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Kaplan KM, Morgan KG. The importance of dystrophin and the dystrophin associated proteins in vascular smooth muscle. Front Physiol 2022; 13:1059021. [PMID: 36505053 PMCID: PMC9732661 DOI: 10.3389/fphys.2022.1059021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/14/2022] [Indexed: 11/26/2022] Open
Abstract
This review details the role of dystrophin and the dystrophin associated proteins (DAPs) in the vascular smooth muscle. Dystrophin is most comprehensively studied in the skeletal muscle due to serious symptoms found related to the skeletal muscle of patients with muscular dystrophy. Mutations in the dystrophin gene, or DAPs genes, result in a wide range of muscular dystrophies. In skeletal muscle, dystrophin is known to act to as a cytoskeletal stabilization protein and protects cells against contraction-induced damage. In skeletal muscle, dystrophin stabilizes the plasma membrane by transmitting forces generated by sarcomeric contraction to the extracellular matrix (ECM). Dystrophin is a scaffold that binds the dystroglycan complex (DGC) and has many associated proteins (DAPs). These DAPs include sarcoglycans, syntrophins, dystroglycans, dystrobrevin, neuronal nitric oxide synthase, and caveolins. The DAPs provide biomechanical support to the skeletal or cardiac plasma membrane during contraction, and loss of one or several of these DAPs leads to plasma membrane fragility. Dystrophin is expressed near the plasma membrane of all muscles, including cardiac and vascular smooth muscle, and some neurons. Dystrophic mice have noted biomechanical irregularities in the carotid arteries and spontaneous motor activity in portal vein altered when compared to wild type mice. Additionally, some studies suggest the vasculature of patients and animal models with muscular dystrophy is abnormal. Although the function of dystrophin and the DAPs in vascular smooth muscle is not thoroughly established in the field, this review makes the point that these proteins are expressed, and important and further study is warranted.
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Li C, Haller G, Weihl CC. Current and Future Approaches to Classify VUSs in LGMD-Related Genes. Genes (Basel) 2022; 13:genes13020382. [PMID: 35205425 PMCID: PMC8871643 DOI: 10.3390/genes13020382] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 02/11/2022] [Accepted: 02/16/2022] [Indexed: 01/09/2023] Open
Abstract
Next-generation sequencing (NGS) has revealed large numbers of genetic variants in LGMD-related genes, with most of them classified as variants of uncertain significance (VUSs). VUSs are genetic changes with unknown pathological impact and present a major challenge in genetic test interpretation and disease diagnosis. Understanding the phenotypic consequences of VUSs can provide clinical guidance regarding LGMD risk and therapy. In this review, we provide a brief overview of the subtypes of LGMD, disease diagnosis, current classification systems for investigating VUSs, and a potential deep mutational scanning approach to classify VUSs in LGMD-related genes.
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Affiliation(s)
- Chengcheng Li
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO 63110, USA; (C.L.); (G.H.)
| | - Gabe Haller
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO 63110, USA; (C.L.); (G.H.)
- Department of Neurological Surgery, Washington University School of Medicine, Saint Louis, MO 63110, USA
- Department of Genetics, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Conrad C. Weihl
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO 63110, USA; (C.L.); (G.H.)
- Correspondence:
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Carson L, Merrick D. Genotype-phenotype correlations in alpha-sarcoglycanopathy: a systematic review. Ir J Med Sci 2022; 191:2743-2750. [PMID: 35040091 DOI: 10.1007/s11845-021-02855-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 10/27/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND Mutations in the alpha-sarcoglycan gene cause limb-girdle muscular dystrophy 2D, an autosomal recessive muscle wasting disorder primarily affecting the muscles of the shoulder and pelvic girdles. To date, no previous study has collated all known mutations in alpha-sarcoglycan and mapped these to the associated phenotypes. AIMS To examine for correlations between mutation locations, or mutation type, and the phenotype caused in all reported mutations in alpha-sarcoglycan. METHODS We present a systematic literature review examining correlations between mutation locations, or mutation type, and the phenotype caused in all reported cases of limb-girdle muscular dystrophy 2D. RESULTS From 134 unique genotypes collated, a strong prevalence of missense mutations (64% of all unique mutations) was found in this gene. Mutation hotspots were noted in exon three and the extracellular domain, with mutation densities varying significantly between both exons and protein domains (p ≤ 0.01). All compound heterozygous limb-girdle muscular dystrophy 2D patients with cardiac involvement contained at least one mutation in exon three, a novel finding. All non-sense mutations in alpha-sarcoglycan give a severe phenotype, as do genotypes involving a combination of exons four and five. This study confirms on a large, diverse cohort the extremely high prevalence of the c.229C > T mutation. CONCLUSIONS This study demonstrates the vast variation in disease severity seen between patients possessing the same mutation, highlighting the difficulty identifying genotype-phenotype correlations in this condition. Novel findings including the involvement of exon three in all compound heterozygous patients who suffered from cardiomyopathy, and the severity of mutations involving exons four and five may help to guide investigations and therapeutic decisions in an era of personalised medicine.
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Affiliation(s)
- Luke Carson
- School of Life Sciences, University of Nottingham, Nottingham, UK.
| | - Deborah Merrick
- School of Life Sciences, University of Nottingham, Nottingham, UK
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Vainzof M, Souza LS, Gurgel-Giannetti J, Zatz M. Sarcoglycanopathies: an update. Neuromuscul Disord 2021; 31:1021-1027. [PMID: 34404573 DOI: 10.1016/j.nmd.2021.07.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/12/2021] [Accepted: 07/16/2021] [Indexed: 11/16/2022]
Abstract
Sarcoglycanopathies are the most severe forms of autosomal recessive limb-girdle muscular dystrophies (LGMDs), constituting about 10-25% of LGMDs. The clinical phenotype is variable, but onset is usually in the first decade of life. Patients present muscle hypertrophy, elevated CK, variable muscle weaknesses, and progressive loss of ambulation. Four subtypes are known: LGMDR3, LGMDR4, LGMDR5 and LGMDR6, caused, respectively, by mutations in the SGCA, SGCB,SGCG and SGCD genes. Their four coded proteins, α-SG, ß-SG, λ-SG and δ-SG are part of the dystrophin-glycoprotein complex (DGC) present in muscle sarcolemma, which acts as a linker between the cytoskeleton of the muscle fiber and the extracellular matrix, providing mechanical support to the sarcolemma during myofiber contraction. Many different mutations have already been identified in all the sarcoglycan genes, with a predominance of some mutations in different populations. The diagnosis is currently based on the molecular screening for these mutations. Therapeutic approaches include the strategy of gene replacement mediated by a vector derived from adeno-associated virus (AAV). Pre-clinical studies have shown detectable levels of SG proteins in the muscle, and some improvement in the phenotype, in animal models. Therapeutic trials in humans are ongoing.
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Affiliation(s)
- Mariz Vainzof
- Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Biosciences Institute, University of São Paulo, São Paulo, Brazil.
| | - Lucas S Souza
- Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Biosciences Institute, University of São Paulo, São Paulo, Brazil
| | - Juliana Gurgel-Giannetti
- Department of Pediatrics, Service of Neuropediatrics from Federal, University of Minas Gerais, Belo Horizonte, Brazil
| | - Mayana Zatz
- Human Genome and Stem Cell Research Center, Department of Genetics and Evolutionary Biology, Biosciences Institute, University of São Paulo, São Paulo, Brazil
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Valera IC, Wacker AL, Hwang HS, Holmes C, Laitano O, Landstrom AP, Parvatiyar MS. Essential roles of the dystrophin-glycoprotein complex in different cardiac pathologies. Adv Med Sci 2021; 66:52-71. [PMID: 33387942 DOI: 10.1016/j.advms.2020.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 12/12/2020] [Accepted: 12/17/2020] [Indexed: 12/20/2022]
Abstract
The dystrophin-glycoprotein complex (DGC), situated at the sarcolemma dynamically remodels during cardiac disease. This review examines DGC remodeling as a common denominator in diseases affecting heart function and health. Dystrophin and the DGC serve as broad cytoskeletal integrators that are critical for maintaining stability of muscle membranes. The presence of pathogenic variants in genes encoding proteins of the DGC can cause absence of the protein and/or alterations in other complex members leading to muscular dystrophies. Targeted studies have allowed the individual functions of affected proteins to be defined. The DGC has demonstrated its dynamic function, remodeling under a number of conditions that stress the heart. Beyond genetic causes, pathogenic processes also impinge on the DGC, causing alterations in the abundance of dystrophin and associated proteins during cardiac insult such as ischemia-reperfusion injury, mechanical unloading, and myocarditis. When considering new therapeutic strategies, it is important to assess DGC remodeling as a common factor in various heart diseases. The DGC connects the internal F-actin-based cytoskeleton to laminin-211 of the extracellular space, playing an important role in the transmission of mechanical force to the extracellular matrix. The essential functions of dystrophin and the DGC have been long recognized. DGC based therapeutic approaches have been primarily focused on muscular dystrophies, however it may be a beneficial target in a number of disorders that affect the heart. This review provides an account of what we now know, and discusses how this knowledge can benefit persistent health conditions in the clinic.
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Affiliation(s)
- Isela C Valera
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - Amanda L Wacker
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - Hyun Seok Hwang
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - Christina Holmes
- Department of Chemical and Biomedical Engineering, Florida A&M University-Florida State University College of Engineering, Tallahassee, FL, USA
| | - Orlando Laitano
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA
| | - Andrew P Landstrom
- Department of Pediatrics, Division of Cardiology, Duke University School of Medicine, Durham, NC, USA; Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA
| | - Michelle S Parvatiyar
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA.
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De Los Santos S, Palma-Flores C, Zentella-Dehesa A, Canto P, Coral-Vázquez RM. (-)-Epicatechin inhibits development of dilated cardiomyopathy in δ sarcoglycan null mouse. Nutr Metab Cardiovasc Dis 2018; 28:1188-1195. [PMID: 30143409 DOI: 10.1016/j.numecd.2018.06.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 06/18/2018] [Accepted: 06/25/2018] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND AIMS Several studies propose that (-)-epicatechin, a flavonol present in high concentration in the cocoa, has cardioprotective effects. This study aimed to evaluate the impact of (-)-epicatechin on the development of dilated cardiomyopathy in a δ sarcoglycan null mouse model. METHODS AND RESULTS δ Sarcoglycan null mice were treated for 15 days with (-)-epicatechin. Histological and morphometric analysis of the hearts treated mutant mice showed significant reduction of the vasoconstrictions in the coronary arteries as well as fewer areas with fibrosis and a reduction in the loss of the ventricular wall. On the contrary, it was observed a thickening of this region. By Western blot analysis, it was shown, and increment in the phosphorylation level of eNOS and PI3K/AKT/mTOR/p70S6K proteins in the heart of the (-)-epicatechin treated animals. On the other hand, we observed a significantly decreased level of the atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) heart failure markers. CONCLUSION All the results indicate that (-)-epicatechin has the potential to prevent the development of dilated cardiomyopathy of genetic origin and encourages the use of this flavonol as a pharmacological therapy for dilated cardiomyopathy and heart failure diseases.
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MESH Headings
- Animals
- Atrial Natriuretic Factor/metabolism
- Cardiomyopathy, Dilated/enzymology
- Cardiomyopathy, Dilated/genetics
- Cardiomyopathy, Dilated/pathology
- Cardiomyopathy, Dilated/prevention & control
- Catechin/pharmacology
- Coronary Vessels/drug effects
- Coronary Vessels/enzymology
- Coronary Vessels/physiopathology
- Disease Models, Animal
- Fibrosis
- Male
- Mice, Knockout
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/pathology
- Natriuretic Peptide, Brain/metabolism
- Nitric Oxide Synthase Type III/metabolism
- Phosphatidylinositol 3-Kinase/metabolism
- Phosphorylation
- Proto-Oncogene Proteins c-akt/metabolism
- Ribosomal Protein S6 Kinases, 70-kDa/metabolism
- Sarcoglycans/deficiency
- Sarcoglycans/genetics
- Signal Transduction/drug effects
- TOR Serine-Threonine Kinases/metabolism
- Vasoconstriction/drug effects
- Ventricular Function, Left/drug effects
- Ventricular Remodeling/drug effects
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Affiliation(s)
- S De Los Santos
- División de Investigación Biomédica, Centro Médico Nacional 20 de Noviembre, Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, Mexico City, Mexico; Unidad de Investigación en Obesidad, División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico; Clínica de Obesidad, Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán", Mexico City, Mexico
| | - C Palma-Flores
- División de Investigación Biomédica, Centro Médico Nacional 20 de Noviembre, Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, Mexico City, Mexico; Catedrático CONACYT, Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico City, México
| | - A Zentella-Dehesa
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico; Unidad de Bioquímica, Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán", Mexico City, Mexico
| | - P Canto
- Unidad de Investigación en Obesidad, División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico; Clínica de Obesidad, Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán", Mexico City, Mexico
| | - R M Coral-Vázquez
- División de Investigación Biomédica, Centro Médico Nacional 20 de Noviembre, Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, Mexico City, Mexico; Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón s/n, Col. Casco de Santo Tomás, Delegación Miguel Hidalgo, Mexico City, 11340, Mexico.
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Different outcome of sarcoglycan missense mutation between human and mouse. PLoS One 2018; 13:e0191274. [PMID: 29360879 PMCID: PMC5779665 DOI: 10.1371/journal.pone.0191274] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 01/02/2018] [Indexed: 01/01/2023] Open
Abstract
Sarcoglycanopathies are rare autosomic limb girdle muscular dystrophies caused by mutations in one of the genes coding for sarcoglycan (α, β, δ, and γ-sarcoglycans). Sarcoglycans form a complex, which is an important part of the dystrophin-associated glycoprotein complex that protects sarcolemma against muscle contraction-induced damages. Absence of one of the sarcoglycan at the plasma membrane induces the disappearance of the whole complex and perturbs muscle fiber membrane integrity. We previously demonstrated that point mutations in the human sarcoglycan genes affects the folding of the corresponding protein, which is then retained in the endoplasmic reticulum by the protein quality control and prematurely degraded by the proteasome. Interestingly, modulation of the quality control using pharmacological compounds allowed the rescue of the membrane localization of the mutated sarcoglycan. Two previously generated mouse models, knock-in for the most common sarcoglycan mutant, R77C α-sarcoglycan, failed in reproducing the dystrophic phenotype observed in human patients. Based on these results and the need to test therapies for these fatal diseases, we decided to generate a new knock-in mouse model carrying the missense mutation T151R in the β-sarcoglycan gene since this is the second sarcoglycan protein with the most frequently reported missense mutations. Muscle analysis, performed at the age of 4 and 9-months, showed the presence of the mutated β-sarcoglycan protein and of the other components of the dystrophin-associated glycoprotein complex at the muscle membrane. In addition, these mice did not develop a dystrophic phenotype, even at a late stage or in condition of stress-inducing exercise. We can speculate that the absence of phenotype in mouse may be due to a higher tolerance of the endoplasmic reticulum quality control for amino-acid changes in mice compared to human.
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Natural disease history of mouse models for limb girdle muscular dystrophy types 2D and 2F. PLoS One 2017; 12:e0182704. [PMID: 28797108 PMCID: PMC5552258 DOI: 10.1371/journal.pone.0182704] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 07/24/2017] [Indexed: 12/22/2022] Open
Abstract
Limb-girdle muscular dystrophy types 2D and 2F (LGMD 2D and 2F) are autosomal recessive disorders caused by mutations in the alpha- and delta sarcoglycan genes, respectively, leading to severe muscle weakness and degeneration. The cause of the disease has been well characterized and a number of animal models are available for pre-clinical studies to test potential therapeutic interventions. To facilitate transition from drug discovery to clinical trials, standardized procedures and natural disease history data were collected for these mouse models. Implementing the TREAD-NMD standardized operating procedures, we here subjected LGMD2D (SGCA-null), LGMD2F (SGCD-null) and wild type (C57BL/6J) mice to five functional tests from the age of 4 to 32 weeks. To assess whether the functional test regime interfered with disease pathology, sedentary groups were taken along. Muscle physiology testing of tibialis anterior muscle was performed at the age of 34 weeks. Muscle histopathology and gene expression was analysed in skeletal muscles and heart. Muscle histopathology and gene expression was analysed in skeletal muscles and heart. Mice successfully accomplished the functional tests, which did not interfere with disease pathology. Muscle function of SGCA- and SGCD-null mice was impaired and declined over time. Interestingly, female SGCD-null mice outperformed males in the two and four limb hanging tests, which proved the most suitable non-invasive tests to assess muscle function. Muscle physiology testing of tibialis anterior muscle revealed lower specific force and higher susceptibility to eccentric-induced damage in LGMD mice. Analyzing muscle histopathology and gene expression, we identified the diaphragm as the most affected muscle in LGMD strains. Cardiac fibrosis was found in SGCD-null mice, being more severe in males than in females. Our study offers a comprehensive natural history dataset which will be useful to design standardized tests and future pre-clinical studies in LGMD2D and 2F mice.
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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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Abstract
Cardiac and skeletal striated muscles are intricately designed machines responsible for muscle contraction. Coordination of the basic contractile unit, the sarcomere, and the complex cytoskeletal networks are critical for contractile activity. The sarcomere is comprised of precisely organized individual filament systems that include thin (actin), thick (myosin), titin, and nebulin. Connecting the sarcomere to other organelles (e.g., mitochondria and nucleus) and serving as the scaffold to maintain cellular integrity are the intermediate filaments. The costamere, on the other hand, tethers the sarcomere to the cell membrane. Unique structures like the intercalated disc in cardiac muscle and the myotendinous junction in skeletal muscle help synchronize and transmit force. Intense investigation has been done on many of the proteins that make up these cytoskeletal assemblies. Yet the details of their function and how they interconnect have just started to be elucidated. A vast number of human myopathies are contributed to mutations in muscle proteins; thus understanding their basic function provides a mechanistic understanding of muscle disorders. In this review, we highlight the components of striated muscle with respect to their interactions, signaling pathways, functions, and connections to disease. © 2017 American Physiological Society. Compr Physiol 7:891-944, 2017.
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Affiliation(s)
- Christine A Henderson
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Christopher G Gomez
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Stefanie M Novak
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Lei Mi-Mi
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
| | - Carol C Gregorio
- Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, Arizona, USA.,Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, USA
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Waite AJ, Carlisle FA, Chan YM, Blake DJ. Myoclonus dystonia and muscular dystrophy: ɛ-sarcoglycan is part of the dystrophin-associated protein complex in brain. Mov Disord 2016; 31:1694-1703. [PMID: 27535350 PMCID: PMC5129563 DOI: 10.1002/mds.26738] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 05/24/2016] [Accepted: 06/27/2016] [Indexed: 11/17/2022] Open
Abstract
Background Myoclonus‐dystonia is a neurogenic movement disorder caused by mutations in the gene encoding ɛ‐sarcoglycan. By contrast, mutations in the α‐, β‐, γ‐, and δ‐sarcoglycan genes cause limb girdle muscular dystrophies. The sarcoglycans are part of the dystrophin‐associated protein complex in muscle that is disrupted in several types of muscular dystrophy. Intriguingly, patients with myoclonus‐dystonia have no muscle pathology; conversely, limb‐girdle muscular dystrophy patients have not been reported to have dystonia‐associated features. To gain further insight into the molecular mechanisms underlying these differences, we searched for evidence of a sarcoglycan complex in the brain. Methods Immunoaffinity chromatography and mass spectrometry were used to purify ubiquitous and brain‐specific ɛ‐sarcoglycan directly from tissue. Cell models were used to determine the effect of mutations on the trafficking and assembly of the brain sarcoglycan complex. Results Ubiquitous and brain‐specific ɛ‐sarcoglycan isoforms copurify with β‐, δ‐, and ζ‐sarcoglycan, β‐dystroglycan, and dystrophin Dp71 from brain. Incorporation of a muscular dystrophy‐associated β‐sarcoglycan mutant into the brain sarcoglycan complex impairs the formation of the βδ‐sarcoglycan core but fails to abrogate the association and membrane trafficking of ɛ‐ and ζ‐sarcoglycan. Conclusions ɛ‐Sarcoglycan is part of the dystrophin‐associated protein complex in brain. Partial preservation of ɛ‐ and ζ‐sarcoglycan in brain may explain the absence of myoclonus dystonia‐like features in muscular dystrophy patients. © 2016 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Adrian J. Waite
- Division of Psychological Medicine and Clinical NeurosciencesMRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff UniversityCardiffUnited Kingdom
| | - Francesca A. Carlisle
- Division of Psychological Medicine and Clinical NeurosciencesMRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff UniversityCardiffUnited Kingdom
| | - Yiumo Michael Chan
- McColl‐Lockwood Laboratory for Muscular Dystrophy ResearchCarolinas Medical CenterCharlotteNorth CarolinaUSA
| | - Derek J. Blake
- Division of Psychological Medicine and Clinical NeurosciencesMRC Centre for Neuropsychiatric Genetics and Genomics, Cardiff UniversityCardiffUnited Kingdom
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Campbell MD, Witcher M, Gopal A, Michele DE. Dilated cardiomyopathy mutations in δ-sarcoglycan exert a dominant-negative effect on cardiac myocyte mechanical stability. Am J Physiol Heart Circ Physiol 2016; 310:H1140-50. [PMID: 26968544 PMCID: PMC4867387 DOI: 10.1152/ajpheart.00521.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 03/07/2016] [Indexed: 01/25/2023]
Abstract
Delta-sarcoglycan is a component of the sarcoglycan subcomplex within the dystrophin-glycoprotein complex located at the plasma membrane of muscle cells. While recessive mutations in δ-sarcoglycan cause limb girdle muscular dystrophy 2F, dominant mutations in δ-sarcoglycan have been linked to inherited dilated cardiomyopathy (DCM). The purpose of this study was to investigate functional cellular defects present in adult cardiac myocytes expressing mutant δ-sarcoglycans harboring the dominant inherited DCM mutations R71T or R97Q. This study demonstrates that DCM mutant δ-sarcoglycans can be stably expressed in adult rat cardiac myocytes and traffic similarly to wild-type δ-sarcoglycan to the plasma membrane, without perturbing assembly of the dystrophin-glycoprotein complex. However, expression of DCM mutant δ-sarcoglycan in adult rat cardiac myocytes is sufficient to alter cardiac myocyte plasma membrane stability in the presence of mechanical strain. Upon cyclical cell stretching, cardiac myocytes expressing mutant δ-sarcoglycan R97Q or R71T have increased cell-impermeant dye uptake and undergo contractures at greater frequencies than myocytes expressing normal δ-sarcoglycan. Additionally, the R71T mutation creates an ectopic N-linked glycosylation site that results in aberrant glycosylation of the extracellular domain of δ-sarcoglycan. Therefore, appropriate glycosylation of δ-sarcoglycan may also be necessary for proper δ-sarcoglycan function and overall dystrophin-glycoprotein complex function. These studies demonstrate that DCM mutations in δ-sarcoglycan can exert a dominant negative effect on dystrophin-glycoprotein complex function leading to myocardial mechanical instability that may underlie the pathogenesis of δ-sarcoglycan-associated DCM.
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Affiliation(s)
- Matthew D Campbell
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan; and
| | - Marc Witcher
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan; and
| | - Anoop Gopal
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan; and
| | - Daniel E Michele
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan; and Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan
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Parvatiyar MS, Marshall JL, Nguyen RT, Jordan MC, Richardson VA, Roos KP, Crosbie-Watson RH. Sarcospan Regulates Cardiac Isoproterenol Response and Prevents Duchenne Muscular Dystrophy-Associated Cardiomyopathy. J Am Heart Assoc 2015; 4:JAHA.115.002481. [PMID: 26702077 PMCID: PMC4845268 DOI: 10.1161/jaha.115.002481] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Background Duchenne muscular dystrophy is a fatal cardiac and skeletal muscle disease resulting from mutations in the dystrophin gene. We have previously demonstrated that a dystrophin‐associated protein, sarcospan (SSPN), ameliorated Duchenne muscular dystrophy skeletal muscle degeneration by activating compensatory pathways that regulate muscle cell adhesion (laminin‐binding) to the extracellular matrix. Conversely, loss of SSPN destabilized skeletal muscle adhesion, hampered muscle regeneration, and reduced force properties. Given the importance of SSPN to skeletal muscle, we investigated the consequences of SSPN ablation in cardiac muscle and determined whether overexpression of SSPN into mdx mice ameliorates cardiac disease symptoms associated with Duchenne muscular dystrophy cardiomyopathy. Methods and Results SSPN‐null mice exhibited cardiac enlargement, exacerbated cardiomyocyte hypertrophy, and increased fibrosis in response to β‐adrenergic challenge (isoproterenol; 0.8 mg/day per 2 weeks). Biochemical analysis of SSPN‐null cardiac muscle revealed reduced sarcolemma localization of many proteins with a known role in cardiomyopathy pathogenesis: dystrophin, the sarcoglycans (α‐, δ‐, and γ‐subunits), and β1D integrin. Transgenic overexpression of SSPN in Duchenne muscular dystrophy mice (mdxTG) improved cardiomyofiber cell adhesion, sarcolemma integrity, cardiac functional parameters, as well as increased expression of compensatory transmembrane proteins that mediate attachment to the extracellular matrix. Conclusions SSPN regulates sarcolemmal expression of laminin‐binding complexes that are critical to cardiac muscle function and protects against transient and chronic injury, including inherited cardiomyopathy.
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Affiliation(s)
- Michelle S Parvatiyar
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA (M.S.P., J.L.M., R.T.N., V.A.R., R.H.C.W.) Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA (M.S.P., J.L.M., M.C.J., V.A.R., K.P.R., R.H.C.W.)
| | - Jamie L Marshall
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA (M.S.P., J.L.M., R.T.N., V.A.R., R.H.C.W.) Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA (M.S.P., J.L.M., M.C.J., V.A.R., K.P.R., R.H.C.W.)
| | - Reginald T Nguyen
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA (M.S.P., J.L.M., R.T.N., V.A.R., R.H.C.W.)
| | - Maria C Jordan
- Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA (M.S.P., J.L.M., M.C.J., V.A.R., K.P.R., R.H.C.W.) Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA (M.C.J., K.P.R.)
| | - Vanitra A Richardson
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA (M.S.P., J.L.M., R.T.N., V.A.R., R.H.C.W.) Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA (M.S.P., J.L.M., M.C.J., V.A.R., K.P.R., R.H.C.W.)
| | - Kenneth P Roos
- Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA (M.S.P., J.L.M., M.C.J., V.A.R., K.P.R., R.H.C.W.) Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, CA (M.C.J., K.P.R.)
| | - Rachelle H Crosbie-Watson
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA (M.S.P., J.L.M., R.T.N., V.A.R., R.H.C.W.) Center for Duchenne Muscular Dystrophy, University of California, Los Angeles, CA (M.S.P., J.L.M., M.C.J., V.A.R., K.P.R., R.H.C.W.) Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA (R.H.C.W.)
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Dystrophin deficiency reduces atherosclerotic plaque development in ApoE-null mice. Sci Rep 2015; 5:13904. [PMID: 26345322 PMCID: PMC4561962 DOI: 10.1038/srep13904] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 08/10/2015] [Indexed: 11/30/2022] Open
Abstract
Dystrophin of the dystrophin-glycoprotein complex connects the actin cytoskeleton to basement membranes and loss of dystrophin results in Duchenne muscular dystrophy. We have previously shown injury-induced neointima formation of the carotid artery in mice with the mdx mutation (causing dystrophin deficiency) to be increased. To investigate the role of dystrophin in intimal recruitment of smooth muscle cells (SMCs) that maintains plaque stability in atherosclerosis we applied a shear stress-modifying cast around the carotid artery of apolipoprotein E (ApoE)-null mice with and without the mdx mutation. The cast induces formation of atherosclerotic plaques of inflammatory and SMC-rich/fibrous phenotypes in regions of low and oscillatory shear stress, respectively. Unexpectedly, presence of the mdx mutation markedly reduced the development of the inflammatory low shear stress plaques. Further characterization of the low shear stress plaques in ApoE-null mdx mice demonstrated reduced infiltration of CD3+ T cells, less laminin and a higher SMC content. ApoE-null mdx mice were also found to have a reduced fraction of CD3+ T cells in the spleen and lower levels of cytokines and monocytes in the circulation. The present study is the first to demonstrate a role for dystrophin in atherosclerosis and unexpectedly shows that this primarily involves immune cells.
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15
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Sharma P, Jha A, Stelmack GL, Detillieux K, Basu S, Klonisch T, Unruh H, Halayko AJ. Characterization of the dystrophin-glycoprotein complex in airway smooth muscle: role of δ-sarcoglycan in airway responsiveness. Can J Physiol Pharmacol 2015; 93:195-202. [PMID: 25692961 DOI: 10.1139/cjpp-2014-0389] [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] [Indexed: 11/22/2022]
Abstract
The dystrophin-glycoprotein complex (DGC) is an integral part of caveolae microdomains, and its interaction with caveolin-1 is essential for the phenotype and functional properties of airway smooth muscle (ASM). The sarcoglycan complex provides stability to the dystroglycan complex, but its role in ASM contraction and lung physiology in not understood. We tested whether δ-sarcoglycan (δ-SG), through its interaction with the DGC, is a determinant of ASM contraction ex vivo and airway mechanics in vivo. We measured methacholine (MCh)-induced isometric contraction and airway mechanics in δ-SG KO and wild-type mice. Last, we performed immunoblotting and transmission electron microscopy to assess DGC protein expression and the ultrastructural features of tracheal smooth muscle. Our results reveal an age-dependent reduction in the MCh-induced tracheal isometric force and significant reduction in airway resistance at high concentrations of MCh (50.0 mg/mL) in δ-SG KO mice. The changes in contraction and lung function correlated with decreased caveolin-1 and β-dystroglycan abundance, as well as an age-dependent loss of caveolae in the cell membrane of tracheal smooth muscle in δ-SG KO mice. Collectively, these results confirm and extend understanding of a functional role for the DGC in the contractile properties of ASM and demonstrate that this results in altered lung function in vivo.
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Affiliation(s)
- Pawan Sharma
- Departments of Physiology and Pathophysiology, University of Manitoba, John Buhler Research Centre, 715 McDermot Avenue, Winnipeg, MB R3E 3P4, Canada., Biology of Breathing Group, Manitoba Institute of Child Health, Winnipeg, Manitoba, Canada
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16
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Townsend D. Finding the sweet spot: assembly and glycosylation of the dystrophin-associated glycoprotein complex. Anat Rec (Hoboken) 2014; 297:1694-705. [PMID: 25125182 PMCID: PMC4135523 DOI: 10.1002/ar.22974] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 03/27/2014] [Indexed: 01/12/2023]
Abstract
The dystrophin-associated glycoprotein complex (DGC) is a collection of glycoproteins that are essential for the normal function of striated muscle and many other tissues. Recent genetic studies have implicated the components of this complex in over a dozen forms of muscular dystrophy. Furthermore, disruption of the DGC has been implicated in many forms of acquired disease. This review aims to summarize the current state of knowledge regarding the processing and assembly of dystrophin-associated proteins with a focus primarily on the dystroglycan heterodimer and the sarcoglycan complex. These proteins form the transmembrane portion of the DGC and undergo a complex multi-step processing with proteolytic cleavage, differential assembly, and both N- and O-glycosylation. The enzymes responsible for this processing and a model describing the sequence and subcellular localization of these events are discussed.
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Affiliation(s)
- Dewayne Townsend
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, Minnesota
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17
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Roque-Ramírez B, Chimal-Monroy J, Canto P, Coral-Vázquez RM. Expression pattern of mRNA A and mRNA B of alpha sarcoglycan gene during mouse embryonic development and regulation of their expression by myogenic and cardiogenic transcription factors. Dev Dyn 2014; 243:1416-28. [PMID: 25091331 DOI: 10.1002/dvdy.24175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 06/26/2014] [Accepted: 07/17/2014] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Type 2D limb-girdle muscular dystrophy (LGM2D) is a progressive disorder caused by mutations in the alpha sarcoglycan (α-SG) gene. In mice, the α-SG gene contains two promoters that regulate the expression of two different mRNAs (A and B). However, their gene expression pattern during embryonic development has not been explored and their regulation by myogenic and cardiogenic transcription factors has been only partially studied. RESULTS During embryonic development, mRNA A and B of α-SG gene were initially detected in hypaxial muscles, heart, stomach, tongue, and mesenchymal cells, which surround the dorsal region of the somites. Moreover, mRNA B was exclusively expressed in the floor plate and notochord and in the interdigits of limbs. In vitro, MyoD and myogenin positively regulated the transcription of mRNA B during skeletal myogenesis, whereas mRNA A was activated only for MyoD in differentiated skeletal muscle. In addition, Gata-4 together with Mef2c may regulate the expression of mRNA B in heart development, whereas Nkx2.5 and myocardin may activate expression of mRNA A in the differentiated cardiomyocyte. CONCLUSIONS The differential expression of α-SG mRNAs during mouse embryonic development may be a consequence of the differential regulation of both promoters by myogenic and cardiogenic factors.
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Affiliation(s)
- Bladimir Roque-Ramírez
- División de Investigación Biomédica, Subdirección de Enseñanza e Investigación, Centro Médico Nacional 20 de Noviembre, Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, México, D.F. México
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18
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Palma-Flores C, Ramírez-Sánchez I, Rosas-Vargas H, Canto P, Coral-Vázquez RM. Description of a utrophin associated protein complex in lipid raft domains of human artery smooth muscle cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:1047-54. [PMID: 24060563 DOI: 10.1016/j.bbamem.2013.09.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 09/06/2013] [Accepted: 09/12/2013] [Indexed: 01/08/2023]
Abstract
The dystrophin-associated protein complex (DAPC) is a multimeric complex that links the extracellular matrix to the actin cytoskeleton, and in some cases dystrophin can be substituted by its autosomal homologue utrophin to form the utrophin-associated protein complex (UAPC). Both complexes maintain the stability of plasma membrane during contraction process and play an important role in transmembrane signaling. Mutations in members of the DAPC are associated with muscular dystrophy and dilated cardiomyopathy. In a previous study with human umbilical cord vessels, we observed that utrophin colocalize with caveolin-1 (Cav-1) which proposed the presence of UAPC in the plasma membrane of vascular smooth muscle (VSM). In the current study, we demonstrated by immunofluorescence analysis, co-immunoprecipitation assays, and subcellular fractionation by sucrose gradients, the existence of an UAPC in lipid raft domains of human umbilical artery smooth muscle cells (HUASMC). This complex is constituted by utrophin, β-DG, ε-SG, α-smooth muscle actin, Cav-1, endothelial nitric oxide synthase (eNOS) and cavin-1. It was also observed the presence of dystrophin, utrophin Dp71, β-SG, δ-SG, δ-SG3 and sarcospan in non-lipid raft fractions. Furthermore, the knockdown of α/β-DG was associated with the decrease in both the synthesis of nitric oxide (NO) and the presence of the phosphorylated (active) form of eNOS; and with a reduction in the downstream activation of some cGMP signaling transduction pathway components. Together these results show the presence of an UAPC complex in HUASMC that may participate in the activity regulation of eNOS and in the vascular function.
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Affiliation(s)
- Carlos Palma-Flores
- División de Investigación Biomédica, Subdirección de Enseñanza e Investigación, Centro Médico Nacional 20 de Noviembre, Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, México, D.F., Mexico
| | - Israel Ramírez-Sánchez
- Sección de Posgrado, Escuela Superior de Medicina, Instituto Politécnico Nacional, México, D.F., Mexico
| | - Haydeé Rosas-Vargas
- Unidad de Investigación Médica en Genética Humana, Hospital de Pediatría, Centro Medico Nacional Siglo XXI-IMSS, Av. Cuauhtémoc No 330, Col Doctores, Delegación Cuauhtémoc, 06725 México, D.F., Mexico
| | - Patricia Canto
- División de Investigación Biomédica, Subdirección de Enseñanza e Investigación, Centro Médico Nacional 20 de Noviembre, Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, México, D.F., Mexico
| | - Ramón Mauricio Coral-Vázquez
- Sección de Posgrado, Escuela Superior de Medicina, Instituto Politécnico Nacional, México, D.F., Mexico; Subdirección de Enseñanza e Investigación, Centro Médico Nacional 20 de Noviembre, Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, México, D.F., Mexico.
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19
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Marshall JL, Crosbie-Watson RH. Sarcospan: a small protein with large potential for Duchenne muscular dystrophy. Skelet Muscle 2013; 3:1. [PMID: 23282144 PMCID: PMC3599653 DOI: 10.1186/2044-5040-3-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Accepted: 11/27/2012] [Indexed: 01/09/2023] Open
Abstract
Purification of the proteins associated with dystrophin, the gene product responsible for Duchenne muscular dystrophy, led to the discovery of the dystrophin-glycoprotein complex. Sarcospan, a 25-kDa transmembrane protein, was the last component to be identified and its function in skeletal muscle has been elusive. This review will focus on progress over the last decade revealing that sarcospan is an important regulator of muscle cell adhesion, strength, and regeneration. Investigations using several transgenic mouse models demonstrate that overexpression of sarcospan in the mouse model for Duchenne muscular dystrophy ameliorates pathology and restores muscle cell binding to laminin. Sarcospan improves cell surface expression of the dystrophin- and utrophin-glycoprotein complexes as well as α7β1 integrin, which are the three major laminin-binding complexes in muscle. Utrophin and α7β1 integrin compensate for the loss of dystrophin and the finding that sarcospan increases their abundance at the extra-synaptic sarcolemma supports the use of sarcospan as a therapeutic target. Newly discovered phenotypes in sarcospan-deficient mice, including a reduction in specific force output and increased drop in force in the diaphragm muscle, result from decreased utrophin and dystrophin expression and further reveal sarcospan’s role in determining abundance of these complexes. Dystrophin protein levels and the specific force output of the diaphragm muscle are further reduced upon genetic removal of α7 integrin (Itga7) in SSPN-deficient mice, demonstrating that interactions between integrin and sarcospan are critical for maintenance of the dystrophin-glycoprotein complex and force production of the diaphragm muscle. Sarcospan is a major regulator of Akt signaling pathways and sarcospan-deficiency significantly impairs muscle regeneration, a process that is dependent on Akt activation. Intriguingly, sarcospan regulates glycosylation of a specific subpopulation of α-dystroglycan, the laminin-binding receptor associated with dystrophin and utrophin, localized to the neuromuscular junction. Understanding the basic mechanisms responsible for assembly and trafficking of the dystrophin- and utrophin-glycoprotein complexes to the cell surface is lacking and recent studies suggest that sarcospan plays a role in these essential processes.
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Affiliation(s)
- Jamie L Marshall
- Department of Integrative Biology and Physiology, University of California Los Angeles, 610 Charles E, Young Drive East, Terasaki Life Sciences Building, Los Angeles, CA, 90095, USA.
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20
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Lehman W, Morgan KG. Structure and dynamics of the actin-based smooth muscle contractile and cytoskeletal apparatus. J Muscle Res Cell Motil 2012; 33:461-9. [PMID: 22311558 DOI: 10.1007/s10974-012-9283-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 01/16/2012] [Indexed: 01/04/2023]
Abstract
The thin filaments of differentiated smooth muscle cells are composed of actin and tropomyosin isoforms and numerous ancillary actin-binding proteins that assemble together into distinct thin filament classes. These different filament classes are segregated in smooth muscle cells into structurally and functionally separated contractile and cytoskeletal cellular domains. Typically, thin filaments in smooth muscle cells have been considered to be relatively stable structures like those in striated cells. However, recent efforts have shown that smooth muscle thin filaments indeed are dynamic and that remodeling of the actin cytoskeleton, in particular, regulates smooth muscle function. Thus, the cytoskeleton of differentiated smooth muscle cells appears to function midway between that of less dynamic striated muscle cells and that of very plastic proliferative cells such as fibroblasts. Michael and Kate Bárány keenly followed and participated in some of these studies, consistent with their broad interest in actin function and smooth muscle mechanisms. As a way of honoring the memory of these two pioneer members of the muscle research community, we review data on distribution and remodeling of thin filaments in smooth muscle cells, one of the many research topics that intrigued them.
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Affiliation(s)
- William Lehman
- Department of Physiology and Biophysics, Boston University School of Medicine, 72 East Concord Street, Boston, MA 02118, USA.
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21
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Abstract
The extracellular matrix (ECM) provides a solid scaffold and signals to cells through ECM receptors. The cell-matrix interactions are crucial for normal biological processes and when disrupted they may lead to pathological processes. In particular, the biological importance of ECM-cell membrane-cytoskeleton interactions in skeletal muscle is accentuated by the number of inherited muscle diseases caused by mutations in proteins conferring these interactions. In this review we introduce laminins, collagens, dystroglycan, integrins, dystrophin and sarcoglycans. Mutations in corresponding genes cause various forms of muscular dystrophy. The muscle disorders are presented as well as advances toward the development of treatment.
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Affiliation(s)
- Virginie Carmignac
- Muscle Biology Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
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22
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Rauch U, Shami A, Zhang F, Carmignac V, Durbeej M, Hultgårdh-Nilsson A. Increased neointimal thickening in dystrophin-deficient mdx mice. PLoS One 2012; 7:e29904. [PMID: 22238670 PMCID: PMC3251593 DOI: 10.1371/journal.pone.0029904] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Accepted: 12/08/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The dystrophin gene, which is mutated in Duchenne muscular dystrophy (DMD), encodes a large cytoskeletal protein present in muscle fibers. While dystrophin in skeletal muscle has been extensively studied, the function of dystrophin in vascular smooth muscle is less clear. Here, we have analyzed the role of dystrophin in injury-induced arterial neointima formation. METHODOLOGY/PRINCIPAL FINDINGS We detected a down-regulation of dystrophin, dystroglycan and β-sarcoglycan mRNA expression when vascular smooth muscle cells de-differentiate in vitro. To further mimic development of intimal lesions, we performed a collar-induced injury of the carotid artery in the mdx mouse, a model for DMD. As compared with control mice, mdx mice develop larger lesions with increased numbers of proliferating cells. In vitro experiments demonstrate increased migration of vascular smooth muscle cells from mdx mice whereas the rate of proliferation was similar in cells isolated from wild-type and mdx mice. CONCLUSIONS/SIGNIFICANCE These results show that dystrophin deficiency stimulates neointima formation and suggest that expression of dystrophin in vascular smooth muscle cells may protect the artery wall against injury-induced intimal thickening.
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MESH Headings
- Animals
- Cell Proliferation
- Cells, Cultured
- Dystrophin/deficiency
- Dystrophin/genetics
- Dystrophin/metabolism
- Dystrophin/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Inbred mdx
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Muscular Dystrophy, Animal/complications
- Muscular Dystrophy, Animal/genetics
- Muscular Dystrophy, Animal/metabolism
- Muscular Dystrophy, Animal/pathology
- Muscular Dystrophy, Duchenne/complications
- Muscular Dystrophy, Duchenne/genetics
- Muscular Dystrophy, Duchenne/metabolism
- Muscular Dystrophy, Duchenne/pathology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/pathology
- Neointima/genetics
- Neointima/metabolism
- Neointima/pathology
- Organ Size
- Up-Regulation
- Vascular System Injuries/genetics
- Vascular System Injuries/metabolism
- Vascular System Injuries/pathology
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Affiliation(s)
- Uwe Rauch
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Annelie Shami
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Feng Zhang
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Virginie Carmignac
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Madeleine Durbeej
- Department of Experimental Medical Science, Lund University, Lund, Sweden
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Arco A, Favaloro A, Gioffrè M, Santoro G, Speciale F, Vermiglio G, Cutroneo G. Sarcoglycans in the Normal and Pathological Breast Tissue of Humans: An Immunohistochemical and Molecular Study. Cells Tissues Organs 2012; 195:550-62. [DOI: 10.1159/000329508] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/18/2011] [Indexed: 11/19/2022] Open
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Lancioni A, Rotundo IL, Kobayashi YM, D'Orsi L, Aurino S, Nigro G, Piluso G, Acampora D, Cacciottolo M, Campbell KP, Nigro V. Combined deficiency of alpha and epsilon sarcoglycan disrupts the cardiac dystrophin complex. Hum Mol Genet 2011; 20:4644-54. [PMID: 21890494 PMCID: PMC3209833 DOI: 10.1093/hmg/ddr398] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cardiomyopathy is a puzzling complication in addition to skeletal muscle pathology for patients with mutations in β-, γ- or δ-sarcoglycan (SG) genes. Patients with mutations in α-SG rarely have associated cardiomyopathy, or their cardiac pathology is very mild. We hypothesize that a fifth SG, ε-SG, may compensate for α-SG deficiency in the heart. To investigate the function of ε-SG in striated muscle, we generated an Sgce-null mouse and a Sgca-;Sgce-null mouse, which lacks both α- and ε-SGs. While Sgce-null mice showed a wild-type phenotype, with no signs of muscular dystrophy or heart disease, the Sgca-;Sgce-null mouse developed a progressive muscular dystrophy and a more anticipated and severe cardiomyopathy. It shows a complete loss of residual SGs and a strong reduction in both dystrophin and dystroglycan. Our data indicate that ε-SG is important in preventing cardiomyopathy in α-SG deficiency.
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Affiliation(s)
- Alessio Lancioni
- Telethon Institute of Genetics and Medicine, Via Pietro Castellino 111, Napoli 80131, Italy
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25
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Blain AM, Straub VW. δ-Sarcoglycan-deficient muscular dystrophy: from discovery to therapeutic approaches. Skelet Muscle 2011; 1:13. [PMID: 21798091 PMCID: PMC3156636 DOI: 10.1186/2044-5040-1-13] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 03/17/2011] [Indexed: 11/10/2022] Open
Abstract
Mutations in the δ-sarcoglycan gene cause limb-girdle muscular dystrophy 2F (LGMD2F), an autosomal recessive disease that causes progressive weakness and wasting of the proximal limb muscles and often has cardiac involvement. Here we review the clinical implications of LGMD2F and discuss the current understanding of the putative mechanisms underlying its pathogenesis. Preclinical research has benefited enormously from various animal models of δ-sarcoglycan deficiency, which have helped researchers to explore therapeutic approaches for both muscular dystrophy and cardiomyopathy.
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Affiliation(s)
- Alison M Blain
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne, NE1 3BZ, UK
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26
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Sharma P, Ghavami S, Stelmack GL, McNeill KD, Mutawe MM, Klonisch T, Unruh H, Halayko AJ. beta-Dystroglycan binds caveolin-1 in smooth muscle: a functional role in caveolae distribution and Ca2+ release. J Cell Sci 2010; 123:3061-70. [PMID: 20736308 DOI: 10.1242/jcs.066712] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The dystrophin-glycoprotein complex (DGC) links the extracellular matrix and actin cytoskeleton. Caveolae form membrane arrays on smooth muscle cells; we investigated the mechanism for this organization. Caveolin-1 and beta-dystroglycan, the core transmembrane DGC subunit, colocalize in airway smooth muscle. Immunoprecipitation revealed the association of caveolin-1 with beta-dystroglycan. Disruption of actin filaments disordered caveolae arrays, reduced association of beta-dystroglycan and caveolin-1 to lipid rafts, and suppressed the sensitivity and responsiveness of methacholine-induced intracellular Ca2+ release. We generated novel human airway smooth muscle cell lines expressing shRNA to stably silence beta-dystroglycan expression. In these myocytes, caveolae arrays were disorganized, caveolae structural proteins caveolin-1 and PTRF/cavin were displaced, the signaling proteins PLCbeta1 and G(alphaq), which are required for receptor-mediated Ca2+ release, were absent from caveolae, and the sensitivity and responsiveness of methacholine-induced intracellular Ca2+ release, was diminished. These data reveal an interaction between caveolin-1 and beta-dystroglycan and demonstrate that this association, in concert with anchorage to the actin cytoskeleton, underpins the spatial organization and functional role of caveolae in receptor-mediated Ca2+ release, which is an essential initiator step in smooth muscle contraction.
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Affiliation(s)
- Pawan Sharma
- Department of Physiology, University of Manitoba, Winnipeg, MB R3A1R8, Canada
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Solares-Pérez A, Alvarez R, Crosbie RH, Vega-Moreno J, Medina-Monares J, Estrada FJ, Ortega A, Coral-Vazquez R. Altered calcium pump and secondary deficiency of gamma-sarcoglycan and microspan in sarcoplasmic reticulum membranes isolated from delta-sarcoglycan knockout mice. Cell Calcium 2010; 48:28-36. [PMID: 20638123 DOI: 10.1016/j.ceca.2010.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Revised: 06/17/2010] [Accepted: 06/21/2010] [Indexed: 11/25/2022]
Abstract
Sarcoglycans (SGs) and sarcospan (SSPN) are transmembrane proteins of the dystrophin-glycoprotein complex. Mutations in the genes encoding SGs cause many inherited forms of muscular dystrophy. In this study, using purified membranes of wild-type (WT) and delta-SG knockout (KO) mice, we found the specific localization of the SG-SSPN isoforms in transverse tubules (TT) and sarcoplasmic reticulum (SR) membranes. Immunoblotting revealed that the absence of delta-SG isoforms in TT and SR results in a secondary deficiency of gamma-SG and microSPN. Our results showed augmented ATP hydrolytic activity, ATP-dependent calcium uptake and passive calcium efflux, probably through SERCA1 in KO compared to WT mice. Furthermore, we found a conformational change in SERCA1 isolated from KO muscle as demonstrated by calorimetric analysis. Following these alterations with mechanical properties, we found an increase in force in KO muscle with the same rate of fatigue but with a decreased fatigue recovery compared to WT. Together our observations suggest, for the first time, that the delta-SG isoforms may stabilize the expression of gamma-SG and microSPN in the TT and SR membranes and that this possible complex may play a role in the maintenance of a stable level of resting cytosolic calcium concentration in skeletal muscle.
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Affiliation(s)
- Alhondra Solares-Pérez
- Sección de Posgrado, Escuela Superior de Medicina, Instituto Politécnico Nacional, México, DF., México
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Michele DE, Kabaeva Z, Davis SL, Weiss RM, Campbell KP. Dystroglycan matrix receptor function in cardiac myocytes is important for limiting activity-induced myocardial damage. Circ Res 2009; 105:984-93. [PMID: 19797173 DOI: 10.1161/circresaha.109.199489] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Genetic mutations in a number of putative glycosyltransferases lead to the loss of glycosylation of dystroglycan and loss of its laminin-binding activity in genetic forms of human muscular dystrophy. Human patients and glycosylation defective myd mice develop cardiomyopathy with loss of dystroglycan matrix receptor function in both striated and smooth muscle. OBJECTIVE To determine the functional role of dystroglycan in cardiac muscle and smooth muscle in the development of cardiomyopathy in muscular dystrophies. METHODS AND RESULTS Using cre/lox-mediated gene targeting, we show here that loss of dystroglycan function in ventricular cardiac myocytes is sufficient to induce a progressive cardiomyopathy in mice characterized by focal cardiac fibrosis, increase in cardiac mass, and dilatation ultimately leading to heart failure. In contrast, disruption of dystroglycan in smooth muscle is not sufficient to induce cardiomyopathy. The specific loss of dystroglycan function in cardiac myocytes causes the accumulation of large, clustered patches of myocytes with membrane damage, which increase in number in response to exercise-induced cardiac stress, whereas exercised mice with normal dystroglycan expression accumulate membrane damage limited to individual myocytes. CONCLUSIONS Our findings suggest dystroglycan function as an extracellular matrix receptor in cardiac myocytes plays a primary role in limiting myocardial damage from spreading to neighboring cardiac myocytes, and loss of dystroglycan matrix receptor function in cardiac muscle cells is likely important in the development of cardiomyopathy in glycosylation-deficient muscular dystrophies.
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Affiliation(s)
- Daniel E Michele
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109-0622, USA.
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29
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Hernández-Hernández JM, Delgado-Olguín P, Aguillón-Huerta V, Furlan-Magaril M, Recillas-Targa F, Coral-Vázquez RM. Sox9 represses alpha-sarcoglycan gene expression in early myogenic differentiation. J Mol Biol 2009; 394:1-14. [PMID: 19729026 DOI: 10.1016/j.jmb.2009.08.057] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2009] [Revised: 07/14/2009] [Accepted: 08/25/2009] [Indexed: 12/28/2022]
Abstract
Alpha sarcoglycan (alpha-SG) is highly expressed in differentiated striated muscle, and its disruption causes limb-girdle muscular dystrophy. Accordingly, the myogenic master regulator MyoD finely modulates its expression. However, the mechanisms preventing alpha-SG gene expression at early stages of myogenic differentiation remain unknown. In this study, we uncovered Sox9, which was not previously known to directly bind muscle gene promoters, as a negative regulator of alpha-SG gene expression. Reporter gene and chromatin immunoprecipitation assays revealed three functional Sox-binding sites that mediate alpha-SG promoter activity repression during early myogenic differentiation. In addition, we show that Sox9-mediated inhibition of alpha-SG gene expression is independent of MyoD. Moreover, we provide evidence suggesting that Smad3 enhances the repressive activity of Sox9 over alpha-SG gene expression in a transforming growth factor-beta-dependent manner. On the basis of these results, we propose that Sox9 and Smad3 are responsible for preventing precocious activation of alpha-SG gene expression during myogenic differentiation.
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Affiliation(s)
- J Manuel Hernández-Hernández
- Unidad de Investigación Médica en Genética Humana, Hospital de Pediatría, Centro Médico Nacional Siglo XXI-IMSS, México, D.F., México
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30
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Kinugawa K, Vidailhet M, Clot F, Apartis E, Grabli D, Roze E. Myoclonus-dystonia: an update. Mov Disord 2009; 24:479-89. [PMID: 19117361 DOI: 10.1002/mds.22425] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Our knowledge of the clinical, neurophysiological, and genetic aspects of myoclonus-dystonia (M-D) has improved markedly in the recent years. Basic research has provided new insights into the complex dysfunctions involved in the pathogenesis of M-D. On the basis of a comprehensive literature search, this review summarizes current knowledge on M-D, with a focus on recent findings. We also propose modified diagnostic criteria and recommendations for clinical management.
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31
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32
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Xu R, DeVries S, Camboni M, Martin PT. Overexpression of Galgt2 reduces dystrophic pathology in the skeletal muscles of alpha sarcoglycan-deficient mice. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 175:235-47. [PMID: 19498002 DOI: 10.2353/ajpath.2009.080967] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Recent studies have shown that a number of genes that are not mutated in various forms of muscular dystrophy may serve as surrogates to protect skeletal myofibers from injury. One such gene is Galgt2, which is also called cytotoxic T cell GalNAc transferase in mice. In this study, we show that Galgt2 overexpression reduces the development of dystrophic pathology in the skeletal muscles of mice lacking alpha sarcoglycan (Sgca), a mouse model for limb girdle muscular dystrophy 2D. Galgt2 transgenic Sgca(-/-) mice showed reduced levels of myofiber damage, as evidenced by i) normal levels of serum creatine kinase activity, ii) a lack of Evans blue dye uptake into myofibers, iii) normal levels of mouse locomotor activity, and iv) near normal percentages of myofibers with centrally located nuclei. In addition, the overexpression of Galgt2 in the early postnatal period using an adeno-associated virus gene therapy vector protected Sgca(-/-) myofibers from damage, as observed using histopathology measurements. Galgt2 transgenic Sgca(-/-) mice also had increased levels of glycosylation of alpha dystroglycan with the CT carbohydrate, but showed no up-regulation of beta, gamma, delta, or epsilon sarcoglycan. These data, coupled with results from our previous studies, show that Galgt2 has therapeutic effects in three distinct forms of muscular dystrophy and may, therefore, have a broad spectrum of therapeutic potential for the treatment of various myopathies.
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Affiliation(s)
- Rui Xu
- the Departments of Pediatrics, Center for Gene Therapy, Physiology and Cell Biology, Ohio State University College of Medicine, Columbus, Ohio 43205, USA
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33
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McNally EM, Pytel P. Muscle diseases: the muscular dystrophies. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2008; 2:87-109. [PMID: 18039094 DOI: 10.1146/annurev.pathol.2.010506.091936] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dystrophic muscle disease can occur at any age. Early- or childhood-onset muscular dystrophies may be associated with profound loss of muscle function, affecting ambulation, posture, and cardiac and respiratory function. Late-onset muscular dystrophies or myopathies may be mild and associated with slight weakness and an inability to increase muscle mass. The phenotype of muscular dystrophy is an endpoint that arises from a diverse set of genetic pathways. Genes associated with muscular dystrophies encode proteins of the plasma membrane and extracellular matrix, and the sarcomere and Z band, as well as nuclear membrane components. Because muscle has such distinctive structural and regenerative properties, many of the genes implicated in these disorders target pathways unique to muscle or more highly expressed in muscle. This chapter reviews the basic structural properties of muscle and genetic mechanisms that lead to myopathy and muscular dystrophies that affect all age groups.
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Affiliation(s)
- Elizabeth M McNally
- Department of Medicine, Section of Cardiology, University of Chicago, Chicago, Illinois 60637, USA.
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34
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Arena S, Favaloro A, Cutroneo G, Consolo A, Arena F, Anastasi G, Di Benedetto V. Sarcoglycan Subcomplex Expression in Refluxing Ureteral Endings. J Urol 2008; 179:1980-6; discussion 1986. [DOI: 10.1016/j.juro.2008.01.059] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Indexed: 10/22/2022]
Affiliation(s)
- Salvatore Arena
- Department of Pediatric Surgery, Unit of Pediatric Surgery, University of Catania, Catania, Italy
| | - Angelo Favaloro
- Departments of Biomorphology and Biotechnologies, University of Messina, Messina, Italy
| | - Giuseppina Cutroneo
- Departments of Biomorphology and Biotechnologies, University of Messina, Messina, Italy
| | - Angela Consolo
- Departments of Biomorphology and Biotechnologies, University of Messina, Messina, Italy
| | - Francesco Arena
- Departments of Medical and Surgical Pediatric Sciences, Unit of Pediatric Surgery, University of Messina, Messina, Italy
| | - Giuseppe Anastasi
- Departments of Biomorphology and Biotechnologies, University of Messina, Messina, Italy
| | - Vincenzo Di Benedetto
- Department of Pediatric Surgery, Unit of Pediatric Surgery, University of Catania, Catania, Italy
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35
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Zhou D, Wang J, Zapala MA, Xue J, Schork NJ, Haddad GG. Gene expression in mouse brain following chronic hypoxia: role of sarcospan in glial cell death. Physiol Genomics 2007; 32:370-9. [PMID: 18056785 DOI: 10.1152/physiolgenomics.00147.2007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hypoxia is a hallmark of respiratory, neurological, or hematological diseases as well as life at high altitude. For example, chronic constant hypoxia (CCH) occurs in chronic lung diseases or at high altitude, whereas chronic intermittent hypoxia (CIH) occurs in diseases such as sleep apnea or sickle cell disease. Despite the fact that such conditions are frequent, the cellular and molecular mechanisms underlying the effect of hypoxia, whether constant or intermittent, are not well understood. In this study, we first determined the effect of CCH and CIH on global gene expression in different regions of mouse brain using microarrays and then investigated the biological role of genes of interest. We found that: 1) in the cortical region, the expression level of 80 genes was significantly altered by CIH (16 up- and 64 downregulated), and this number increased to 137 genes following CCH (34 up- and 103 downregulated); 2) a similar number of gene alterations was identified in the hippocampal area, and the majority of the changes in this region were upregulations; 3) two genes (Sspn and Ttc27) were downregulated in both brain regions and following both treatments; and 4) RNA interference-mediated knockdown of Sspn increased cell death in hypoxia in a cell culture system. We conclude that CIH or CCH induced significant and distinguishable alterations in gene expression in cortex and hippocampus and that Sspn seems to play a critical role in inducing cell death under hypoxic conditions.
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Affiliation(s)
- Dan Zhou
- Department of Pediatrics (Section of Respiratory Medicine) and Neuroscience, University of California San Diego, La Jolla, CA 92093-0735, USA
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36
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Sharma P, Tran T, Stelmack GL, McNeill K, Gosens R, Mutawe MM, Unruh H, Gerthoffer WT, Halayko AJ. Expression of the dystrophin-glycoprotein complex is a marker for human airway smooth muscle phenotype maturation. Am J Physiol Lung Cell Mol Physiol 2007; 294:L57-68. [PMID: 17993586 DOI: 10.1152/ajplung.00378.2007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Airway smooth muscle (ASM) cells may contribute to asthma pathogenesis through their capacity to switch between a synthetic/proliferative and a contractile phenotype. The multimeric dystrophin-glycoprotein complex (DGC) spans the sarcolemma, linking the actin cytoskeleton and extracellular matrix. The DGC is expressed in smooth muscle tissue, but its functional role is not fully established. We tested whether contractile phenotype maturation of human ASM is associated with accumulation of DGC proteins. We compared subconfluent, serum-fed cultures and confluent cultures subjected to serum deprivation, which express a contractile phenotype. Western blotting confirmed that beta-dystroglycan, beta-, delta-, and epsilon-sarcoglycan, and dystrophin abundance increased six- to eightfold in association with smooth muscle myosin heavy chain (smMHC) and calponin accumulation during 4-day serum deprivation. Immunocytochemistry showed that the accumulation of DGC subunits was specifically localized to a subset of cells that exhibit robust staining for smMHC. Laminin competing peptide (YIGSR, 1 microM) and phosphatidylinositol 3-kinase (PI3K) inhibitors (20 microM LY-294002 or 100 nM wortmannin) abrogated the accumulation of smMHC, calponin, and DGC proteins. These studies demonstrate that the accumulation of DGC is an integral feature for phenotype maturation of human ASM cells. This provides a strong rationale for future studies investigating the role of the DGC in ASM smooth muscle physiology in health and disease.
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Affiliation(s)
- Pawan Sharma
- Department of Physiology, Section of Respiratory Disease, Univ. of Manitoba, Winnipeg, MB, Canada
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37
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Böhm S, Jin H, Hughes SM, Roberts RG, Hinits Y. Dystrobrevin and dystrophin family gene expression in zebrafish. Gene Expr Patterns 2007; 8:71-8. [PMID: 18042440 DOI: 10.1016/j.modgep.2007.10.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Revised: 09/21/2007] [Accepted: 10/16/2007] [Indexed: 10/22/2022]
Abstract
Dystrophin/dystrobrevin superfamily proteins play structural and signalling roles at the plasma membrane of many cell types. Defects in them or the associated multiprotein complex cause a range of neuromuscular disorders. Members of the dystrophin branch of the family form heterodimers with members of the dystrobrevin branch, mediated by their coiled-coil domains. To determine which combinations of these proteins might interact during embryonic development, we set out to characterise the gene expression pattern of dystrophin and dystrobrevin family members in zebrafish. gamma-dystrobrevin (dtng), a novel dystrobrevin recently identified in fish, is the predominant form of dystrobrevin in embryonic development. Dtng and dmd (dystrophin) have similar spatial and temporal expression patterns in muscle, where transcripts are localized to the ends of differentiated fibres at the somite borders. Dtng is expressed in the notochord while dmd is expressed in the chordo-neural hinge and then in floor plate and hypochord. In addition, dtng is dynamically expressed in rhombomeres 2 and 4-6 of the hindbrain and in the ventral midbrain. alpha-dystrobrevin (dtna) is expressed widely in the brain with particularly strong expression in the hypothalamus and the telencephalon; drp2 is also expressed widely in the brain. Utrophin expression is found in early pronephros and lateral line development and utrophin and dystrophin are both expressed later in the gut. beta-dystrobrevin (dtnb) is expressed in the pronephric duct and widely at low levels. In summary, we find clear instances of co-expression of dystrophin and dystrobrevin family members in muscle, brain and pronephric duct development and many examples of strong and specific expression of members of one family but not the other, an intriguing finding given the presumed heterodimeric state of these molecules.
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Affiliation(s)
- Sabrina Böhm
- Department of Medical & Molecular Genetics, Guy's Campus, King's College London, London SE1 9RT, UK
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38
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Hultgårdh-Nilsson A, Durbeej M. Role of the extracellular matrix and its receptors in smooth muscle cell function: implications in vascular development and disease. Curr Opin Lipidol 2007; 18:540-5. [PMID: 17885425 DOI: 10.1097/mol.0b013e3282ef77e9] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
PURPOSE OF REVIEW Cardiovascular disease affects millions of people worldwide, while the sarcoglycan deficient cardiomyopathies are rare disorders. One important common feature, however, is the vascular smooth muscle. Here we focus on the roles of extracellular matrix components and their receptors in the functions of vascular smooth muscle cells. RECENT FINDINGS Recent observations highlight the importance of integrins and the dystrophin-glycoprotein complex in development and cardiomyopathy. For example, integrin alpha4 and alpha7 subunits are important for distributing vascular smooth muscle cells during blood vessel development. Studies on delta-sarcoglycan deficient animals have revealed abnormal vascular smooth muscle proliferation and apoptosis. Furthermore, data suggest that perlecan, by affecting smooth muscle cell proliferation, participates in the atherosclerotic process. Overexpression of decorin leads to reduced progression of atherosclerosis and thrombospondin-1 has been implicated in regulation of smooth muscle cell contractility via inhibition of nitric oxide. Novel findings on versican suggest that the binding of versican to fibulin is of great importance for regulating smooth muscle cell function. SUMMARY By regulating migration, proliferation and apoptosis as well as extracellular matrix synthesis and assembly, proteoglycans, integrins and the dystrophin-glycoprotein complex may be of great importance both during development and in vascular disease.
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Affiliation(s)
- Anna Hultgårdh-Nilsson
- Vessel Wall Biology Unit, Sweden bMuscle Biology Unit, University of Lund, Lund, Sweden.
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39
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Anastasi G, Cutroneo G, Sidoti A, Rinaldi C, Bruschetta D, Rizzo G, D'Angelo R, Tarone G, Amato A, Favaloro A. Sarcoglycan subcomplex expression in normal human smooth muscle. J Histochem Cytochem 2007; 55:831-43. [PMID: 17438352 DOI: 10.1369/jhc.6a7145.2007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The sarcoglycan complex (SGC) is a multimember transmembrane complex interacting with other members of the dystrophin-glycoprotein complex (DGC) to provide a mechanosignaling connection from the cytoskeleton to the extracellular matrix. The SGC consists of four proteins (alpha, beta, gamma, and delta). A fifth sarcoglycan subunit, epsilon-sarcoglycan, shows a wider tissue distribution. Recently, a novel sarcoglycan, the zeta-sarcoglycan, has been identified. All reports about the structure of SGC showed a common assumption of a tetrameric arrangement of sarcoglycans. Addressing this issue, our immunofluorescence and molecular results showed, for the first time, that all sarcoglycans are always detectable in all observed samples. Therefore, one intriguing possibility is the existence of a pentameric or hexameric complex considering zeta-sarcoglycan of SGC, which could present a higher or lower expression of a single sarcoglycan in conformity with muscle type--skeletal, cardiac, or smooth--or also in conformity with the origin of smooth muscle.
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Affiliation(s)
- Giuseppe Anastasi
- Department of Biomorphology and Biotechnologies, University of Messina, Via Consolare Valeria, 1 IT-98125, Messina, Italy
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40
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Danièle N, Richard I, Bartoli M. Ins and outs of therapy in limb girdle muscular dystrophies. Int J Biochem Cell Biol 2007; 39:1608-24. [PMID: 17339125 DOI: 10.1016/j.biocel.2007.02.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Revised: 02/02/2007] [Accepted: 02/05/2007] [Indexed: 12/11/2022]
Abstract
Muscular dystrophies are hereditary degenerative muscle diseases that cause life-long disability in patients. They comprise the well-known Duchenne Muscular Dystrophy (DMD) but also the group of Limb Girdle Muscular Dystrophies (LGMD) which account for a third to a fourth of DMD cases. From the clinical point of view, LGMD are characterised by predominant effects on the proximal limb muscles. The LGMD group is still growing today and consists of 19 autosomal dominant and recessive forms (LGMD1A to LGMD1G and LGMD2A to LGMD2M). The proteins involved are very diverse and include sarcomeric, sarcolemmal and enzymatic proteins. With respect to this variability and in line with the intense search for a potent therapeutic approach for DMD, many different strategies have been tested in rodent models. These include replacing the lost function by gene transfer or stem cell transplantation, using a related protein for functional substitution, increasing muscle mass, or blocking the molecular pathological mechanisms by pharmacological means to alleviate the symptoms. The purpose of this review is to summarize current data arising from these preclinical studies and to examine the potential of the tested strategies to lead to clinical applications.
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41
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Esapa CT, Waite A, Locke M, Benson MA, Kraus M, McIlhinney RAJ, Sillitoe RV, Beesley PW, Blake DJ. SGCE missense mutations that cause myoclonus-dystonia syndrome impair ε-sarcoglycan trafficking to the plasma membrane: modulation by ubiquitination and torsinA. Hum Mol Genet 2007; 16:327-42. [PMID: 17200151 DOI: 10.1093/hmg/ddl472] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Myoclonus-dystonia syndrome (MDS) is a genetically heterogeneous disorder characterized by myoclonic jerks often seen in combination with dystonia and psychiatric co-morbidities and epilepsy. Mutations in the gene encoding epsilon-sarcoglycan (SGCE) have been found in some patients with MDS. SGCE is a maternally imprinted gene with the disease being inherited in an autosomal dominant pattern with reduced penetrance upon maternal transmission. In the central nervous system, epsilon-sarcoglycan is widely expressed in neurons of the cerebral cortex, basal ganglia, hippocampus, cerebellum and the olfactory bulb. epsilon-Sarcoglycan is located at the plasma membrane in neurons, muscle and transfected cells. To determine the effect of MDS-associated mutations on the function of epsilon-sarcoglycan we examined the biosynthesis and trafficking of wild-type and mutant proteins in cultured cells. In contrast to the wild-type protein, disease-associated epsilon-sarcoglycan missense mutations (H36P, H36R and L172R) produce proteins that are undetectable at the cell surface and are retained intracellularly. These mutant proteins become polyubiquitinated and are rapidly degraded by the proteasome. Furthermore, torsinA, that is mutated in DYT1 dystonia, a rare type of primary dystonia, binds to and promotes the degradation of epsilon-sarcoglycan mutants when both proteins are co-expressed. These data demonstrate that some MDS-associated mutations in SGCE impair trafficking of the mutant protein to the plasma membrane and suggest a role for torsinA and the ubiquitin proteasome system in the recognition and processing of misfolded epsilon-sarcoglycan.
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Affiliation(s)
- Christopher T Esapa
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
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42
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Romo-Yáñez J, Ceja V, Ilarraza-Lomelí R, Coral-Vázquez R, Velázquez F, Mornet D, Rendón A, Montañez C. Dp71ab/DAPs complex composition changes during the differentiation process in PC12 cells. J Cell Biochem 2007; 102:82-97. [PMID: 17390338 DOI: 10.1002/jcb.21281] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PC12 cells express different Dp71 isoforms originated from alternative splicing; one of them, Dp71ab lacks exons 71 and 78. To gain insight into the function of Dp71 isoforms we identified dystrophin associated proteins (DAPs) that associate in vivo with Dp71ab during nerve growth factor (NGF) induced differentiation of PC12 cells. DAPs expression was analyzed by RT-PCR, Western blot and indirect immunofluorescence, showing the presence of each mRNA and protein corresponding to alpha-, beta-, gamma-, delta-, and epsilon-sarcoglycans as well as zeta-sarcoglycan mRNA. Western blot analysis also revealed the expression of beta-dystroglycan, alpha1-syntrophin, alpha1-, and beta-dystrobrevins. We have established that Dp71ab forms a complex with beta-dystroglycan, alpha1-syntrophin, beta-dystrobrevin, and alpha-, beta- and gamma-sarcoglycans in undifferentiated PC12 cells. In differentiated PC12 cells, the complex composition changes since Dp71ab associates only with beta-dystroglycan, alpha1-syntrophin, beta-dystrobrevin, and delta-sarcoglycan. Interestingly, neuronal nitric oxide synthase associates with the Dp71ab/DAPs complex during NGF treatment, raising the possibility that Dp71ab may be involved in signal transduction events during neuronal differentiation.
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Affiliation(s)
- J Romo-Yáñez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del IPN, Avenida Instituto Politécnico Nacional 2508, Apartado Postal 14-740, C.P. 07000, Ciudad de México, México
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43
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Rafii MS, Hagiwara H, Mercado ML, Seo NS, Xu T, Dugan T, Owens RT, Hook M, McQuillan DJ, Young MF, Fallon JR. Biglycan binds to alpha- and gamma-sarcoglycan and regulates their expression during development. J Cell Physiol 2006; 209:439-47. [PMID: 16883602 PMCID: PMC2929672 DOI: 10.1002/jcp.20740] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The dystrophin-associated protein complex (DAPC), which links the cytoskeleton to the extracellular matrix, is essential for muscle cell survival, and is defective in a wide range of muscular dystrophies. The DAPC contains two transmembrane subcomplexes-the dystroglycans and the sarcoglycans. Although several extracellular binding partners have been identified for the dystroglycans, none have been described for the sarcoglycan subcomplex. Here we show that the small leucine-rich repeat (LRR) proteoglycan biglycan binds to alpha- and gamma-sarcoglycan as judged by ligand blot overlay and co-immunoprecipitation assays. Our studies with biglycan-decorin chimeras show that alpha- and gamma-sarcoglycan bind to distinct sites on the polypeptide core of biglycan. Both biglycan proteoglycan as well as biglycan polypeptide lacking glycosaminoglycan (GAG) side chains are components of the dystrophin glycoprotein complex isolated from adult skeletal muscle membranes. Finally, our immunohistochemical and biochemical studies with biglycan null mice show that the expression of alpha- and gamma-sarcoglycan is selectively reduced in muscle from young (P14-P21) animals, while levels in adult muscle (> or = P35) are unchanged. We conclude that biglycan is a ligand for two members of the sarcoglycan complex and regulates their expression at discrete developmental ages.
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Affiliation(s)
- Michael S. Rafii
- Department of Neuroscience, Brown University, Providence RI, 02912
| | - Hiroki Hagiwara
- Department of Neuroscience, Brown University, Providence RI, 02912
| | | | | | - Tianshun Xu
- Craniofacial and Skeletal Diseases Branch, National Institutes of Dental Research, National Institutes of Health, Bethesda MD, 20892
| | - Tracey Dugan
- Texas A&M University System Health Science Center Institute of Biosciences and Technology
| | | | - Magnus Hook
- Texas A&M University System Health Science Center Institute of Biosciences and Technology
| | | | - Marian F. Young
- Craniofacial and Skeletal Diseases Branch, National Institutes of Dental Research, National Institutes of Health, Bethesda MD, 20892
| | - Justin R. Fallon
- Department of Neuroscience, Brown University, Providence RI, 02912
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44
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Shiga K, Yoshioka H, Matsumiya T, Kimura I, Takeda S, Imamura M. ζ-Sarcoglycan is a functional homologue of γ-sarcoglycan in the formation of the sarcoglycan complex. Exp Cell Res 2006; 312:2083-92. [PMID: 16635485 DOI: 10.1016/j.yexcr.2006.03.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 03/06/2006] [Accepted: 03/08/2006] [Indexed: 11/28/2022]
Abstract
The sarcoglycans (SGs), transmembrane components of the dystrophin-associated glycoprotein complex, are stable and functional only when they assemble into a tetrameric complex in muscle cells. A defect in any one of the four SG members disrupts the entire SG complex (SGC) and causes limb-girdle muscular dystrophy. zeta-SG has been recently found as a transmembrane protein homologous to gamma-SG and delta-SG. To characterize zeta-SG in complex formation, we co-transfected expression vectors encoding all six SGs (alpha-, beta-, gamma-, delta-, epsilon- and zeta-SG) and dystroglycan into Chinese hamster ovary cells. Immunoprecipitation analysis showed that zeta-SG or gamma-SG formed a SGC with beta-SG and delta-SG plus alpha-SG or epsilon-SG, revealing that zeta-SG can form two types of SGCs (alpha-beta-zeta-delta or epsilon-beta-zeta-delta). This result indicates the functional resemblance of zeta-SG to gamma-SG rather than delta-SG, although phylogenetic analysis suggests that zeta-SG is evolutionally closer to delta-SG than to gamma-SG. Reverse transcription (RT)-PCR showed that the expression pattern of the transcript was almost the reciprocal of that of gamma-SG in various mouse tissues and that the zeta-SG transcript was especially abundant in the brain, suggesting that zeta-SG might play a particular role in the central nervous system.
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Affiliation(s)
- Kazuo Shiga
- Department of Molecular Therapy, National Institute of Neuroscience, NCNP, 4-1-1 Ogawahigashi-cho, Kodaira, Tokyo 187-8502, Japan
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45
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Halayko AJ, Stelmack GL. The association of caveolae, actin, and the dystrophin-glycoprotein complex: a role in smooth muscle phenotype and function? Can J Physiol Pharmacol 2006; 83:877-91. [PMID: 16333360 DOI: 10.1139/y05-107] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Smooth muscle cells exhibit phenotypic and mechanical plasticity. During maturation, signalling pathways controlling actin dynamics modulate contractile apparatus-associated gene transcription and contractile apparatus remodelling resulting from length change. Differentiated myocytes accumulate abundant caveolae that evolve from the structural association of lipid rafts with caveolin-1, a protein with domains that confer unique functional properties. Caveolae and caveolin-1 modulate and participate in receptor-mediated signalling, and thus contribute to functional diversity of phenotypically similar myocytes. In mature smooth muscle, caveolae are partitioned into discrete linear domains aligned with structural proteins that tether actin to the extracellular matrix. Caveolin-1 binds with beta-dystroglycan, a subunit of the dystrophin glycoprotein complex (DGC), and with filamin, an actin binding protein that organizes cortical actin, to which integrins and focal adhesion complexes are anchored. The DGC is linked to the actin cytoskeleton by a dystrophin subunit and is a receptor for extracellular laminin. Thus, caveolae and caveolin-associated signalling proteins and receptors are linked via structural proteins to a dynamic filamentous actin network. Despite development of transgenic models to investigate caveolins and membrane-associated actin-linking proteins in skeletal and cardiac muscle function, only superficial understanding of this association in smooth muscle phenotype and function has emerged.
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Affiliation(s)
- Andrew J Halayko
- Department of Physiology, University of Manitoba, Winnipeg, Canada.
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46
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Estrada FJ, Mornet D, Rosas-Vargas H, Angulo A, Hernández M, Becker V, Rendón A, Ramos-Kuri M, Coral-Vázquez RM. A novel isoform of delta-sarcoglycan is localized at the sarcoplasmic reticulum of mouse skeletal muscle. Biochem Biophys Res Commun 2005; 340:865-71. [PMID: 16403451 PMCID: PMC1952693 DOI: 10.1016/j.bbrc.2005.12.083] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2005] [Accepted: 12/12/2005] [Indexed: 11/22/2022]
Abstract
The sarcoglycan-sarcospan complex (alpha-, beta-, gamma-, delta-, epsilon-, and zeta-SG-SSPN), a component of the dystrophin-associated glycoprotein complex (DAGC), is located at the sarcolemma of muscle fibers where it contributes to maintain cell integrity during contraction-relaxation cycles; gamma- and delta-SG are also expressed in the sarcoplasmic reticulum (SR). In this study, we report the identification of a novel isoform of murine delta-SG produced by alternative splicing that we named delta-SG3. This isoform is present at transcript level in several tissues, with its highest expression in skeletal and cardiac muscle. The delta-SG3 protein lacks the last 122 amino acids at the C-terminal, which are replaced by 10 new amino acids (EGFLNMQLAG). Interestingly, double immunofluorescence analysis for delta-SG3 and the dihydropyridine receptor (DHPR) shows a close localization of these two proteins. We propose the subcellular distribution of this novel delta-SG3 isoform at the SR and its involvement in intracellular calcium concentration regulation.
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Affiliation(s)
- Francisco J. Estrada
- Unidad de Investigacion Medica en Genetica Humana
Hospital de pediatria Centro Medico Nacional Siglo WXI-IMSSAv. Cuauhtémoc 330, Col. Doctores, C.P. 06725 México,MX
- Laboratorio de Biologia Molecular
Escuela de Medicina Universidad PanamericanaMéxico y Escuela Nacional de Ciencias Biológicas-IPN,MX
| | - Dominique Mornet
- Muscles et pathologies chroniques
Université Montpellier I EA701Institut de Biologie, Boulevard Henry IV, 34062 Montpellier,FR
| | - Haydeé Rosas-Vargas
- Unidad de Investigacion Medica en Genetica Humana
Hospital de pediatria Centro Medico Nacional Siglo WXI-IMSSAv. Cuauhtémoc 330, Col. Doctores, C.P. 06725 México,MX
| | - Alexandra Angulo
- Unidad de Investigacion Medica en Genetica Humana
Hospital de pediatria Centro Medico Nacional Siglo WXI-IMSSAv. Cuauhtémoc 330, Col. Doctores, C.P. 06725 México,MX
| | - Manuel Hernández
- Unidad de Investigacion Medica en Genetica Humana
Hospital de pediatria Centro Medico Nacional Siglo WXI-IMSSAv. Cuauhtémoc 330, Col. Doctores, C.P. 06725 México,MX
| | - Viola Becker
- Unidad de Investigacion Medica en Genetica Humana
Hospital de pediatria Centro Medico Nacional Siglo WXI-IMSSAv. Cuauhtémoc 330, Col. Doctores, C.P. 06725 México,MX
| | - Alvaro Rendón
- Laboratoire de Physiopathologie Cellulaire et Moleculaire de la Retine
INSERM : U592Université Pierre et Marie Curie - Paris VIHopital Saint-Antoine PARIS VI
184, Rue du Faubourg Saint-Antoine
75571 PARIS CEDEX 12,FR
| | - Manuel Ramos-Kuri
- Laboratorio de Biologia Molecular
Escuela de Medicina Universidad PanamericanaMéxico y Escuela Nacional de Ciencias Biológicas-IPN,MX
| | - Ramón M. Coral-Vázquez
- Unidad de Investigacion Medica en Genetica Humana
Hospital de pediatria Centro Medico Nacional Siglo WXI-IMSSAv. Cuauhtémoc 330, Col. Doctores, C.P. 06725 México,MX
- * Correspondence should be adressed to: Ramón M. Coral-Vázquez
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47
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Fort P, Estrada FJ, Bordais A, Mornet D, Sahel JA, Picaud S, Vargas HR, Coral-Vázquez RM, Rendon A. The sarcoglycan-sarcospan complex localization in mouse retina is independent from dystrophins. Neurosci Res 2005; 53:25-33. [PMID: 15993965 PMCID: PMC1952695 DOI: 10.1016/j.neures.2005.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2005] [Revised: 05/20/2005] [Accepted: 05/26/2005] [Indexed: 11/16/2022]
Abstract
The sarcoglycan-sarcospan (SG-SSPN) complex is part of the dystrophin-glycoprotein complex that has been extensively characterized in muscle. To establish the framework for functional studies of sarcoglycans in retina here, we quantified sarcoglycans mRNA levels with real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and performed immunohistochemistry to determine their cellular and subcellular distribution. We showed that the beta-, delta-, gamma-, epsilon-sarcoglycans and sarcospan are expressed in mouse retina. They are localized predominantly in the outer and the inner limiting membranes, probably in the Müller cells and also in the ganglion cells axons where the expression of dystrophins have never been reported. We also investigated the status of the sarcoglycans in the retina of mdx(3cv) mutant mice for all Duchene Muscular Dystrophy (DMD) gene products. The absence of dystrophin did not produce any change in the sarcoglycan-sarcospan components expression and distribution.
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Affiliation(s)
- Patrice Fort
- Laboratoire de Physiopathologie Cellulaire et Moleculaire de la Retine
INSERM : U592Université Pierre et Marie Curie - Paris VIHopital Saint-Antoine PARIS VI
184, Rue du Faubourg Saint-Antoine
75571 PARIS CEDEX 12,FR
| | - Francisco-Javier Estrada
- Unidad de Investigacion Medica en Genetica Humana
Hopital de Pediatria Centro Medico Nacional Siglo XXI-IMSSAv. Cuauhtemoc 330 Col.Doctores, CP 06725 Mexico, MX
- Molecular Biology Laboratory
Medical School Universidad Panamericana Mexico and Biological Sciences IPNMX
| | - Agnès Bordais
- Laboratoire de Physiopathologie Cellulaire et Moleculaire de la Retine
INSERM : U592Université Pierre et Marie Curie - Paris VIHopital Saint-Antoine PARIS VI
184, Rue du Faubourg Saint-Antoine
75571 PARIS CEDEX 12,FR
| | - Dominique Mornet
- Muscles et pathologies chroniques
Université Montpellier I EA701Institut de Biologie, Boulevard Henry IV, 34062 Montpellier,FR
| | - José-Alain Sahel
- Laboratoire de Physiopathologie Cellulaire et Moleculaire de la Retine
INSERM : U592Université Pierre et Marie Curie - Paris VIHopital Saint-Antoine PARIS VI
184, Rue du Faubourg Saint-Antoine
75571 PARIS CEDEX 12,FR
| | - Serge Picaud
- Laboratoire de Physiopathologie Cellulaire et Moleculaire de la Retine
INSERM : U592Université Pierre et Marie Curie - Paris VIHopital Saint-Antoine PARIS VI
184, Rue du Faubourg Saint-Antoine
75571 PARIS CEDEX 12,FR
| | - Haydeé Rosas Vargas
- Unidad de Investigacion Medica en Genetica Humana
Hopital de Pediatria Centro Medico Nacional Siglo XXI-IMSSAv. Cuauhtemoc 330 Col.Doctores, CP 06725 Mexico, MX
| | - Ramón M. Coral-Vázquez
- Unidad de Investigacion Medica en Genetica Humana
Hopital de Pediatria Centro Medico Nacional Siglo XXI-IMSSAv. Cuauhtemoc 330 Col.Doctores, CP 06725 Mexico, MX
| | - Alvaro Rendon
- Laboratoire de Physiopathologie Cellulaire et Moleculaire de la Retine
INSERM : U592Université Pierre et Marie Curie - Paris VIHopital Saint-Antoine PARIS VI
184, Rue du Faubourg Saint-Antoine
75571 PARIS CEDEX 12,FR
- * Correspondence should be adressed to: Alvaro Rendon
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48
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Yokoi F, Dang MT, Mitsui S, Li Y. Exclusive paternal expression and novel alternatively spliced variants of epsilon-sarcoglycan mRNA in mouse brain. FEBS Lett 2005; 579:4822-8. [PMID: 16099459 DOI: 10.1016/j.febslet.2005.07.065] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Revised: 07/01/2005] [Accepted: 07/27/2005] [Indexed: 10/25/2022]
Abstract
Mutations of SGCE encoding epsilon-sarcoglycan cause myoclonus-dystonia. SGCE is paternally expressed; however, 5-10% of patients show maternal inheritance of the disease. We found Sgce was exclusively paternally expressed in mice by using a novel polymorphism marker. The result was confirmed in Sgce heterozygous knockout mice. This finding suggests that maternally inherited myoclonus-dystonia may not result from maternal expression of SGCE. Furthermore, we report a new family of alternatively spliced Sgce mRNA expressed in the brain coding for different C-terminal sequences possessing a PDZ-binding motif. Our results provide a better basis for diagnosis and understanding of the pathogenesis of myoclonus-dystonia.
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Affiliation(s)
- Fumiaki Yokoi
- Department of Molecular and Integrative Physiology, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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49
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Gingras J, Spicer J, Altares M, Zhu Q, Kuchel GA, Ferns M. Agrin becomes concentrated at neuroeffector junctions in developing rodent urinary bladder. Cell Tissue Res 2005; 320:115-25. [PMID: 15711988 DOI: 10.1007/s00441-004-1045-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2004] [Accepted: 10/29/2004] [Indexed: 10/25/2022]
Abstract
The formation of somatic neuromuscular junctions in skeletal muscle is regulated by an extracellular matrix protein called agrin. Here, we have examined the expression and localization of agrin during development of the rodent urinary bladder, as a first step to examining its possible role at autonomic neuroeffector junctions in smooth muscle. We have found that agrin is expressed on the surface of developing smooth muscle cells and in the basement membrane underlying the urothelium. More importantly, agrin is progressively concentrated at parasympathetic varicosities during postnatal development and is present at virtually all junctions in mature muscle. Reverse transcription/polymerase chain reaction analysis has shown that pelvic ganglion neurons that innervate the bladder express LN/z8 agrin, whereas bladder smooth muscle expresses LN/z- agrin. Together, these results demonstrate that nerve and/or muscle agrin becomes localized at cholinergic parasympathetic varicosities in smooth muscle, where it could play a role in the maturation of the neuroeffector junction.
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Affiliation(s)
- J Gingras
- Centre for Research in Neuroscience, Research Institute of McGill University Health Centre, Montreal, QC, Canada, H3G 1A4
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50
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Ramírez-Sánchez I, Rosas-Vargas H, Ceballos-Reyes G, Salamanca F, Coral-Vázquez RM. Expression Analysis of the SG-SSPN Complex in Smooth Muscle and Endothelial Cells of Human Umbilical Cord Vessels. J Vasc Res 2005; 42:1-7. [PMID: 15583476 DOI: 10.1159/000082528] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2004] [Accepted: 09/27/2004] [Indexed: 11/19/2022] Open
Abstract
Recently, participation of the sarcoglycan (SG)-sarcospan (SSPN) complex in the development of cardiomyopathy in patients with limb-girdle muscular dystrophy has been shown, and presence of the complex in smooth muscle may be important for the contraction/dilation process of vessels. However, there are few studies determining the SG-SSPN complex in vascular smooth muscle and endothelial cells of vessels. In this study, we analyzed by reverse transcriptase-polymerase chain reaction and immunofluorescence the expression of different components of the complex in vein/artery smooth muscle and endothelial cells of the human umbilical cord. By RNA analysis, we observed expression of alpha-, beta-, gamma-, delta-, epsilon-SG, and SSPN in smooth muscle cells. In endothelial cells, RNA expression was restricted to beta-, delta-, epsilon-SG, and SSPN. At protein level, we observed in smooth muscle the presence of beta-, delta-, epsilon-SG, and SSPN. In endothelial cells, immunostaining only evidenced the presence of epsilon-SG and SSPN. However, colocalization of SGs and SSPN with dystrophin and utrophin was noted. These results, interestingly, suggest that the SG-SSPN complex may either form with dystrophin or utrophin in smooth muscle cells, and with utrophin in endothelial cells. Additionally, we also observed in some smooth muscle regions the colocalization of the SG-SSPN complex with caveolin, with colocalization being more pronounced between epsilon-SG-SSPN and caveolin in endothelial cells.
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Affiliation(s)
- I Ramírez-Sánchez
- Unidad de Investigación Médica en Genética Humana, Hospital de Pediatría, Centro Médico Nacional Siglo XXI-IMSS, Mexico, D.F., Mexico
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