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Gharibi S, Vaillend C, Lindsay A. The unconditioned fear response in vertebrates deficient in dystrophin. Prog Neurobiol 2024; 235:102590. [PMID: 38484964 DOI: 10.1016/j.pneurobio.2024.102590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/31/2024] [Accepted: 03/05/2024] [Indexed: 03/19/2024]
Abstract
Dystrophin loss due to mutations in the Duchenne muscular dystrophy (DMD) gene is associated with a wide spectrum of neurocognitive comorbidities, including an aberrant unconditioned fear response to stressful/threat stimuli. Dystrophin-deficient animal models of DMD demonstrate enhanced stress reactivity that manifests as sustained periods of immobility. When the threat is repetitive or severe in nature, dystrophinopathy phenotypes can be exacerbated and even cause sudden death. Thus, it is apparent that enhanced sensitivity to stressful/threat stimuli in dystrophin-deficient vertebrates is a legitimate cause of concern for patients with DMD that could impact neurocognition and pathophysiology. This review discusses our current understanding of the mechanisms and consequences of the hypersensitive fear response in preclinical models of DMD and the potential challenges facing clinical translatability.
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Affiliation(s)
- Saba Gharibi
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Cyrille Vaillend
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, Saclay 91400, France.
| | - Angus Lindsay
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia; School of Biological Sciences, University of Canterbury, Christchurch 8041, New Zealand; Department of Medicine, University of Otago, Christchurch 8014, New Zealand.
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Hildyard JCW, Piercy RJ. When Size Really Matters: The Eccentricities of Dystrophin Transcription and the Hazards of Quantifying mRNA from Very Long Genes. Biomedicines 2023; 11:2082. [PMID: 37509720 PMCID: PMC10377302 DOI: 10.3390/biomedicines11072082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/10/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
At 2.3 megabases in length, the dystrophin gene is enormous: transcription of a single mRNA requires approximately 16 h. Principally expressed in skeletal muscle, the dystrophin protein product protects the muscle sarcolemma against contraction-induced injury, and dystrophin deficiency results in the fatal muscle-wasting disease, Duchenne muscular dystrophy. This gene is thus of key clinical interest, and therapeutic strategies aimed at eliciting dystrophin restoration require quantitative analysis of its expression. Approaches for quantifying dystrophin at the protein level are well-established, however study at the mRNA level warrants closer scrutiny: measured expression values differ in a sequence-dependent fashion, with significant consequences for data interpretation. In this manuscript, we discuss these nuances of expression and present evidence to support a transcriptional model whereby the long transcription time is coupled to a short mature mRNA half-life, with dystrophin transcripts being predominantly nascent as a consequence. We explore the effects of such a model on cellular transcriptional dynamics and then discuss key implications for the study of dystrophin gene expression, focusing on both conventional (qPCR) and next-gen (RNAseq) approaches.
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Affiliation(s)
- John C W Hildyard
- Comparative Neuromuscular Disease Laboratory, Department of Clinical Science and Services, Royal Veterinary College, London NW1 0TU, UK
| | - Richard J Piercy
- Comparative Neuromuscular Disease Laboratory, Department of Clinical Science and Services, Royal Veterinary College, London NW1 0TU, UK
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3
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Zhang XF, Luo YY, Jiang L, Hong SQ. Clinical study on cognitive impairment in Duchenne muscular dystrophy. Neuromuscul Disord 2023; 33:596-604. [PMID: 37385106 DOI: 10.1016/j.nmd.2023.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 05/29/2023] [Accepted: 06/01/2023] [Indexed: 07/01/2023]
Abstract
Our study aimed to explore the intellectual function of patients with Duchenne muscular dystrophy (DMD) in China and examine the correlation of full-scale intelligence quotient (FSIQ) with age, mutation locations, mutation class, and dystrophin isoforms. We assessed 64 boys with DMD using The Wechsler Intelligence Scales for Children-Fourth Edition and compared intellectual function at enrollment and follow-up in the 15 patients who completed the follow-up. Our findings confirm that boys with DMD may exhibit cognitive impairment, with the Working Memory Index being the most impaired. There was no significant correlation between FSIQ and age; however, a positive correlation was noted between age and the Verbal Comprehension Index. FSIQ was not associated with mutation class, the number of affected mutated exons, or mutation locations. However, there was a significant difference in FSIQ between the groups with intact and deficient Dp140. Fifteen participants adhered to glucocorticoid therapy throughout the two-year follow-up period, and eleven of them showed an improvement in FSIQ compared to their initial scores, with improvement ranging from 2 to 20. In conclusion, patients with the cumulative loss of isoforms in the brain are at a higher risk of cognitive deficits and may require early cognitive interventions.
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Affiliation(s)
- Xiao-Fang Zhang
- Department of Neurology Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation base of Child development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Yuan-Yuan Luo
- Department of Neurology Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation base of Child development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Li Jiang
- Department of Neurology Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation base of Child development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Chongqing, China
| | - Si-Qi Hong
- Department of Neurology Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, China International Science and Technology Cooperation base of Child development and Critical Disorders, Chongqing Key Laboratory of Pediatrics, Chongqing, China.
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4
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Jackson T, Seifi M, Górecki DC, Swinny JD. Specific Dystrophins Selectively Associate with Inhibitory and Excitatory Synapses of the Mouse Cerebellum and their Loss Alters Expression of P2X7 Purinoceptors and Pro-Inflammatory Mediators. Cell Mol Neurobiol 2022; 42:2357-2377. [PMID: 34101068 PMCID: PMC9418305 DOI: 10.1007/s10571-021-01110-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 05/27/2021] [Indexed: 02/07/2023]
Abstract
Duchenne muscular dystrophy (DMD) patients, having mutations of the DMD gene, present with a range of neuropsychiatric disorders, in addition to the quintessential muscle pathology. The neurobiological basis remains poorly understood because the contributions of different DMD gene products (dystrophins) to the different neural networks underlying such symptoms are yet to be fully characterised. While full-length dystrophin clusters in inhibitory synapses, with inhibitory neurotransmitter receptors, the precise subcellular expression of truncated DMD gene products with excitatory synapses remains unresolved. Furthermore, inflammation, involving P2X purinoceptor 7 (P2RX7) accompanies DMD muscle pathology, yet any association with brain dystrophins is yet to be established. The aim of this study was to investigate the comparative expression of different dystrophins, alongside ionotropic glutamate receptors and P2RX7s, within the cerebellar circuitry known to express different dystrophin isoforms. Immunoreactivity for truncated DMD gene products was targeted to Purkinje cell (PC) distal dendrites adjacent to, or overlapping with, signal for GluA1, GluA4, GluN2A, and GluD2 receptor subunits. P2X7R immunoreactivity was located in Bergmann glia profiles adjacent to PC-dystrophin immunoreactivity. Ablation of all DMD gene products coincided with decreased mRNA expression for Gria2, Gria3, and Grin2a and increased GluD2 immunoreactivity. Finally, dystrophin-null mice showed decreased brain mRNA expression of P2rx7 and several inflammatory mediators. The data suggest that PCs target different dystrophin isoforms to molecularly and functionally distinct populations of synapses. In contrast to muscle, dystrophinopathy in brain leads to the dampening of the local immune system.
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Affiliation(s)
- Torquil Jackson
- School of Pharmacy & Biomedical Sciences, University of Portsmouth, St Michael's Building, White Swan Road, Portsmouth, PO12DT, UK
| | - Mohsen Seifi
- Leicester School of Pharmacy, De Montfort University, Leicester, LE1 9BH, UK
| | - Dariusz C Górecki
- School of Pharmacy & Biomedical Sciences, University of Portsmouth, St Michael's Building, White Swan Road, Portsmouth, PO12DT, UK
- Military Institute of Hygiene and Epidemiology, Kozielska 4, 01-001, Warsaw, Poland
| | - Jerome D Swinny
- School of Pharmacy & Biomedical Sciences, University of Portsmouth, St Michael's Building, White Swan Road, Portsmouth, PO12DT, UK.
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Crawford AH, Hildyard JCW, Rushing SAM, Wells DJ, Diez-Leon M, Piercy RJ. Validation of DE50-MD dogs as a model for the brain phenotype of Duchenne muscular dystrophy. Dis Model Mech 2022; 15:273974. [PMID: 35019137 PMCID: PMC8906169 DOI: 10.1242/dmm.049291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 12/21/2021] [Indexed: 11/20/2022] Open
Abstract
Duchenne muscular dystrophy (DMD), a fatal musculoskeletal disease, is associated with neurodevelopmental disorders and cognitive impairment caused by brain dystrophin deficiency. Dog models of DMD represent key translational tools to study dystrophin biology and to develop novel therapeutics. However, characterisation of dystrophin expression and function in the canine brain is lacking. We studied the DE50-MD canine model of DMD that has a missense mutation in the donor splice site of exon 50. Using a battery of cognitive tests, we detected a neurocognitive phenotype in DE50-MD dogs, including reduced attention, problem solving and exploration of novel objects. Through a combination of capillary immunoelectrophoresis, immunolabelling, quantitative PCR and RNAScope in situ hybridisation, we show that regional dystrophin expression in the adult canine brain reflects that of humans, and that the DE50-MD dog lacks full-length dystrophin (Dp427) protein expression but retains expression of the two shorter brain-expressed isoforms, Dp140 and Dp71. Thus, the DE50-MD dog is a translationally relevant pre-clinical model to study the consequences of Dp427 deficiency in the brain and to develop therapeutic strategies for the neurological sequelae of DMD. Summary: The DE50-MD canine model of Duchenne muscular dystrophy (DMD) shows cognitive and brain biochemical changes secondary to dystrophin deficiency in the brain, and is a relevant pre-clinical model to develop therapies for DMD.
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Affiliation(s)
- Abbe H Crawford
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Science and Services, Royal Veterinary College, London, United Kingdom
| | - John C W Hildyard
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Science and Services, Royal Veterinary College, London, United Kingdom
| | - Sophie A M Rushing
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Science and Services, Royal Veterinary College, London, United Kingdom
| | - Dominic J Wells
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom
| | - Maria Diez-Leon
- Pathobiology and Population Sciences, Royal Veterinary College, London, United Kingdom
| | - Richard J Piercy
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Science and Services, Royal Veterinary College, London, United Kingdom
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Lim KRQ, Shah MNA, Woo S, Wilton-Clark H, Zhabyeyev P, Wang F, Maruyama R, Oudit GY, Yokota T. Natural History of a Mouse Model Overexpressing the Dp71 Dystrophin Isoform. Int J Mol Sci 2021; 22:ijms222312617. [PMID: 34884423 PMCID: PMC8657860 DOI: 10.3390/ijms222312617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 11/18/2022] Open
Abstract
Dystrophin is a 427 kDa protein that stabilizes muscle cell membranes through interactions with the cytoskeleton and various membrane-associated proteins. Loss of dystrophin as in Duchenne muscular dystrophy (DMD) causes progressive skeletal muscle weakness and cardiac dysfunction. Multiple promoters along the dystrophin gene (DMD) give rise to a number of shorter isoforms. Of interest is Dp71, a 71 kDa isoform implicated in DMD pathology by various animal and patient studies. Strong evidence supporting such a role for Dp71, however, is lacking. Here, we use del52;WT mice to understand how Dp71 overexpression affects skeletal and cardiac muscle phenotypes. Apart from the mouse Dmd gene, del52;WT mice are heterozygous for a full-length, exon 52-deleted human DMD transgene expected to only permit Dp71 expression in muscle. Thus, del52;WT mice overexpress Dp71 through both the human and murine dystrophin genes. We observed elevated Dp71 protein in del52;WT mice, significantly higher than wild-type in the heart but not the tibialis anterior. Moreover, del52;WT mice had generally normal skeletal muscle but impaired cardiac function, exhibiting significant systolic dysfunction as early as 3 months. No histological abnormalities were found in the tibialis anterior and heart. Our results suggest that Dp71 overexpression may have more detrimental effects on the heart than on skeletal muscles, providing insight into the role of Dp71 in DMD pathogenesis.
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Affiliation(s)
- Kenji Rowel Q. Lim
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G2H7, Canada; (K.R.Q.L.); (M.N.A.S.); (S.W.); (H.W.-C.); (R.M.)
| | - Md Nur Ahad Shah
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G2H7, Canada; (K.R.Q.L.); (M.N.A.S.); (S.W.); (H.W.-C.); (R.M.)
| | - Stanley Woo
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G2H7, Canada; (K.R.Q.L.); (M.N.A.S.); (S.W.); (H.W.-C.); (R.M.)
| | - Harry Wilton-Clark
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G2H7, Canada; (K.R.Q.L.); (M.N.A.S.); (S.W.); (H.W.-C.); (R.M.)
| | - Pavel Zhabyeyev
- Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G2G3, Canada; (P.Z.); (F.W.)
| | - Faqi Wang
- Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G2G3, Canada; (P.Z.); (F.W.)
| | - Rika Maruyama
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G2H7, Canada; (K.R.Q.L.); (M.N.A.S.); (S.W.); (H.W.-C.); (R.M.)
| | - Gavin Y. Oudit
- Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G2G3, Canada; (P.Z.); (F.W.)
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, AB T6G2B7, Canada
- Correspondence: (G.Y.O.); (T.Y.)
| | - Toshifumi Yokota
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G2H7, Canada; (K.R.Q.L.); (M.N.A.S.); (S.W.); (H.W.-C.); (R.M.)
- Muscular Dystrophy Canada Research Chair, Edmonton, AB T6G2H7, Canada
- Correspondence: (G.Y.O.); (T.Y.)
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Paúl-González S, Aragón J, Rodríguez-Martínez G, Romo-Yáñez J, Montanez C. Differential expression of Dp71 and Dp40 isoforms in proliferating and differentiated neural stem cells: Identification of Dp40 splicing variants. Biochem Biophys Res Commun 2021; 560:152-158. [PMID: 33989907 DOI: 10.1016/j.bbrc.2021.03.142] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 03/25/2021] [Indexed: 11/29/2022]
Abstract
Dp71 and Dp40 are the main products of the DMD gene in the central nervous system, and they are developmentally regulated from the early stages of embryonic development to adulthood. To further study the roles of Dp71 and Dp40 during cell proliferation and neural differentiation, we analyzed Dp71/Dp40 isoform expression at the mRNA level by RT-PCR assays to identify alternative splicing (AS) in the isoforms expressed in rat neural stem/progenitor cells (NSPCs) and in differentiated cells (neurons and glia). We found that proliferating NSPCs expressed Dp71d, Dp71dΔ71, Dp71f, Dp71fΔ71, Dp71dΔ74 and Dp40, as well as two Dp40 isoforms: Dp40Δ63,64 and Dp40Δ64-67. In differentiated cells we also found the expression of Dp71d, Dp71dΔ71, Dp71f, Dp71fΔ71 and Dp40. However, the expression frequencies were different in both stages. In addition, in differentiated cells, we found Dp71fΔ71-74, and interestingly, we did not find the expression of Dp71dΔ74 or the newly identified Dp40 isoforms. In this work we show that NSPC differentiation is accompanied by changes in Dp71/Dp40 isoform expression, suggesting different roles for these isoforms in NSPCs proliferation and neuronal differentiation, and we describe, for the first time, alternative splicing of Dp40.
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Affiliation(s)
- Sandra Paúl-González
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, 07360, Ciudad de México, Mexico
| | - Jorge Aragón
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, 07360, Ciudad de México, Mexico
| | - Griselda Rodríguez-Martínez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, 07360, Ciudad de México, Mexico
| | - José Romo-Yáñez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, 07360, Ciudad de México, Mexico
| | - Cecilia Montanez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, 07360, Ciudad de México, Mexico.
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8
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Cellular pathology of the human heart in Duchenne muscular dystrophy (DMD): lessons learned from in vitro modeling. Pflugers Arch 2021; 473:1099-1115. [DOI: 10.1007/s00424-021-02589-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 05/24/2021] [Accepted: 05/27/2021] [Indexed: 02/07/2023]
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Stephenson AA, Flanigan KM. Gene editing and modulation for Duchenne muscular dystrophy. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2021; 182:225-255. [PMID: 34175043 DOI: 10.1016/bs.pmbts.2021.01.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Duchenne muscular dystrophy (DMD) is a progressive muscle disease caused by loss of dystrophin protein, encoded by the DMD gene. DMD manifests early in childhood as difficulty walking, progresses to loss of ambulation by the teens, and leads to death in early adulthood. Adeno-associated virus-vectorized gene therapies to restore dystrophin protein expression using gene replacement or antisense oligonucleotide-mediated pre-mRNA splicing modulation have emerged, making great strides in uncovering barriers to gene therapies for DMD and other genetic diseases. While this first-generation of DMD therapies are being evaluated in ongoing clinical trials, uncertainties regarding durability and therapeutic efficacy prompted the development of new experimental therapies for DMD that take advantage of somatic cell gene editing. These experimental therapies continue to advance toward clinic trials, but questions remain unanswered regarding safety and translatable efficacy. Here we review the advancements toward treatment of DMD using gene editing and modulation therapies, with an emphasis on those nearest to clinical applications.
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Affiliation(s)
- Anthony A Stephenson
- Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, United States
| | - Kevin M Flanigan
- Center for Gene Therapy, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, United States; Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, OH, United States; Department of Neurology, College of Medicine, The Ohio State University, Columbus, OH, United States.
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10
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Abstract
Duchenne muscular dystrophy is a severe, progressive, muscle-wasting disease that leads to difficulties with movement and, eventually, to the need for assisted ventilation and premature death. The disease is caused by mutations in DMD (encoding dystrophin) that abolish the production of dystrophin in muscle. Muscles without dystrophin are more sensitive to damage, resulting in progressive loss of muscle tissue and function, in addition to cardiomyopathy. Recent studies have greatly deepened our understanding of the primary and secondary pathogenetic mechanisms. Guidelines for the multidisciplinary care for Duchenne muscular dystrophy that address obtaining a genetic diagnosis and managing the various aspects of the disease have been established. In addition, a number of therapies that aim to restore the missing dystrophin protein or address secondary pathology have received regulatory approval and many others are in clinical development.
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Affiliation(s)
- Dongsheng Duan
- Department of Molecular Microbiology and Immunology and Department of Neurology, School of Medicine; Department of Biomedical Sciences, College of Veterinary Medicine; Department of Biomedical, Biological & Chemical Engineering, College of Engineering, University of Missouri, Columbia, MO, USA
| | - Nathalie Goemans
- Department of Child Neurology, University Hospitals Leuven, Leuven, Belgium
| | | | - Eugenio Mercuri
- Centro Clinico Nemo, Policlinico Gemelli, Rome, Italy
- Peadiatric Neurology, Catholic University, Rome, Italy
| | - Annemieke Aartsma-Rus
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
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11
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Mournetas V, Massouridès E, Dupont JB, Kornobis E, Polvèche H, Jarrige M, Dorval ARL, Gosselin MRF, Manousopoulou A, Garbis SD, Górecki DC, Pinset C. Myogenesis modelled by human pluripotent stem cells: a multi-omic study of Duchenne myopathy early onset. J Cachexia Sarcopenia Muscle 2021; 12:209-232. [PMID: 33586340 PMCID: PMC7890274 DOI: 10.1002/jcsm.12665] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/25/2020] [Accepted: 12/16/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) causes severe disability of children and death of young men, with an incidence of approximately 1/5000 male births. Symptoms appear in early childhood, with a diagnosis made mostly around 4 years old, a time where the amount of muscle damage is already significant, preventing early therapeutic interventions that could be more efficient at halting disease progression. In the meantime, the precise moment at which disease phenotypes arise-even asymptomatically-is still unknown. Thus, there is a critical need to better define DMD onset as well as its first manifestations, which could help identify early disease biomarkers and novel therapeutic targets. METHODS We have used both human tissue-derived myoblasts and human induced pluripotent stem cells (hiPSCs) from DMD patients to model skeletal myogenesis and compared their differentiation dynamics with that of healthy control cells by a comprehensive multi-omic analysis at seven time points. Results were strengthened with the analysis of isogenic CRISPR-edited human embryonic stem cells and through comparisons against published transcriptomic and proteomic datasets from human DMD muscles. The study was completed with DMD knockdown/rescue experiments in hiPSC-derived skeletal muscle progenitor cells and adenosine triphosphate measurement in hiPSC-derived myotubes. RESULTS Transcriptome and miRnome comparisons combined with protein analyses demonstrated that hiPSC differentiation (i) leads to embryonic/foetal myotubes that mimic described DMD phenotypes at the differentiation endpoint and (ii) homogeneously and robustly recapitulates key developmental steps-mesoderm, somite, and skeletal muscle. Starting at the somite stage, DMD dysregulations concerned almost 10% of the transcriptome. These include mitochondrial genes whose dysregulations escalate during differentiation. We also describe fibrosis as an intrinsic feature of DMD skeletal muscle cells that begins early during myogenesis. All the omics data are available online for exploration through a graphical interface at https://muscle-dmd.omics.ovh/. CONCLUSIONS Our data argue for an early developmental manifestation of DMD whose onset is triggered before the entry into the skeletal muscle compartment, data leading to a necessary reconsideration of dystrophin roles during muscle development. This hiPSC model of skeletal muscle differentiation offers the possibility to explore these functions as well as find earlier DMD biomarkers and therapeutic targets.
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Affiliation(s)
| | | | | | - Etienne Kornobis
- Biomics, C2RT, Institut Pasteur, Paris, France.,Hub de Bioinformatique et Biostatistique - Département BiologieComputationnelle, Paris, France
| | | | | | | | - Maxime R F Gosselin
- Molecular Medicine, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK
| | - Antigoni Manousopoulou
- Department of Immuno-Oncology, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA, USA
| | - Spiros D Garbis
- Unit for Cancer Sciences, Centre for Proteomics Research, Institute for Life Sciences, University of Southampton, Southampton, UK.,Proteas Bioanalytics Inc., BioLabs at The Lundquist Institute, Torrance, CA, USA
| | - Dariusz C Górecki
- Molecular Medicine, School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK.,Military Institute of Hygiene and Epidemiology, Warsaw, Poland
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12
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Hoffman EP. Causes of clinical variability in Duchenne and Becker muscular dystrophies and implications for exon skipping therapies. ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2020; 39:179-186. [PMID: 33458572 PMCID: PMC7783439 DOI: 10.36185/2532-1900-020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 11/09/2020] [Indexed: 12/20/2022]
Abstract
Becker muscular dystrophy is caused by mutations in the DMD gene that permit significant residual dystrophin protein expression in patient muscle. This is in contrast to DMD gene mutations in Duchenne muscular dystrophy where little or no dystrophin is produced (typically < 3% normal levels). Clinically, Becker muscular dystrophy is extremely variable, from slightly milder than DMD, to asymptomatic hyperCKemia at old age. The factors driving clinical variability in Becker muscular dystrophy have now been studied in some depth, and the findings are likely highly relevant to anticipated clinical findings in exon skipping therapy in DMD. The specific mutations in Becker dystrophy play an important role, and clinical variability is less with high frequency mutations (deletions exons 45-47, 45-48). The percentage of dystrophin content in patient muscle is not well-correlated with clinical findings. Muscle MRI findings (degree of fibrofatty replacement) are very well-correlated with the degree of patient disability, regardless of mutation or muscle dystrophin content. Taken together, data to date suggest that the main determinant driving clinical disability in Becker dystrophy patients is the degree of fibrofatty replacement in muscle. Thus, as with DMD, DMD gene mutations and resulting dystrophin protein abnormalities initiate the disease process, but downstream tissue pathophysiology plays a dominant role in disease progression. Factors influencing the age-dependent rate of fibrofatty replacement of muscles are responsible for much of the clinical variability seen in Becker dystrophy, as well as Duchenne dystrophy. These fibrosis-related factors include genetic modifiers, degree of muscle inflammation, and induction of microRNAs in muscle that bind to dystrophin mRNA and down-regulate dystrophin protein content in patient muscle. Studies to date regarding clinical variability in Becker dystrophy suggest that exon skipping therapy in DMD may show variable efficacy from patient to patient.
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Affiliation(s)
- Eric P Hoffman
- School of Pharmacy and Pharmaceutical Sciences; Binghamton University, State University of New York, Binghamton NY, USA
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Trucco F, Domingos JP, Tay CG, Ridout D, Maresh K, Munot P, Sarkozy A, Robb S, Quinlivan R, Riley M, Burch M, Fenton M, Wallis C, Chan E, Abel F, Manzur AY, Muntoni F. Cardiorespiratory Progression Over 5 Years and Role of Corticosteroids in Duchenne Muscular Dystrophy. Chest 2020; 158:1606-1616. [DOI: 10.1016/j.chest.2020.04.043] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 03/29/2020] [Accepted: 04/01/2020] [Indexed: 12/20/2022] Open
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14
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Hildyard JCW, Rawson F, Wells DJ, Piercy RJ. Multiplex in situ hybridization within a single transcript: RNAscope reveals dystrophin mRNA dynamics. PLoS One 2020; 15:e0239467. [PMID: 32970731 PMCID: PMC7514052 DOI: 10.1371/journal.pone.0239467] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 09/08/2020] [Indexed: 01/22/2023] Open
Abstract
Dystrophin plays a vital role in maintaining muscle health, yet low mRNA expression, lengthy transcription time and the limitations of traditional in-situ hybridization (ISH) methodologies mean that the dynamics of dystrophin transcription remain poorly understood. RNAscope is highly sensitive ISH method that can be multiplexed, allowing detection of individual transcript molecules at sub-cellular resolution, with different target mRNAs assigned to distinct fluorophores. We instead multiplex within a single transcript, using probes targeted to the 5' and 3' regions of muscle dystrophin mRNA. Our approach shows this method can reveal transcriptional dynamics in health and disease, resolving both nascent myonuclear transcripts and exported mature mRNAs in quantitative fashion (with the latter absent in dystrophic muscle, yet restored following therapeutic intervention). We show that even in healthy muscle, immature dystrophin mRNA predominates (60-80% of total), with the surprising implication that the half-life of a mature transcript is markedly shorter than the time invested in transcription: at the transcript level, supply may exceed demand. Our findings provide unique spatiotemporal insight into the behaviour of this long transcript (with implications for therapeutic approaches), and further suggest this modified multiplex ISH approach is well-suited to long genes, offering a highly tractable means to reveal complex transcriptional dynamics.
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Affiliation(s)
- John C. W. Hildyard
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Science and Services, Royal Veterinary College, London, United Kingdom
| | - Faye Rawson
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Science and Services, Royal Veterinary College, London, United Kingdom
| | - Dominic J. Wells
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom
| | - Richard J. Piercy
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Science and Services, Royal Veterinary College, London, United Kingdom
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Hendriksen JGM, Thangarajh M, Kan HE, Muntoni F. 249th ENMC International Workshop: The role of brain dystrophin in muscular dystrophy: Implications for clinical care and translational research, Hoofddorp, The Netherlands, November 29th-December 1st 2019. Neuromuscul Disord 2020; 30:782-794. [PMID: 32912717 DOI: 10.1016/j.nmd.2020.08.357] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 07/27/2020] [Accepted: 08/10/2020] [Indexed: 01/16/2023]
Affiliation(s)
- Jos G M Hendriksen
- Kempenhaeghe Center For Neurological Learning Disabilities, Heeze, the Netherlands; Duchenne Center, the Netherlands
| | - Mathula Thangarajh
- Department of Neurology, Virginia Commonwealth University, Richmond, USA
| | - Hermien E Kan
- Duchenne Center, the Netherlands; C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
| | - Francesco Muntoni
- The Dubowitz Neuromuscular Centre, University College London, Great Ormond Street Institute of Child Health, London, UK; NIHR Great Ormond Street Hospital Biomedical Research Centre, London, UK
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Hildyard JCW, Crawford AH, Rawson F, Riddell DO, Harron RCM, Piercy RJ. Single-transcript multiplex in situ hybridisation reveals unique patterns of dystrophin isoform expression in the developing mammalian embryo. Wellcome Open Res 2020; 5:76. [PMID: 32724863 PMCID: PMC7372313 DOI: 10.12688/wellcomeopenres.15762.2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/03/2020] [Indexed: 12/24/2022] Open
Abstract
Background: The dystrophin gene has multiple isoforms: full-length dystrophin (dp427) is principally known for its expression in skeletal and cardiac muscle, but is also expressed in the brain, and several internal promoters give rise to shorter, N-terminally truncated isoforms with wider tissue expression patterns (dp260 in the retina, dp140 in the brain and dp71 in many tissues). These isoforms are believed to play unique cellular roles both during embryogenesis and in adulthood, but their shared sequence identity at both mRNA and protein levels makes study of distinct isoforms challenging by conventional methods. Methods: RNAscope is a novel in-situ hybridisation technique that offers single-transcript resolution and the ability to multiplex, with different target sequences assigned to distinct fluorophores. Using probes designed to different regions of the dystrophin transcript (targeting 5', central and 3' sequences of the long dp427 mRNA), we can simultaneously detect and distinguish multiple dystrophin mRNA isoforms at sub-cellular histological levels. We have used these probes in healthy and dystrophic canine embryos to gain unique insights into isoform expression and distribution in the developing mammal. Results: Dp427 is found in developing muscle as expected, apparently enriched at nascent myotendinous junctions. Endothelial and epithelial surfaces express dp71 only. Within the brain and spinal cord, all three isoforms are expressed in spatially distinct regions: dp71 predominates within proliferating germinal layer cells, dp140 within maturing, migrating cells and dp427 appears within more established cell populations. Dystrophin is also found within developing bones and teeth, something previously unreported, and our data suggests orchestrated involvement of multiple isoforms in formation of these tissues. Conclusions: Overall, shorter isoforms appear associated with proliferation and migration, and longer isoforms with terminal lineage commitment: we discuss the distinct structural contributions and transcriptional demands suggested by these findings.
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Affiliation(s)
- John C. W. Hildyard
- Department of Clinical Science and Services, Royal Veterinary College, London, Camden, London, NW1 0TU, UK
| | - Abbe H. Crawford
- Department of Clinical Science and Services, Royal Veterinary College, London, Camden, London, NW1 0TU, UK
| | - Faye Rawson
- Department of Clinical Science and Services, Royal Veterinary College, London, Camden, London, NW1 0TU, UK
| | - Dominique O. Riddell
- Department of Clinical Science and Services, Royal Veterinary College, London, Camden, London, NW1 0TU, UK
| | - Rachel C. M. Harron
- Department of Clinical Science and Services, Royal Veterinary College, London, Camden, London, NW1 0TU, UK
| | - Richard J. Piercy
- Department of Clinical Science and Services, Royal Veterinary College, London, Camden, London, NW1 0TU, UK
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Tyagi R, Kumar S, Dalal A, Mohammed F, Mohanty M, Kaur P, Anand A. Repurposing Pathogenic Variants of DMD Gene and its Isoforms for DMD Exon Skipping Intervention. Curr Genomics 2020; 20:519-530. [PMID: 32655290 PMCID: PMC7327972 DOI: 10.2174/1389202920666191107142754] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Background
Duchenne Muscular Dystrophy (DMD) is a progressive, fatal neuromuscular disorder caused by mutations in the DMD gene. Emerging antisense oligomer based exon skipping therapy provides hope for the restoration of the reading frame. Objectives
Population-based DMD mutation database may enable exon skipping to be used for the benefit of patients. Hence, we planned this study to identify DMD gene variants in North Indian DMD cases. Methods
A total of 100 DMD cases were recruited and Multiplex ligation-dependent probe amplification (MLPA) analysis was performed to obtain the deletion and duplication profile. Results
Copy number variations (deletion/duplication) were found in 80.85% of unrelated DMD cases. Sixty-eight percent of cases were found to have variations in the distal hotspot region (Exon 45-55) of the DMD gene. Exon 44/45 variations were found to be the most prominent among single exon variations, whereas exon 49/50 was found to be the most frequently mutated locations in single/multiple exon variations. As per Leiden databases, 86.84% cases harboured out-of-frame mutations. Domain wise investigation revealed that 68% of mutations were localized in the region of spectrin repeats. Dp140 isoform was predicted to be absent in 62/76 (81.57%) cases. A total of 45/80 (56.25%) and 23/80 (28.70%) DMD subjects were predicted to be amenable to exon 51 and exon 45 skipping trials, respectively. Conclusion
A major proportion of DMD subjects (80%) could be diagnosed by the MLPA technique. The data generated from our study may be beneficial for strengthening of mutation database in the North Indian population.
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Affiliation(s)
- Rahul Tyagi
- 1Neuroscience Research Lab, Department of Neurology, Postgraduate Institute of Medical Education and Research, Chandigarh, India; 2Diagnostics Division, Center for DNA fingerprinting and Diagnostics, Hyderabad, India; 3Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology, New Delhi, India; 4Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Sumit Kumar
- 1Neuroscience Research Lab, Department of Neurology, Postgraduate Institute of Medical Education and Research, Chandigarh, India; 2Diagnostics Division, Center for DNA fingerprinting and Diagnostics, Hyderabad, India; 3Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology, New Delhi, India; 4Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Ashwin Dalal
- 1Neuroscience Research Lab, Department of Neurology, Postgraduate Institute of Medical Education and Research, Chandigarh, India; 2Diagnostics Division, Center for DNA fingerprinting and Diagnostics, Hyderabad, India; 3Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology, New Delhi, India; 4Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Faruq Mohammed
- 1Neuroscience Research Lab, Department of Neurology, Postgraduate Institute of Medical Education and Research, Chandigarh, India; 2Diagnostics Division, Center for DNA fingerprinting and Diagnostics, Hyderabad, India; 3Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology, New Delhi, India; 4Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Manju Mohanty
- 1Neuroscience Research Lab, Department of Neurology, Postgraduate Institute of Medical Education and Research, Chandigarh, India; 2Diagnostics Division, Center for DNA fingerprinting and Diagnostics, Hyderabad, India; 3Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology, New Delhi, India; 4Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Paramvir Kaur
- 1Neuroscience Research Lab, Department of Neurology, Postgraduate Institute of Medical Education and Research, Chandigarh, India; 2Diagnostics Division, Center for DNA fingerprinting and Diagnostics, Hyderabad, India; 3Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology, New Delhi, India; 4Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Akshay Anand
- 1Neuroscience Research Lab, Department of Neurology, Postgraduate Institute of Medical Education and Research, Chandigarh, India; 2Diagnostics Division, Center for DNA fingerprinting and Diagnostics, Hyderabad, India; 3Genomics and Molecular Medicine Unit, Institute of Genomics and Integrative Biology, New Delhi, India; 4Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India
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Congenital hearing impairment associated with peripheral cochlear nerve dysmyelination in glycosylation-deficient muscular dystrophy. PLoS Genet 2020; 16:e1008826. [PMID: 32453729 PMCID: PMC7274486 DOI: 10.1371/journal.pgen.1008826] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 06/05/2020] [Accepted: 05/04/2020] [Indexed: 02/06/2023] Open
Abstract
Hearing loss (HL) is one of the most common sensory impairments and etiologically and genetically heterogeneous disorders in humans. Muscular dystrophies (MDs) are neuromuscular disorders characterized by progressive degeneration of skeletal muscle accompanied by non-muscular symptoms. Aberrant glycosylation of α-dystroglycan causes at least eighteen subtypes of MD, now categorized as MD-dystroglycanopathy (MD-DG), with a wide spectrum of non-muscular symptoms. Despite a growing number of MD-DG subtypes and increasing evidence regarding their molecular pathogeneses, no comprehensive study has investigated sensorineural HL (SNHL) in MD-DG. Here, we found that two mouse models of MD-DG, Largemyd/myd and POMGnT1-KO mice, exhibited congenital, non-progressive, and mild-to-moderate SNHL in auditory brainstem response (ABR) accompanied by extended latency of wave I. Profoundly abnormal myelination was found at the peripheral segment of the cochlear nerve, which is rich in the glycosylated α-dystroglycan–laminin complex and demarcated by “the glial dome.” In addition, patients with Fukuyama congenital MD, a type of MD-DG, also had latent SNHL with extended latency of wave I in ABR. Collectively, these findings indicate that hearing impairment associated with impaired Schwann cell-mediated myelination at the peripheral segment of the cochlear nerve is a notable symptom of MD-DG. Hearing loss (HL) is one of the most common sensory impairments and heterogeneous disorders in humans. Up to 60% of HL cases are caused by genetic factors, and approximately 30% of genetic HL cases are syndromic. Although 400–700 genetic syndromes are associated with sensorineural HL (SNHL), caused due to problems in the nerve pathways from the cochlea to the brain, only about 45 genes are known to be associated with syndromic HL. Muscular dystrophies (MDs) are neuromuscular disorders characterized by progressive degeneration of skeletal muscle accompanied by non-muscular symptoms. MD-dystroglycanopathy (MD-DG), caused by aberrant glycosylation of α-dystroglycan, is an MD subtype with a wide spectrum of non-muscular symptoms. Despite a growing number of MD-DG subtypes (at least 18), no comprehensive study has investigated SNHL in MD-DG. Here, we found that hearing impairment was associated with abnormal myelination of the peripheral segment of the cochlear nerve caused by impaired dystrophin–dystroglycan complex in two mouse models (type 3 and 6) of MD-DG and in patients (type 4) with MD-DG. This is the first comprehensive study investigating SNHL in MD-DG. Our findings may provide new insights into understanding the pathogenic characteristics and mechanisms underlying inherited syndromic hearing impairment.
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Doorenweerd N. Combining genetics, neuropsychology and neuroimaging to improve understanding of brain involvement in Duchenne muscular dystrophy - a narrative review. Neuromuscul Disord 2020; 30:437-442. [PMID: 32522501 DOI: 10.1016/j.nmd.2020.05.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 11/24/2022]
Abstract
Duchenne muscular dystrophy is a multifactorial disease including a cognitive phenotype. It is caused by mutations in the X-chromosomal DMD gene from which dystrophin is synthesized. Multiple isoforms of dystrophin have been identified. The full length dystrophin isoform Dp427m is expressed predominantly in muscle. Other isoforms include: Dp427c, Dp427p, Dp260, Dp140, Dp116, Dp71 and Dp40. The majority of these isoforms are expressed in brain and several hypotheses exist on their role in subtypes of neurons and astrocytes. However, their function in relation to cognition remains unclear. Unlike progressive muscle wasting, cognitive involvement is not seen in all DMD patients and the severity varies greatly. To achieve a better understanding of brain involvement in DMD, a multidisciplinary approach is required. Here, we review the latest findings on dystrophin isoform expression in the brain; specific DMD-associated learning and behavioural difficulties; and imaging and spectroscopy findings relating to brain structure, networks, perfusion and metabolism. The main challenge lies in determining links between these different findings. If we can determine which factors play a role in the differentiation between severe and minor cognitive problems in DMD in the near future, we can both provide better advise for the patients and also develop targeted therapeutic interventions.
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Affiliation(s)
- Nathalie Doorenweerd
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, C-03-Q, P.O. Box 9600, 2300 RC Leiden, The Netherlands; John Walton Muscular Dystrophy Research Centre, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle Upon Tyne, United Kingdom.
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20
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Hildyard JCW, Crawford AH, Rawson F, Riddell DO, Harron RCM, Piercy RJ. Single-transcript multiplex in situ hybridisation reveals unique patterns of dystrophin isoform expression in the developing mammalian embryo. Wellcome Open Res 2020; 5:76. [PMID: 32724863 PMCID: PMC7372313 DOI: 10.12688/wellcomeopenres.15762.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2020] [Indexed: 07/30/2023] Open
Abstract
Background: The dystrophin gene has multiple isoforms: full-length dystrophin (dp427) is principally known for its expression in skeletal and cardiac muscle, but is also expressed in the brain, and several internal promoters give rise to shorter, N-terminally truncated isoforms with wider tissue expression patterns (dp260 in the retina, dp140 in the brain and dp71 in many tissues). These isoforms are believed to play unique cellular roles both during embryogenesis and in adulthood, but their shared sequence identity at both mRNA and protein levels makes study of distinct isoforms challenging by conventional methods. Methods: RNAscope is a novel in-situ hybridisation technique that offers single-transcript resolution and the ability to multiplex, with different target sequences assigned to distinct fluorophores. Using probes designed to different regions of the dystrophin transcript (targeting 5', central and 3' sequences of the long dp427 mRNA), we can simultaneously detect and distinguish multiple dystrophin mRNA isoforms at sub-cellular histological levels. We have used these probes in healthy and dystrophic canine embryos to gain unique insights into isoform expression and distribution in the developing mammal. Results: Dp427 is found in developing muscle as expected, apparently enriched at nascent myotendinous junctions. Endothelial and epithelial surfaces express dp71 only. Within the brain and spinal cord, all three isoforms are expressed in spatially distinct regions: dp71 predominates within proliferating germinal layer cells, dp140 within maturing, migrating cells and dp427 appears within more established cell populations. Dystrophin is also found within developing bones and teeth, something previously unreported, and our data suggests orchestrated involvement of multiple isoforms in formation of these tissues. Conclusions: Overall, shorter isoforms appear associated with proliferation and migration, and longer isoforms with terminal lineage commitment: we discuss the distinct structural contributions and transcriptional demands suggested by these findings.
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Affiliation(s)
- John C. W. Hildyard
- Department of Clinical Science and Services, Royal Veterinary College, London, Camden, London, NW1 0TU, UK
| | - Abbe H. Crawford
- Department of Clinical Science and Services, Royal Veterinary College, London, Camden, London, NW1 0TU, UK
| | - Faye Rawson
- Department of Clinical Science and Services, Royal Veterinary College, London, Camden, London, NW1 0TU, UK
| | - Dominique O. Riddell
- Department of Clinical Science and Services, Royal Veterinary College, London, Camden, London, NW1 0TU, UK
| | - Rachel C. M. Harron
- Department of Clinical Science and Services, Royal Veterinary College, London, Camden, London, NW1 0TU, UK
| | - Richard J. Piercy
- Department of Clinical Science and Services, Royal Veterinary College, London, Camden, London, NW1 0TU, UK
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Naidoo M, Anthony K. Dystrophin Dp71 and the Neuropathophysiology of Duchenne Muscular Dystrophy. Mol Neurobiol 2020; 57:1748-1767. [PMID: 31836945 PMCID: PMC7060961 DOI: 10.1007/s12035-019-01845-w] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 11/22/2019] [Indexed: 12/13/2022]
Abstract
Duchenne muscular dystrophy (DMD) is caused by frameshift mutations in the DMD gene that prevent the body-wide translation of its protein product, dystrophin. Besides a severe muscle phenotype, cognitive impairment and neuropsychiatric symptoms are prevalent. Dystrophin protein 71 (Dp71) is the major DMD gene product expressed in the brain and mutations affecting its expression are associated with the DMD neuropsychiatric syndrome. As with dystrophin in muscle, Dp71 localises to dystrophin-associated protein complexes in the brain. However, unlike in skeletal muscle; in the brain, Dp71 is alternatively spliced to produce many isoforms with differential subcellular localisations and diverse cellular functions. These include neuronal differentiation, adhesion, cell division and excitatory synapse organisation as well as nuclear functions such as nuclear scaffolding and DNA repair. In this review, we first describe brain involvement in DMD and the abnormalities observed in the DMD brain. We then review the gene expression, RNA processing and functions of Dp71. We review genotype-phenotype correlations and discuss emerging cellular/tissue evidence for the involvement of Dp71 in the neuropathophysiology of DMD. The literature suggests changes observed in the DMD brain are neurodevelopmental in origin and that their risk and severity is associated with a cumulative loss of distal DMD gene products such as Dp71. The high risk of neuropsychiatric syndromes in Duchenne patients warrants early intervention to achieve the best possible quality of life. Unravelling the function and pathophysiological significance of dystrophin in the brain has become a high research priority to inform the development of brain-targeting treatments for Duchenne.
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Affiliation(s)
- Michael Naidoo
- Centre for Physical Activity and Life Sciences, Faculty of Arts, Science and Technology, University of Northampton, University Drive, Northampton, Northamptonshire, NN1 5PH, UK
| | - Karen Anthony
- Centre for Physical Activity and Life Sciences, Faculty of Arts, Science and Technology, University of Northampton, University Drive, Northampton, Northamptonshire, NN1 5PH, UK.
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Schwann cell-specific Dp116 is expressed in glioblastoma cells, revealing two novel DMD gene splicing patterns. Biochem Biophys Rep 2019; 20:100703. [PMID: 31737793 PMCID: PMC6849142 DOI: 10.1016/j.bbrep.2019.100703] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 07/26/2019] [Accepted: 10/28/2019] [Indexed: 11/24/2022] Open
Abstract
Background The DMD gene is one of the largest human genes, being composed of 79 exons. Dystrophin Dp116 expressed from the promoter in intron 55 is a Schwann cell-specific isoform. The pathophysiological roles of Dp116 are largely unknown, because of its limited expression. This study assessed the expression of Dp116 in glioblastoma cells and evaluated the splicing patterns of the DMD gene in these cells. Methods Full-length Dp116 cDNA was PCR amplified from U-251 glioblastoma cells. Dp116 protein was analyzed by Western blotting. Results Full-length Dp116 cDNA, extending from exon S1 to exon 79, was PCR amplified to avoid confusion with other DMD isoforms. The full-length Dp116 transcript was amplified as nearly 3 kb in size. Western blotting of U-251 cell lysates revealed a signal at a position corresponding to vector-expressed Dp116 protein, indicating that Dp116 is expressed in glioblastoma cells. Sequencing of the amplified product revealed five splice variants, all skipping exon 78. The most abundant transcript lacked only exon 78 (Dp116b), whereas the second most abundant transcript lacked both exons 71 and 78 (Dp116ab). A third transcript lacking exons 71–74 and 78 was also identified (Dp116bc). Two novel splicing patterns were also observed, one with a deletion of exons 68 and 69 (Dp116bΔ68-69) and the other with a 100 bp deletion in the 5’ terminal end of exon 75 (75s), which was produced by the activation of a cryptic splice acceptor site (Dp116b75s). However, the splicing patterns in glioblastoma cells of DMD exons in Dp116 and Dp71 showed no significant differences. Conclusions Dp116 is expressed in glioblastoma cells as five splicing variants, with Dp116b being the most abundant. Two novel splicing patterns of DMD exons were observed. Dp116 is a Schwann cell-specific dystrophin isoform. Dp116 was shown to be expressed in glioblastoma, a lethal cerebral malignancy. Skipping of exon 78 was the default pathway. Of the five alternatively spliced variants detected, Dp116b was the most abundant. DMD exons showed two novel splicing patterns, one with cryptic splice activation.
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Bucher F, Friedlander MS, Aguilar E, Kurihara T, Krohne TU, Usui Y, Friedlander M. The long dystrophin gene product Dp427 modulates retinal function and vascular morphology in response to age and retinal ischemia. Neurochem Int 2019; 129:104489. [DOI: 10.1016/j.neuint.2019.104489] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 06/08/2019] [Accepted: 06/10/2019] [Indexed: 01/07/2023]
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Yamamoto T, Awano H, Zhang Z, Sakuma M, Kitaaki S, Matsumoto M, Nagai M, Sato I, Imanishi T, Hayashi N, Matsuo M, Iijima K, Saegusa J. Cardiac Dysfunction in Duchenne Muscular Dystrophy Is Less Frequent in Patients With Mutations in the Dystrophin Dp116 Coding Region Than in Other Regions. CIRCULATION-GENOMIC AND PRECISION MEDICINE 2019; 11:e001782. [PMID: 29874176 PMCID: PMC6319568 DOI: 10.1161/circgen.117.001782] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 11/07/2017] [Indexed: 01/16/2023]
Abstract
Supplemental Digital Content is available in the text. Background: Duchenne muscular dystrophy (DMD), the most common inherited muscular disease in childhood, is caused by dystrophin deficiency because of mutations in the DMD gene. Although DMD is characterized by fatal progressive muscle wasting, cardiomyopathy is the most important nonmuscle symptom threatening the life of patients with DMD. The relationship between cardiac involvement and dystrophin isoforms has not been analyzed. Methods and Results: The results of 1109 echocardiograms obtained from 181 Japanese DMD patients with confirmed mutations in the DMD gene were retrospectively analyzed. Patients showed an age-related decline in left ventricular ejection fraction. Patients were divided by patterns of dystrophin isoform deficiency into 5 groups. The cardiac dysfunction-free survival was significantly higher in the group with mutations in the Dp116 coding region than the others, whereas no significant differences in the other 3 groups. At age 25 years, the cardiac dysfunction-free rate was 0.6 in the Dp116 group, but only 0.1 in others. PCR amplification of Dp116 transcript in human cardiac muscle indicated promoter activation. Conclusions: Left ventricular ejection fraction in DMD declined stepwise with age. Cardiac dysfunction was less frequent in Dp116-deficient than other patients with DMD. Dp116 transcript was identified in human cardiac muscle for the first time. These results indicate that Dp116 is associated with cardiac involvement in DMD.
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Affiliation(s)
- Tetsushi Yamamoto
- From the Department of Clinical Laboratory, Kobe University Hospital, Kobe, Japan (T.Y., S.K., I.S., T.I., N.H., J.S.); Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan (H.A., M. Matsumoto, M.N., K.I.); Department of Pathology, Medical School of Nankai University, Tianjin, China (Z.Z.); Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan (Z.Z., M. Matsuo); and Department of Clinical Epidemiology, Hyogo College of Medicine, Nishinomiya, Japan (M.E.-S.)
| | - Hiroyuki Awano
- From the Department of Clinical Laboratory, Kobe University Hospital, Kobe, Japan (T.Y., S.K., I.S., T.I., N.H., J.S.); Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan (H.A., M. Matsumoto, M.N., K.I.); Department of Pathology, Medical School of Nankai University, Tianjin, China (Z.Z.); Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan (Z.Z., M. Matsuo); and Department of Clinical Epidemiology, Hyogo College of Medicine, Nishinomiya, Japan (M.E.-S.)
| | - Zhujun Zhang
- From the Department of Clinical Laboratory, Kobe University Hospital, Kobe, Japan (T.Y., S.K., I.S., T.I., N.H., J.S.); Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan (H.A., M. Matsumoto, M.N., K.I.); Department of Pathology, Medical School of Nankai University, Tianjin, China (Z.Z.); Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan (Z.Z., M. Matsuo); and Department of Clinical Epidemiology, Hyogo College of Medicine, Nishinomiya, Japan (M.E.-S.)
| | - Mio Sakuma
- From the Department of Clinical Laboratory, Kobe University Hospital, Kobe, Japan (T.Y., S.K., I.S., T.I., N.H., J.S.); Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan (H.A., M. Matsumoto, M.N., K.I.); Department of Pathology, Medical School of Nankai University, Tianjin, China (Z.Z.); Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan (Z.Z., M. Matsuo); and Department of Clinical Epidemiology, Hyogo College of Medicine, Nishinomiya, Japan (M.E.-S.)
| | - Shoko Kitaaki
- From the Department of Clinical Laboratory, Kobe University Hospital, Kobe, Japan (T.Y., S.K., I.S., T.I., N.H., J.S.); Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan (H.A., M. Matsumoto, M.N., K.I.); Department of Pathology, Medical School of Nankai University, Tianjin, China (Z.Z.); Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan (Z.Z., M. Matsuo); and Department of Clinical Epidemiology, Hyogo College of Medicine, Nishinomiya, Japan (M.E.-S.)
| | - Masaaki Matsumoto
- From the Department of Clinical Laboratory, Kobe University Hospital, Kobe, Japan (T.Y., S.K., I.S., T.I., N.H., J.S.); Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan (H.A., M. Matsumoto, M.N., K.I.); Department of Pathology, Medical School of Nankai University, Tianjin, China (Z.Z.); Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan (Z.Z., M. Matsuo); and Department of Clinical Epidemiology, Hyogo College of Medicine, Nishinomiya, Japan (M.E.-S.)
| | - Masashi Nagai
- From the Department of Clinical Laboratory, Kobe University Hospital, Kobe, Japan (T.Y., S.K., I.S., T.I., N.H., J.S.); Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan (H.A., M. Matsumoto, M.N., K.I.); Department of Pathology, Medical School of Nankai University, Tianjin, China (Z.Z.); Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan (Z.Z., M. Matsuo); and Department of Clinical Epidemiology, Hyogo College of Medicine, Nishinomiya, Japan (M.E.-S.)
| | - Itsuko Sato
- From the Department of Clinical Laboratory, Kobe University Hospital, Kobe, Japan (T.Y., S.K., I.S., T.I., N.H., J.S.); Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan (H.A., M. Matsumoto, M.N., K.I.); Department of Pathology, Medical School of Nankai University, Tianjin, China (Z.Z.); Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan (Z.Z., M. Matsuo); and Department of Clinical Epidemiology, Hyogo College of Medicine, Nishinomiya, Japan (M.E.-S.)
| | - Takamitsu Imanishi
- From the Department of Clinical Laboratory, Kobe University Hospital, Kobe, Japan (T.Y., S.K., I.S., T.I., N.H., J.S.); Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan (H.A., M. Matsumoto, M.N., K.I.); Department of Pathology, Medical School of Nankai University, Tianjin, China (Z.Z.); Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan (Z.Z., M. Matsuo); and Department of Clinical Epidemiology, Hyogo College of Medicine, Nishinomiya, Japan (M.E.-S.)
| | - Nobuhide Hayashi
- From the Department of Clinical Laboratory, Kobe University Hospital, Kobe, Japan (T.Y., S.K., I.S., T.I., N.H., J.S.); Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan (H.A., M. Matsumoto, M.N., K.I.); Department of Pathology, Medical School of Nankai University, Tianjin, China (Z.Z.); Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan (Z.Z., M. Matsuo); and Department of Clinical Epidemiology, Hyogo College of Medicine, Nishinomiya, Japan (M.E.-S.)
| | - Masafumi Matsuo
- From the Department of Clinical Laboratory, Kobe University Hospital, Kobe, Japan (T.Y., S.K., I.S., T.I., N.H., J.S.); Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan (H.A., M. Matsumoto, M.N., K.I.); Department of Pathology, Medical School of Nankai University, Tianjin, China (Z.Z.); Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan (Z.Z., M. Matsuo); and Department of Clinical Epidemiology, Hyogo College of Medicine, Nishinomiya, Japan (M.E.-S.).
| | - Kazumoto Iijima
- From the Department of Clinical Laboratory, Kobe University Hospital, Kobe, Japan (T.Y., S.K., I.S., T.I., N.H., J.S.); Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan (H.A., M. Matsumoto, M.N., K.I.); Department of Pathology, Medical School of Nankai University, Tianjin, China (Z.Z.); Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan (Z.Z., M. Matsuo); and Department of Clinical Epidemiology, Hyogo College of Medicine, Nishinomiya, Japan (M.E.-S.)
| | - Jun Saegusa
- From the Department of Clinical Laboratory, Kobe University Hospital, Kobe, Japan (T.Y., S.K., I.S., T.I., N.H., J.S.); Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan (H.A., M. Matsumoto, M.N., K.I.); Department of Pathology, Medical School of Nankai University, Tianjin, China (Z.Z.); Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe, Japan (Z.Z., M. Matsuo); and Department of Clinical Epidemiology, Hyogo College of Medicine, Nishinomiya, Japan (M.E.-S.)
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25
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Abstract
Duchenne muscular dystrophy (DMD) is a progressive X-linked degenerative muscle disease due to mutations in the DMD gene. Genetic confirmation has become standard in recent years. Improvements in the standard of care for DMD have led to improved survival. Novel treatments for DMD have focused on reducing the dystrophic mechanism of the muscle disease, modulating utrophin protein expression, and restoring dystrophin protein expression. Among the strategies to reduce the dystrophic mechanisms are 1) inhibiting inflammation, 2) promoting muscle growth and regeneration, 3) reducing fibrosis, and 4) facilitating mitochondrial function. The agents under investigation include a novel steroid, myostatin inhibitors, idebenone, an anti-CTGF antibody, a histone deacetylase inhibitor, and cardiosphere-derived cells. For utrophin modulation, AAV-mediated gene therapy with GALGT2 is currently being investigated to upregulate utrophin expression. Finally, the strategies for dystrophin protein restoration include 1) nonsense readthrough, 2) synthetic antisense oligonucleotides for exon skipping, and 3) AAV-mediated micro/minidystrophin gene delivery. With newer agents, we are witnessing the use of more advanced biotechnological methods. Although these potential breakthroughs provide significant promise, they may also raise new questions regarding treatment effect and safety.
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Affiliation(s)
- Perry B Shieh
- Department of Neurology, University of California, Los Angeles, 300 Medical Plaza, Suite B-200, Los Angeles, CA, 90095, USA.
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26
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Tyers L, Davids LM, Wilmshurst JM, Esterhuizen AI. Skin cells for use in an alternate diagnostic method for Duchenne muscular dystrophy. Neuromuscul Disord 2018; 28:553-563. [PMID: 29958823 DOI: 10.1016/j.nmd.2018.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 03/27/2018] [Accepted: 05/02/2018] [Indexed: 01/08/2023]
Abstract
The importance of molecular diagnosis and identification of disease-associated variants for Duchenne muscular dystrophy (DMD) is evident in the age of gene-based therapies and personalised medicine. Detection of the causative DMD variant and determination of its effects on dystrophin expression is best achieved by analysis of RNA extracted from muscle biopsy material. However, this is not done routinely, as the procedure can be traumatic, especially to young children, and carries risk of complications related to the use of anaesthetic. As skin biopsies are safer and straightforward to perform than muscle biopsies, we investigated the utility of cultured human epidermal melanocytes and dermal fibroblasts as alternative tools for RNA-based diagnosis of DMD. Shallow skin biopsies from 5 boys with genetically confirmed diagnoses of DMD were used to culture fibroblasts and melanocytes. Biopsies were sampled, and tolerated without complications, using local anaesthetic cream. Dystrophin expression in the cultured cells was assessed using immunocytochemical staining, quantitative real-time PCR and cDNA sequencing methodologies. We observed differential expression of the full-length dystrophin muscle transcript, with significantly more robust expression in melanocytes, compared to that in fibroblasts. Our results suggest that cultured skin melanocytes may present an alternative tool for RNA-based genetic diagnosis of DMD.
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Affiliation(s)
- Lynn Tyers
- Division of Human Genetics, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town 7935, South Africa.
| | | | - Jo M Wilmshurst
- Division of Human Genetics, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town 7935, South Africa; Department of Paediatric Neurology and Neurophysiology, Neuroscience Institute, Red Cross War Memorial Children's Hospital, University of Cape Town, Rondebosch, Cape Town 7700, South Africa
| | - Alina I Esterhuizen
- Division of Human Genetics, Department of Pathology, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town 7935, South Africa; National Health Laboratory Service, Groote Schuur Hospital, Observatory, Cape Town 7935, South Africa
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27
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Becerril-Esquivel C, Peñuelas-Urquides K, Blancas-Sánchez E, Zapata-Benavides P, Silva-Ramírez B, Chávez-Reyes A, Castorena-Torres F, Cisneros B, Bermúdez de León M. The polyaromatic hydrocarbon β-naphthoflavone alters binding of YY1, Sp1, and Sp3 transcription factors to the Dp71 promoter in hepatic cells. Mol Med Rep 2018; 17:6150-6155. [PMID: 29484433 DOI: 10.3892/mmr.2018.8626] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 01/19/2018] [Indexed: 11/06/2022] Open
Abstract
The smallest product of the Duchenne muscular dystrophy gene, dystrophin (Dp)71, is ubiquitously expressed in nonmuscle tissues. We previously showed that Dp71 expression in hepatic cells is modulated in part by stimulating factor 1 (Sp1), stimulating protein 3 (Sp3), and yin yang 1 (YY1) transcription factors, and that the polyaromatic hydrocarbon, β-naphthoflavone (β‑NF), downregulates Dp71 expression. The aim of the present study was to determine whether β‑NF represses Dp71 expression by altering mRNA stability or its promoter activity. Reverse transcription‑quantitative polymerase chain reaction was used to measure half‑life mRNA levels in β‑NF‑treated cells exposed to actinomycin D, an inhibitor of transcription, for 0, 4, 8, 12 and 16 h. Transient transfections with a plasmid carrying the Dp71 basal promoter fused to luciferase reporter gene were carried out in control and β‑NF‑treated cells. Electrophoretic mobility shift assays (EMSAs) were performed with labeled probes, corresponding to Dp71 promoter sequences, and nuclear extracts of control and β‑NF‑treated cells. To the best of our knowledge, the results demonstrated for the first time that this negative regulation takes place at the promoter level rather than the mRNA stability level. Interestingly, using EMSAs, β‑NF reduced binding of YY1, Sp1, and Sp3 to the Dp71 promoter. It also suggests that β‑NF may modulate the expression of other genes regulated by these transcription factors. In conclusion, β‑NF represses Dp71 expression in hepatic cells by altering binding of YY1, Sp1, and Sp3 to the Dp71 promoter.
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Affiliation(s)
- Carolina Becerril-Esquivel
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León 64720, México
| | - Katia Peñuelas-Urquides
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León 64720, México
| | - Erik Blancas-Sánchez
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León 64720, México
| | - Pablo Zapata-Benavides
- Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Biológicas, San Nicolás de los Garza, Nuevo León 66451, México
| | - Beatriz Silva-Ramírez
- Departamento de Inmunogenética, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León 64720, México
| | - Arturo Chávez-Reyes
- Centro de Investigación y de Estudios Avanzados del IPN Unidad Monterrey, Apodaca, Nuevo León 66600, México
| | | | - Bulmaro Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN unidad Zacatenco, Ciudad de México 07360, México
| | - Mario Bermúdez de León
- Departamento de Biología Molecular, Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León 64720, México
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28
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Timing and localization of human dystrophin isoform expression provide insights into the cognitive phenotype of Duchenne muscular dystrophy. Sci Rep 2017; 7:12575. [PMID: 28974727 PMCID: PMC5626779 DOI: 10.1038/s41598-017-12981-5] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 09/13/2017] [Indexed: 01/14/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) is a muscular dystrophy with high incidence of learning and behavioural problems and is associated with neurodevelopmental disorders. To gain more insights into the role of dystrophin in this cognitive phenotype, we performed a comprehensive analysis of the expression patterns of dystrophin isoforms across human brain development, using unique transcriptomic data from Allen Human Brain and BrainSpan atlases. Dystrophin isoforms show large changes in expression through life with pronounced differences between the foetal and adult human brain. The Dp140 isoform was expressed in the cerebral cortex only in foetal life stages, while in the cerebellum it was also expressed postnatally. The Purkinje isoform Dp427p was virtually absent. The expression of dystrophin isoforms was significantly associated with genes implicated in neurodevelopmental disorders, like autism spectrum disorders or attention-deficit hyper-activity disorders, which are known to be associated to DMD. We also identified relevant functional associations of the different isoforms, like an association with axon guidance or neuron differentiation during early development. Our results point to the crucial role of several dystrophin isoforms in the development and function of the human brain.
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29
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Matsuo M, Awano H, Matsumoto M, Nagai M, Kawaguchi T, Zhang Z, Nishio H. Dystrophin Dp116: A yet to Be Investigated Product of the Duchenne Muscular Dystrophy Gene. Genes (Basel) 2017; 8:genes8100251. [PMID: 28974057 PMCID: PMC5664101 DOI: 10.3390/genes8100251] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 09/26/2017] [Indexed: 12/12/2022] Open
Abstract
The Duchenne muscular dystrophy (DMD) gene is one of the largest genes in the human genome. The gene exhibits a complex arrangement of seven alternative promoters, which drive the expression of three full length and four shorter isoforms. Dp116, the second smallest product of the DMD gene, is a Schwann cell-specific isoform encoded by a transcript corresponding to DMD exons 56–79, starting from a promoter/exon S1 within intron 55. The physiological roles of Dp116 are poorly understood, because of its extensive homology with other isoforms and its expression in specific tissues. This review summarizes studies on Dp116, focusing on clinical findings and alternative activation of the upstream translation initiation codon that is predicted to produce Dp118.
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Affiliation(s)
- Masafumi Matsuo
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe 651-2180, Japan.
| | - Hiroyuki Awano
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan.
| | - Masaaki Matsumoto
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan.
| | - Masashi Nagai
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan.
| | - Tatsuya Kawaguchi
- Biomedical Analysis and Pathology Research Group, Discovery Science and Technology Department, Daiichi Sankyo RD Novare Co., Tokyo 134-8630, Japan.
| | - Zhujun Zhang
- Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe 651-2180, Japan.
| | - Hisahide Nishio
- Department of Community Medicine and Social Healthcare Sciences, Kobe University Graduate School of Medicine, Kobe 650-0017, Japan.
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Delalande O, Czogalla A, Hubert JF, Sikorski A, Le Rumeur E. Dystrophin and Spectrin, Two Highly Dissimilar Sisters of the Same Family. Subcell Biochem 2017; 82:373-403. [PMID: 28101868 DOI: 10.1007/978-3-319-49674-0_12] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Dystrophin and Spectrin are two proteins essential for the organization of the cytoskeleton and for the stabilization of membrane cells. The comparison of these two sister proteins, and with the dystrophin homologue utrophin, enables us to emphasise that, despite a similar topology with common subdomains and a common structural basis of a three-helix coiled-coil, they show a large range of dissimilarities in terms of genetics, cell expression and higher level structural organisation. Interactions with cellular partners, including proteins and membrane phospholipids, also show both strikingly similar and very different behaviours. The differences between dystrophin and spectrin are also illustrated by the large variety of pathological anomalies emerging from the dysfunction or the absence of these proteins, showing that they are keystones in their function of providing a scaffold that sustains cell structure.
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Affiliation(s)
- Olivier Delalande
- Institut de Génétique et Développement de Rennes, UMR CNRS 6290, Université de Rennes 1, Rennes, France.
| | - Aleksander Czogalla
- Biotechnology Faculty, Department of Cytobiochemistry, University of Wrocław, ul. joliot-Curie 14a, 50-383, Wroclaw, Poland
| | - Jean-François Hubert
- Institut de Génétique et Développement de Rennes, UMR CNRS 6290, Université de Rennes 1, Rennes, France
| | - Aleksander Sikorski
- Biotechnology Faculty, Department of Cytobiochemistry, University of Wrocław, ul. joliot-Curie 14a, 50-383, Wroclaw, Poland
| | - Elisabeth Le Rumeur
- Institut de Génétique et Développement de Rennes, UMR CNRS 6290, Université de Rennes 1, Rennes, France
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31
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Lo Cascio CM, Goetze O, Latshang TD, Bluemel S, Frauenfelder T, Bloch KE. Gastrointestinal Dysfunction in Patients with Duchenne Muscular Dystrophy. PLoS One 2016; 11:e0163779. [PMID: 27736891 PMCID: PMC5063332 DOI: 10.1371/journal.pone.0163779] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 09/14/2016] [Indexed: 12/14/2022] Open
Abstract
Background In adult patients with Duchenne muscular dystrophy (DMD) life-threatening constipation has been reported. Since gastrointestinal function in DMD has not been rigorously studied we investigated objective and subjective manifestations of gastrointestinal disturbances in DMD patients. Methods In 33 patients with DMD, age 12–41 years, eating behavior and gastrointestinal symptoms were evaluated by questionnaires. Gastric emptying half time (T1/2) and oro-cecal transit time (OCTT) were evaluated by analyzing 13CO2 exhalation curves after ingestion of 13C labeled test meals. Colonic transit time (CTT) was measured by abdominal radiography following ingestion of radiopaque markers. Results The median (quartiles) T1/2 was 187 (168, 220) minutes, the OCTT was 6.3 (5.0, 7.9) hours, both substantially longer than normal data (Goetze 2005, T1/2: 107±10; Geypens 1999, OCTT 4.3±0.1 hours). The median CTT was 60 (48, 82) hours despite extensive use of laxative measures (Meier 1995, upper limit of normal: 60 hours). T1/2 and OCTT did not correlate with symptoms evaluated by the Gastroparesis Cardinal Symptom Index (GCSI) (Spearman r = -0.3, p = 0.1; and r = -0.15, p = 0.4, respectively). CTT was not correlated with symptoms of constipation assessed by ROME III criteria (r = 0.12, p = 0.5). Conclusions DMD patients have a markedly disturbed gastrointestinal motor function. Since objective measures of impaired gastrointestinal transport are not correlated with symptoms of gastroparesis or constipation our findings suggest that measures assuring adequate intestinal transport should be taken independent of the patient’s perception in order to prevent potentially life threatening constipation, particularly in older DMD patients.
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Affiliation(s)
- Christian M. Lo Cascio
- Pulmonary Division, University Hospital of Zurich, Neuromuscular and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
- Center for Human Integrative Physiology, University of Zurich, Zurich, Switzerland
| | - Oliver Goetze
- Division of Gastroenterology and Hepatology, University Hospital of Zurich, Zurich, Switzerland
- Division of Hepatology, Department of Medicine II, University Hospital Würzburg, Würzburg, Germany
| | - Tsogyal D. Latshang
- Pulmonary Division, University Hospital of Zurich, Neuromuscular and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
- Center for Human Integrative Physiology, University of Zurich, Zurich, Switzerland
| | - Sena Bluemel
- Division of Gastroenterology and Hepatology, University Hospital of Zurich, Zurich, Switzerland
| | - Thomas Frauenfelder
- Institute of Diagnostic and Interventional Radiology, University Hospital of Zurich, Zurich, Switzerland
| | - Konrad E. Bloch
- Pulmonary Division, University Hospital of Zurich, Neuromuscular and Sleep Disorders Center, University Hospital of Zurich, Zurich, Switzerland
- Center for Human Integrative Physiology, University of Zurich, Zurich, Switzerland
- * E-mail:
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32
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Petkova MV, Morales-Gonzales S, Relizani K, Gill E, Seifert F, Radke J, Stenzel W, Garcia L, Amthor H, Schuelke M. Characterization of a Dmd (EGFP) reporter mouse as a tool to investigate dystrophin expression. Skelet Muscle 2016; 6:25. [PMID: 27382459 PMCID: PMC4932663 DOI: 10.1186/s13395-016-0095-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 06/08/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Dystrophin is a rod-shaped cytoplasmic protein that provides sarcolemmal stability as a structural link between the cytoskeleton and the extracellular matrix via the dystrophin-associated protein complex (DAPC). Mutations in the dystrophin-encoding DMD gene cause X-linked dystrophinopathies with variable phenotypes, the most severe being Duchenne muscular dystrophy (DMD) characterized by progressive muscle wasting and fibrosis. However, dystrophin deficiency does not only impair the function of skeletal and heart muscle but may also affect other organ systems such as the brain, eye, and gastrointestinal tract. The generation of a dystrophin reporter mouse would facilitate research into dystrophin muscular and extramuscular pathophysiology without the need for immunostaining. RESULTS We generated a Dmd (EGFP) reporter mouse through the in-frame insertion of the EGFP coding sequence behind the last Dmd exon 79, which is known to be expressed in all major dystrophin isoforms. We analyzed EGFP and dystrophin expression in various tissues and at the single muscle fiber level. Immunostaining of various members of the DAPC was done to confirm the correct subsarcolemmal location of dystrophin-binding partners. We found strong natural EGFP fluorescence at all expected sites of dystrophin expression in the skeletal and smooth muscle, heart, brain, and retina. EGFP fluorescence exactly colocalized with dystrophin immunostaining. In the skeletal muscle, dystrophin and other proteins of the DAPC were expressed at their correct sarcolemmal/subsarcolemmal localization. Skeletal muscle maintained normal tissue architecture, suggesting the correct function of the dystrophin-EGFP fusion protein. EGFP expression could be easily verified in isolated myofibers as well as in satellite cell-derived myotubes. CONCLUSIONS The novel dystrophin reporter mouse provides a valuable tool for direct visualization of dystrophin expression and will allow the study of dystrophin expression in vivo and in vitro in various tissues by live cell imaging.
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Affiliation(s)
- Mina V Petkova
- Department of Neuropediatrics, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany ; NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Susanne Morales-Gonzales
- Department of Neuropediatrics, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany ; NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Karima Relizani
- Université de Versailles St-Quentin, INSERM U1179 and LIA BAHN Centre Scientifique de Monaco, Montigny-le Bretonneux, France
| | - Esther Gill
- Department of Neuropediatrics, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany ; NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Franziska Seifert
- Department of Neuropediatrics, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany ; NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Josefine Radke
- Institute of Neuropathology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Werner Stenzel
- Institute of Neuropathology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Luis Garcia
- Université de Versailles St-Quentin, INSERM U1179 and LIA BAHN Centre Scientifique de Monaco, Montigny-le Bretonneux, France
| | - Helge Amthor
- Université de Versailles St-Quentin, INSERM U1179 and LIA BAHN Centre Scientifique de Monaco, Montigny-le Bretonneux, France
| | - Markus Schuelke
- Department of Neuropediatrics, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany ; NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
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Transcription factors YY1, Sp1 and Sp3 modulate dystrophin Dp71 gene expression in hepatic cells. Biochem J 2016; 473:1967-76. [PMID: 27143785 DOI: 10.1042/bcj20160163] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 05/03/2016] [Indexed: 11/17/2022]
Abstract
Dystrophin Dp71, the smallest product encoded by the Duchenne muscular dystrophy gene, is ubiquitously expressed in all non-muscle cells. Although Dp71 is involved in various cellular processes, the mechanisms underlying its expression have been little studied. In hepatic cells, Dp71 expression is down-regulated by the xenobiotic β-naphthoflavone. However, the effectors of this regulation remain unknown. In the present study we aimed at identifying DNA elements and transcription factors involved in Dp71 expression in hepatic cells. Relevant DNA elements on the Dp71 promoter were identified by comparing Dp71 5'-end flanking regions between species. The functionality of these elements was demonstrated by site-directed mutagenesis. Using EMSAs and ChIP, we showed that the Sp1 (specificity protein 1), Sp3 (specificity protein 3) and YY1 (Yin and Yang 1) transcription factors bind to the Dp71 promoter region. Knockdown of Sp1, Sp3 and YY1 in hepatic cells increased endogenous Dp71 expression, but reduced Dp71 promoter activity. In summary, Dp71 expression in hepatic cells is carried out, in part, by YY1-, Sp1- and Sp3-mediated transcription from the Dp71 promoter.
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Muskiewicz KR, Frank NY, Flint AF, Gussoni E. Myogenic Potential of Muscle Side and Main Population Cells after Intravenous Injection into Sub-lethally IrradiatedmdxMice. J Histochem Cytochem 2016; 53:861-73. [PMID: 15995145 DOI: 10.1369/jhc.4a6573.2005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Muscle side population (SP) cells have demonstrated hematopoietic and myogenic activities in vivo upon intravenous (IV) injection into lethally irradiated mdx mice. In contrast, muscle main population (MP) cells were unable to rescue the bone marrow of lethally irradiated mice and, consequently, their in vivo myogenic potential could not be assessed using this method. In the current study, muscle SP or MP cells derived from syngeneic wild-type male mice were delivered to sub-lethally irradiated mdx female mice by single or serial IV injections. Recipient mice were euthanized 12 weeks after transplantation at which time the quadriceps and diaphragm muscles were analyzed for the presence of donor-derived cells. Mice injected with 104muscle SP cells or with 106MP cells appeared to have similar numbers of dystrophin-positive myofibers containing fused donor nuclei. Analysis of the remaining tissue via real-time quantitative PCR indicated that mice injected with muscle SP cells had a higher percentage of donor-derived Y-DNA in the quadriceps than mice injected with MP cells, suggesting that muscle SP cells may be enriched for progenitors able to engraft dystrophic skeletal muscles from the circulation. Although the overall engraftment did not reach therapeutically significant levels, these results indicate that further optimization of cell delivery techniques may lead to improved efficacy of cell-mediated therapy using muscle SP cells.
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Affiliation(s)
- Kristina R Muskiewicz
- Division of Genetics, Program in Genomics, Children's Hospital Boston, 320 Longwood Avenue, Boston, MA 02115, USA
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35
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Annese T, Corsi P, Ruggieri S, Tamma R, Marinaccio C, Picocci S, Errede M, Specchia G, De Luca A, Frassanito MA, Desantis V, Vacca A, Ribatti D, Nico B. Isolation and characterization of neural stem cells from dystrophic mdx mouse. Exp Cell Res 2016; 343:190-207. [DOI: 10.1016/j.yexcr.2016.03.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 03/17/2016] [Accepted: 03/19/2016] [Indexed: 10/22/2022]
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Holland A, Murphy S, Dowling P, Ohlendieck K. Pathoproteomic profiling of the skeletal muscle matrisome in dystrophinopathy associated myofibrosis. Proteomics 2015; 16:345-66. [PMID: 26256116 DOI: 10.1002/pmic.201500158] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 06/12/2015] [Accepted: 07/24/2015] [Indexed: 12/14/2022]
Abstract
The gradual accumulation of collagen and associated proteins of the extracellular matrix is a crucial myopathological parameter of many neuromuscular disorders. Progressive tissue damage and fibrosis play a key pathobiochemical role in the dysregulation of contractile functions and often correlates with poor motor outcome in muscular dystrophies. Following a brief introduction into the role of the extracellular matrix in skeletal muscles, we review here the proteomic profiling of myofibrosis and its intrinsic role in X-linked muscular dystrophy. Although Duchenne muscular dystrophy is primarily a disease of the membrane cytoskeleton, one of its most striking histopathological features is a hyperactive connective tissue and tissue scarring. We outline the identification of novel factors involved in the modulation of the extracellular matrix in muscular dystrophy, such as matricellular proteins. The establishment of novel proteomic markers will be helpful in improving the diagnosis, prognosis, and therapy monitoring in relation to fibrotic substitution of contractile tissue. In the future, the prevention of fibrosis will be crucial for providing optimum conditions to apply novel pharmacological treatments, as well as establish cell-based approaches or gene therapeutic interventions. The elimination of secondary abnormalities in the matrisome promises to reduce tissue scarring and the loss of skeletal muscle elasticity.
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Affiliation(s)
- Ashling Holland
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare, Ireland
| | - Sandra Murphy
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare, Ireland
| | - Paul Dowling
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare, Ireland
| | - Kay Ohlendieck
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare, Ireland
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Nichols B, Takeda S, Yokota T. Nonmechanical Roles of Dystrophin and Associated Proteins in Exercise, Neuromuscular Junctions, and Brains. Brain Sci 2015; 5:275-98. [PMID: 26230713 PMCID: PMC4588140 DOI: 10.3390/brainsci5030275] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 06/29/2015] [Accepted: 07/21/2015] [Indexed: 02/06/2023] Open
Abstract
Dystrophin-glycoprotein complex (DGC) is an important structural unit in skeletal muscle that connects the cytoskeleton (f-actin) of a muscle fiber to the extracellular matrix (ECM). Several muscular dystrophies, such as Duchenne muscular dystrophy, Becker muscular dystrophy, congenital muscular dystrophies (dystroglycanopathies), and limb-girdle muscular dystrophies (sarcoglycanopathies), are caused by mutations in the different DGC components. Although many early studies indicated DGC plays a crucial mechanical role in maintaining the structural integrity of skeletal muscle, recent studies identified novel roles of DGC. Beyond a mechanical role, these DGC members play important signaling roles and act as a scaffold for various signaling pathways. For example, neuronal nitric oxide synthase (nNOS), which is localized at the muscle membrane by DGC members (dystrophin and syntrophins), plays an important role in the regulation of the blood flow during exercise. DGC also plays important roles at the neuromuscular junction (NMJ) and in the brain. In this review, we will focus on recently identified roles of DGC particularly in exercise and the brain.
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Affiliation(s)
- Bailey Nichols
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry.
| | - Shin'ichi Takeda
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1, Ogawa-higashi, Kodaira, Tokyo 187-8502, Japan.
| | - Toshifumi Yokota
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry.
- Muscular Dystrophy Canada Research Chair, 8812-112 St, Edmonton, AB T6G 2H7, Canada.
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Abstract
Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy during childhood. Mutations in dystrophin (DMD) gene are also recognized as a cause of cognitive impairment. We aimed to determine the association between intelligence level and mutation location in DMD genes in Serbian patients with DMD. Forty-one male patients with DMD, aged 3 to 16 years, were recruited at the Clinic for Neurology and Psychiatry for Children and Youth in Belgrade, Serbia. All patients had defined DMD gene deletions or duplications [multiplex ligation-dependent probe amplification (MLPA), polymerase chain reaction (PCR)] and cognitive status assessment (Wechsler Intelligence Scale for Children, Brunet-Lezine scale, Vineland-Doll scale). In 37 patients with an estimated full scale intelligence quotient (FSIQ), six (16.22%) had borderline intelligence (70<FSIQ ≤85), while seven (18.92%) were intellectually impaired (FSIQ <70). The FSIQ was not associated with proximal and distal mutations when boundaries were set at exons 30 and 45. However, FSIQ was statistically significantly associated with mutation location when we assumed their functional consequence on dystrophin isoforms and when mutations in the 5′-untranslated region (5′UTR) of Dp140 (exons 45–50) were assigned to affect only Dp427 and Dp260. Mutations affecting Dp140 and Dp71/Dp40 have been associated with more frequent and more severe cognitive impairment. Finally, the same classification of mutations explained the greater proportion of FSIQ variability associated with cumulative loss of dystrophin isoforms. In conclusion, cumulative loss of dystrophin isoforms increases the risk of intellectual impairment in DMD and characterizing the genotype can define necessity of early cognitive interventions in DMD patients.
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Swiderski K, Shaffer SA, Gallis B, Odom GL, Arnett AL, Scott Edgar J, Baum DM, Chee A, Naim T, Gregorevic P, Murphy KT, Moody J, Goodlett DR, Lynch GS, Chamberlain JS. Phosphorylation within the cysteine-rich region of dystrophin enhances its association with β-dystroglycan and identifies a potential novel therapeutic target for skeletal muscle wasting. Hum Mol Genet 2014; 23:6697-711. [PMID: 25082828 DOI: 10.1093/hmg/ddu388] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mutations in dystrophin lead to Duchenne muscular dystrophy, which is among the most common human genetic disorders. Dystrophin nucleates assembly of the dystrophin-glycoprotein complex (DGC), and a defective DGC disrupts an essential link between the intracellular cytoskeleton and the basal lamina, leading to progressive muscle wasting. In vitro studies have suggested that dystrophin phosphorylation may affect interactions with actin or syntrophin, yet whether this occurs in vivo or affects protein function remains unknown. Utilizing nanoflow liquid chromatography mass spectrometry, we identified 18 phosphorylated residues within endogenous dystrophin. Mutagenesis revealed that phosphorylation at S3059 enhances the dystrophin-dystroglycan interaction and 3D modeling utilizing the Rosetta software program provided a structural model for how phosphorylation enhances this interaction. These findings demonstrate that phosphorylation is a key mechanism regulating the interaction between dystrophin and the DGC and reveal that posttranslational modification of a single amino acid directly modulates the function of dystrophin.
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Affiliation(s)
- Kristy Swiderski
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195-7720, USA
| | - Scott A Shaffer
- Department of Medicinal Chemistry, University of Washington School of Medicine, Seattle, WA 98195-7610, USA
| | - Byron Gallis
- Department of Medicinal Chemistry, University of Washington School of Medicine, Seattle, WA 98195-7610, USA
| | - Guy L Odom
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195-7720, USA
| | - Andrea L Arnett
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195-7720, USA
| | - J Scott Edgar
- Department of Medicinal Chemistry, University of Washington School of Medicine, Seattle, WA 98195-7610, USA
| | - Dale M Baum
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - Annabel Chee
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - Timur Naim
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - Paul Gregorevic
- Muscle Biology and Therapeutics Laboratory, Baker IDI Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
| | - Kate T Murphy
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - James Moody
- Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195-7350, USA and Program in Molecular and Cellular Biology, University of Washington School of Medicine, Seattle, WA 98195-7275, USA
| | - David R Goodlett
- Department of Medicinal Chemistry, University of Washington School of Medicine, Seattle, WA 98195-7610, USA
| | - Gordon S Lynch
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, VIC 3010, Australia
| | - Jeffrey S Chamberlain
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195-7720, USA Department of Biochemistry, University of Washington School of Medicine, Seattle, WA 98195-7350, USA and Program in Molecular and Cellular Biology, University of Washington School of Medicine, Seattle, WA 98195-7275, USA
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von Boxberg Y, Soares S, Féréol S, Fodil R, Bartolami S, Taxi J, Tricaud N, Nothias F. Giant scaffolding protein AHNAK1 interacts with β-dystroglycan and controls motility and mechanical properties of Schwann cells. Glia 2014; 62:1392-406. [PMID: 24796807 DOI: 10.1002/glia.22685] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 04/11/2014] [Accepted: 04/17/2014] [Indexed: 01/02/2023]
Abstract
The profound morphofunctional changes that Schwann cells (SCs) undergo during their migration and elongation on axons, as well as during axon sorting, ensheathment, and myelination, require their close interaction with the surrounding laminin-rich basal lamina. In contrast to myelinating central nervous system glia, SCs strongly and constitutively express the giant scaffolding protein AHNAK1, localized essentially underneath the outer, abaxonal plasma membrane. Using electron microscopy, we show here that in the sciatic nerve of ahnak1(-) (/) (-) mice the ultrastructure of myelinated, and unmyelinated (Remak) fibers is affected. The major SC laminin receptor β-dystroglycan co-immunoprecipitates with AHNAK1 shows reduced expression in ahnak1(-) (/) (-) SCs, and is no longer detectable in Cajal bands on myelinated fibers in ahnak1(-) (/) (-) sciatic nerve. Reduced migration velocity in a scratch wound assay of purified ahnak1(-) (/) (-) primary SCs cultured on a laminin substrate indicated a function of AHNAK1 in SC motility. This was corroborated by atomic force microscopy measurements, which revealed a greater mechanical rigidity of shaft and leading tip of ahnak1(-) (/) (-) SC processes. Internodal lengths of large fibers are decreased in ahnak1(-) (/) (-) sciatic nerve, and longitudinal extension of myelin segments is even more strongly reduced after acute knockdown of AHNAK1 in SCs of developing sciatic nerve. Together, our results suggest that by interfering in the cross-talk between the transmembrane form of the laminin receptor dystroglycan and F-actin, AHNAK1 influences the cytoskeleton organization of SCs, and thus plays a role in the regulation of their morphology and motility and lastly, the myelination process.
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Affiliation(s)
- Ysander von Boxberg
- Sorbonne Universités, UPMC CR18 (NPS), Paris, France; Neuroscience Paris Seine (NPS), CNRS UMR 8246, Paris, France; Neuroscience Paris Seine (NPS), INSERM U1130, Paris, France
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41
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Suárez-Sánchez R, Aguilar A, Wagstaff KM, Velez G, Azuara-Medina PM, Gomez P, Vásquez-Limeta A, Hernández-Hernández O, Lieu KG, Jans DA, Cisneros B. Nucleocytoplasmic shuttling of the Duchenne muscular dystrophy gene product dystrophin Dp71d is dependent on the importin α/β and CRM1 nuclear transporters and microtubule motor dynein. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1843:985-1001. [PMID: 24486332 DOI: 10.1016/j.bbamcr.2014.01.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Revised: 12/17/2013] [Accepted: 01/24/2014] [Indexed: 01/08/2023]
Abstract
Even though the Duchenne muscular dystrophy (DMD) gene product Dystrophin Dp71d is involved in various key cellular processes through its role as a scaffold for structural and signalling proteins at the plasma membrane as well as the nuclear envelope, its subcellular trafficking is poorly understood. Here we map the nuclear import and export signals of Dp71d by truncation and point mutant analysis, showing for the first time that Dp71d shuttles between the nucleus and cytoplasm mediated by the conventional nuclear transporters, importin (IMP) α/β and the exportin CRM1. Binding was confirmed in cells using pull-downs, while in vitro binding assays showed direct, high affinity (apparent dissociation coefficient of c. 0.25nM) binding of Dp71d to IMPα/β. Interestingly, treatment of cells with the microtubule depolymerizing reagent nocodazole or the dynein inhibitor EHNA both decreased Dp71d nuclear localization, implying that Dp71d nuclear import may be facilitated by microtubules and the motor protein dynein. The role of Dp71d in the nucleus appears to relate in part to interaction with the nuclear envelope protein emerin, and maintenance of the integrity of the nuclear architecture. The clear implication is that Dp71d's previously unrecognised nuclear transport properties likely contribute to various, important physiological roles.
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Affiliation(s)
- R Suárez-Sánchez
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico; Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación, México D.F, Mexico
| | - A Aguilar
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - K M Wagstaff
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - G Velez
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - P M Azuara-Medina
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - P Gomez
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - A Vásquez-Limeta
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico
| | - O Hernández-Hernández
- Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación, México D.F, Mexico
| | - K G Lieu
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - D A Jans
- Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia.
| | - B Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México D.F, Mexico.
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Cia D, Simonutti M, Fort PE, Doly M, Rendon A. Slight Alteration of the Electroretinogram in Mice Lacking Dystrophin Dp71. Ophthalmic Res 2014; 51:196-203. [DOI: 10.1159/000357272] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 11/11/2013] [Indexed: 11/19/2022]
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Dystrophin complex functions as a scaffold for signalling proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:635-42. [DOI: 10.1016/j.bbamem.2013.08.023] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 08/22/2013] [Accepted: 08/28/2013] [Indexed: 11/23/2022]
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Rozkalne A, Adkin C, Meng J, Lapan A, Morgan JE, Gussoni E. Mouse regenerating myofibers detected as false-positive donor myofibers with anti-human spectrin. Hum Gene Ther 2013; 25:73-81. [PMID: 24152287 DOI: 10.1089/hum.2013.126] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Abstract Stem cell transplantation is being tested as a potential therapy for a number of diseases. Stem cells isolated directly from tissue specimens or generated via reprogramming of differentiated cells require rigorous testing for both safety and efficacy in preclinical models. The availability of mice with immune-deficient background that carry additional mutations in specific genes facilitates testing the efficacy of cell transplantation in disease models. The muscular dystrophies are a heterogeneous group of disorders, of which Duchenne muscular dystrophy is the most severe and common type. Cell-based therapy for muscular dystrophy has been under investigation for several decades, with a wide selection of cell types being studied, including tissue-specific stem cells and reprogrammed stem cells. Several immune-deficient mouse models of muscular dystrophy have been generated, in which human cells obtained from various sources are injected to assess their preclinical potential. After transplantation, the presence of engrafted human cells is detected via immunofluorescence staining, using antibodies that recognize human, but not mouse, proteins. Here we show that one antibody specific to human spectrin, which is commonly used to evaluate the efficacy of transplanted human cells in mouse muscle, detects myofibers in muscles of NOD/Rag1(null)mdx(5cv), NOD/LtSz-scid IL2Rγ(null) mice, or mdx nude mice, irrespective of whether they were injected with human cells. These "reactive" clusters are regenerating myofibers, which are normally present in dystrophic tissue and the spectrin antibody is likely recognizing utrophin, which contains spectrin-like repeats. Therefore, caution should be used in interpreting data based on detection of single human-specific proteins, and evaluation of human stem cell engraftment should be performed using multiple human-specific labeling strategies.
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Affiliation(s)
- Anete Rozkalne
- 1 Program in Genomics and Division of Genetics, Boston Children's Hospital , Boston, MA 02115
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45
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Barnabei MS, Martindale JM, Townsend D, Metzger JM. Exercise and muscular dystrophy: implications and analysis of effects on musculoskeletal and cardiovascular systems. Compr Physiol 2013; 1:1353-63. [PMID: 23733645 DOI: 10.1002/cphy.c100062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The muscular dystrophies are a heterogeneous collection of progressive, inherited diseases of muscle weakness and degeneration. Although these diseases can vary widely in their etiology and presentation, nearly all muscular dystrophies cause exercise intolerance to some degree. Here, we focus on Duchenne muscular dystrophy (DMD), the most common form of muscular dystrophy, as a paradigm for the effects of muscle disease on exercise capacity. First described in the mid-1800s, DMD is a rapidly progressive and lethal muscular dystrophy caused by mutations in the dystrophin gene. Dystrophin is a membrane-associated cytoskeletal protein, the loss of which causes numerous cellular defects including mechanical instability of the sarcolemma, increased influx of extracellular calcium, and cell signaling defects. Here, we discuss the physiological basis for exercise intolerance in DMD, focusing on the molecular and cellular defects caused by loss of dystrophin and how these manifest as organ-level dysfunction and reduced exercise capacity. The main focus of this article is the defects present in dystrophin-deficient striated muscle. However, discussion regarding the effects of dystrophin loss on other tissues, including vascular smooth muscle is also included. Collectively, the goal of this article is to summarize the current state of knowledge regarding the mechanistic basis for exercise intolerance in DMD, which may serve as an archetype for other muscular dystrophies and diseases of muscle wasting.
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Affiliation(s)
- Matthew S Barnabei
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
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47
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Abstract
The presence of variable degrees of non progressive cognitive impairment is recognized as a clinical feature of patients with Duchenne and Becker muscular dystrophies (DMD and BMD), but its pathogenesis still remains a matter of debate. A number of findings have proved that rearrangements located in the second part of the
dystrophin
(
DMD
) gene seem to be preferentially associated with cognitive impairment. Dp140 is a distal dystrophin isoform, mainly expressed during fetal brain development, whose role for neuropsychological functioning was suggested.
The aims of the current study were to explore the possible association between cognitive impairment and DNA mutations affecting the regulatory regions of Dp140, as well as to compare the neuropsychological functioning of patients affected with DMD and Intermediate muscular dystrophy (IMD) with those affected by Becker muscular dystrophy (BMD). Fiftythree patients genetically diagnosed with DMD, IMD and BMD, subdivided according to sites of mutations along the
DMD
gene, underwent a neuropsychological assessment, evaluating their general cognitive abilities, verbal memory, attention and executive functions. Twenty patients with mutations, terminating in exon 44 or starting at exon 45 were tested by polymerase chain reaction (PCR) amplification of microsatellites STR44, SK12, SK21 and P20 DXS269, in order to evaluate the integrity of the Dp140 promoter region.
According to our statistical results, there was not a significant difference in terms of general intelligence between the allelic forms of the disease, a higher frequency of mental retardation was observed in DMD patients. The patients with BMD had better results on tests, measuring long-term verbal learning memory and executive functions. We found that patients lacking Dp140 performed more poorly on all neuropsychological tests compared to those with preserved Dp140. Overall, our findings suggest that the loss of Dp140 is associated with a higher risk of intellectual impairment among patients with dystrophinopathies and highlights the possible role of this distal isoform in normal cognitive development.
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48
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de Brouwer APM, Nabuurs SB, Verhaart IEC, Oudakker AR, Hordijk R, Yntema HG, Hordijk-Hos JM, Voesenek K, de Vries BBA, van Essen T, Chen W, Hu H, Chelly J, den Dunnen JT, Kalscheuer VM, Aartsma-Rus AM, Hamel BCJ, van Bokhoven H, Kleefstra T. A 3-base pair deletion, c.9711_9713del, in DMD results in intellectual disability without muscular dystrophy. Eur J Hum Genet 2013; 22:480-5. [PMID: 23900271 DOI: 10.1038/ejhg.2013.169] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 05/21/2013] [Accepted: 07/02/2013] [Indexed: 11/09/2022] Open
Abstract
We have identified a deletion of 3 base pairs in the dystrophin gene (DMD), c.9711_9713del, in a family with nonspecific X-linked intellectual disability (ID) by sequencing of the exons of 86 known X-linked ID genes. This in-frame deletion results in the deletion of a single-amino-acid residue, Leu3238, in the brain-specific isoform Dp71 of dystrophin. Linkage analysis supported causality as the mutation was present in the 7.6 cM linkage interval on Xp22.11-Xp21.1 with a maximum positive LOD score of 2.41 (MRX85 locus). Molecular modeling predicts that the p.(Leu3238del) deletion results in the destabilization of the C-terminal domain of dystrophin and hence reduces the ability to interact with β-dystroglycan. Correspondingly, Dp71 protein levels in lymphoblastoid cells from the index patient are 6.7-fold lower than those in control cell lines (P=0.08). Subsequent determination of the creatine kinase levels in blood of the index patient showed a mild but significant elevation in serum creatine kinase, which is in line with impaired dystrophin function. In conclusion, we have identified the first DMD mutation in Dp71 that results in ID without muscular dystrophy.
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Affiliation(s)
- Arjan P M de Brouwer
- 1] Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands [2] Institute of Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands [3] Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Sander B Nabuurs
- Centre for Molecular and Biomolecular Informatics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Ingrid E C Verhaart
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Astrid R Oudakker
- 1] Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands [2] Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Roel Hordijk
- Department of Genetics, University Medical Center Groningen, Groningen, The Netherlands
| | - Helger G Yntema
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Jannet M Hordijk-Hos
- Department of Genetics, University Medical Center Groningen, Groningen, The Netherlands
| | - Krysta Voesenek
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Bert B A de Vries
- 1] Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands [2] Institute of Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Ton van Essen
- Department of Genetics, University Medical Center Groningen, Groningen, The Netherlands
| | - Wei Chen
- Department Human Molecular Genetics, Max Planck Institute for Molecular Genetics, Ihnestrasse 73, Berlin, Germany
| | - Hao Hu
- Department Human Molecular Genetics, Max Planck Institute for Molecular Genetics, Ihnestrasse 73, Berlin, Germany
| | - Jamel Chelly
- Institut Cochin, INSERM Unité 1016, CNRS UMR 8104, Paris, France
| | - Johan T den Dunnen
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Vera M Kalscheuer
- Department Human Molecular Genetics, Max Planck Institute for Molecular Genetics, Ihnestrasse 73, Berlin, Germany
| | | | - Ben C J Hamel
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Hans van Bokhoven
- 1] Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands [2] Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Tjitske Kleefstra
- 1] Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands [2] Institute of Genetic and Metabolic Disease, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands [3] Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, The Netherlands
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Echigoya Y, Lee J, Rodrigues M, Nagata T, Tanihata J, Nozohourmehrabad A, Panesar D, Miskew B, Aoki Y, Yokota T. Mutation types and aging differently affect revertant fiber expansion in dystrophic mdx and mdx52 mice. PLoS One 2013; 8:e69194. [PMID: 23894429 PMCID: PMC3722172 DOI: 10.1371/journal.pone.0069194] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 06/05/2013] [Indexed: 11/18/2022] Open
Abstract
Duchenne muscular dystrophy (DMD), one of the most common and lethal genetic disorders, and the mdx mouse myopathies are caused by a lack of dystrophin protein. These dystrophic muscles contain sporadic clusters of dystrophin-expressing revertant fibers (RFs), as detected by immunohistochemistry. RFs are known to arise from muscle precursor cells with spontaneous exon skipping (alternative splicing) and clonally expand in size with increasing age through the process of muscle degeneration/regeneration. The expansion of revertant clusters is thought to represent the cumulative history of muscle regeneration and proliferation of such precursor cells. However, the precise mechanisms by which RFs arise and expand are poorly understood. Here, to test the effects of mutation types and aging on RF expansion and muscle regeneration, we examined the number of RFs in mdx mice (containing a nonsense mutation in exon 23) and mdx52 mice (containing deletion mutation of exon 52) with the same C57BL/6 background at 2, 6, 12, and 18months of age. Mdx mice displayed a significantly higher number of RFs compared to mdx52 mice in all age groups, suggesting that revertant fiber expansion largely depends on the type of mutation and/or location in the gene. A significant increase in the expression and clustering levels of RFs was found beginning at 6months of age in mdx mice compared with mdx52 mice. In contrast to the significant expansion of RFs with increasing age, the number of centrally nucleated fibers and embryonic myosin heavy chain-positive fibers (indicative of cumulative and current muscle regeneration, respectively) decreased with age in both mouse strains. These results suggest that mutation types and aging differently affect revertant fiber expansion in mdx and mdx52 mice.
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Affiliation(s)
- Yusuke Echigoya
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada
| | - Joshua Lee
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada
| | - Merryl Rodrigues
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada
| | - Tetsuya Nagata
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Jun Tanihata
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
| | - Ashkan Nozohourmehrabad
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada
| | - Dharminder Panesar
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada
| | - Bailey Miskew
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada
| | - Yoshitsugu Aoki
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Toshifumi Yokota
- Department of Medical Genetics, University of Alberta Faculty of Medicine and Dentistry, Edmonton, Alberta, Canada
- The Friends of Garrett Cumming Research and Muscular Dystrophy Canada HM Toupin Neurological Science Research Chair, Edmonton, Alberta, Canada
- * E-mail:
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50
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Walko G, Wögenstein KL, Winter L, Fischer I, Feltri ML, Wiche G. Stabilization of the dystroglycan complex in Cajal bands of myelinating Schwann cells through plectin-mediated anchorage to vimentin filaments. Glia 2013; 61:1274-87. [PMID: 23836526 DOI: 10.1002/glia.22514] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Accepted: 03/28/2013] [Indexed: 11/06/2022]
Abstract
Previous studies have unmasked plectin, a uniquely versatile intermediate filament-associated cytolinker protein, to be essential for skin and skeletal muscle integrity. Different sets of isoforms of the protein were found to stabilize cells mechanically, regulate cytoskeletal dynamics, and serve as a scaffolding platform for signaling molecules. Here, we investigated whether a similar scenario prevails in myelinating Schwann cells. Using isoform-specific antibodies, the two plectin variants predominantly expressed in the cytoplasmic compartment (Cajal bands) of Schwann cells were identified as plectin (P)1 and P1c. Coimmunoprecipitation and immunolocalization experiments revealed complex formation of Cajal band plectin with β-dystroglycan, the core component of the dystrophin glycoprotein complex that in Schwann cells is crucial for the compartmentalization and stabilization of the myelin sheath. To study the functional implications of Schwann cell-specific plectin-β-dystroglycan interaction, we generated conditional (Schwann cell-restricted) plectin knockout mice. Ablation of plectin in myelinating Schwann cells (SCs) was found not to affect myelin sheath formation but to abrogate the tight association of the dystroglycan complex with the intermediate filament cytoskeleton. We show that the disruption of this association leads to the destabilization of the dystroglycan complex combined with increased myelin sheath deformations observed in the peripheral nerve during ageing of the animal.
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Affiliation(s)
- Gernot Walko
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, Center for Molecular Biology, University of Vienna, Vienna, Austria
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