMCID: PMC9614327 DOI: 10.3389/fcell.2022.986930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 09/26/2022] [Indexed: 11/05/2023] Open
Abstract
Oculopharyngeal muscular dystrophy (OPMD) is a late-onset dominant disease that primarily affects craniofacial muscles. Despite the fact that the genetic cause of OPMD is known to be expansion mutations in the gene encoding the nuclear polyadenosine RNA binding protein PABPN1, the molecular mechanisms of pathology are unknown and no pharmacologic treatments are available. Due to the limited availability of patient tissues, several animal models have been employed to study the pathology of OPMD. However, none of these models have demonstrated functional deficits in the muscles of the pharynx, which are predominantly affected by OPMD. Here, we used a knock-in mouse model of OPMD, Pabpn1 +/A17 , that closely genocopies patients. In Pabpn1 +/A17 mice, we detected impaired pharyngeal muscle function, and impaired pharyngeal satellite cell proliferation and fusion. Molecular studies revealed that basal autophagy, which is required for normal satellite cell function, is higher in pharynx-derived myoblasts than in myoblasts derived from limb muscles. Interestingly, basal autophagy is impaired in cells derived from Pabpn1 +/A17 mice. Pabpn1 knockdown in pharyngeal myoblasts failed to recapitulate the autophagy defect detected in Pabpn1 +/A17 myoblasts suggesting that loss of PABPN1 function does not contribute to the basal autophagy defect. Taken together, these studies provide the first evidence for pharyngeal muscle and satellite cell pathology in a mouse model of OPMD and suggest that aberrant gain of PABPN1 function contributes to the craniofacial pathology in OPMD.
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Affiliation(s)
- Yu Zhang
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Christopher Zeuthen
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Carol Zhu
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Fang Wu
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Allison T. Mezzell
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Thomas J. Whitlow
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Hyojung J. Choo
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, United States
| | - Katherine E. Vest
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, United States
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4
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Fujiwara N, Shigemoto M, Hirayama M, Fujita KI, Seno S, Matsuda H, Nagahama M, Masuda S. MPP6 stimulates both RRP6 and DIS3 to degrade a specified subset of MTR4-sensitive substrates in the human nucleus. Nucleic Acids Res 2022; 50:8779-8806. [PMID: 35902094 PMCID: PMC9410898 DOI: 10.1093/nar/gkac559] [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: 09/24/2021] [Revised: 06/10/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022] Open
Abstract
Recent in vitro reconstitution analyses have proven that the physical interaction between the exosome core and MTR4 helicase, which promotes the exosome activity, is maintained by either MPP6 or RRP6. However, knowledge regarding the function of MPP6 with respect to in vivo exosome activity remains scarce. Here, we demonstrate a facilitative function of MPP6 that composes a specific part of MTR4-dependent substrate decay by the human exosome. Using RNA polymerase II-transcribed poly(A)+ substrate accumulation as an indicator of a perturbed exosome, we found functional redundancy between RRP6 and MPP6 in the decay of these poly(A)+ transcripts. MTR4 binding to the exosome core via MPP6 was essential for MPP6 to exert its redundancy with RRP6. However, at least for the decay of our identified exosome substrates, MTR4 recruitment by MPP6 was not functionally equivalent to recruitment by RRP6. Genome-wide classification of substrates based on their sensitivity to each exosome component revealed that MPP6 deals with a specific range of substrates and highlights the importance of MTR4 for their decay. Considering recent findings of competitive binding to the exosome between auxiliary complexes, our results suggest that the MPP6-incorporated MTR4-exosome complex is one of the multiple alternative complexes rather than the prevailing one.
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Affiliation(s)
- Naoko Fujiwara
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan
| | - Maki Shigemoto
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan
| | - Mizuki Hirayama
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan
| | - Ken-Ichi Fujita
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan.,Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Shigeto Seno
- Graduate School of Information Science and Technology, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hideo Matsuda
- Graduate School of Information Science and Technology, Osaka University, Suita, Osaka 565-0871, Japan
| | - Masami Nagahama
- Laboratory of Molecular and Cellular Biochemistry, Meiji Pharmaceutical University, Kiyose, Tokyo 204-8588, Japan
| | - Seiji Masuda
- Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto 606-8502, Japan.,Department of Food Science and Nutrition, Faculty of Agriculture Kindai University, Nara, Nara 631-8505, Japan.,Agricultural Technology and Innovation Research Institute, Kindai University, Nara, Nara 631-8505, Japan.,Antiaging center, Kindai University, Higashiosaka, Osaka 577-8502, Japan
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5
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Ribot C, Soler C, Chartier A, Al Hayek S, Naït-Saïdi R, Barbezier N, Coux O, Simonelig M. Activation of the ubiquitin-proteasome system contributes to oculopharyngeal muscular dystrophy through muscle atrophy. PLoS Genet 2022; 18:e1010015. [PMID: 35025870 PMCID: PMC8791501 DOI: 10.1371/journal.pgen.1010015] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 01/26/2022] [Accepted: 01/01/2022] [Indexed: 12/05/2022] Open
Abstract
Oculopharyngeal muscular dystrophy (OPMD) is a late-onset disorder characterized by progressive weakness and degeneration of specific muscles. OPMD is due to extension of a polyalanine tract in poly(A) binding protein nuclear 1 (PABPN1). Aggregation of the mutant protein in muscle nuclei is a hallmark of the disease. Previous transcriptomic analyses revealed the consistent deregulation of the ubiquitin-proteasome system (UPS) in OPMD animal models and patients, suggesting a role of this deregulation in OPMD pathogenesis. Subsequent studies proposed that UPS contribution to OPMD involved PABPN1 aggregation. Here, we use a Drosophila model of OPMD to address the functional importance of UPS deregulation in OPMD. Through genome-wide and targeted genetic screens we identify a large number of UPS components that are involved in OPMD. Half dosage of UPS genes reduces OPMD muscle defects suggesting a pathological increase of UPS activity in the disease. Quantification of proteasome activity confirms stronger activity in OPMD muscles, associated with degradation of myofibrillar proteins. Importantly, improvement of muscle structure and function in the presence of UPS mutants does not correlate with the levels of PABPN1 aggregation, but is linked to decreased degradation of muscle proteins. Oral treatment with the proteasome inhibitor MG132 is beneficial to the OPMD Drosophila model, improving muscle function although PABPN1 aggregation is enhanced. This functional study reveals the importance of increased UPS activity that underlies muscle atrophy in OPMD. It also provides a proof-of-concept that inhibitors of proteasome activity might be an attractive pharmacological approach for OPMD. Oculopharyngeal muscular dystrophy (OPMD) is a genetic disease characterized by progressive weakness of specific muscles, leading to swallowing difficulties (dysphagia), eyelid drooping (ptosis) and walking difficulties at later stages. No drug treatments are currently available. OPMD is due to mutations in a nuclear protein called poly(A) binding protein nuclear 1 (PABPN1) that is involved in processing of different classes of RNAs in the nucleus. We have used an animal model of OPMD that we have developed in the fly Drosophila to investigate the role in OPMD of the ubiquitin-proteasome system, a pathway specialized in protein degradation. We report an increased activity of the ubiquitin-proteasome system that is associated with degradation of muscular proteins in the OPMD Drosophila model. We propose that higher activity of the ubiquitin-proteasome system leads to muscle atrophy in OPMD. Importantly, oral treatment of this OPMD animal model with an inhibitor of proteasome activity reduces muscle defects. A number of proteasome inhibitors are approved drugs used in clinic against cancers, therefore our results provide a proof-of-concept that inhibitors of proteasome might be of interest in future treatments of OPMD.
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Affiliation(s)
- Cécile Ribot
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, Montpellier, France
| | - Cédric Soler
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, Montpellier, France
| | - Aymeric Chartier
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, Montpellier, France
| | - Sandy Al Hayek
- GReD Laboratory, Clermont-Auvergne University, INSERM U1103, CNRS UMR6293, Clermont-Ferrand, France
| | - Rima Naït-Saïdi
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, Montpellier, France
| | - Nicolas Barbezier
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, Montpellier, France
| | - Olivier Coux
- Ubiquitin-proteasome system and cell cycle control, Montpellier Cell Biology Research Center, UMR5237 CNRS-Univ Montpellier, Montpellier, France
| | - Martine Simonelig
- mRNA Regulation and Development, Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, Montpellier, France
- * E-mail:
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Rasmussen M, Jin JP. Troponin Variants as Markers of Skeletal Muscle Health and Diseases. Front Physiol 2021; 12:747214. [PMID: 34733179 PMCID: PMC8559874 DOI: 10.3389/fphys.2021.747214] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 09/01/2021] [Indexed: 12/21/2022] Open
Abstract
Ca2 +-regulated contractility is a key determinant of the quality of muscles. The sarcomeric myofilament proteins are essential players in the contraction of striated muscles. The troponin complex in the actin thin filaments plays a central role in the Ca2+-regulation of muscle contraction and relaxation. Among the three subunits of troponin, the Ca2+-binding subunit troponin C (TnC) is a member of the calmodulin super family whereas troponin I (TnI, the inhibitory subunit) and troponin T (TnT, the tropomyosin-binding and thin filament anchoring subunit) are striated muscle-specific regulatory proteins. Muscle type-specific isoforms of troponin subunits are expressed in fast and slow twitch fibers and are regulated during development and aging, and in adaptation to exercise or disuse. TnT also evolved with various alternative splice forms as an added capacity of muscle functional diversity. Mutations of troponin subunits cause myopathies. Owing to their physiological and pathological importance, troponin variants can be used as specific markers to define muscle quality. In this focused review, we will explore the use of troponin variants as markers for the fiber contents, developmental and differentiation states, contractile functions, and physiological or pathophysiological adaptations of skeletal muscle. As protein structure defines function, profile of troponin variants illustrates how changes at the myofilament level confer functional qualities at the fiber level. Moreover, understanding of the role of troponin modifications and mutants in determining muscle contractility in age-related decline of muscle function and in myopathies informs an approach to improve human health.
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Affiliation(s)
- Monica Rasmussen
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, United States
| | - Jian-Ping Jin
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, United States
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, United States
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7
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Bamia A, Sinane M, Naït-Saïdi R, Dhiab J, Keruzoré M, Nguyen PH, Bertho A, Soubigou F, Halliez S, Blondel M, Trollet C, Simonelig M, Friocourt G, Béringue V, Bihel F, Voisset C. Anti-prion Drugs Targeting the Protein Folding Activity of the Ribosome Reduce PABPN1 Aggregation. Neurotherapeutics 2021; 18:1137-1150. [PMID: 33533011 PMCID: PMC8423950 DOI: 10.1007/s13311-020-00992-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2020] [Indexed: 01/10/2023] Open
Abstract
Prion diseases are caused by the propagation of PrPSc, the pathological conformation of the PrPC prion protein. The molecular mechanisms underlying PrPSc propagation are still unsolved and no therapeutic solution is currently available. We thus sought to identify new anti-prion molecules and found that flunarizine inhibited PrPSc propagation in cell culture and significantly prolonged survival of prion-infected mice. Using an in silico therapeutic repositioning approach based on similarities with flunarizine chemical structure, we tested azelastine, duloxetine, ebastine, loperamide and metixene and showed that they all have an anti-prion activity. Like flunarizine, these marketed drugs reduced PrPSc propagation in cell culture and in mouse cerebellum organotypic slice culture, and inhibited the protein folding activity of the ribosome (PFAR). Strikingly, some of these drugs were also able to alleviate phenotypes due to PABPN1 nuclear aggregation in cell and Drosophila models of oculopharyngeal muscular dystrophy (OPMD). These data emphasize the therapeutic potential of anti-PFAR drugs for neurodegenerative and neuromuscular proteinopathies.
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Affiliation(s)
- Aline Bamia
- Inserm, Univ Brest, EFS, UMR 1078, GGB, F-29200, Brest, France
| | - Maha Sinane
- Inserm, Univ Brest, EFS, UMR 1078, GGB, F-29200, Brest, France
| | - Rima Naït-Saïdi
- Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, mRNA Regulation and Development, Montpellier, France
| | - Jamila Dhiab
- Sorbanne Université, Inserm, Institut de Myologie, Centre de Recherche en Myologie, F75013, Paris, France
| | - Marc Keruzoré
- Inserm, Univ Brest, EFS, UMR 1078, GGB, F-29200, Brest, France
| | - Phu Hai Nguyen
- Inserm, Univ Brest, EFS, UMR 1078, GGB, F-29200, Brest, France
- Host Parasite Interactions Section, Laboratory of Intracellular Parasites, NIAID, NIH, Rocky Mountain Laboratories, Hamilton, MT, USA
| | - Agathe Bertho
- Inserm, Univ Brest, EFS, UMR 1078, GGB, F-29200, Brest, France
| | - Flavie Soubigou
- Inserm, Univ Brest, EFS, UMR 1078, GGB, F-29200, Brest, France
- Centre for Gene Regulation and Expression, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Sophie Halliez
- INRAE, UVSQ, VIM, Université Paris-Saclay, Jouy-en-Josas, France
- Inserm, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, Univ. Lille, F-59000, Lille, France
| | - Marc Blondel
- Inserm, Univ Brest, EFS, UMR 1078, GGB, F-29200, Brest, France
| | - Capucine Trollet
- Sorbanne Université, Inserm, Institut de Myologie, Centre de Recherche en Myologie, F75013, Paris, France
| | - Martine Simonelig
- Institute of Human Genetics, UMR9002 CNRS-Univ Montpellier, mRNA Regulation and Development, Montpellier, France
| | | | - Vincent Béringue
- INRAE, UVSQ, VIM, Université Paris-Saclay, Jouy-en-Josas, France
| | - Frédéric Bihel
- Laboratoire d'Innovation Thérapeutique, LIT, UMR7200, IMS MEDALIS, Faculty of Pharmacy, CNRS, Université de Strasbourg, Illkirch, F-67400, France.
| | - Cécile Voisset
- Inserm, Univ Brest, EFS, UMR 1078, GGB, F-29200, Brest, France.
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Zhang J, Ao Y, Zhang Z, Mo Y, Peng L, Jiang Y, Wang Z, Liu B. Lamin A safeguards the m 6 A methylase METTL14 nuclear speckle reservoir to prevent cellular senescence. Aging Cell 2020; 19:e13215. [PMID: 32813328 PMCID: PMC7576246 DOI: 10.1111/acel.13215] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 04/29/2020] [Accepted: 07/03/2020] [Indexed: 12/28/2022] Open
Abstract
Mutations in LMNA gene are frequently identified in patients suffering from a genetic disorder known as Hutchison–Gilford progeria syndrome (HGPS), providing an ideal model for the understanding of the mechanisms of aging. Lamin A, encoded by LMNA, is an essential component of the subnuclear domain‒nuclear speckles; however, the functional significance in aging is unclear. Here, we show that Lamin A interacts with the m6A methyltransferases, METTL3 and METTL14 in nuclear speckles. Lamin A deficiency compromises the nuclear speckle METTL3/14 reservoir and renders these methylases susceptible to proteasome‐mediated degradation. Moreover, METTL3/14 levels progressively decline in cells undergoing replicative senescence. Overexpression of METTL14 attenuates both replicative senescence and premature senescence. The data reveal an essential role for Lamin A in safeguarding the nuclear speckle reservoir of the m6A methylase METTL14 to antagonize cellular senescence.
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Affiliation(s)
- Jie Zhang
- Shenzhen Key Laboratory for Systemic Aging and Intervention National Engineering Research Center for Biotechnology (Shenzhen) Shenzhen University Shenzhen China
- Department of Biochemistry & Molecular Biology Guangdong Key Laboratory of Genome Stability and Human Disease Prevention School of Basic Medical Sciences Shenzhen University Shenzhen China
- Shenzhen University‐Friedrich Schiller Universität Jena Joint PhD Program Friedrich Schiller Universität Jena Germany
| | - Ying Ao
- Shenzhen Key Laboratory for Systemic Aging and Intervention National Engineering Research Center for Biotechnology (Shenzhen) Shenzhen University Shenzhen China
- Department of Biochemistry & Molecular Biology Guangdong Key Laboratory of Genome Stability and Human Disease Prevention School of Basic Medical Sciences Shenzhen University Shenzhen China
| | - Zhen Zhang
- Shenzhen Key Laboratory for Systemic Aging and Intervention National Engineering Research Center for Biotechnology (Shenzhen) Shenzhen University Shenzhen China
- Department of Biochemistry & Molecular Biology Guangdong Key Laboratory of Genome Stability and Human Disease Prevention School of Basic Medical Sciences Shenzhen University Shenzhen China
- Shenzhen University‐Friedrich Schiller Universität Jena Joint PhD Program Friedrich Schiller Universität Jena Germany
| | - Yanzhen Mo
- Department of Biochemistry & Molecular Biology Guangdong Key Laboratory of Genome Stability and Human Disease Prevention School of Basic Medical Sciences Shenzhen University Shenzhen China
| | - Linyuan Peng
- Shenzhen Key Laboratory for Systemic Aging and Intervention National Engineering Research Center for Biotechnology (Shenzhen) Shenzhen University Shenzhen China
- Department of Biochemistry & Molecular Biology Guangdong Key Laboratory of Genome Stability and Human Disease Prevention School of Basic Medical Sciences Shenzhen University Shenzhen China
| | - Yue Jiang
- Shenzhen Key Laboratory for Systemic Aging and Intervention National Engineering Research Center for Biotechnology (Shenzhen) Shenzhen University Shenzhen China
- Department of Biochemistry & Molecular Biology Guangdong Key Laboratory of Genome Stability and Human Disease Prevention School of Basic Medical Sciences Shenzhen University Shenzhen China
| | - Zimei Wang
- Shenzhen Key Laboratory for Systemic Aging and Intervention National Engineering Research Center for Biotechnology (Shenzhen) Shenzhen University Shenzhen China
- Department of Biochemistry & Molecular Biology Guangdong Key Laboratory of Genome Stability and Human Disease Prevention School of Basic Medical Sciences Shenzhen University Shenzhen China
- Carson International Cancer Center Shenzhen University Shenzhen China
| | - Baohua Liu
- Shenzhen Key Laboratory for Systemic Aging and Intervention National Engineering Research Center for Biotechnology (Shenzhen) Shenzhen University Shenzhen China
- Department of Biochemistry & Molecular Biology Guangdong Key Laboratory of Genome Stability and Human Disease Prevention School of Basic Medical Sciences Shenzhen University Shenzhen China
- Carson International Cancer Center Shenzhen University Shenzhen China
- Guangdong Provincial Key Laboratory of Regional Immunity and Diseases School of Basic Medical Sciences Shenzhen University Health Science Center Shenzhen China
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9
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Malerba A, Klein P, Lu-Nguyen N, Cappellari O, Strings-Ufombah V, Harbaran S, Roelvink P, Suhy D, Trollet C, Dickson G. Established PABPN1 intranuclear inclusions in OPMD muscle can be efficiently reversed by AAV-mediated knockdown and replacement of mutant expanded PABPN1. Hum Mol Genet 2020; 28:3301-3308. [PMID: 31294444 DOI: 10.1093/hmg/ddz167] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 06/21/2019] [Accepted: 07/08/2019] [Indexed: 11/12/2022] Open
Abstract
Oculopharyngeal muscular dystrophy (OPMD) is a rare autosomal dominant late-onset muscular dystrophy affecting approximately 1:100 000 individuals in Europe. OPMD is mainly characterized by progressive eyelid drooping (ptosis) and dysphagia although muscles of the limbs can also be affected late in life. This muscle disease is due to a trinucleotide repeat expansion in the polyA-binding protein nuclear-1 gene. Patients express a protein with an 11-18 alanine tract that is misfolded and prone to form intranuclear inclusions, which are the hallmark of the disease. Other features of OPMD include muscle fibrosis and atrophy in affected muscles. Currently, no pharmacological treatments are available, and OPMD patients can only be referred to surgeons for cricopharyngeal myotomy or corrective surgery of extraocular muscles to ease ptosis. We recently tested a two-AAV `silence' and `replace' vector-based gene therapy treatment in a mouse model of OPMD. We demonstrate here that this gene therapy approach can revert already established insoluble aggregates and partially rescues the muscle from atrophy, which are both crucially important since in most cases OPMD patients already have an established disease when diagnosed. This strategy also prevents the formation of muscle fibrosis and stabilizes the muscle strength to the level of healthy muscles. Furthermore, we show here that similar results can be obtained using a single AAV vector incorporating both the `silence' and `replace' cassettes. These results further support the application of a gene therapy approach as a novel treatment for OPMD in humans.
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Affiliation(s)
- Alberto Malerba
- Centres of Gene and Cell Therapy and Biomedical Sciences, School of Biological Sciences, Royal Holloway, University of London, Egham TW20 0EX, Surrey, UK
| | - Pierre Klein
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, 75013 Paris, France
| | - Ngoc Lu-Nguyen
- Centres of Gene and Cell Therapy and Biomedical Sciences, School of Biological Sciences, Royal Holloway, University of London, Egham TW20 0EX, Surrey, UK
| | - Ornella Cappellari
- Comparative Biomedical Sciences, Royal Veterinary College, London NW1 0TU, UK
| | | | | | | | - David Suhy
- Benitec Biopharma, Hayward, CA 94545, USA
| | - Capucine Trollet
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, 75013 Paris, France
| | - George Dickson
- Centres of Gene and Cell Therapy and Biomedical Sciences, School of Biological Sciences, Royal Holloway, University of London, Egham TW20 0EX, Surrey, UK
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10
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Malerba A, Roth F, Harish P, Dhiab J, Lu-Nguyen N, Cappellari O, Jarmin S, Mahoudeau A, Ythier V, Lainé J, Negroni E, Abgueguen E, Simonelig M, Guedat P, Mouly V, Butler-Browne G, Voisset C, Dickson G, Trollet C. Pharmacological modulation of the ER stress response ameliorates oculopharyngeal muscular dystrophy. Hum Mol Genet 2020; 28:1694-1708. [PMID: 30649389 DOI: 10.1093/hmg/ddz007] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 01/03/2019] [Accepted: 01/03/2019] [Indexed: 12/23/2022] Open
Abstract
Oculopharyngeal muscular dystrophy (OPMD) is a rare late onset genetic disease leading to ptosis, dysphagia and proximal limb muscles at later stages. A short abnormal (GCN) triplet expansion in the polyA-binding protein nuclear 1 (PABPN1) gene leads to PABPN1-containing aggregates in the muscles of OPMD patients. Here we demonstrate that treating mice with guanabenz acetate (GA), an FDA-approved antihypertensive drug, reduces the size and number of nuclear aggregates, improves muscle force, protects myofibers from the pathology-derived turnover and decreases fibrosis. GA targets various cell processes, including the unfolded protein response (UPR), which acts to attenuate endoplasmic reticulum (ER) stress. We demonstrate that GA increases both the phosphorylation of the eukaryotic translation initiation factor 2α subunit and the splicing of Xbp1, key components of the UPR. Altogether these data show that modulation of protein folding regulation is beneficial for OPMD and promote the further development of GA or its derivatives for treatment of OPMD in humans. Furthermore, they support the recent evidences that treating ER stress could be therapeutically relevant in other more common proteinopathies.
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Affiliation(s)
- Alberto Malerba
- School of Biological Sciences, Centers of Gene and Cell Therapy and Biomedical Sciences, Royal Holloway, University of London, TW20 OEX Surrey, UK
| | - Fanny Roth
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | - Pradeep Harish
- School of Biological Sciences, Centers of Gene and Cell Therapy and Biomedical Sciences, Royal Holloway, University of London, TW20 OEX Surrey, UK
| | - Jamila Dhiab
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | - Ngoc Lu-Nguyen
- School of Biological Sciences, Centers of Gene and Cell Therapy and Biomedical Sciences, Royal Holloway, University of London, TW20 OEX Surrey, UK
| | - Ornella Cappellari
- Comparative Biomedical Sciences, The Royal Veterinary College, London, UK
| | - Susan Jarmin
- School of Biological Sciences, Centers of Gene and Cell Therapy and Biomedical Sciences, Royal Holloway, University of London, TW20 OEX Surrey, UK
| | - Alexandrine Mahoudeau
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | - Victor Ythier
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | - Jeanne Lainé
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | - Elisa Negroni
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | | | - Martine Simonelig
- Institute of Human Genetics, CNRS UMR9002-University of Montpellier, mRNA Regulation and Development, Montpellier, France
| | | | - Vincent Mouly
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | - Gillian Butler-Browne
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
| | - Cécile Voisset
- UMR1078 'Genetic, Functional Genomic and Biotechnologies', INSERM, EFS, Brest University, IBSAM, Brest, France
| | - George Dickson
- School of Biological Sciences, Centers of Gene and Cell Therapy and Biomedical Sciences, Royal Holloway, University of London, TW20 OEX Surrey, UK
| | - Capucine Trollet
- Sorbonne Université, INSERM, Association Institut de Myologie, Centre de Recherche en Myologie, UMRS974, 47 bd de l'Hôpital, Paris, France
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11
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Phillips BL, Banerjee A, Sanchez BJ, Di Marco S, Gallouzi IE, Pavlath GK, Corbett AH. Post-transcriptional regulation of Pabpn1 by the RNA binding protein HuR. Nucleic Acids Res 2019; 46:7643-7661. [PMID: 29939290 PMCID: PMC6125628 DOI: 10.1093/nar/gky535] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 06/08/2018] [Indexed: 01/14/2023] Open
Abstract
RNA processing is critical for proper spatial and temporal control of gene expression. The ubiquitous nuclear polyadenosine RNA binding protein, PABPN1, post-transcriptionally regulates multiple steps of gene expression. Mutations in the PABPN1 gene expanding an N-terminal alanine tract in the PABPN1 protein from 10 alanines to 11–18 alanines cause the muscle-specific disease oculopharyngeal muscular dystrophy (OPMD), which affects eyelid, pharynx, and proximal limb muscles. Previous work revealed that the Pabpn1 transcript is unstable, contributing to low steady-state Pabpn1 mRNA and protein levels in vivo, specifically in skeletal muscle, with even lower levels in muscles affected in OPMD. Thus, low levels of PABPN1 protein could predispose specific tissues to pathology in OPMD. However, no studies have defined the mechanisms that regulate Pabpn1 expression. Here, we define multiple cis-regulatory elements and a trans-acting factor, HuR, which regulate Pabpn1 expression specifically in mature muscle in vitro and in vivo. We exploit multiple models including C2C12 myotubes, primary muscle cells, and mice to determine that HuR decreases Pabpn1 expression. Overall, we have uncovered a mechanism in mature muscle that negatively regulates Pabpn1 expression in vitro and in vivo, which could provide insight to future studies investigating therapeutic strategies for OPMD treatment.
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Affiliation(s)
- Brittany L Phillips
- Department of Biology, Emory University, Atlanta, GA 30322, USA.,Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA.,Genetics and Molecular Biology Graduate Program, Emory University, Atlanta, GA 30322, USA
| | - Ayan Banerjee
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Brenda J Sanchez
- Department of Biochemistry, Goodman Cancer Center, McGill University, Montreal, Quebec, Canada
| | - Sergio Di Marco
- Department of Biochemistry, Goodman Cancer Center, McGill University, Montreal, Quebec, Canada
| | - Imed-Eddine Gallouzi
- Department of Biochemistry, Goodman Cancer Center, McGill University, Montreal, Quebec, Canada.,Hamad Bin Khalifa University (HBKU), Life Sciences Division, College of Sciences and Engineering, Education City, Doha, Qatar
| | - Grace K Pavlath
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Anita H Corbett
- Department of Biology, Emory University, Atlanta, GA 30322, USA
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12
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Zuo Y, Feng F, Qi W, Song R. Dek42 encodes an RNA-binding protein that affects alternative pre-mRNA splicing and maize kernel development. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2019; 61:728-748. [PMID: 30839161 DOI: 10.1111/jipb.12798] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 02/28/2019] [Indexed: 05/22/2023]
Abstract
RNA-binding proteins (RBPs) play an important role in post-transcriptional gene regulation. However, the functions of RBPs in plants remain poorly understood. Maize kernel mutant dek42 has small defective kernels and lethal seedlings. Dek42 was cloned by Mutator tag isolation and further confirmed by an independent mutant allele and clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 materials. Dek42 encodes an RRM_RBM48 type RNA-binding protein that localizes to the nucleus. Dek42 is constitutively expressed in various maize tissues. The dek42 mutation caused a significant reduction in the accumulation of DEK42 protein in mutant kernels. RNA-seq analysis showed that the dek42 mutation significantly disturbed the expression of thousands of genes during maize kernel development. Sequence analysis also showed that the dek42 mutation significantly changed alternative splicing in expressed genes, which were especially enriched for the U12-type intron-retained type. Yeast two-hybrid screening identified SF3a1 as a DEK42-interacting protein. DEK42 also interacts with the spliceosome component U1-70K. These results suggested that DEK42 participates in the regulation of pre-messenger RNA splicing through its interaction with other spliceosome components. This study showed the function of a newly identified RBP and provided insights into alternative splicing regulation during maize kernel development.
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Affiliation(s)
- Yi Zuo
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center, Beijing Key Laboratory of Crop Genetic Improvement, Joint International Research Laboratory of Crop Molecular Breeding, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China
| | - Fan Feng
- Shanghai Key Laboratory of Bio-Energy Crops, Plant Science Center, School of Life Sciences, Shanghai University, Shanghai, 200444, China
| | - Weiwei Qi
- Shanghai Key Laboratory of Bio-Energy Crops, Plant Science Center, School of Life Sciences, Shanghai University, Shanghai, 200444, China
| | - Rentao Song
- State Key Laboratory of Plant Physiology and Biochemistry, National Maize Improvement Center, Beijing Key Laboratory of Crop Genetic Improvement, Joint International Research Laboratory of Crop Molecular Breeding, College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China
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13
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Nikonova E, Kao SY, Ravichandran K, Wittner A, Spletter ML. Conserved functions of RNA-binding proteins in muscle. Int J Biochem Cell Biol 2019; 110:29-49. [PMID: 30818081 DOI: 10.1016/j.biocel.2019.02.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 02/21/2019] [Accepted: 02/23/2019] [Indexed: 12/13/2022]
Abstract
Animals require different types of muscle for survival, for example for circulation, motility, reproduction and digestion. Much emphasis in the muscle field has been placed on understanding how transcriptional regulation generates diverse types of muscle during development. Recent work indicates that alternative splicing and RNA regulation are as critical to muscle development, and altered function of RNA-binding proteins causes muscle disease. Although hundreds of genes predicted to bind RNA are expressed in muscles, many fewer have been functionally characterized. We present a cross-species view summarizing what is known about RNA-binding protein function in muscle, from worms and flies to zebrafish, mice and humans. In particular, we focus on alternative splicing regulated by the CELF, MBNL and RBFOX families of proteins. We discuss the systemic nature of diseases associated with loss of RNA-binding proteins in muscle, focusing on mis-regulation of CELF and MBNL in myotonic dystrophy. These examples illustrate the conservation of RNA-binding protein function and the marked utility of genetic model systems in understanding mechanisms of RNA regulation.
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Affiliation(s)
- Elena Nikonova
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University München, Großhaderner Str. 9, 82152, Martinsried-Planegg, Germany
| | - Shao-Yen Kao
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University München, Großhaderner Str. 9, 82152, Martinsried-Planegg, Germany
| | - Keshika Ravichandran
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University München, Großhaderner Str. 9, 82152, Martinsried-Planegg, Germany
| | - Anja Wittner
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University München, Großhaderner Str. 9, 82152, Martinsried-Planegg, Germany
| | - Maria L Spletter
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University München, Großhaderner Str. 9, 82152, Martinsried-Planegg, Germany; Center for Integrated Protein Science Munich (CIPSM) at the Department of Chemistry, Ludwig-Maximilians-Universität München, Munich, Germany.
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14
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Harish P, Dickson G, Malerba A. Advances in emerging therapeutics for oculopharyngeal muscular dystrophy. Expert Opin Orphan Drugs 2018. [DOI: 10.1080/21678707.2018.1536542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Pradeep Harish
- School of Biological Sciences, Centres of Gene and Cell therapy and Biomedical sciences, Royal Holloway University of London, Egham, Surrey, UK
| | - George Dickson
- School of Biological Sciences, Centres of Gene and Cell therapy and Biomedical sciences, Royal Holloway University of London, Egham, Surrey, UK
| | - Alberto Malerba
- School of Biological Sciences, Centres of Gene and Cell therapy and Biomedical sciences, Royal Holloway University of London, Egham, Surrey, UK
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15
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An Y, Zou Y, Cao Y, Yao M, Ma N, Wu Y, Yang J, Liu H, Zhang B. The nuclear GSK-3β regulated post-transcriptional processing of mRNA through phosphorylation of SC35. Mol Cell Biochem 2018; 451:55-67. [PMID: 30030778 DOI: 10.1007/s11010-018-3393-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/26/2018] [Indexed: 01/02/2023]
Abstract
Glycogen synthase kinase-3β (GSK-3β) is a multifunctional serine/threonine kinase and regulates a variety of biological processes. Recent studies show GSK-3β can regulate pre-mRNA processing and transcription through phosphorylation of multiple splicing factors, but the detailed mechanism is still undetermined. In this study, we further proved that GSK-3β could specifically co-localize with SC35 in nuclear speckles depending on its kinase activity. Immunofluorescence and FISH studies showed the activity of nuclear GSK-3β regulated the assembly of nuclear speckles and consequently modulated the post-transcriptional processing of mRNA. In addition, GSK-3β phosphorylated SC35 and promoted its hyperphosphorylation, in which the unique C-terminal sequences were particularly important to efficiently sequential multiple phosphorylation of SC35. Hyperphosphorylated SC35 converged into cluster and lost its ability to perform splicing in nuclear speckles. More importantly, the nuclear GSK-3β activity could be a part of Wnt/β-catenin signaling activation by TCF4 and might take part in embryonic or tumorigenesis of cells.
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Affiliation(s)
- Yu An
- Department of Pathology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - YongXin Zou
- Eye Hospital, China Academy of Chinese Medical Sciences, Beijing, 100040, China
| | - YaNan Cao
- Department of Pathology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - MengFei Yao
- Department of Pathology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - NingNing Ma
- Department of Pathology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - YaQian Wu
- Department of Pathology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Jing Yang
- Department of Pathology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - HaiJing Liu
- Department of Pathology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Bo Zhang
- Department of Pathology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, 100191, China.
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16
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Narcís JO, Tapia O, Tarabal O, Piedrafita L, Calderó J, Berciano MT, Lafarga M. Accumulation of poly(A) RNA in nuclear granules enriched in Sam68 in motor neurons from the SMNΔ7 mouse model of SMA. Sci Rep 2018; 8:9646. [PMID: 29941967 PMCID: PMC6018117 DOI: 10.1038/s41598-018-27821-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 06/11/2018] [Indexed: 01/07/2023] Open
Abstract
Spinal muscular atrophy (SMA) is a severe motor neuron (MN) disease caused by the deletion or mutation of the survival motor neuron 1 (SMN1) gene, which results in reduced levels of the SMN protein and the selective degeneration of lower MNs. The best-known function of SMN is the biogenesis of spliceosomal snRNPs, the major components of the pre-mRNA splicing machinery. Therefore, SMN deficiency in SMA leads to widespread splicing abnormalities. We used the SMN∆7 mouse model of SMA to investigate the cellular reorganization of polyadenylated mRNAs associated with the splicing dysfunction in MNs. We demonstrate that SMN deficiency induced the abnormal nuclear accumulation in euchromatin domains of poly(A) RNA granules (PARGs) enriched in the splicing regulator Sam68. However, these granules lacked other RNA-binding proteins, such as TDP43, PABPN1, hnRNPA12B, REF and Y14, which are essential for mRNA processing and nuclear export. These effects were accompanied by changes in the alternative splicing of the Sam68-dependent Bcl-x and Nrnx1 genes, as well as changes in the relative accumulation of the intron-containing Chat, Chodl, Myh9 and Myh14 mRNAs, which are all important for MN functions. PARG-containing MNs were observed at presymptomatic SMA stage, increasing their number during the symptomatic stage. Moreover, the massive accumulations of poly(A) RNA granules in MNs was accompanied by the cytoplasmic depletion of polyadenylated mRNAs for their translation. We suggest that the SMN-dependent abnormal accumulation of polyadenylated mRNAs and Sam68 in PARGs reflects a severe dysfunction of both mRNA processing and translation, which could contribute to SMA pathogenesis.
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Affiliation(s)
- J Oriol Narcís
- Department of Anatomy and Cell Biology and "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)", University of Cantabria-IDIVAL, Santander, Spain
| | - Olga Tapia
- Department of Anatomy and Cell Biology and "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)", University of Cantabria-IDIVAL, Santander, Spain
| | - Olga Tarabal
- Department of Experimental Medicine, School of Medicine, University of Lleida and "Institut de Recerca Biomèdica de Lleida" (IRBLLEIDA), Lleida, Spain
| | - Lídia Piedrafita
- Department of Experimental Medicine, School of Medicine, University of Lleida and "Institut de Recerca Biomèdica de Lleida" (IRBLLEIDA), Lleida, Spain
| | - Jordi Calderó
- Department of Experimental Medicine, School of Medicine, University of Lleida and "Institut de Recerca Biomèdica de Lleida" (IRBLLEIDA), Lleida, Spain
| | - Maria T Berciano
- Department of Anatomy and Cell Biology and "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)", University of Cantabria-IDIVAL, Santander, Spain.,Department of Molecular Biology and CIBERNED, University of Cantabria-IDIVAL, Santander, Spain
| | - Miguel Lafarga
- Department of Anatomy and Cell Biology and "Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)", University of Cantabria-IDIVAL, Santander, Spain.
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17
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Wegener M, Müller-McNicoll M. Nuclear retention of mRNAs - quality control, gene regulation and human disease. Semin Cell Dev Biol 2017; 79:131-142. [PMID: 29102717 DOI: 10.1016/j.semcdb.2017.11.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 10/30/2017] [Accepted: 11/01/2017] [Indexed: 12/21/2022]
Abstract
Nuclear retention of incompletely spliced or mature mRNAs emerges as a novel, previously underappreciated layer of gene regulation, which enables the cell to rapidly respond to stress, viral infection, differentiation cues or changing environmental conditions. Focusing on mammalian cells, we discuss recent insights into the mechanisms and functions of nuclear retention, describe retention-promoting features in protein-coding transcripts and propose mechanisms for their regulated release into the cytoplasm. Moreover, we discuss examples of how aberrant nuclear retention of mRNAs may lead to human diseases.
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Affiliation(s)
- Marius Wegener
- RNA Regulation Group, Cluster of Excellence 'Macromolecular Complexes', Goethe University Frankfurt, Institute of Cell Biology and Neuroscience, Max-von-Laue-Str. 13, 60438 Frankfurt/Main, Germany
| | - Michaela Müller-McNicoll
- RNA Regulation Group, Cluster of Excellence 'Macromolecular Complexes', Goethe University Frankfurt, Institute of Cell Biology and Neuroscience, Max-von-Laue-Str. 13, 60438 Frankfurt/Main, Germany.
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18
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Banerjee A, Vest KE, Pavlath GK, Corbett AH. Nuclear poly(A) binding protein 1 (PABPN1) and Matrin3 interact in muscle cells and regulate RNA processing. Nucleic Acids Res 2017; 45:10706-10725. [PMID: 28977530 PMCID: PMC5737383 DOI: 10.1093/nar/gkx786] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 08/27/2017] [Indexed: 01/01/2023] Open
Abstract
The polyadenylate binding protein 1 (PABPN1) is a ubiquitously expressed RNA binding protein vital for multiple steps in RNA metabolism. Although PABPN1 plays a critical role in the regulation of RNA processing, mutation of the gene encoding this ubiquitously expressed RNA binding protein causes a specific form of muscular dystrophy termed oculopharyngeal muscular dystrophy (OPMD). Despite the tissue-specific pathology that occurs in this disease, only recently have studies of PABPN1 begun to explore the role of this protein in skeletal muscle. We have used co-immunoprecipitation and mass spectrometry to identify proteins that interact with PABPN1 in mouse skeletal muscles. Among the interacting proteins we identified Matrin 3 (MATR3) as a novel protein interactor of PABPN1. The MATR3 gene is mutated in a form of distal myopathy and amyotrophic lateral sclerosis (ALS). We demonstrate, that like PABPN1, MATR3 is critical for myogenesis. Furthermore, MATR3 controls critical aspects of RNA processing including alternative polyadenylation and intron retention. We provide evidence that MATR3 also binds and regulates the levels of long non-coding RNA (lncRNA) Neat1 and together with PABPN1 is required for normal paraspeckle function. We demonstrate that PABPN1 and MATR3 are required for paraspeckles, as well as for adenosine to inosine (A to I) RNA editing of Ctn RNA in muscle cells. We provide a functional link between PABPN1 and MATR3 through regulation of a common lncRNA target with downstream impact on paraspeckle morphology and function. We extend our analysis to a mouse model of OPMD and demonstrate altered paraspeckle morphology in the presence of endogenous levels of alanine-expanded PABPN1. In this study, we report protein-binding partners of PABPN1, which could provide insight into novel functions of PABPN1 in skeletal muscle and identify proteins that could be sequestered with alanine-expanded PABPN1 in the nuclear aggregates found in OPMD.
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Affiliation(s)
- Ayan Banerjee
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Katherine E Vest
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Grace K Pavlath
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Anita H Corbett
- Department of Biology, Emory University, Atlanta, GA 30322, USA
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19
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Galganski L, Urbanek MO, Krzyzosiak WJ. Nuclear speckles: molecular organization, biological function and role in disease. Nucleic Acids Res 2017; 45:10350-10368. [PMID: 28977640 PMCID: PMC5737799 DOI: 10.1093/nar/gkx759] [Citation(s) in RCA: 285] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/18/2017] [Indexed: 12/13/2022] Open
Abstract
The nucleoplasm is not homogenous; it consists of many types of nuclear bodies, also known as nuclear domains or nuclear subcompartments. These self-organizing structures gather machinery involved in various nuclear activities. Nuclear speckles (NSs) or splicing speckles, also called interchromatin granule clusters, were discovered as sites for splicing factor storage and modification. Further studies on transcription and mRNA maturation and export revealed a more general role for splicing speckles in RNA metabolism. Here, we discuss the functional implications of the localization of numerous proteins crucial for epigenetic regulation, chromatin organization, DNA repair and RNA modification to nuclear speckles. We highlight recent advances suggesting that NSs facilitate integrated regulation of gene expression. In addition, we consider the influence of abundant regulatory and signaling proteins, i.e. protein kinases and proteins involved in protein ubiquitination, phosphoinositide signaling and nucleoskeletal organization, on pre-mRNA synthesis and maturation. While many of these regulatory proteins act within NSs, direct evidence for mRNA metabolism events occurring in NSs is still lacking. NSs contribute to numerous human diseases, including cancers and viral infections. In addition, recent data have demonstrated close relationships between these structures and the development of neurological disorders.
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Affiliation(s)
- Lukasz Galganski
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Martyna O Urbanek
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Wlodzimierz J Krzyzosiak
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
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20
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Vest KE, Phillips BL, Banerjee A, Apponi LH, Dammer EB, Xu W, Zheng D, Yu J, Tian B, Pavlath GK, Corbett AH. Novel mouse models of oculopharyngeal muscular dystrophy (OPMD) reveal early onset mitochondrial defects and suggest loss of PABPN1 may contribute to pathology. Hum Mol Genet 2017; 26:3235-3252. [PMID: 28575395 PMCID: PMC5886286 DOI: 10.1093/hmg/ddx206] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 05/14/2017] [Accepted: 05/23/2017] [Indexed: 01/09/2023] Open
Abstract
Oculopharyngeal muscular dystrophy (OPMD) is a late onset disease caused by polyalanine expansion in the poly(A) binding protein nuclear 1 (PABPN1). Several mouse models have been generated to study OPMD; however, most of these models have employed transgenic overexpression of alanine-expanded PABPN1. These models do not recapitulate the OPMD patient genotype and PABPN1 overexpression could confound molecular phenotypes. We have developed a knock-in mouse model of OPMD (Pabpn1+/A17) that contains one alanine-expanded Pabpn1 allele under the control of the native promoter and one wild-type Pabpn1 allele. This mouse is the closest available genocopy of OPMD patients. We show that Pabpn1+/A17 mice have a mild myopathic phenotype in adult and aged animals. We examined early molecular and biochemical phenotypes associated with expressing native levels of A17-PABPN1 and detected shorter poly(A) tails, modest changes in poly(A) signal (PAS) usage, and evidence of mitochondrial damage in these mice. Recent studies have suggested that a loss of PABPN1 function could contribute to muscle pathology in OPMD. To investigate a loss of function model of pathology, we generated a heterozygous Pabpn1 knock-out mouse model (Pabpn1+/Δ). Like the Pabpn1+/A17 mice, Pabpn1+/Δ mice have mild histologic defects, shorter poly(A) tails, and evidence of mitochondrial damage. However, the phenotypes detected in Pabpn1+/Δ mice only partially overlap with those detected in Pabpn1+/A17 mice. These results suggest that loss of PABPN1 function could contribute to but may not completely explain the pathology detected in Pabpn1+/A17 mice.
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Affiliation(s)
- Katherine E. Vest
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
- Department of Biology, Emory University, Atlanta, GA, USA
| | - Brittany L. Phillips
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
- Department of Biology, Emory University, Atlanta, GA, USA
| | - Ayan Banerjee
- Department of Biology, Emory University, Atlanta, GA, USA
| | - Luciano H. Apponi
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
| | - Eric B. Dammer
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, USA
| | - Weiting Xu
- Department of Microbiology, Biochemistry, and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Dinghai Zheng
- Department of Microbiology, Biochemistry, and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Julia Yu
- Department of Biology, Emory University, Atlanta, GA, USA
| | - Bin Tian
- Department of Microbiology, Biochemistry, and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Grace K. Pavlath
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA, USA
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21
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García-Castañeda M, Vega AV, Rodríguez R, Montiel-Jaen MG, Cisneros B, Zarain-Herzberg A, Avila G. Functional impact of an oculopharyngeal muscular dystrophy mutation in PABPN1. J Physiol 2017; 595:4167-4187. [PMID: 28303574 DOI: 10.1113/jp273948] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 03/11/2017] [Indexed: 01/14/2023] Open
Abstract
KEY POINTS Mutations in the gene encoding poly(A)-binding protein nuclear 1 (PABPN1) result in oculopharyngeal muscular dystrophy (OPMD). This disease is of late-onset, but the underlying mechanism is unclear. Ca2+ stimulates muscle growth and contraction and, because OPMD courses with muscle atrophy and weakness, we hypothesized that the homeostasis of Ca2+ is altered in this disorder. C2C12 myotubes were transfected with cDNAs encoding either PABPN1 or the PABPN1-17A OPMD mutation. Subsequently, they were investigated concerning not only excitation-contraction coupling (ECC) and intracellular levels of Ca2+ , but also differentiation stage and nuclear structure. PABPN1-17A gave rise to: inhibition of Ca2+ release during ECC, depletion of sarcoplasmic reticulum Ca2+ content, reduced expression of ryanodine receptors, altered nuclear morphology and incapability to stimulate myoblast fusion. PABPN1-17A failed to inhibit ECC in adult muscle fibres, suggesting that its effects are primarily related to muscle regeneration. ABSTRACT Oculopharyngeal muscular dystrophy (OPMD) is linked to mutations in the gene encoding poly(A)-binding protein nuclear 1 (PABPN1). OPMD mutations consist of an expansion of a tract that contains 10 alanines (to 12-17). This disease courses with muscle weakness that begins in adulthood, but the underlying mechanism is unclear. In the present study, we investigated the functional effects of PABPN1 and an OPMD mutation (PABPN1-17A) using myotubes transfected with cDNAs encoding these proteins (GFP-tagged). PABPN1 stimulated myoblast fusion (100%), whereas PABPN1-17A failed to mimic this effect. Additionally, the OPMD mutation markedly altered nuclear morphology; specifically, it led to nuclei with a more convoluted and ovoid shape. Although PABPN1 and PABPN1-17A modified the expression of sarcoplasmic/endoplasmic reticulum Ca2+ -ATPase and calsequestrin, the corresponding changes did not have a clear impact on [Ca2+ ]. Interestingly, neither L-type Ca2+ channels, nor voltage-gated sarcoplasmic reticulum (SR) Ca2+ release (VGCR) was altered by PABPN1. However, PABPN1-17A produced a selective inhibition of VGCR (50%). This effect probably arises from both lower expression of RyR1 and depletion of SR Ca2+ . The latter, however, was not related to inhibition of store-operated Ca2+ entry. Both PABPN1 constructs promoted a moderated decrease in cytosolic [Ca2+ ], which apparently results from down-regulation of excitation-coupled Ca2+ entry. On the other hand, PABPN1-17A did not alter ECC in muscle fibres, suggesting that adult muscle is less prone to developing deleterious effects. These results demonstrate that PABPN1 proteins regulate essential processes during myotube formation and support the notion that OPMD involves disruption of myogenesis, nuclear structure and homeostasis of Ca2+ .
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Affiliation(s)
| | - Ana Victoria Vega
- UBIMED FES-Iztacala, National Autonomous University of Mexico, Mexico City, México
| | - Rocío Rodríguez
- Department of Molecular Biology, Cinvestav-IPN AP 14-740, México City, México
| | | | - Bulmaro Cisneros
- Department of Molecular Biology, Cinvestav-IPN AP 14-740, México City, México
| | - Angel Zarain-Herzberg
- Department of Biochemistry, School of Medicine, National Autonomous University of Mexico, Mexico City, México
| | - Guillermo Avila
- Department of Biochemistry, Cinvestav-IPN AP 14-740, México City, México
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22
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Abstract
In eukaryote genomes, the polyadenylation site marks termination of mature RNA transcripts by a poly-adenine tail. The polyadenylation site is recognized by a dynamic protein complex, among which the poly-adenine-binding protein nuclear1 plays a key role. Reduced poly-adenine-binding protein nuclear1 levels are found in aged muscles and are even lower in oculopharyngeal muscular dystrophy patients. Oculopharyngeal muscular dystrophy is a rare, late onset autosomal dominant myopathy, and is caused by an alanine expansion mutation in poly-adenine-binding protein nuclear1. Mutant poly-adenine-binding protein nuclear1 forms insoluble nuclear aggregates leading to depletion of functional poly-adenine-binding protein nuclear1 levels. In oculopharyngeal muscular dystrophy models, increased utilization of proximal polyadenylation sites has been observed in tandem 3'-untranslated regions, and most often cause gene upregulation. However, global alterations in expression profiles canonly partly be explained by polyadenylation site switches within the most distal 3'-untranslated region. Most poly-adenine signals are found at the distal 3'-untranslated region, but a significant part is also found in internal gene regions, like introns, exons, and internal 3'-untranslated regions. Here, we investigated poly-adenine-binding protein nuclear1's role in polyadenylation site utilization in internal gene regions. In the quadriceps muscle of oculopharyngeal muscular dystrophy mice expressing expPABPN1 we found significant polyadenylation site switches between gene regions in 17% of genes with polyadenylation site in multiple regions (N = 574; 5% False Discovery Rate). Polyadenylation site switches between gene regions were associated with differences in transcript expression levels and alterations in open reading frames. Transcripts ending at internal polyadenylation site were confirmed in tibialis anterior muscles from the same mice and in mouse muscle cell cultures overexpressing expPABPN1. The polyadenylation site switches were associated with nuclear accumulation of full-length transcripts. Our results provide further insights into the diverse roles of poly-adenine-binding protein nuclear1 in the post-transcriptional control of muscle gene expression and its relevance for oculopharyngeal muscular dystrophy pathology and muscle aging.
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23
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Malerba A, Klein P, Bachtarzi H, Jarmin SA, Cordova G, Ferry A, Strings V, Espinoza MP, Mamchaoui K, Blumen SC, St Guily JL, Mouly V, Graham M, Butler-Browne G, Suhy DA, Trollet C, Dickson G. PABPN1 gene therapy for oculopharyngeal muscular dystrophy. Nat Commun 2017; 8:14848. [PMID: 28361972 PMCID: PMC5380963 DOI: 10.1038/ncomms14848] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 02/07/2017] [Indexed: 01/14/2023] Open
Abstract
Oculopharyngeal muscular dystrophy (OPMD) is an autosomal dominant, late-onset muscle disorder characterized by ptosis, swallowing difficulties, proximal limb weakness and nuclear aggregates in skeletal muscles. OPMD is caused by a trinucleotide repeat expansion in the PABPN1 gene that results in an N-terminal expanded polyalanine tract in polyA-binding protein nuclear 1 (PABPN1). Here we show that the treatment of a mouse model of OPMD with an adeno-associated virus-based gene therapy combining complete knockdown of endogenous PABPN1 and its replacement by a wild-type PABPN1 substantially reduces the amount of insoluble aggregates, decreases muscle fibrosis, reverts muscle strength to the level of healthy muscles and normalizes the muscle transcriptome. The efficacy of the combined treatment is further confirmed in cells derived from OPMD patients. These results pave the way towards a gene replacement approach for OPMD treatment. Oculopharyngeal muscular dystrophy is caused by trinucleotide repeat expansions in the PABPN1 gene. Here the authors use AAV-based gene therapy to knockdown the mutant gene and replace it with a wild-type allele, and show effectiveness in mice and in patient cells.
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Affiliation(s)
- A Malerba
- School of Biological Sciences, Royal Holloway, University of London, Egham Hill, Egham, TW20 0EX Surrey, UK
| | - P Klein
- Sorbonne Universités, UPMC Univ Paris 06, UM76, INSERM U974, Institut de Myologie, CNRS FRE3617, 47 bd de l'Hôpital, 75013 Paris, France
| | - H Bachtarzi
- School of Biological Sciences, Royal Holloway, University of London, Egham Hill, Egham, TW20 0EX Surrey, UK
| | - S A Jarmin
- School of Biological Sciences, Royal Holloway, University of London, Egham Hill, Egham, TW20 0EX Surrey, UK
| | - G Cordova
- Sorbonne Universités, UPMC Univ Paris 06, UM76, INSERM U974, Institut de Myologie, CNRS FRE3617, 47 bd de l'Hôpital, 75013 Paris, France
| | - A Ferry
- Sorbonne Universités, UPMC Univ Paris 06, UM76, INSERM U974, Institut de Myologie, CNRS FRE3617, 47 bd de l'Hôpital, 75013 Paris, France.,Sorbonne Paris Cité, Université Paris Descartes, 75006 Paris, France
| | - V Strings
- Benitec Biopharma, 3940 Trust Way, Hayward, California 94545, USA
| | - M Polay Espinoza
- Sorbonne Universités, UPMC Univ Paris 06, UM76, INSERM U974, Institut de Myologie, CNRS FRE3617, 47 bd de l'Hôpital, 75013 Paris, France
| | - K Mamchaoui
- Sorbonne Universités, UPMC Univ Paris 06, UM76, INSERM U974, Institut de Myologie, CNRS FRE3617, 47 bd de l'Hôpital, 75013 Paris, France
| | - S C Blumen
- Department of Neurology, Hillel Yaffe Medical Center, Hadera and Rappaport Faculty of Medicine, The Technion, 1 Efron Street, Haifa 31096, Israel
| | - J Lacau St Guily
- Sorbonne Universités, UPMC Univ Paris 06, UM76, INSERM U974, Institut de Myologie, CNRS FRE3617, 47 bd de l'Hôpital, 75013 Paris, France.,Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine and University Pierre-et-Marie-Curie, Paris VI, Tenon Hospital, Assistance Publique des Hopitaux de Paris, 75252 Paris, France
| | - V Mouly
- Sorbonne Universités, UPMC Univ Paris 06, UM76, INSERM U974, Institut de Myologie, CNRS FRE3617, 47 bd de l'Hôpital, 75013 Paris, France
| | - M Graham
- Benitec Biopharma, 3940 Trust Way, Hayward, California 94545, USA
| | - G Butler-Browne
- Sorbonne Universités, UPMC Univ Paris 06, UM76, INSERM U974, Institut de Myologie, CNRS FRE3617, 47 bd de l'Hôpital, 75013 Paris, France
| | - D A Suhy
- Benitec Biopharma, 3940 Trust Way, Hayward, California 94545, USA
| | - C Trollet
- Sorbonne Universités, UPMC Univ Paris 06, UM76, INSERM U974, Institut de Myologie, CNRS FRE3617, 47 bd de l'Hôpital, 75013 Paris, France
| | - G Dickson
- School of Biological Sciences, Royal Holloway, University of London, Egham Hill, Egham, TW20 0EX Surrey, UK
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