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Malik SO, Wierenga A, Gao C, Akaaboune M. Plasticity and structural alterations of mitochondria and sarcoplasmic organelles in muscles of mice deficient in α-dystrobrevin, a component of the dystrophin-glycoprotein complex. Hum Mol Genet 2024; 33:1107-1119. [PMID: 38507070 DOI: 10.1093/hmg/ddae039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 02/03/2024] [Accepted: 03/01/2024] [Indexed: 03/22/2024] Open
Abstract
The dystrophin-glycoprotein complex (DGC) plays a crucial role in maintaining the structural integrity of the plasma membrane and the neuromuscular junction. In this study, we investigated the impact of the deficiency of α-dystrobrevin (αdbn), a component of the DGC, on the homeostasis of intracellular organelles, specifically mitochondria and the sarcoplasmic reticulum (SR). In αdbn deficient muscles, we observed a significant increase in the membrane-bound ATP synthase complex levels, a marker for mitochondria in oxidative muscle fiber types compared to wild-type. Furthermore, examination of muscle fibers deficient in αdbn using electron microscopy revealed profound alterations in the organization of mitochondria and the SR within certain myofibrils of muscle fibers. This included the formation of hyper-branched intermyofibrillar mitochondria with extended connections, an extensive network spanning several myofibrils, and a substantial increase in the number/density of subsarcolemmal mitochondria. Concurrently, in some cases, we observed significant structural alterations in mitochondria, such as cristae loss, fragmentation, swelling, and the formation of vacuoles and inclusions within the mitochondrial matrix cristae. Muscles deficient in αdbn also displayed notable alterations in the morphology of the SR, along with the formation of distinct anomalous concentric SR structures known as whorls. These whorls were prevalent in αdbn-deficient mice but were absent in wild-type muscles. These results suggest a crucial role of the DGC αdbn in regulating intracellular organelles, particularly mitochondria and the SR, within muscle cells. The remodeling of the SR and the formation of whorls may represent a novel mechanism of the unfolded protein response (UPR) in muscle cells.
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Affiliation(s)
- Saad O Malik
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 4164 Biological Sciences Building, 1105 N. University Avenue, Ann Arbor, MI 48109, United States
| | - Alissa Wierenga
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 4164 Biological Sciences Building, 1105 N. University Avenue, Ann Arbor, MI 48109, United States
| | - Chenlang Gao
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 4164 Biological Sciences Building, 1105 N. University Avenue, Ann Arbor, MI 48109, United States
| | - Mohammed Akaaboune
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 4164 Biological Sciences Building, 1105 N. University Avenue, Ann Arbor, MI 48109, United States
- Michigan Neuroscience Institute, University of Michigan, 205 Zina Pitcher Pl, Ann Arbor, MI 48109, United States
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Navarro-Martínez A, Vicente-García C, Carvajal JJ. NMJ-related diseases beyond the congenital myasthenic syndromes. Front Cell Dev Biol 2023; 11:1216726. [PMID: 37601107 PMCID: PMC10436495 DOI: 10.3389/fcell.2023.1216726] [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: 05/04/2023] [Accepted: 07/21/2023] [Indexed: 08/22/2023] Open
Abstract
Neuromuscular junctions (NMJs) are a special type of chemical synapse that transmits electrical stimuli from motor neurons (MNs) to their innervating skeletal muscle to induce a motor response. They are an ideal model for the study of synapses, given their manageable size and easy accessibility. Alterations in their morphology or function lead to neuromuscular disorders, such as the congenital myasthenic syndromes, which are caused by mutations in proteins located in the NMJ. In this review, we highlight novel potential candidate genes that may cause or modify NMJs-related pathologies in humans by exploring the phenotypes of hundreds of mouse models available in the literature. We also underscore the fact that NMJs may differ between species, muscles or even sexes. Hence the importance of choosing a good model organism for the study of NMJ-related diseases: only taking into account the specific features of the mammalian NMJ, experimental results would be efficiently translated to the clinic.
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Affiliation(s)
| | - Cristina Vicente-García
- Centro Andaluz de Biología del Desarrollo, CSIC-UPO-JA, Universidad Pablo de Olavide, Sevilla, Spain
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Babu V, Bahari R, Laban N, Kulaga J, Abdul Z, Zakkar B, Al-Najjar A, Lesus J, Al-Rifai AAR, Sattar H, Irukulla S, Gunniya P, Requena T, Lysakowski A. RotaRod and acoustic startle reflex performance of two potential mouse models for Meniere's disease. Eur J Neurosci 2023; 58:2708-2723. [PMID: 37461313 DOI: 10.1111/ejn.16083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 06/11/2023] [Accepted: 06/17/2023] [Indexed: 08/04/2023]
Abstract
Meniere's disease (MD) is a disorder of the inner ear characterized by chronic episodes of vertigo, tinnitus, increased aural pressure, and sensorineural hearing loss. Causes of MD are unknown, but endolymphatic hydrops is a hallmark. In addition, 5%-15% of MD cases have been identified as familial. Whole-genome sequencing studies of individuals with familial MD identified DTNA and FAM136A as candidate genes for autosomal dominant inheritance of MD. Although the exact roles of these genes in MD are unknown, FAM136A encodes a mitochondrial protein, and DTNA encodes a cytoskeletal protein involved in synapse formation and maintenance, important for maintaining the blood-brain barrier. It is also associated with a particular aquaporin. We tested vestibular and auditory function in dtna and fam136a knockout (KO) mice, using RotaRod and startle reflex-based clicker tests, respectively. Three-factor analysis of variance (ANOVA) results indicated that sex, age, and genotype were significantly correlated with reduced mean latencies to fall ("latencies") for male dtna KO mice, while only age was a significant factor for fam136a KO mice. Fam136a KO mice lost their hearing months before WTs (9-11 months vs. 15-20 months). In male dtna KO mice, divergence in mean latencies compared with other genotypes was first evident at 4 months of age, with older males having an even greater decrease. Our results indicate that fam136a gene mutations generate hearing problems, while dtna gene mutations produce balance deficits. Both mouse models should help to elucidate hearing loss and balance-related symptoms associated with MD.
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Affiliation(s)
- Vidya Babu
- University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
| | - Rose Bahari
- University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
| | - Nora Laban
- University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
| | - Jacob Kulaga
- University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
| | - Zahid Abdul
- University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
| | - Basil Zakkar
- University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
| | - Ahmad Al-Najjar
- University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
| | - Joseph Lesus
- University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
| | | | - Heba Sattar
- University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
| | - Suhitha Irukulla
- University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
| | - Pranav Gunniya
- University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
| | - Teresa Requena
- Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - Anna Lysakowski
- University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
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4
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Nascimento A, Bruels CC, Donkervoort S, Foley AR, Codina A, Milisenda JC, Estrella EA, Li C, Pijuan J, Draper I, Hu Y, Stafki SA, Pais LS, Ganesh VS, O'Donnell-Luria A, Syeda SB, Carrera-García L, Expósito-Escudero J, Yubero D, Martorell L, Pinal-Fernandez I, Lidov HGW, Mammen AL, Grau-Junyent JM, Ortez C, Palau F, Ghosh PS, Darras BT, Jou C, Kunkel LM, Hoenicka J, Bönnemann CG, Kang PB, Natera-de Benito D. Variants in DTNA cause a mild, dominantly inherited muscular dystrophy. Acta Neuropathol 2023; 145:479-496. [PMID: 36799992 PMCID: PMC10923638 DOI: 10.1007/s00401-023-02551-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/10/2023] [Accepted: 02/10/2023] [Indexed: 02/18/2023]
Abstract
DTNA encodes α-dystrobrevin, a component of the macromolecular dystrophin-glycoprotein complex (DGC) that binds to dystrophin/utrophin and α-syntrophin. Mice lacking α-dystrobrevin have a muscular dystrophy phenotype, but variants in DTNA have not previously been associated with human skeletal muscle disease. We present 12 individuals from four unrelated families with two different monoallelic DTNA variants affecting the coiled-coil domain of α-dystrobrevin. The five affected individuals from family A harbor a c.1585G > A; p.Glu529Lys variant, while the recurrent c.1567_1587del; p.Gln523_Glu529del DTNA variant was identified in the other three families (family B: four affected individuals, family C: one affected individual, and family D: two affected individuals). Myalgia and exercise intolerance, with variable ages of onset, were reported in 10 of 12 affected individuals. Proximal lower limb weakness with onset in the first decade of life was noted in three individuals. Persistent elevations of serum creatine kinase (CK) levels were detected in 11 of 12 affected individuals, 1 of whom had an episode of rhabdomyolysis at 20 years of age. Autism spectrum disorder or learning disabilities were reported in four individuals with the c.1567_1587 deletion. Muscle biopsies in eight affected individuals showed mixed myopathic and dystrophic findings, characterized by fiber size variability, internalized nuclei, and slightly increased extracellular connective tissue and inflammation. Immunofluorescence analysis of biopsies from five affected individuals showed reduced α-dystrobrevin immunoreactivity and variably reduced immunoreactivity of other DGC proteins: dystrophin, α, β, δ and γ-sarcoglycans, and α and β-dystroglycans. The DTNA deletion disrupted an interaction between α-dystrobrevin and syntrophin. Specific variants in the coiled-coil domain of DTNA cause skeletal muscle disease with variable penetrance. Affected individuals show a spectrum of clinical manifestations, with severity ranging from hyperCKemia, myalgias, and exercise intolerance to childhood-onset proximal muscle weakness. Our findings expand the molecular etiologies of both muscular dystrophy and paucisymptomatic hyperCKemia, to now include monoallelic DTNA variants as a novel cause of skeletal muscle disease in humans.
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Affiliation(s)
- Andres Nascimento
- Neuromuscular Unit, Department of Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Déu 2, Esplugues de Llobregat, Barcelona, Spain
- Applied Research in Neuromuscular Diseases, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Christine C Bruels
- Department of Neurology, Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, 420 Delaware Street SE, MMC 295, Minneapolis, MN, 55455, USA
| | - Sandra Donkervoort
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - A Reghan Foley
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Anna Codina
- Applied Research in Neuromuscular Diseases, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
- Department of Pathology, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Jose C Milisenda
- Department of Internal Medicine, Hospital Clinic of Barcelona, University of Barcelona, Barcelona, Spain
| | - Elicia A Estrella
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Chengcheng Li
- Division of Pediatric Neurology, University of Florida College of Medicine, Gainesville, FL, 32610, USA
| | - Jordi Pijuan
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Laboratory of Neurogenetics and Molecular Medicine-IPER, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Isabelle Draper
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA, 02111, USA
| | - Ying Hu
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Seth A Stafki
- Department of Neurology, Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, 420 Delaware Street SE, MMC 295, Minneapolis, MN, 55455, USA
| | - Lynn S Pais
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
- Program in Medical and Population Genetics, Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Vijay S Ganesh
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
- Program in Medical and Population Genetics, Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA
| | - Anne O'Donnell-Luria
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
- Program in Medical and Population Genetics, Center for Mendelian Genomics, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Analytic and Translational Genetics Unit and Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Safoora B Syeda
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Laura Carrera-García
- Neuromuscular Unit, Department of Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Déu 2, Esplugues de Llobregat, Barcelona, Spain
- Applied Research in Neuromuscular Diseases, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Jessica Expósito-Escudero
- Neuromuscular Unit, Department of Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Déu 2, Esplugues de Llobregat, Barcelona, Spain
- Applied Research in Neuromuscular Diseases, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Delia Yubero
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Department of Genetic and Molecular Medicine-IPER, Hospital Sant Joan de Déu and Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Loreto Martorell
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Department of Genetic and Molecular Medicine-IPER, Hospital Sant Joan de Déu and Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Iago Pinal-Fernandez
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Hart G W Lidov
- Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Andrew L Mammen
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Josep M Grau-Junyent
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Department of Internal Medicine, Hospital Clinic of Barcelona, University of Barcelona, Barcelona, Spain
| | - Carlos Ortez
- Neuromuscular Unit, Department of Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Déu 2, Esplugues de Llobregat, Barcelona, Spain
- Applied Research in Neuromuscular Diseases, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Francesc Palau
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Laboratory of Neurogenetics and Molecular Medicine-IPER, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
- Department of Genetic and Molecular Medicine-IPER, Hospital Sant Joan de Déu and Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Partha S Ghosh
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Basil T Darras
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Cristina Jou
- Applied Research in Neuromuscular Diseases, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Department of Pathology, Hospital Sant Joan de Déu, Barcelona, Spain
| | - Louis M Kunkel
- Division of Genetics and Genomics, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Janet Hoenicka
- Center for Biomedical Research Network on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
- Laboratory of Neurogenetics and Molecular Medicine-IPER, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Peter B Kang
- Department of Neurology, Paul and Sheila Wellstone Muscular Dystrophy Center, University of Minnesota Medical School, 420 Delaware Street SE, MMC 295, Minneapolis, MN, 55455, USA.
- Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA.
| | - Daniel Natera-de Benito
- Neuromuscular Unit, Department of Neurology, Hospital Sant Joan de Déu, Passeig Sant Joan de Déu 2, Esplugues de Llobregat, Barcelona, Spain.
- Applied Research in Neuromuscular Diseases, Institut de Recerca Sant Joan de Déu, Barcelona, Spain.
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Donen G, Milad N, Bernatchez P. Humanization of the mdx Mouse Phenotype for Duchenne Muscular Dystrophy Modeling: A Metabolic Perspective. J Neuromuscul Dis 2023; 10:1003-1012. [PMID: 37574742 PMCID: PMC10657711 DOI: 10.3233/jnd-230126] [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] [Accepted: 07/25/2023] [Indexed: 08/15/2023]
Abstract
Duchenne muscular dystrophy (DMD) is a severe form of muscular dystrophy (MD) that is characterized by early muscle wasting and lethal cardiorespiratory failure. While the mdx mouse is the most common model of DMD, it fails to replicate the severe loss of muscle mass and other complications observed in patients, in part due to the multiple rescue pathways found in mice. This led to several attempts at improving DMD animal models by interfering with these rescue pathways through double transgenic approaches, resulting in more severe phenotypes with mixed relevance to the human pathology. As a growing body of literature depicts DMD as a multi-system metabolic disease, improvements in mdx-based modeling of DMD may be achieved by modulating whole-body metabolism instead of muscle homeostasis. This review provides an overview of the established dual-transgenic approaches that exacerbate the mild mdx phenotype by primarily interfering with muscle homeostasis and highlights how advances in DMD modeling coincide with inducing whole-body metabolic changes. We focus on the DBA2/J strain-based D2.mdx mouse with heightened transforming growth factor (TGF)-β signaling and the dyslipidemic mdx/apolipoprotein E (mdx/ApoE) knock-out (KO) mouse, and summarize how these novel models emulate the metabolic changes observed in DMD.
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Affiliation(s)
| | | | - Pascal Bernatchez
- Correspondence to: Dr. Pascal Bernatchez, Department of Anesthesiology, Pharmacology & Therapeutics, University of British Columbia, 2176 Health Sciences mall, room 217, Vancouver BC, V6T 1Z3, Canada. Tel.: +1 604 806 8346 /Ext.66060; E-mail:
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6
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Requena T, Keder A, zur Lage P, Albert JT, Jarman AP. A Drosophila model for Meniere's disease: Dystrobrevin is required for support cell function in hearing and proprioception. Front Cell Dev Biol 2022; 10:1015651. [PMID: 36438562 PMCID: PMC9688402 DOI: 10.3389/fcell.2022.1015651] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 10/27/2022] [Indexed: 08/04/2023] Open
Abstract
Meniere's disease (MD) is an inner ear disorder characterised by recurrent vertigo attacks associated with sensorineural hearing loss and tinnitus. Evidence from epidemiology and Whole Exome Sequencing (WES) suggests a genetic susceptibility involving multiple genes, including α-Dystrobrevin (DTNA). Here we investigate a Drosophila model. We show that mutation, or knockdown, of the DTNA orthologue in Drosophila, Dystrobrevin (Dyb), results in defective proprioception and impaired function of Johnston's Organ (JO), the fly's equivalent of the inner ear. Dyb and another component of the dystrophin-glycoprotein complex (DGC), Dystrophin (Dys), are expressed in support cells within JO. Their specific locations suggest that they form part of support cell contacts, thereby helping to maintain the integrity of the hemolymph-neuron diffusion barrier, which is equivalent to a blood-brain barrier. These results have important implications for the human condition, and notably, we note that DTNA is expressed in equivalent cells of the mammalian inner ear.
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Affiliation(s)
- T. Requena
- Biomedical Sciences: Centre for Discovery Brain Sciences, Edinburgh Medical School, University of Edinburgh, Edinburgh, United Kingdom
- Division of Functional Genetics and Development, The Royal Dick School of Veterinary Sciences, The Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - A. Keder
- Ear Institute, University College London, London, United Kingdom
| | - P. zur Lage
- Biomedical Sciences: Centre for Discovery Brain Sciences, Edinburgh Medical School, University of Edinburgh, Edinburgh, United Kingdom
| | - J. T. Albert
- Ear Institute, University College London, London, United Kingdom
| | - A. P. Jarman
- Biomedical Sciences: Centre for Discovery Brain Sciences, Edinburgh Medical School, University of Edinburgh, Edinburgh, United Kingdom
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Wu Y, Guo X, Han T, Feng K, Zhang P, Xu Y, Yang Y, Xia Y, Chen Y, Xi J, Yang H, Wan X, Kang J. Cmarr/miR-540-3p axis promotes cardiomyocyte maturation transition by orchestrating Dtna expression. MOLECULAR THERAPY - NUCLEIC ACIDS 2022; 29:481-497. [PMID: 36035750 PMCID: PMC9382425 DOI: 10.1016/j.omtn.2022.07.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 07/20/2022] [Indexed: 10/31/2022]
Abstract
The immature phenotype of embryonic stem cell-derived cardiomyocytes (ESC-CMs) limits their application. However, the molecular mechanisms of cardiomyocyte maturation remain largely unexplored. This study found that overexpression of long noncoding RNA (lncRNA)-Cmarr, which was highly expressed in cardiomyocytes, promoted the maturation change and physiological maturation of mouse ESC-CMs (mESC-CMs). Moreover, transplantation of cardiac patch overexpressing Cmarr exhibited better retention of mESC-CMs, reduced infarct area by enhancing vascular density in the host heart, and improved cardiac function in mice after myocardial infarction. Mechanism studies identified that Cmarr acted as a competitive endogenous RNA to impede the repression of miR-540-3p on Dtna expression and promoted the binding of the dystrophin-glycoprotein complex (DGC) and yes-associated protein (YAP), which in turn reduced the proportion of nuclear YAP and the expression of YAP target genes. Therefore, this study revealed the function and mechanism of Cmarr in promoting cardiomyocyte maturation and provided a lncRNA that can be used as a functional factor in the construction of cardiac patches for the treatment of myocardial infarction.
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8
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Valenzuela IMPY, Chen PJ, Barden J, Kosloski O, Akaaboune M. Distinct roles of the dystrophin-glycoprotein complex: α-dystrobrevin and α-syntrophin in the maintenance of the postsynaptic apparatus of the neuromuscular synapse. Hum Mol Genet 2022; 31:2370-2385. [PMID: 35157076 PMCID: PMC9307313 DOI: 10.1093/hmg/ddac041] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 01/25/2022] [Accepted: 02/09/2022] [Indexed: 02/02/2023] Open
Abstract
α-syntrophin (α-syn) and α-dystrobrevin (α-dbn), two components of the dystrophin-glycoprotein complex, are essential for the maturation and maintenance of the neuromuscular junction (NMJ) and mice deficient in either α-syn or α-dbn exhibit similar synaptic defects. However, the functional link between these two proteins and whether they exert distinct or redundant functions in the postsynaptic organization of the NMJ remain largely unknown. We generated and analyzed the synaptic phenotype of double heterozygote (α-dbn+/-, α-syn+/-), and double homozygote knockout (α-dbn-/-; α-syn-/-) mice and examined the ability of individual molecules to restore their defects in the synaptic phenotype. We showed that in double heterozygote mice, NMJs have normal synaptic phenotypes and no signs of muscular dystrophy. However, in double knockout mice (α-dbn-/-; α-syn-/-), the synaptic phenotype (the density, the turnover and the distribution of AChRs within synaptic branches) is more severely impaired than in single α-dbn-/- or α-syn-/- mutants. Furthermore, double mutant and single α-dbn-/- mutant mice showed more severe exercise-induced fatigue and more significant reductions in grip strength than single α-syn-/- mutant and wild-type. Finally, we showed that the overexpression of the transgene α-syn-GFP in muscles of double mutant restores primarily the abnormal extensions of membrane containing AChRs that extend beyond synaptic gutters and lack synaptic folds, whereas the overexpression of α-dbn essentially restores the abnormal dispersion of patchy AChR aggregates in the crests of synaptic folds. Altogether, these data suggest that α-syn and α-dbn act in parallel pathways and exert distinct functions on the postsynaptic structural organization of NMJs.
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Affiliation(s)
| | - Po-Ju Chen
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Joseph Barden
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Olivia Kosloski
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Mohammed Akaaboune
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
- Program in Neuroscience, University of Michigan, Ann Arbor, MI, USA
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Schultz TI, Raucci FJ, Salloum FN. Cardiovascular Disease in Duchenne Muscular Dystrophy. JACC Basic Transl Sci 2022; 7:608-625. [PMID: 35818510 PMCID: PMC9270569 DOI: 10.1016/j.jacbts.2021.11.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 11/06/2021] [Indexed: 12/11/2022]
Abstract
Cardiomyopathy is the leading cause of death in patients with DMD. DMD has no cure, and there is no current consensus for treatment of DMD cardiomyopathy. This review discusses therapeutic strategies to potentially reduce or prevent cardiac dysfunction in DMD patients. Additional studies are needed to firmly establish optimal treatment modalities for DMD cardiomyopathy.
Duchenne muscular dystrophy (DMD) is a devastating disease affecting approximately 1 in every 3,500 male births worldwide. Multiple mutations in the dystrophin gene have been implicated as underlying causes of DMD. However, there remains no cure for patients with DMD, and cardiomyopathy has become the most common cause of death in the affected population. Extensive research is under way investigating molecular mechanisms that highlight potential therapeutic targets for the development of pharmacotherapy for DMD cardiomyopathy. In this paper, the authors perform a literature review reporting on recent ongoing efforts to identify novel therapeutic strategies to reduce, prevent, or reverse progression of cardiac dysfunction in DMD.
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Tks5 Regulates Synaptic Podosome Formation and Stabilization of the Postsynaptic Machinery at the Neuromuscular Junction. Int J Mol Sci 2021; 22:ijms222112051. [PMID: 34769479 PMCID: PMC8585010 DOI: 10.3390/ijms222112051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/03/2021] [Accepted: 11/04/2021] [Indexed: 11/16/2022] Open
Abstract
Currently, the etiology of many neuromuscular disorders remains unknown. Many of them are characterized by aberrations in the maturation of the neuromuscular junction (NMJ) postsynaptic machinery. Unfortunately, the molecular factors involved in this process are still largely unknown, which poses a great challenge for identifying potential therapeutic targets. Here, we identified Tks5 as a novel interactor of αdystrobrevin-1, which is a crucial component of the NMJ postsynaptic machinery. Tks5 has been previously shown in cancer cells to be an important regulator of actin-rich structures known as invadosomes. However, a role of this scaffold protein at a synapse has never been studied. We show that Tks5 is crucial for remodeling of the NMJ postsynaptic machinery by regulating the organization of structures similar to the invadosomes, known as synaptic podosomes. Additionally, it is involved in the maintenance of the integrity of acetylcholine receptor (AChR) clusters and regulation of their turnover. Lastly, our data indicate that these Tks5 functions may be mediated by its involvement in recruitment of actin filaments to the postsynaptic machinery. Collectively, we show for the first time that the Tks5 protein is involved in regulation of the postsynaptic machinery.
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11
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The α-dystrobrevins play a key role in maintaining the structure and function of the extracellular matrix-significance for protein elimination failure arteriopathies. Acta Neuropathol Commun 2021; 9:171. [PMID: 34674769 PMCID: PMC8532274 DOI: 10.1186/s40478-021-01274-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 10/11/2021] [Indexed: 01/08/2023] Open
Abstract
The extracellular matrix (ECM) of the cerebral vasculature provides a pathway for the flow of interstitial fluid (ISF) and solutes out of the brain by intramural periarterial drainage (IPAD). Failure of IPAD leads to protein elimination failure arteriopathies such as cerebral amyloid angiopathy (CAA). The ECM consists of a complex network of glycoproteins and proteoglycans that form distinct basement membranes (BM) around different vascular cell types. Astrocyte endfeet that are localised against the walls of blood vessels are tethered to these BMs by dystrophin associated protein complex (DPC). Alpha-dystrobrevin (α-DB) is a key dystrophin associated protein within perivascular astrocyte endfeet; its deficiency leads to a reduction in other dystrophin associated proteins, loss of AQP4 and altered ECM. In human dementia cohorts there is a positive correlation between dystrobrevin gene expression and CAA. In the present study, we test the hypotheses that (a) the positive correlation between dystrobrevin gene expression and CAA is associated with elevated expression of α-DB at glial-vascular endfeet and (b) a deficiency in α-DB results in changes to the ECM and failure of IPAD. We used human post-mortem brain tissue with different severities of CAA and transgenic α-DB deficient mice. In human post-mortem tissue we observed a significant increase in vascular α-DB with CAA (CAA vrs. Old p < 0.005, CAA vrs. Young p < 0.005). In the mouse model of α-DB deficiency, there was early modifications to vascular ECM (collagen IV and BM thickening) that translated into reduced IPAD efficiency. Our findings highlight the important role of α-DB in maintaining structure and function of ECM, particularly as a pathway for the flow of ISF and solutes out of the brain by IPAD.
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12
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A Role for Caveolin-3 in the Pathogenesis of Muscular Dystrophies. Int J Mol Sci 2020; 21:ijms21228736. [PMID: 33228026 PMCID: PMC7699313 DOI: 10.3390/ijms21228736] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 11/16/2020] [Accepted: 11/17/2020] [Indexed: 12/14/2022] Open
Abstract
Caveolae are the cholesterol-rich small invaginations of the plasma membrane present in many cell types including adipocytes, endothelial cells, epithelial cells, fibroblasts, smooth muscles, skeletal muscles and cardiac muscles. They serve as specialized platforms for many signaling molecules and regulate important cellular processes like energy metabolism, lipid metabolism, mitochondria homeostasis, and mechano-transduction. Caveolae can be internalized together with associated cargo. The caveolae-dependent endocytic pathway plays a role in the withdrawal of many plasma membrane components that can be sent for degradation or recycled back to the cell surface. Caveolae are formed by oligomerization of caveolin proteins. Caveolin-3 is a muscle-specific isoform, whose malfunction is associated with several diseases including diabetes, cancer, atherosclerosis, and cardiovascular diseases. Mutations in Caveolin-3 are known to cause muscular dystrophies that are collectively called caveolinopathies. Altered expression of Caveolin-3 is also observed in Duchenne’s muscular dystrophy, which is likely a part of the pathological process leading to muscle weakness. This review summarizes the major functions of Caveolin-3 in skeletal muscles and discusses its involvement in the pathology of muscular dystrophies.
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13
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Banks GB, Chamberlain JS, Odom GL. Microutrophin expression in dystrophic mice displays myofiber type differences in therapeutic effects. PLoS Genet 2020; 16:e1009179. [PMID: 33175853 PMCID: PMC7682874 DOI: 10.1371/journal.pgen.1009179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 11/23/2020] [Accepted: 10/06/2020] [Indexed: 12/28/2022] Open
Abstract
Gene therapy approaches for DMD using recombinant adeno-associated viral (rAAV) vectors to deliver miniaturized (or micro) dystrophin genes to striated muscles have shown significant progress. However, concerns remain about the potential for immune responses against dystrophin in some patients. Utrophin, a developmental paralogue of dystrophin, may provide a viable treatment option. Here we examine the functional capacity of an rAAV-mediated microutrophin (μUtrn) therapy in the mdx4cv mouse model of DMD. We found that rAAV-μUtrn led to improvement in dystrophic histopathology & mostly restored the architecture of the neuromuscular and myotendinous junctions. Physiological studies of tibialis anterior muscles indicated peak force maintenance, with partial improvement of specific force. A fundamental question for μUtrn therapeutics is not only can it replace critical functions of dystrophin, but whether full-length utrophin impacts the therapeutic efficacy of the smaller, highly expressed μUtrn. As such, we found that μUtrn significantly reduced the spacing of the costameric lattice relative to full-length utrophin. Further, immunostaining suggested the improvement in dystrophic pathophysiology was largely influenced by favored correction of fast 2b fibers. However, unlike μUtrn, μdystrophin (μDys) expression did not show this fiber type preference. Interestingly, μUtrn was better able to protect 2a and 2d fibers in mdx:utrn-/- mice than in mdx4cv mice where the endogenous full-length utrophin was most prevalent. Altogether, these data are consistent with the role of steric hindrance between full-length utrophin & μUtrn within the sarcolemma. Understanding the stoichiometry of this effect may be important for predicting clinical efficacy.
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MESH Headings
- Animals
- Dependovirus/genetics
- Disease Models, Animal
- Dystrophin/genetics
- Gene Transfer Techniques
- Genetic Therapy/methods
- Genetic Vectors/genetics
- HEK293 Cells
- Humans
- Mice
- Mice, Inbred mdx
- Microscopy, Electron
- Muscle Contraction
- Muscle Fibers, Skeletal/cytology
- Muscle Fibers, Skeletal/pathology
- Muscle Fibers, Skeletal/ultrastructure
- Muscle, Skeletal
- Muscular Dystrophy, Duchenne/genetics
- Muscular Dystrophy, Duchenne/pathology
- Muscular Dystrophy, Duchenne/therapy
- Neuromuscular Junction/pathology
- Neuromuscular Junction/ultrastructure
- Sarcolemma/pathology
- Sarcolemma/ultrastructure
- Utrophin/genetics
- Utrophin/therapeutic use
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Affiliation(s)
- Glen B. Banks
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington, United States of America
| | - Jeffrey S. Chamberlain
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington, United States of America
- Department of BioChemistry, University of Washington, Seattle, Washington, United States of America
| | - Guy L. Odom
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington, United States of America
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14
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Nelson DM, Fasbender EK, Jakubiak MC, Lindsay A, Lowe DA, Ervasti JM. Rapid, redox-mediated mechanical susceptibility of the cortical microtubule lattice in skeletal muscle. Redox Biol 2020; 37:101730. [PMID: 33002761 PMCID: PMC7527753 DOI: 10.1016/j.redox.2020.101730] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/12/2020] [Accepted: 09/12/2020] [Indexed: 01/25/2023] Open
Abstract
The highly ordered cortical microtubule lattice of skeletal muscle is disorganized in dystrophin-deficient mdx mice. Implicated mechanisms include loss of dystrophin binding, altered α-tubulin posttranslational modification, expression of a β-tubulin involved in regeneration, and reactive oxygen species (ROS). Here we show that the transverse microtubules in mdx muscle expressing miniaturized dystrophins are rapidly lost after eccentric contraction. Analysis of mdx lines expressing different dystrophin constructs demonstrate that spectrin-like repeats R4-15 and R20-23 were required for mechanically stable microtubules. Microtubule loss was prevented by the non-specific antioxidant N-acetylcysteine while inhibition of NADPH oxidase 2 had only a partial effect, suggesting that ROS from multiple sources mediate the rapid loss of transverse microtubules after eccentric contraction. Finally, ablation of α-dystrobrevin, β- or γ-cytoplasmic actin phenocopied the transverse microtubule instability of miniaturized dystrophins. Our data demonstrate that multiple dystrophin domains, α-dystrobrevin and cytoplasmic actins are necessary for mechanically stable microtubules.
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Affiliation(s)
- D'anna M Nelson
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Elizabeth K Fasbender
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA; College of Biological Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Margurite C Jakubiak
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA; College of Biological Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Angus Lindsay
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA; Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Dawn A Lowe
- Department of Rehabilitation Medicine, University of Minnesota, Minneapolis, MN, USA
| | - James M Ervasti
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
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15
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Tamiyakul H, Kemter E, Kösters M, Ebner S, Blutke A, Klymiuk N, Flenkenthaler F, Wolf E, Arnold GJ, Fröhlich T. Progressive Proteome Changes in the Myocardium of a Pig Model for Duchenne Muscular Dystrophy. iScience 2020; 23:101516. [PMID: 32927262 PMCID: PMC7495112 DOI: 10.1016/j.isci.2020.101516] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 08/14/2020] [Accepted: 08/27/2020] [Indexed: 12/17/2022] Open
Abstract
Duchenne muscular dystrophy (DMD), caused by mutations in the dystrophin gene, is characterized by progressive muscle weakness. Even though DMD manifests first in skeletal muscle, heart failure is a major cause of death in late-stage DMD. To get insights into DMD-associated cardiomyopathy, we performed a proteome analysis of myocardium from a genetically engineered porcine DMD model resembling clinical and pathological hallmarks of human DMD. To capture DMD progression, samples from 2-day- and 3-month-old animals were analyzed. Dystrophin was absent in all DMD samples, and components of the dystrophin-associated protein complex were decreased, suggesting destabilization of the cardiomyocyte plasma membrane and impaired cellular signaling. Furthermore, abundance alterations of proteins known to be associated with human cardiomyopathy were observed. Compared with data from skeletal muscle, we found clear evidence that DMD progression in myocardium is not only slower than in skeletal muscle but also involves different biological and biochemical pathways.
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Affiliation(s)
- Hathaichanok Tamiyakul
- Laboratory for Functional Genome Analysis, LAFUGA, Gene Center, LMU Munich, 81377 Munich, Germany
| | - Elisabeth Kemter
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, 81377 Munich, Germany
- Center for Innovative Medical Models (CiMM), LMU Munich, 85764 Oberschleißheim, Germany
| | - Miwako Kösters
- Laboratory for Functional Genome Analysis, LAFUGA, Gene Center, LMU Munich, 81377 Munich, Germany
| | - Stefanie Ebner
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, 81377 Munich, Germany
| | - Andreas Blutke
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Nikolai Klymiuk
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, 81377 Munich, Germany
- Center for Innovative Medical Models (CiMM), LMU Munich, 85764 Oberschleißheim, Germany
| | - Florian Flenkenthaler
- Laboratory for Functional Genome Analysis, LAFUGA, Gene Center, LMU Munich, 81377 Munich, Germany
| | - Eckhard Wolf
- Laboratory for Functional Genome Analysis, LAFUGA, Gene Center, LMU Munich, 81377 Munich, Germany
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, 81377 Munich, Germany
- Center for Innovative Medical Models (CiMM), LMU Munich, 85764 Oberschleißheim, Germany
| | - Georg J. Arnold
- Laboratory for Functional Genome Analysis, LAFUGA, Gene Center, LMU Munich, 81377 Munich, Germany
| | - Thomas Fröhlich
- Laboratory for Functional Genome Analysis, LAFUGA, Gene Center, LMU Munich, 81377 Munich, Germany
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16
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Chen PJ, Zelada D, Belhasan DC, Akaaboune M. Phosphorylation of α-dystrobrevin is essential for αkap accumulation and acetylcholine receptor stability. J Biol Chem 2020; 295:10677-10688. [PMID: 32532815 DOI: 10.1074/jbc.ra120.013952] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/08/2020] [Indexed: 01/26/2023] Open
Abstract
The maintenance of a high density of the acetylcholine receptor (AChR) is the hallmark of the neuromuscular junction. Muscle-specific anchoring protein (αkap) encoded within the calcium/calmodulin-dependent protein kinase IIα (CAMK2A) gene is essential for the maintenance of AChR clusters both in vivo and in cultured muscle cells. The underlying mechanism by which αkap is maintained and regulated remains unknown. Here, using human cell lines, fluorescence microscopy, and pulldown and immunoblotting assays, we show that α-dystrobrevin (α-dbn), an intracellular component of the dystrophin glycoprotein complex, directly and robustly promotes the stability of αkap in a concentration-dependent manner. Mechanistically, we found that the phosphorylatable tyrosine residues of α-dbn are essential for the stability of α-dbn itself and its interaction with αkap, with substitution of three tyrosine residues in the α-dbn C terminus with phenylalanine compromising the αkap-α-dbn interaction and significantly reducing both αkap and α-dbn accumulation. Moreover, the αkap-α-dbn interaction was critical for αkap accumulation and stability. We also found that the absence of either αkap or α-dbn markedly reduces AChRα accumulation and that overexpression of α-dbn or αkap in cultured muscle cells promotes the formation of large agrin-induced AChR clusters. Collectively, these results indicate that the stability of αkap and α-dbn complex plays an important role in the maintenance of high-level expression of AChRs.
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Affiliation(s)
- Po-Ju Chen
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Diego Zelada
- Department of Cell Biology, Universidad de Concepción, Concepción, Chile
| | - Dina Cheryne Belhasan
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Mohammed Akaaboune
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA .,Program in Neuroscience, University of Michigan, Ann Arbor, Michigan, USA
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17
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Bernadzki KM, Daszczuk P, Rojek KO, Pęziński M, Gawor M, Pradhan BS, de Cicco T, Bijata M, Bijata K, Włodarczyk J, Prószyński TJ, Niewiadomski P. Arhgef5 Binds α-Dystrobrevin 1 and Regulates Neuromuscular Junction Integrity. Front Mol Neurosci 2020; 13:104. [PMID: 32587503 PMCID: PMC7299196 DOI: 10.3389/fnmol.2020.00104] [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] [Received: 02/27/2020] [Accepted: 05/13/2020] [Indexed: 01/09/2023] Open
Abstract
The neuromuscular junctions (NMJs) connect muscle fibers with motor neurons and enable the coordinated contraction of skeletal muscles. The dystrophin-associated glycoprotein complex (DGC) is an essential component of the postsynaptic machinery of the NMJ and is important for the maintenance of NMJ structural integrity. To identify novel proteins that are important for NMJ organization, we performed a mass spectrometry-based screen for interactors of α-dystrobrevin 1 (aDB1), one of the components of the DGC. The guanidine nucleotide exchange factor (GEF) Arhgef5 was found to be one of the aDB1 binding partners that is recruited to Tyr-713 in a phospho-dependent manner. We show here that Arhgef5 localizes to the NMJ and that its genetic depletion in the muscle causes the fragmentation of the synapses in conditional knockout mice. Arhgef5 loss in vivo is associated with a reduction in the levels of active GTP-bound RhoA and Cdc42 GTPases, highlighting the importance of actin dynamics regulation for the maintenance of NMJ integrity.
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Affiliation(s)
- Krzysztof M Bernadzki
- Laboratory of Synaptogenesis, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Patrycja Daszczuk
- Laboratory of Synaptogenesis, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Katarzyna O Rojek
- Laboratory of Synaptogenesis, Nencki Institute of Experimental Biology, Warsaw, Poland.,Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Marcin Pęziński
- Laboratory of Synaptogenesis, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Marta Gawor
- Laboratory of Synaptogenesis, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Bhola S Pradhan
- Laboratory of Synaptogenesis, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Teresa de Cicco
- Laboratory of Synaptogenesis, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Monika Bijata
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Krystian Bijata
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Jakub Włodarczyk
- Laboratory of Cell Biophysics, Nencki Institute of Experimental Biology, Warsaw, Poland
| | - Tomasz J Prószyński
- Laboratory of Synaptogenesis, Nencki Institute of Experimental Biology, Warsaw, Poland.,Łukasiewicz Research Network - PORT Polish Center for Technology Development, Wrocław, Poland
| | - Paweł Niewiadomski
- Laboratory of Synaptogenesis, Nencki Institute of Experimental Biology, Warsaw, Poland.,Laboratory of Molecular and Cellular Signaling, Centre of New Technologies, University of Warsaw, Warsaw, Poland
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18
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Law ML, Cohen H, Martin AA, Angulski ABB, Metzger JM. Dysregulation of Calcium Handling in Duchenne Muscular Dystrophy-Associated Dilated Cardiomyopathy: Mechanisms and Experimental Therapeutic Strategies. J Clin Med 2020; 9:jcm9020520. [PMID: 32075145 PMCID: PMC7074327 DOI: 10.3390/jcm9020520] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 02/06/2020] [Indexed: 02/07/2023] Open
Abstract
: Duchenne muscular dystrophy (DMD) is an X-linked recessive disease resulting in the loss of dystrophin, a key cytoskeletal protein in the dystrophin-glycoprotein complex. Dystrophin connects the extracellular matrix with the cytoskeleton and stabilizes the sarcolemma. Cardiomyopathy is prominent in adolescents and young adults with DMD, manifesting as dilated cardiomyopathy (DCM) in the later stages of disease. Sarcolemmal instability, leading to calcium mishandling and overload in the cardiac myocyte, is a key mechanistic contributor to muscle cell death, fibrosis, and diminished cardiac contractile function in DMD patients. Current therapies for DMD cardiomyopathy can slow disease progression, but they do not directly target aberrant calcium handling and calcium overload. Experimental therapeutic targets that address calcium mishandling and overload include membrane stabilization, inhibition of stretch-activated channels, ryanodine receptor stabilization, and augmentation of calcium cycling via modulation of the Serca2a/phospholamban (PLN) complex or cytosolic calcium buffering. This paper addresses what is known about the mechanistic basis of calcium mishandling in DCM, with a focus on DMD cardiomyopathy. Additionally, we discuss currently utilized therapies for DMD cardiomyopathy, and review experimental therapeutic strategies targeting the calcium handling defects in DCM and DMD cardiomyopathy.
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Affiliation(s)
- Michelle L. Law
- Department of Family and Consumer Sciences, Robbins College of Health and Human Sciences, Baylor University, Waco, TX 76706, USA;
| | - Houda Cohen
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA; (H.C.); (A.A.M.); (A.B.B.A.)
| | - Ashley A. Martin
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA; (H.C.); (A.A.M.); (A.B.B.A.)
| | - Addeli Bez Batti Angulski
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA; (H.C.); (A.A.M.); (A.B.B.A.)
| | - Joseph M. Metzger
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN 55455, USA; (H.C.); (A.A.M.); (A.B.B.A.)
- Correspondence: ; Tel.: +1-612-625-5902; Fax: +1-612-625-5149
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19
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Kolwicz SC, Hall JK, Moussavi-Harami F, Chen X, Hauschka SD, Chamberlain JS, Regnier M, Odom GL. Gene Therapy Rescues Cardiac Dysfunction in Duchenne Muscular Dystrophy Mice by Elevating Cardiomyocyte Deoxy-Adenosine Triphosphate. JACC Basic Transl Sci 2019; 4:778-791. [PMID: 31998848 PMCID: PMC6978556 DOI: 10.1016/j.jacbts.2019.06.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 06/20/2019] [Accepted: 06/20/2019] [Indexed: 01/13/2023]
Abstract
Mutations in the gene encoding for dystrophin leads to structural and functional deterioration of cardiomyocytes and is a hallmark of cardiomyopathy in Duchenne muscular dystrophy (DMD) patients. Administration of recombinant adeno-associated viral vectors delivering microdystrophin or ribonucleotide reductase (RNR), under muscle-specific regulatory control, rescues both baseline and high workload-challenged hearts in an aged, DMD mouse model. However, only RNR treatments improved both systolic and diastolic function under those conditions. Cardiac-specific recombinant adeno-associated viral treatment of RNR holds therapeutic promise for improvement of cardiomyopathy in DMD patients.
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Key Words
- CK8, miniaturized murine creatine kinase regulatory cassette
- CMV, cytomegalovirus
- DMD, Duchenne muscular dystrophy
- RNR, ribonucleotide reductase
- cTnT, cardiac troponin T
- cardiomyopathy
- dADP, deoxy-adenosine diphosphate
- dATP, deoxy-adenosine triphosphate
- diastolic dysfunction
- dystrophin
- mdx, mouse muscular dystrophy model
- rAAV, recombinant adeno-associated viral vector
- recombinant adeno-associated virus vectors
- ribonucleotide reductase
- μDys, microdystrophin
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Affiliation(s)
- Stephen C. Kolwicz
- Mitochondria and Metabolism Center, University of Washington, Seattle, Washington
| | - John K. Hall
- Department of Neurology, University of Washington, Seattle, Washington
| | - Farid Moussavi-Harami
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington
| | - Xiolan Chen
- Department of Biochemistry, University of Washington, Seattle, Washington
- Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington
| | - Stephen D. Hauschka
- Department of Biochemistry, University of Washington, Seattle, Washington
- Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington
| | - Jeffrey S. Chamberlain
- Department of Neurology, University of Washington, Seattle, Washington
- Department of Biochemistry, University of Washington, Seattle, Washington
- Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington
| | - Michael Regnier
- Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington
- Department of Bioengineering, University of Washington, Seattle, Washington
- Center for Cardiovascular Biology, University of Washington, Seattle, Washington
| | - Guy L. Odom
- Department of Neurology, University of Washington, Seattle, Washington
- Wellstone Muscular Dystrophy Specialized Research Center, University of Washington, Seattle, Washington
- Center for Cardiovascular Biology, University of Washington, Seattle, Washington
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20
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Adams ME, Odom GL, Kim MJ, Chamberlain JS, Froehner SC. Syntrophin binds directly to multiple spectrin-like repeats in dystrophin and mediates binding of nNOS to repeats 16-17. Hum Mol Genet 2019; 27:2978-2985. [PMID: 29790927 DOI: 10.1093/hmg/ddy197] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 05/14/2018] [Indexed: 11/12/2022] Open
Abstract
Mutation of the gene encoding dystrophin leads to Duchenne and Becker muscular dystrophy (DMD and BMD). Currently, dystrophin is thought to function primarily as a structural protein, connecting the muscle cell actin cytoskeleton to the extra-cellular matrix. In addition to this structural role, dystrophin also plays an important role as a scaffold that organizes an array of signaling proteins including sodium, potassium, and calcium channels, kinases, and nitric oxide synthase (nNOS). Many of these signaling proteins are linked to dystrophin via syntrophin, an adapter protein that is known to bind directly to two sites in the carboxyl terminal region of dystrophin. A search of the dystrophin sequence revealed three additional potential syntrophin binding sites (SBSs) within the spectrin-like repeat (SLR) region of dystrophin. Binding assays revealed that the site at SLR 17 bound specifically to the α isoform of syntrophin while the site at SLR 22 bound specifically to the β-syntrophins. The SLR 17 α-SBS contained the core sequence known to be required for nNOS-dystrophin interaction. In vitro and in vivo assays indicate that α-syntrophin facilitates the nNOS-dystrophin interaction at this site rather than nNOS binding directly to dystrophin as previously reported. The identification of multiple SBSs within the SLR region of dystrophin demonstrates that this region functions as a signaling scaffold. The signaling role of the SLR region of dystrophin will need to be considered for effective gene replacement or exon skipping based DMD/BMD therapies.
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Affiliation(s)
- Marvin E Adams
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195-7290, USA
| | - Guy L Odom
- Department of Neurology, University of Washington, Seattle, WA 98195-7290, USA.,Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Washington, Seattle, WA 98195-7720, USA
| | - Min Jeong Kim
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195-7290, USA
| | - Jeffrey S Chamberlain
- Department of Neurology, University of Washington, Seattle, WA 98195-7290, USA.,Department of Biochemistry, University of Washington, Seattle, WA 98195-7290, USA.,Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Washington, Seattle, WA 98195-7720, USA
| | - Stanley C Froehner
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195-7290, USA
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21
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Taghizadeh E, Rezaee M, Barreto GE, Sahebkar A. Prevalence, pathological mechanisms, and genetic basis of limb-girdle muscular dystrophies: A review. J Cell Physiol 2018; 234:7874-7884. [PMID: 30536378 DOI: 10.1002/jcp.27907] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 10/23/2018] [Indexed: 12/17/2022]
Abstract
Limb-girdle muscular dystrophies (LGMDs) are a highly heterogeneous group of neuromuscular disorders that are associated with weakness and wasting of muscles in legs and arms. Signs and symptoms may begin at any age and usually worsen by time. LGMDs are autosomal disorders with different types and their prevalence is not the same in different areas. New technologies such as next-generation sequencing can accelerate their diagnosis. Several important pathological mechanisms that are involved in the pathology of the LGMD include abnormalities in dystrophin-glycoprotein complex, the sarcomere, glycosylation of dystroglycan, vesicle and molecular trafficking, signal transduction pathways, and nuclear functions. Here, we provide a comprehensive review that integrates LGMD clinical manifestations, prevalence, and some pathological mechanisms involved in LGMDs.
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Affiliation(s)
- Eskandar Taghizadeh
- Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran.,Department of Medical Genetics, Faculity of Medicine, Mashhad University of Medical Science, Mashhad, Iran
| | - Mehdi Rezaee
- Department of Medical Biotechnology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C, Colombia.,Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Science, Mashhad, Iran.,Neurogenic Inflammation Research Center, Mashhad University of Medical Science, Mashhad, Iran.,School of Pharmacy, Mashhad University of Medical Science, Mashhad, Iran
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22
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Patel A, Zhao J, Yue Y, Zhang K, Duan D, Lai Y. Dystrophin R16/17-syntrophin PDZ fusion protein restores sarcolemmal nNOSμ. Skelet Muscle 2018; 8:36. [PMID: 30466494 PMCID: PMC6251231 DOI: 10.1186/s13395-018-0182-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 11/07/2018] [Indexed: 12/18/2022] Open
Abstract
Background Loss of sarcolemmal nNOSμ is a common manifestation in a wide variety of muscle diseases and contributes to the dysregulation of multiple muscle activities. Given the critical role sarcolemmal nNOSμ plays in muscle, restoration of sarcolemmal nNOSμ should be considered as an important therapeutic goal. Methods nNOSμ is anchored to the sarcolemma by dystrophin spectrin-like repeats 16 and 17 (R16/17) and the syntrophin PDZ domain (Syn PDZ). To develop a strategy that can independently restore sarcolemmal nNOSμ, we engineered an R16/17-Syn PDZ fusion construct and tested whether this construct alone is sufficient to anchor nNOSμ to the sarcolemma in three different mouse models of Duchenne muscular dystrophy (DMD). Results Membrane-associated nNOSμ is completely lost in DMD. Adeno-associated virus (AAV)-mediated delivery of the R16/17-Syn PDZ fusion construct successfully restored sarcolemmal nNOSμ in all three models. Further, nNOS restoration was independent of the dystrophin-associated protein complex. Conclusions Our results suggest that the R16/17-Syn PDZ fusion construct is sufficient to restore sarcolemmal nNOSμ in the dystrophin-null muscle. Electronic supplementary material The online version of this article (10.1186/s13395-018-0182-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Aman Patel
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Medical Sciences Building, One Hospital Drive, Columbia, MO, 65212, USA
| | - Junling Zhao
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Medical Sciences Building, One Hospital Drive, Columbia, MO, 65212, USA
| | - Yongping Yue
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Medical Sciences Building, One Hospital Drive, Columbia, MO, 65212, USA
| | - Keqing Zhang
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Medical Sciences Building, One Hospital Drive, Columbia, MO, 65212, USA
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Medical Sciences Building, One Hospital Drive, Columbia, MO, 65212, USA. .,Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65212, USA. .,Department of Neurology, School of Medicine, University of Missouri, Columbia, MO, 65212, USA. .,Department of Bioengineering, University of Missouri, Columbia, MO, 65212, USA.
| | - Yi Lai
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Medical Sciences Building, One Hospital Drive, Columbia, MO, 65212, USA.
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23
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Abstract
Activation of the electrical signal and its transmission as a depolarizing wave in the whole heart requires highly organized myocyte architecture and cell-cell contacts. In addition, complex trafficking and anchoring intracellular machineries regulate the proper surface expression of channels and their targeting to distinct membrane domains. An increasing list of proteins, lipids, and second messengers can contribute to the normal targeting of ion channels in cardiac myocytes. However, their precise roles in the electrophysiology of the heart are far from been extensively understood. Nowadays, much effort in the field focuses on understanding the mechanisms that regulate ion channel targeting to sarcolemma microdomains and their organization into macromolecular complexes. The purpose of the present section is to provide an overview of the characterized partners of the main cardiac sodium channel, NaV1.5, involved in regulating the functional expression of this channel both in terms of trafficking and targeting into microdomains.
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24
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Dombernowsky NW, Ölmestig JNE, Witting N, Kruuse C. Role of neuronal nitric oxide synthase (nNOS) in Duchenne and Becker muscular dystrophies - Still a possible treatment modality? Neuromuscul Disord 2018; 28:914-926. [PMID: 30352768 DOI: 10.1016/j.nmd.2018.09.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 08/07/2018] [Accepted: 09/05/2018] [Indexed: 02/08/2023]
Abstract
Neuronal nitric oxide synthase (nNOS) is involved in nitric oxide (NO) production and suggested to play a crucial role in blood flow regulation of skeletal muscle. During activation of the muscle, NO helps attenuate the sympathetic vasoconstriction to accommodate increased metabolic demands, a phenomenon known as functional sympatholysis. In inherited myopathies such as the dystrophinopathies Duchenne and Becker muscle dystrophies (DMD and BMD), nNOS is lost from the sarcolemma. The loss of nNOS may cause functional ischemia contributing to skeletal and cardiac muscle cell injury. Effects of NO is augmented by inhibiting degradation of the second messenger cyclic guanosine monophosphate (cGMP) using sildenafil and tadalafil, both of which inhibit the enzyme phosphodiesterase 5 (PDE5). In animal models of DMD, PDE5-inhibitors prevent functional ischemia, reduce post-exercise skeletal muscle pathology and fatigue, show amelioration of cardiac muscle cell damage and increase cardiac performance. However, effect on clinical outcomes in DMD and BMD patients have been disappointing with minor effects on upper limb performance and none on ambulation. This review aims to summarize the current knowledge of nNOS function related to functional sympatholysis in skeletal muscle and studies on PDE5-inhibitor treatment in nNOS-deficient animal models and patients.
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Affiliation(s)
- Nanna W Dombernowsky
- Department of Neurology, Rigshospitalet Glostrup, University of Copenhagen, Denmark
| | - Joakim N E Ölmestig
- Department of Neurology, Neurovascular Research Unit, Herlev Gentofte Hospital, University of Copenhagen, Denmark
| | - Nanna Witting
- Department of Neurology, Rigshospitalet Glostrup, University of Copenhagen, Denmark
| | - Christina Kruuse
- Department of Neurology, Neurovascular Research Unit, Herlev Gentofte Hospital, University of Copenhagen, Denmark; PDE Research Group, Lundbeck Foundation Center for Neurovascular Research (LUCENS), Denmark.
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25
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Sarcoglycan Alpha Mitigates Neuromuscular Junction Decline in Aged Mice by Stabilizing LRP4. J Neurosci 2018; 38:8860-8873. [PMID: 30171091 DOI: 10.1523/jneurosci.0860-18.2018] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 08/07/2018] [Accepted: 08/22/2018] [Indexed: 01/08/2023] Open
Abstract
During aging, acetylcholine receptor (AChR) clusters become fragmented and denervated at the neuromuscular junction (NMJ). Underpinning molecular mechanisms are not well understood. We showed that LRP4, a receptor for agrin and critical for NMJ formation and maintenance, was reduced at protein level in aged mice, which was associated with decreased MuSK tyrosine phosphorylation, suggesting compromised agrin-LRP4-MuSK signaling in aged muscles. Transgenic expression of LRP4 in muscles alleviated AChR fragmentation and denervation and improved neuromuscular transmission in aged mice. LRP4 ubiquitination was augmented in aged muscles, suggesting increased LRP4 degradation as a mechanism for reduced LRP4. We found that sarcoglycan α (SGα) interacted with LRP4 and delayed LRP4 degradation in cotransfected cells. AAV9-mediated expression of SGα in muscles mitigated AChR fragmentation and denervation and improved neuromuscular transmission in aged mice. These observations support a model where compromised agrin-LRP4-MuSK signaling serves as a pathological mechanism of age-related NMJ decline and identify a novel function of SGα in stabilizing LRP4 for NMJ stability in aged mice.SIGNIFICANCE STATEMENT This study provides evidence that LRP4, a receptor of agrin that is critical for NMJ formation and maintenance, is reduced at protein level in aged muscles. Transgenic expression of LRP4 in muscles ameliorates AChR fragmentation and denervation and improves neuromuscular transmission in aged mice, demonstrating a critical role of the agrin-LRP4-MuSK signaling. Our study also reveals a novel function of SGα to prevent LRP4 degradation in aged muscles. Finally, we show that NMJ decline in aged mice can be mitigated by AAV9-mediated expression of SGα in muscles. These observations provide insight into pathological mechanisms of age-related NMJ decline and suggest that improved agrin-LRP4-MuSK signaling may be a target for potential therapeutic intervention.
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26
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Abstract
PURPOSE OF REVIEW To construct a framework to understand the different molecular interventions for muscular dystrophy. RECENT FINDINGS The recent approval of antisense oligonucleotides treatment for Duchenne muscular dystrophy and spinal muscular atrophy and current clinical trials using recombinant adeno-associated virus for the treatment of those diseases suggests that we are at a tipping point where we are able to treat and potentially cure muscular dystrophies. Understanding the basic molecular pathogenesis of muscular dystrophies and the molecular biology of the treatment allows for critical evaluation of the proposed therapies.
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Affiliation(s)
- Ava Y Lin
- Department of Neurology, University of Washington, Box 356465, 1959 NE Pacific Street, Seattle, WA, 98195-6465, USA
| | - Leo H Wang
- Department of Neurology, University of Washington, Box 356465, 1959 NE Pacific Street, Seattle, WA, 98195-6465, USA.
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27
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Cho EB, Yoo W, Yoon SK, Yoon JB. β-dystroglycan is regulated by a balance between WWP1-mediated degradation and protection from WWP1 by dystrophin and utrophin. Biochim Biophys Acta Mol Basis Dis 2018; 1864:2199-2213. [PMID: 29635000 DOI: 10.1016/j.bbadis.2018.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 03/20/2018] [Accepted: 04/03/2018] [Indexed: 01/07/2023]
Abstract
Dystroglycan is a ubiquitous membrane protein that functions as a mechanical connection between the extracellular matrix and cytoskeleton. In skeletal muscle, dystroglycan plays an indispensable role in regulating muscle regeneration; a malfunction in dystroglycan is associated with muscular dystrophy. The regulation of dystroglycan stability is poorly understood. Here, we report that WWP1, a member of NEDD4 E3 ubiquitin ligase family, promotes ubiquitination and subsequent degradation of β-dystroglycan. Our results indicate that dystrophin and utrophin protect β-dystroglycan from WWP1-mediated degradation by competing with WWP1 for the shared binding site at the cytosolic tail of β-dystroglycan. In addition, we show that a missense mutation (arginine 440 to glutamine) in WWP1-which is known to cause muscular dystrophy in chickens-increases the ubiquitin ligase-mediated ubiquitination of both β-dystroglycan and WWP1. The R440Q missense mutation in WWP1 decreases HECT domain-mediated intramolecular interactions to relieve autoinhibition of the enzyme. Our results provide new insight into the regulation of β-dystroglycan degradation by WWP1 and other Nedd4 family members and improves our understanding of dystroglycan-related disorders.
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Affiliation(s)
- Eun-Bee Cho
- Department of Biochemistry, College of Life Science & Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
| | - Wonjin Yoo
- Department of Biochemistry, College of Life Science & Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea
| | - Sungjoo Kim Yoon
- Department of Medical Lifesciences, The Catholic University of Korea, Seoul 137-701, Republic of Korea
| | - Jong-Bok Yoon
- Department of Biochemistry, College of Life Science & Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea.
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28
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Humanizing the mdx mouse model of DMD: the long and the short of it. NPJ Regen Med 2018; 3:4. [PMID: 29479480 PMCID: PMC5816599 DOI: 10.1038/s41536-018-0045-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 12/19/2017] [Accepted: 01/04/2018] [Indexed: 12/26/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a common fatal heritable myopathy, with cardiorespiratory failure occurring by the third decade of life. There is no specific treatment for DMD cardiomyopathy, in large part due to a lack of understanding of the mechanisms underlying the cardiac failure. Mdx mice, which have the same dystrophin mutation as human patients, are of limited use, as they do not develop early dilated cardiomyopathy as seen in patients. Here we summarize the usefulness of the various commonly used DMD mouse models, highlight a model with shortened telomeres like humans, and identify directions that warrant further investigation.
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29
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Gawor M, Prószyński TJ. The molecular cross talk of the dystrophin-glycoprotein complex. Ann N Y Acad Sci 2017; 1412:62-72. [DOI: 10.1111/nyas.13500] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 08/29/2017] [Accepted: 09/04/2017] [Indexed: 12/25/2022]
Affiliation(s)
- Marta Gawor
- Laboratory of Synaptogenesis; Nencki Institute of Experimental Biology; Polish Academy of Sciences Warsaw Poland
| | - Tomasz J. Prószyński
- Laboratory of Synaptogenesis; Nencki Institute of Experimental Biology; Polish Academy of Sciences Warsaw Poland
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30
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Bernadzki KM, Gawor M, Pęziński M, Mazurek P, Niewiadomski P, Rędowicz MJ, Prószyński TJ. Liprin-α-1 is a novel component of the murine neuromuscular junction and is involved in the organization of the postsynaptic machinery. Sci Rep 2017; 7:9116. [PMID: 28831123 PMCID: PMC5567263 DOI: 10.1038/s41598-017-09590-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/25/2017] [Indexed: 01/26/2023] Open
Abstract
Neuromuscular junctions (NMJs) are specialized synapses that connect motor neurons to skeletal muscle fibers and orchestrate proper signal transmission from the nervous system to muscles. The efficient formation and maintenance of the postsynaptic machinery that contains acetylcholine receptors (AChR) are indispensable for proper NMJ function. Abnormalities in the organization of synaptic components often cause severe neuromuscular disorders, such as muscular dystrophy. The dystrophin-associated glycoprotein complex (DGC) was shown to play an important role in NMJ development. We recently identified liprin-α-1 as a novel binding partner for one of the cytoplasmic DGC components, α-dystrobrevin-1. In the present study, we performed a detailed analysis of localization and function of liprin-α-1 at the murine NMJ. We showed that liprin-α-1 localizes to both pre- and postsynaptic compartments at the NMJ, and its synaptic enrichment depends on the presence of the nerve. Using cultured muscle cells, we found that liprin-α-1 plays an important role in AChR clustering and the organization of cortical microtubules. Our studies provide novel insights into the function of liprin-α-1 at vertebrate neuromuscular synapses.
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Affiliation(s)
- Krzysztof M Bernadzki
- Laboratory of Synaptogenesis, Polish Academy of Sciences, 3 Pasteura Street, Warsaw, 02-093, Poland
| | - Marta Gawor
- Laboratory of Synaptogenesis, Polish Academy of Sciences, 3 Pasteura Street, Warsaw, 02-093, Poland
| | - Marcin Pęziński
- Laboratory of Synaptogenesis, Polish Academy of Sciences, 3 Pasteura Street, Warsaw, 02-093, Poland
| | - Paula Mazurek
- Laboratory of Synaptogenesis, Polish Academy of Sciences, 3 Pasteura Street, Warsaw, 02-093, Poland
| | - Paweł Niewiadomski
- Laboratory of Synaptogenesis, Polish Academy of Sciences, 3 Pasteura Street, Warsaw, 02-093, Poland
| | - Maria J Rędowicz
- Laboratory of Molecular Basis of Cell Motility, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteura Street, Warsaw, 02-093, Poland
| | - Tomasz J Prószyński
- Laboratory of Synaptogenesis, Polish Academy of Sciences, 3 Pasteura Street, Warsaw, 02-093, Poland.
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31
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Bhat HF, Mir SS, Dar KB, Bhat ZF, Shah RA, Ganai NA. ABC of multifaceted dystrophin glycoprotein complex (DGC). J Cell Physiol 2017; 233:5142-5159. [DOI: 10.1002/jcp.25982] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 05/01/2017] [Indexed: 01/16/2023]
Affiliation(s)
- Hina F. Bhat
- Division of BiotechnologySher‐e‐Kashmir University of Agricultural Sciences and Technology of Kashmir SKUAST‐KShuhama, SrinagarJammu and KashmirIndia
| | - Saima S. Mir
- Department of BiotechnologyUniversity of KashmirHazratbal, SrinagarJammu and KashmirIndia
| | - Khalid B. Dar
- Department of BiochemistryUniversity of KashmirHazratbal, SrinagarJammu and KashmirIndia
| | - Zuhaib F. Bhat
- Division of Livestock Products and TechnologySher‐e‐Kashmir University of Agricultural Sciences and Technology of Jammu (SKUAST‐J), R.S. PoraJammuJammu and KashmirIndia
| | - Riaz A. Shah
- Division of BiotechnologySher‐e‐Kashmir University of Agricultural Sciences and Technology of Kashmir SKUAST‐KShuhama, SrinagarJammu and KashmirIndia
| | - Nazir A. Ganai
- Division of BiotechnologySher‐e‐Kashmir University of Agricultural Sciences and Technology of Kashmir SKUAST‐KShuhama, SrinagarJammu and KashmirIndia
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32
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Li N, Tang Y, Liu B, Cong W, Liu C, Xiao J. Retinoid acid-induced microRNA-27b-3p impairs C2C12 myoblast proliferation and differentiation by suppressing α-dystrobrevin. Exp Cell Res 2016; 350:301-311. [PMID: 27889377 DOI: 10.1016/j.yexcr.2016.11.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 11/01/2016] [Accepted: 11/15/2016] [Indexed: 02/06/2023]
Abstract
We previously reported that excess retinoic acid (RA) resulted in hypoplastic and derangement of myofilaments in embryonic tongue by inhibiting myogenic proliferation and differentiation through CamKIID pathway. Our further studies revealed that the expression of a series of miRNAs was altered by RA administration in embryonic tongue as well as in C2C12 cells. Thus, if excess RA impairs myogenic proliferation and differentiation through miRNAs is taken into account. In present study, miR-27b-3p was found up-regulated in RA-treated C2C12 cells as in embryonic tongue, and predicted to target the 3'UTR of α-dystrobrevin (DTNA). Luciferase reporter assays confirmed the direct interaction between miR-27b-3p and the 3'UTR of DTNA. MiR-27b-3p mimics recapitulated the RA repression on DTNA expression, C2C12 proliferation and differentiation, while the miR-27b-3p inhibitor circumvented these defects resulting from excess RA. As expected, the effects of siDTNA on C2C12 were coincided with those by RA treatment or miR-27b-3p mimics. Therefore, these findings indicated that excess RA inhibited the myoblast proliferation and differentiation by up-regulating miR-27b-3p to target DTNA, which implied a new mechanism in myogenic hypoplasia.
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Affiliation(s)
- Nan Li
- Department of Oral Pathology, College of Stomatology, Dalian Medical University, Dalian, Liaoning 116044, China
| | - Yi Tang
- Department of Oral Pathology, College of Stomatology, Dalian Medical University, Dalian, Liaoning 116044, China
| | - Bo Liu
- Department of Oral Pathology, College of Stomatology, Dalian Medical University, Dalian, Liaoning 116044, China
| | - Wei Cong
- Department of Oral Pathology, College of Stomatology, Dalian Medical University, Dalian, Liaoning 116044, China
| | - Chao Liu
- Department of Oral Pathology, College of Stomatology, Dalian Medical University, Dalian, Liaoning 116044, China.
| | - Jing Xiao
- Department of Oral Pathology, College of Stomatology, Dalian Medical University, Dalian, Liaoning 116044, China.
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33
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Bi P, Yue F, Sato Y, Wirbisky S, Liu W, Shan T, Wen Y, Zhou D, Freeman J, Kuang S. Stage-specific effects of Notch activation during skeletal myogenesis. eLife 2016; 5. [PMID: 27644105 PMCID: PMC5070950 DOI: 10.7554/elife.17355] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 09/17/2016] [Indexed: 12/16/2022] Open
Abstract
Skeletal myogenesis involves sequential activation, proliferation, self-renewal/differentiation and fusion of myogenic stem cells (satellite cells). Notch signaling is known to be essential for the maintenance of satellite cells, but its function in late-stage myogenesis, i.e. post-differentiation myocytes and post-fusion myotubes, is unknown. Using stage-specific Cre alleles, we uncovered distinct roles of Notch1 in mononucleated myocytes and multinucleated myotubes. Specifically, constitutive Notch1 activation dedifferentiates myocytes into Pax7 quiescent satellite cells, leading to severe defects in muscle growth and regeneration, and postnatal lethality. By contrast, myotube-specific Notch1 activation improves the regeneration and exercise performance of aged and dystrophic muscles. Mechanistically, Notch1 activation in myotubes upregulates the expression of Notch ligands, which modulate Notch signaling in the adjacent satellite cells to enhance their regenerative capacity. These results highlight context-dependent effects of Notch activation during myogenesis, and demonstrate that Notch1 activity improves myotube's function as a stem cell niche.
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Affiliation(s)
- Pengpeng Bi
- Department of Animal Sciences, Purdue University, West Lafayette, United States
| | - Feng Yue
- Department of Animal Sciences, Purdue University, West Lafayette, United States
| | - Yusuke Sato
- Department of Animal Sciences, Purdue University, West Lafayette, United States
| | - Sara Wirbisky
- School of Health Sciences, Purdue University, West Lafayette, United States
| | - Weiyi Liu
- Department of Animal Sciences, Purdue University, West Lafayette, United States
| | - Tizhong Shan
- Department of Animal Sciences, Purdue University, West Lafayette, United States
| | - Yefei Wen
- Department of Animal Sciences, Purdue University, West Lafayette, United States
| | - Daoguo Zhou
- Department of Biological Sciences, Purdue University, West Lafayette, United States
| | - Jennifer Freeman
- School of Health Sciences, Purdue University, West Lafayette, United States.,Center for Cancer Research, Purdue University, West Lafayette, United States
| | - Shihuan Kuang
- Department of Animal Sciences, Purdue University, West Lafayette, United States.,Center for Cancer Research, Purdue University, West Lafayette, United States
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34
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Rogers RS, Nishimune H. The role of laminins in the organization and function of neuromuscular junctions. Matrix Biol 2016; 57-58:86-105. [PMID: 27614294 DOI: 10.1016/j.matbio.2016.08.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 08/10/2016] [Accepted: 08/17/2016] [Indexed: 01/11/2023]
Abstract
The synapse between motor neurons and skeletal muscle is known as the neuromuscular junction (NMJ). Proper alignment of presynaptic and post-synaptic structures of motor neurons and muscle fibers, respectively, is essential for efficient motor control of skeletal muscles. The synaptic cleft between these two cells is filled with basal lamina. Laminins are heterotrimer extracellular matrix molecules that are key members of the basal lamina. Laminin α4, α5, and β2 chains specifically localize to NMJs, and these laminin isoforms play a critical role in maintenance of NMJs and organization of synaptic vesicle release sites known as active zones. These individual laminin chains exert their role in organizing NMJs by binding to their receptors including integrins, dystroglycan, and voltage-gated calcium channels (VGCCs). Disruption of these laminins or the laminin-receptor interaction occurs in neuromuscular diseases including Pierson syndrome and Lambert-Eaton myasthenic syndrome (LEMS). Interventions to maintain proper level of laminins and their receptor interactions may be insightful in treating neuromuscular diseases and aging related degeneration of NMJs.
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Affiliation(s)
- Robert S Rogers
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, Kansas, USA.
| | - Hiroshi Nishimune
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, Kansas, USA.
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35
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Hernández-Ibarra JA, Laredo-Cisneros MS, Mondragón-González R, Santamaría-Guayasamín N, Cisneros B. Localization of α-Dystrobrevin in Cajal Bodies and Nucleoli: A New Role for α-Dystrobrevin in the Structure/Stability of the Nucleolus. J Cell Biochem 2016; 116:2755-65. [PMID: 25959029 DOI: 10.1002/jcb.25218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 05/05/2015] [Indexed: 11/11/2022]
Abstract
α-Dystrobrevin (α-DB) is a cytoplasmic component of the dystrophin-associated complex involved in cell signaling; however, its recently revealed nuclear localization implies a role for this protein in the nucleus. Consistent with this, we demonstrated, in a previous work that α-DB1 isoform associates with the nuclear lamin to maintain nuclei morphology. In this study, we show the distribution of the α-DB2 isoform in different subnuclear compartments of N1E115 neuronal cells, including nucleoli and Cajal bodies, where it colocalizes with B23/nucleophosmin and Nopp140 and with coilin, respectively. Recovery in a pure nucleoli fraction undoubtedly confirms the presence of α-DB2 in the nucleolus. α-DB2 redistributes in a similar fashion to that of fibrillarin and Nopp140 upon actinomycin-mediated disruption of nucleoli and to that of coilin after disorganization of Cajal bodies through ultraviolet-irradiation, with relocalization of the proteins to the corresponding reassembled structures after cessation of the insults, which implies α-DB2 in the plasticity of these nuclear bodies. That localization of α-DB2 in the nucleolus is physiologically relevant is demonstrated by the fact that downregulation of α-DB2 resulted in both altered nucleoli structure and decreased levels of B23/nucleophosmin, fibrillarin, and Nopp140. Since α-DB2 interacts with B23/nucleophosmin and overexpression of the latter protein favors nucleolar accumulation of α-DB2, it appears that targeting of α-DB2 to the nucleolus is dependent on B23/nucleophosmin. In conclusion, we show for the first time localization of α-DB2 in nucleoli and Cajal bodies and provide evidence that α-DB2 is involved in the structure of nucleoli and might modulate nucleolar functions.
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Affiliation(s)
- Jose Anselmo Hernández-Ibarra
- Departamento de Gen, é, tica y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV- IPN), Mexico City, Mexico
| | - Marco Samuel Laredo-Cisneros
- Departamento de Gen, é, tica y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV- IPN), Mexico City, Mexico
| | - Ricardo Mondragón-González
- Departamento de Gen, é, tica y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV- IPN), Mexico City, Mexico
| | - Natalie Santamaría-Guayasamín
- Departamento de Ciencias de la Vida, Carrera de Ingeniería en Biotecnología, Universidad de las Fuerzas Armadas-ESPE, Sangolquí, Ecuador
| | - Bulmaro Cisneros
- Departamento de Gen, é, tica y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV- IPN), Mexico City, Mexico
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36
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Quaranta MT, Spinello I, Paolillo R, Macchia G, Boe A, Ceccarini M, Labbaye C, Macioce P. Identification of β-Dystrobrevin as a Direct Target of miR-143: Involvement in Early Stages of Neural Differentiation. PLoS One 2016; 11:e0156325. [PMID: 27223470 PMCID: PMC4880309 DOI: 10.1371/journal.pone.0156325] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 05/12/2016] [Indexed: 11/25/2022] Open
Abstract
Duchenne Muscular Dystrophy, a genetic disorder that results in a gradual breakdown of muscle, is associated to mild to severe cognitive impairment in about one-third of dystrophic patients. The brain dysfunction is independent of the muscular pathology, occurs early, and is most likely due to defects in the assembly of the Dystrophin-associated Protein Complex (DPC) during embryogenesis. We have recently described the interaction of the DPC component β-dystrobrevin with members of complexes that regulate chromatin dynamics, and suggested that β-dystrobrevin may play a role in the initiation of neuronal differentiation. Since oxygen concentrations and miRNAs appear as well to be involved in the cellular processes related to neuronal development, we have studied how these factors act on β-dystrobrevin and investigated the possibility of their functional interplay using the NTera-2 cell line, a well-established model for studying neurogenesis. We followed the pattern of expression and regulation of β-dystrobrevin during the early stages of neuronal differentiation induced by exposure to retinoic acid (RA) under hypoxia as compared with normoxia, and found that β-dystrobrevin expression is regulated during RA-induced differentiation of NTera-2 cells. We also found that β-dystrobrevin pattern is delayed under hypoxic conditions, together with a delay in the differentiation and an increase in the proliferation rate of cells. We identified miRNA-143 as a direct regulator of β-dystrobrevin expression, demonstrated that β-dystrobrevin is expressed in the nucleus and showed that, in line with our previous in vitro results, β-dystrobrevin is a repressor of synapsin I in live cells. Altogether the newly identified regulatory pathway miR-143/β-dystrobrevin/synapsin I provides novel insights into the functions of β-dystrobrevin and opens up new perspectives for elucidating the molecular mechanisms underlying the neuronal involvement in muscular dystrophy.
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Affiliation(s)
- Maria Teresa Quaranta
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Isabella Spinello
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Rosa Paolillo
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Gianfranco Macchia
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
| | - Alessandra Boe
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Marina Ceccarini
- National Centre for Rare Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Catherine Labbaye
- Department of Hematology, Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Pompeo Macioce
- Department of Cell Biology and Neurosciences, Istituto Superiore di Sanità, Rome, Italy
- * E-mail:
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Abstract
The dystrophin complex stabilizes the plasma membrane of striated muscle cells. Loss of function mutations in the genes encoding dystrophin, or the associated proteins, trigger instability of the plasma membrane, and myofiber loss. Mutations in dystrophin have been extensively cataloged, providing remarkable structure-function correlation between predicted protein structure and clinical outcomes. These data have highlighted dystrophin regions necessary for in vivo function and fueled the design of viral vectors and now, exon skipping approaches for use in dystrophin restoration therapies. However, dystrophin restoration is likely more complex, owing to the role of the dystrophin complex as a broad cytoskeletal integrator. This review will focus on dystrophin restoration, with emphasis on the regions of dystrophin essential for interacting with its associated proteins and discuss the structural implications of these approaches.
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Affiliation(s)
- Quan Q Gao
- Committee on Development, Regeneration and Stem Cell Biology, The University of Chicago, Chicago, Illinois, USA
| | - Elizabeth M McNally
- Center for Genetic Medicine, Northwestern University, Chicago, Chicago, Illinois, USA
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Zlotina A, Nikulina T, Yany N, Moiseeva O, Pervunina T, Grekhov E, Kostareva A. Ring chromosome 18 in combination with 18q12.1 (DTNA) interstitial microdeletion in a patient with multiple congenital defects. Mol Cytogenet 2016; 9:18. [PMID: 26893613 PMCID: PMC4758088 DOI: 10.1186/s13039-016-0229-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 02/10/2016] [Indexed: 11/20/2022] Open
Abstract
Background Ring chromosome 18 [r(18)] syndrome represents a relatively rare condition with a complex clinical picture including multiple congenital dysmorphia and varying degrees of mental retardation. The condition is cytogenetically characterized by a complete or mosaic form of ring chromosome 18, with ring formation being usually accompanied by the partial loss of both chromosomal arms. Here we observed a 20-year-old male patient who along with the features typical for r(18) carriers additionally manifested a severe congenital subaortic stenosis. To define the genetic basis of such a compound phenotype, standard cytogenetic and high-resolution molecular-cytogenetic analysis of the patient was performed. Case presentation Standard chromosome analysis of cultured lymphocytes confirmed 46, XY, r(18) karyotype. Array-based comparative genomic hybridization (array-CGH) allowed to define precisely the breakpoints of 18p and 18q terminal deletions, thus identifying the hemizygosity extent, and to reveal an additional duplication adjoining the breakpoint of the 18p deletion. Apart from the terminal imbalances, we found an interstitial microdeletion of 442 kb in size (18q12.1) that encompassed DTNA gene encoding α-dystrobrevin, a member of dystrophin-associated glycoprotein complex. While limited data on the role of DTNA missense mutations in pathogenesis of human cardiac abnormalities exist, a microdeletion corresponding to whole DTNA sequence and not involving other genes has not been earlier described. Conclusions A detailed molecular-cytogenetic characterization of the patient with multiple congenital abnormalities enabled to unravel a combination of genetic defects, namely, a ring chromosome 18 with terminal imbalances and DTNA whole-gene deletion. We suggest that such combination could contribute to the complex phenotype. The findings obtained allow to extend the knowledge of the role of DTNA haploinsufficiency in congenital heart malformation, though further comprehensive functional studies are required. Electronic supplementary material The online version of this article (doi:10.1186/s13039-016-0229-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anna Zlotina
- Almazov Federal Medical Research Centre, Saint-Petersburg, 197341 Russia ; Institute of translational Medicine, ITMO University, Saint-Petersburg, 199034 Russia ; Cytology and Histology Department, Saint Petersburg State University, Saint-Petersburg, 199034 Russia
| | - Tatiana Nikulina
- Almazov Federal Medical Research Centre, Saint-Petersburg, 197341 Russia
| | - Natalia Yany
- Almazov Federal Medical Research Centre, Saint-Petersburg, 197341 Russia
| | - Olga Moiseeva
- Almazov Federal Medical Research Centre, Saint-Petersburg, 197341 Russia
| | - Tatiana Pervunina
- Almazov Federal Medical Research Centre, Saint-Petersburg, 197341 Russia
| | - Eugeny Grekhov
- Almazov Federal Medical Research Centre, Saint-Petersburg, 197341 Russia
| | - Anna Kostareva
- Almazov Federal Medical Research Centre, Saint-Petersburg, 197341 Russia ; Department of Women's and Children's Health, Center for Molecular Medicine, Karolinska Institute, Stockholm, 17176 Sweden
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Allen DG, Whitehead NP, Froehner SC. Absence of Dystrophin Disrupts Skeletal Muscle Signaling: Roles of Ca2+, Reactive Oxygen Species, and Nitric Oxide in the Development of Muscular Dystrophy. Physiol Rev 2016; 96:253-305. [PMID: 26676145 DOI: 10.1152/physrev.00007.2015] [Citation(s) in RCA: 272] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Dystrophin is a long rod-shaped protein that connects the subsarcolemmal cytoskeleton to a complex of proteins in the surface membrane (dystrophin protein complex, DPC), with further connections via laminin to other extracellular matrix proteins. Initially considered a structural complex that protected the sarcolemma from mechanical damage, the DPC is now known to serve as a scaffold for numerous signaling proteins. Absence or reduced expression of dystrophin or many of the DPC components cause the muscular dystrophies, a group of inherited diseases in which repeated bouts of muscle damage lead to atrophy and fibrosis, and eventually muscle degeneration. The normal function of dystrophin is poorly defined. In its absence a complex series of changes occur with multiple muscle proteins showing reduced or increased expression or being modified in various ways. In this review, we will consider the various proteins whose expression and function is changed in muscular dystrophies, focusing on Ca(2+)-permeable channels, nitric oxide synthase, NADPH oxidase, and caveolins. Excessive Ca(2+) entry, increased membrane permeability, disordered caveolar function, and increased levels of reactive oxygen species are early changes in the disease, and the hypotheses for these phenomena will be critically considered. The aim of the review is to define the early damage pathways in muscular dystrophy which might be appropriate targets for therapy designed to minimize the muscle degeneration and slow the progression of the disease.
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Affiliation(s)
- David G Allen
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| | - Nicholas P Whitehead
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
| | - Stanley C Froehner
- Sydney Medical School & Bosch Institute, University of Sydney, New South Wales, Australia; and Department of Physiology & Biophysics, University of Washington, Seattle, Washington
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Gingras J, Gawor M, Bernadzki KM, Grady RM, Hallock P, Glass DJ, Sanes JR, Proszynski TJ. Α-Dystrobrevin-1 recruits Grb2 and α-catulin to organize neurotransmitter receptors at the neuromuscular junction. J Cell Sci 2016; 129:898-911. [PMID: 26769899 DOI: 10.1242/jcs.181180] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/11/2016] [Indexed: 12/17/2022] Open
Abstract
Neuromuscular junctions (NMJs), the synapses made by motor neurons on muscle fibers, form during embryonic development but undergo substantial remodeling postnatally. Several lines of evidence suggest that α-dystrobrevin, a component of the dystrophin-associated glycoprotein complex (DGC), is a crucial regulator of the remodeling process and that tyrosine phosphorylation of one isoform, α-dystrobrevin-1, is required for its function at synapses. We identified a functionally important phosphorylation site on α-dystrobrevin-1, generated phosphorylation-specific antibodies to it and used them to demonstrate dramatic increases in phosphorylation during the remodeling period, as well as in nerve-dependent regulation in adults. We then identified proteins that bind to this site in a phosphorylation-dependent manner and others that bind to α-dystrobrevin-1 in a phosphorylation-independent manner. They include multiple members of the DGC, as well as α-catulin, liprin-α1, Usp9x, PI3K, Arhgef5 and Grb2. Finally, we show that two interactors, α-catulin (phosphorylation independent) and Grb2 (phosphorylation dependent) are localized to NMJs in vivo, and that they are required for proper organization of neurotransmitter receptors on myotubes.
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Affiliation(s)
- Jacinthe Gingras
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Marta Gawor
- Laboratory of Synaptogenesis, Dept. of Cell Biology, Nencki Institute of Experimental Biology, Warsaw 02-093, Poland
| | - Krzysztof M Bernadzki
- Laboratory of Synaptogenesis, Dept. of Cell Biology, Nencki Institute of Experimental Biology, Warsaw 02-093, Poland
| | - R Mark Grady
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Peter Hallock
- Novartis Biomedical Institute, Cambridge, MA 02139, USA
| | - David J Glass
- Novartis Biomedical Institute, Cambridge, MA 02139, USA
| | - Joshua R Sanes
- Department of Molecular and Cellular Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA Department of Anatomy and Neurobiology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Tomasz J Proszynski
- Laboratory of Synaptogenesis, Dept. of Cell Biology, Nencki Institute of Experimental Biology, Warsaw 02-093, Poland
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Abstract
Neuromuscular diseases can affect the survival of peripheral neurons, their axons extending to peripheral targets, their synaptic connections onto those targets, or the targets themselves. Examples include motor neuron diseases such as Amyotrophic Lateral Sclerosis, peripheral neuropathies such as Charcot-Marie-Tooth diseases, myasthenias, and muscular dystrophies. Characterizing these phenotypes in mouse models requires an integrated approach, examining both the nerve and muscle histologically, anatomically, and functionally by electrophysiology. Defects observed at these levels can be related back to onset, severity, and progression, as assessed by "Quality of life measures" including tests of gross motor performance such as gait or grip strength. This chapter describes methods for assessing neuromuscular disease models in mice, and how interpretation of these tests can be complicated by the inter-relatedness of the phenotypes.
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Affiliation(s)
- Robert W Burgess
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA.
| | - Gregory A Cox
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Kevin L Seburn
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
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42
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McGreevy JW, Hakim CH, McIntosh MA, Duan D. Animal models of Duchenne muscular dystrophy: from basic mechanisms to gene therapy. Dis Model Mech 2015; 8:195-213. [PMID: 25740330 PMCID: PMC4348559 DOI: 10.1242/dmm.018424] [Citation(s) in RCA: 316] [Impact Index Per Article: 35.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a progressive muscle-wasting disorder. It is caused by loss-of-function mutations in the dystrophin gene. Currently, there is no cure. A highly promising therapeutic strategy is to replace or repair the defective dystrophin gene by gene therapy. Numerous animal models of DMD have been developed over the last 30 years, ranging from invertebrate to large mammalian models. mdx mice are the most commonly employed models in DMD research and have been used to lay the groundwork for DMD gene therapy. After ~30 years of development, the field has reached the stage at which the results in mdx mice can be validated and scaled-up in symptomatic large animals. The canine DMD (cDMD) model will be excellent for these studies. In this article, we review the animal models for DMD, the pros and cons of each model system, and the history and progress of preclinical DMD gene therapy research in the animal models. We also discuss the current and emerging challenges in this field and ways to address these challenges using animal models, in particular cDMD dogs.
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Affiliation(s)
- Joe W McGreevy
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
| | - Chady H Hakim
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
| | - Mark A McIntosh
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65212, USA Department of Neurology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
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Abstract
INTRODUCTION Duchenne muscular dystrophy (DMD) is a relatively common inherited disorder caused by defective expression of the protein dystrophin. The most direct approach to treating this disease would be to restore dystrophin production in muscle. Recent progress has greatly increased the prospects for successful gene therapy of DMD, and here we summarize the most promising developments. AREAS COVERED Gene transfer using vectors derived from adeno-associated virus (AAV) has emerged as a promising method to restore dystrophin production in muscles bodywide, and represents a treatment option applicable to all DMD patients. Using information gleaned from PubMed searches of the literature, attendance at scientific conferences and results from our own lab, we provide an overview of the potential for gene therapy of DMD using AAV vectors including a summary of promising developments and issues that need to be resolved prior to large-scale therapeutic implementation. EXPERT OPINION Of the many approaches being pursued to treat DMD and BMD, gene therapy based on AAV-mediated delivery of microdystrophin is the most direct and promising method to treat the cause of the disorder. The major challenges to this approach are ensuring that microdystrophin can be delivered safely and efficiently without eliciting an immune response.
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Affiliation(s)
- Julian Ramos
- University of Washington, Wellstone Muscular Dystrophy Research Center, Department of Neurology, Seattle, WA, 98195-7720, USA
| | - Jeffrey S Chamberlain
- University of Washington, Wellstone Muscular Dystrophy Research Center, Department of Neurology, Seattle, WA, 98195-7720, USA
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The knockdown of αkap alters the postsynaptic apparatus of neuromuscular junctions in living mice. J Neurosci 2015; 35:5118-27. [PMID: 25834039 DOI: 10.1523/jneurosci.3951-14.2015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A muscle-specific nonkinase anchoring protein (αkap), encoded within the calcium/calmodulin kinase II (camk2) α gene, was recently found to control the stability of acetylcholine receptor (AChR) clusters on the surface of cultured myotubes. However, it remains unknown whether this protein has any effect on receptor stability and the maintenance of the structural integrity of neuromuscular synapses in vivo. By knocking down the endogenous expression of αkap in mouse sternomastoid muscles with shRNA, we found that the postsynaptic receptor density was dramatically reduced, the turnover rate of receptors at synaptic sites was significantly increased, and the insertion rates of both newly synthesized and recycled receptors into the postsynaptic membrane were depressed. Moreover, we found that αkap shRNA knockdown impaired synaptic structure as postsynaptic AChR clusters and their associated postsynaptic scaffold proteins within the neuromuscular junction were completely eliminated. These results provide new mechanistic insight into the role of αkap in regulating the stability of the postsynaptic apparatus of neuromuscular synapses.
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45
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Godoy TF, Moreira GCM, Boschiero C, Gheyas AA, Gasparin G, Paduan M, Andrade SCS, Montenegro H, Burt DW, Ledur MC, Coutinho LL. SNP and INDEL detection in a QTL region on chicken chromosome 2 associated with muscle deposition. Anim Genet 2015; 46:158-63. [PMID: 25690762 DOI: 10.1111/age.12271] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2014] [Indexed: 11/28/2022]
Abstract
Genetic improvement is important for the poultry industry, contributing to increased efficiency of meat production and quality. Because breast muscle is the most valuable part of the chicken carcass, knowledge of polymorphisms influencing this trait can help breeding programs. Therefore, the complete genome of 18 chickens from two different experimental lines (broiler and layer) from EMBRAPA was sequenced, and SNPs and INDELs were detected in a QTL region for breast muscle deposition on chicken chromosome 2 between microsatellite markers MCW0185 and MCW0264 (105,849-112,649 kb). Initially, 94,674 unique SNPs and 10,448 unique INDELs were identified in the target region. After quality filtration, 77% of the SNPs (85,765) and 60% of the INDELs (7828) were retained. The studied region contains 66 genes, and functional annotation of the filtered variants identified 517 SNPs and three INDELs in exonic regions. Of these, 357 SNPs were classified as synonymous, 153 as non-synonymous, three as stopgain, four INDELs as frameshift and three INDELs as non-frameshift. These exonic mutations were identified in 37 of the 66 genes from the target region, three of which are related to muscle development (DTNA, RB1CC1 and MOS). Fifteen non-tolerated SNPs were detected in several genes (MEP1B, PRKDC, NSMAF, TRAPPC8, SDR16C5, CHD7, ST18 and RB1CC1). These loss-of-function and exonic variants present in genes related to muscle development can be considered candidate variants for further studies in chickens. Further association studies should be performed with these candidate mutations as should validation in commercial populations to allow a better explanation of QTL effects.
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Affiliation(s)
- T F Godoy
- Departamento de Zootecnia, ESALQ/USP, Av. Pádua Dias 11, Piracicaba, São Paulo, 13419-900, Brazil
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Aguilar A, Wagstaff KM, Suárez-Sánchez R, Zinker S, Jans DA, Cisneros B. Nuclear localization of the dystrophin-associated protein α-dystrobrevin through importin α2/β1 is critical for interaction with the nuclear lamina/maintenance of nuclear integrity. FASEB J 2015; 29:1842-58. [PMID: 25636738 DOI: 10.1096/fj.14-257147] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 12/31/2014] [Indexed: 01/06/2023]
Abstract
Although α-dystrobrevin (DB) is assembled into the dystrophin-associated protein complex, which is central to cytoskeletal organization, it has also been found in the nucleus. Here we delineate the nuclear import pathway responsible for nuclear targeting of α-DB for the first time, together with the importance of nuclear α-DB in determining nuclear morphology. We map key residues of the nuclear localization signal of α-DB within the zinc finger domain (ZZ) using various truncated versions of the protein, and site-directed mutagenesis. Pulldown, immunoprecipitation, and AlphaScreen assays showed that the importin (IMP) α2/β1 heterodimer interacts with high affinity with the ZZ domain of α-DB. In vitro nuclear import assays using antibodies to specific importins, as well as in vivo studies using siRNA or a dominant negative importin construct, confirmed the key role of IMPα2/β1 in α-DB nuclear translocation. Knockdown of α-DB expression perturbed cell cycle progression in C2C12 myoblasts, with decreased accumulation of cells in S phase and, significantly, altered localization of lamins A/C, B1, and B2 with accompanying gross nuclear morphology defects. Because α-DB interacts specifically with lamin B1 in vivo and in vitro, nuclear α-DB would appear to play a key role in nuclear shape maintenance through association with the nuclear lamina.
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Affiliation(s)
- Areli Aguilar
- *Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México City, Mexico; Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia; and Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación, México City, Mexico
| | - Kylie M Wagstaff
- *Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México City, Mexico; Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia; and Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación, México City, Mexico
| | - Rocío Suárez-Sánchez
- *Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México City, Mexico; Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia; and Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación, México City, Mexico
| | - Samuel Zinker
- *Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México City, Mexico; Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia; and Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación, México City, Mexico
| | - David A Jans
- *Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México City, Mexico; Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia; and Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación, México City, Mexico
| | - Bulmaro Cisneros
- *Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México City, Mexico; Nuclear Signalling Laboratory, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia; and Laboratorio de Medicina Genómica, Departamento de Genética, Instituto Nacional de Rehabilitación, México City, Mexico
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Liu N, Bassel-Duby R. Regulation of skeletal muscle development and disease by microRNAs. Results Probl Cell Differ 2015; 56:165-90. [PMID: 25344671 DOI: 10.1007/978-3-662-44608-9_8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The identification of microRNAs (miRNA) in vertebrates has uncovered new mechanisms regulating skeletal muscle development and disease. miRNAs are inhibitors and act by silencing specific mRNAs or by repressing protein translation. In many cases, miRNAs are involved in physiological or pathological stress, suggesting they function to exacerbate or protect the organism during stress or disease. Although many skeletal muscle diseases differ in clinical and pathological manifestations, they all have a common feature of dysregulation of miRNA expression. In particular, analysis of miRNA expression patterns in skeletal muscle diseases reveals miRNA signatures, showing many miRNAs are dysregulated during disease. Emerging identification of miRNA targets and involvement in genetic regulatory networks serve to reveal new regulatory pathways in skeletal muscle biology. This chapter features the findings pertaining to skeletal muscle miRNAs in skeletal muscle development and disease and highlights therapeutic applications of miRNA-based technology in diagnosis and treatment of skeletal muscle myopathies.
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Affiliation(s)
- Ning Liu
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA,
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48
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Whitmore C, Morgan J. What do mouse models of muscular dystrophy tell us about the DAPC and its components? Int J Exp Pathol 2014; 95:365-77. [PMID: 25270874 PMCID: PMC4285463 DOI: 10.1111/iep.12095] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 08/16/2014] [Indexed: 12/17/2022] Open
Abstract
There are over 30 mouse models with mutations or inactivations in the dystrophin-associated protein complex. This complex is thought to play a crucial role in the functioning of muscle, as both a shock absorber and signalling centre, although its role in the pathogenesis of muscular dystrophy is not fully understood. The first mouse model of muscular dystrophy to be identified with a mutation in a component of the dystrophin-associated complex (dystrophin) was the mdx mouse in 1984. Here, we evaluate the key characteristics of the mdx in comparison with other mouse mutants with inactivations in DAPC components, along with key modifiers of the disease phenotype. By discussing the differences between the individual phenotypes, we show that the functioning of the DAPC and consequently its role in the pathogenesis is more complicated than perhaps currently appreciated.
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Affiliation(s)
- Charlotte Whitmore
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, Institute of Child Health, University College LondonLondon, UK
| | - Jennifer Morgan
- Dubowitz Neuromuscular Centre, Molecular Neurosciences Section, Developmental Neurosciences Programme, Institute of Child Health, University College LondonLondon, UK
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Jiang K, Li W, Li W, Jiao S, Castel L, Van Wagoner DR, Yu X. Rapid multislice T1 mapping of mouse myocardium: Application to quantification of manganese uptake in α-Dystrobrevin knockout mice. Magn Reson Med 2014; 74:1370-9. [PMID: 25408542 DOI: 10.1002/mrm.25533] [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: 05/17/2014] [Revised: 09/26/2014] [Accepted: 10/23/2014] [Indexed: 12/27/2022]
Abstract
PURPOSE The aim of this study was to develop a rapid, multislice cardiac T1 mapping method in mice and to apply the method to quantify manganese (Mn(2+)) uptake in a mouse model with altered Ca(2+) channel activity. METHODS An electrocardiography-triggered multislice saturation-recovery Look-Locker method was developed and validated both in vitro and in vivo. A two-dose study was performed to investigate the kinetics of T1 shortening, Mn(2+) relaxivity in myocardium, and the impact of Mn(2+) on cardiac function. The sensitivity of Mn(2+)-enhanced MRI in detecting subtle changes in altered Ca(2+) channel activity was evaluated in a mouse model with α-dystrobrevin knockout. RESULTS Validation studies showed strong agreement between the current method and an established method. High Mn(2+) dose led to significantly accelerated T1 shortening. Heart rate decreased during Mn(2+) infusion, while ejection ratio increased slightly at the end of imaging protocol. No statistical difference in cardiac function was detected between the two dose groups. Mice with α-dystrobrevin knockout showed enhanced Mn(2+) uptake in vivo. In vitro patch-clamp study showed increased Ca(2+) channel activity. CONCLUSION The saturation recovery method provides rapid T1 mapping in mouse hearts, which allowed sensitive detection of subtle changes in Mn(2+) uptake in α-dystrobrevin knockout mice.
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Affiliation(s)
- Kai Jiang
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Wen Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Wei Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Sen Jiao
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Laurie Castel
- Department of Molecular Cardiology, Cleveland Clinic, Cleveland, Ohio, USA
| | | | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA.,Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA.,Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA
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50
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Strakova J, Dean JD, Sharpe KM, Meyers TA, Odom GL, Townsend D. Dystrobrevin increases dystrophin's binding to the dystrophin-glycoprotein complex and provides protection during cardiac stress. J Mol Cell Cardiol 2014; 76:106-15. [PMID: 25158611 DOI: 10.1016/j.yjmcc.2014.08.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 08/14/2014] [Accepted: 08/16/2014] [Indexed: 01/05/2023]
Abstract
Duchenne muscular dystrophy is a fatal progressive disease of both cardiac and skeletal muscle resulting from the mutations in the DMD gene and loss of the protein dystrophin. Alpha-dystrobrevin (α-DB) tightly associates with dystrophin but the significance of this interaction within cardiac myocytes is poorly understood. In the current study, the functional role of α-DB in cardiomyocytes and its implications for dystrophin function are examined. Cardiac stress testing demonstrated significant heart disease in α-DB null (adbn(-/-)) mice, which displayed mortality and lesion sizes that were equivalent to those seen in dystrophin-deficient mdx mice. Despite normal expression and subcellular localization of dystrophin in the adbn(-/-) heart, there is a significant decrease in the strength of dystrophin's interaction with the membrane-bound dystrophin-associated glycoprotein complex (DGC). A similar weakening of the dystrophin-membrane interface was observed in mice lacking the sarcoglycan complex. Cardiomyocytes from adbn(-/-) mice were smaller and responded less to adrenergic receptor induced hypertrophy. The basal decrease in size could not be attributed to aberrant Akt activation. In addition, the organization of the microtubule network was significantly altered in adbn(-/-) cardiac myocytes, while the total expression of tubulin was unchanged in adbn(-/-) hearts. These studies demonstrate that α-DB is a multifunctional protein that increases dystrophin's binding to the dystrophin-glycoprotein complex, and is critical for the full functionality of dystrophin.
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Affiliation(s)
- Jana Strakova
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Jon D Dean
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Katharine M Sharpe
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Tatyana A Meyers
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Guy L Odom
- Department of Neurology, University of Washington, Seattle, WA, USA
| | - DeWayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA.
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