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Dowling P, Murphy S, Zweyer M, Raucamp M, Swandulla D, Ohlendieck K. Emerging proteomic biomarkers of X-linked muscular dystrophy. Expert Rev Mol Diagn 2019; 19:739-755. [PMID: 31359811 DOI: 10.1080/14737159.2019.1648214] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Introduction: Progressive skeletal muscle wasting is the manifesting symptom of Duchenne muscular dystrophy, an X-linked inherited disorder triggered by primary abnormalities in the DMD gene. The almost complete loss of dystrophin isoform Dp427 causes a multi-system pathology that features in addition to skeletal muscle weakness also late-onset cardio-respiratory deficiencies, impaired metabolism and abnormalities in the central nervous system. Areas covered: This review focuses on the mass spectrometry-based proteomic characterization of X-linked muscular dystrophy with special emphasis on the identification of novel biomarker candidates in skeletal muscle tissues, as well as non-muscle tissues and various biofluids. Individual sections focus on molecular and cellular aspects of the pathogenic changes in dystrophinopathy, proteomic workflows used in biomarker research, the proteomics of the dystrophin-glycoprotein complex and the potential usefulness of newly identified protein markers involved in fibre degeneration, fibrosis and inflammation. Expert opinion: The systematic application of large-scale proteomic surveys has identified a distinct cohort of both tissue- and biofluid-associated protein species with considerable potential for improving diagnostic, prognostic and therapy-monitoring procedures. Novel proteomic markers include components involved in fibre contraction, cellular signalling, ion homeostasis, cellular stress response, energy metabolism and the immune response, as well as maintenance of the cytoskeletal and extracellular matrix.
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Affiliation(s)
- Paul Dowling
- Department of Biology, Maynooth University, National University of Ireland , Kildare , Ireland.,Human Health Research Institute, Maynooth University , Kildare , Ireland
| | - Sandra Murphy
- Newcastle Fibrosis Research Group, Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University , Newcastle upon Tyne , UK
| | - Margit Zweyer
- Institute of Physiology II, University of Bonn , Bonn , Germany
| | - Maren Raucamp
- Institute of Physiology II, University of Bonn , Bonn , Germany
| | | | - Kay Ohlendieck
- Department of Biology, Maynooth University, National University of Ireland , Kildare , Ireland.,Human Health Research Institute, Maynooth University , Kildare , Ireland
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Dowling P, Zweyer M, Swandulla D, Ohlendieck K. Characterization of Contractile Proteins from Skeletal Muscle Using Gel-Based Top-Down Proteomics. Proteomes 2019; 7:proteomes7020025. [PMID: 31226838 PMCID: PMC6631179 DOI: 10.3390/proteomes7020025] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 06/14/2019] [Accepted: 06/17/2019] [Indexed: 12/22/2022] Open
Abstract
The mass spectrometric analysis of skeletal muscle proteins has used both peptide-centric and protein-focused approaches. The term 'top-down proteomics' is often used in relation to studying purified proteoforms and their post-translational modifications. Two-dimensional gel electrophoresis, in combination with peptide generation for the identification and characterization of intact proteoforms being present in two-dimensional spots, plays a critical role in specific applications of top-down proteomics. A decisive bioanalytical advantage of gel-based and top-down approaches is the initial bioanalytical focus on intact proteins, which usually enables the swift identification and detailed characterisation of specific proteoforms. In this review, we describe the usage of two-dimensional gel electrophoretic top-down proteomics and related approaches for the systematic analysis of key components of the contractile apparatus, with a special focus on myosin heavy and light chains and their associated regulatory proteins. The detailed biochemical analysis of proteins belonging to the thick and thin skeletal muscle filaments has decisively improved our biochemical understanding of structure-function relationships within the contractile apparatus. Gel-based and top-down proteomics has clearly established a variety of slow and fast isoforms of myosin, troponin and tropomyosin as excellent markers of fibre type specification and dynamic muscle transition processes.
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Affiliation(s)
- Paul Dowling
- Department of Biology, Maynooth University, Maynooth, W23F2H6 Co. Kildare, Ireland.
- MU Human Health Research Institute, Maynooth University, Maynooth, W23F2H6 Co. Kildare, Ireland.
| | - Margit Zweyer
- Institute of Physiology II, University of Bonn, D-53115 Bonn, Germany.
| | - Dieter Swandulla
- Institute of Physiology II, University of Bonn, D-53115 Bonn, Germany.
| | - Kay Ohlendieck
- Department of Biology, Maynooth University, Maynooth, W23F2H6 Co. Kildare, Ireland.
- MU Human Health Research Institute, Maynooth University, Maynooth, W23F2H6 Co. Kildare, Ireland.
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Murphy S, Dowling P, Ohlendieck K. Comparative Skeletal Muscle Proteomics Using Two-Dimensional Gel Electrophoresis. Proteomes 2016; 4:proteomes4030027. [PMID: 28248237 PMCID: PMC5217355 DOI: 10.3390/proteomes4030027] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 08/31/2016] [Accepted: 09/07/2016] [Indexed: 12/16/2022] Open
Abstract
The pioneering work by Patrick H. O’Farrell established two-dimensional gel electrophoresis as one of the most important high-resolution protein separation techniques of modern biochemistry (Journal of Biological Chemistry1975, 250, 4007–4021). The application of two-dimensional gel electrophoresis has played a key role in the systematic identification and detailed characterization of the protein constituents of skeletal muscles. Protein changes during myogenesis, muscle maturation, fibre type specification, physiological muscle adaptations and natural muscle aging were studied in depth by the original O’Farrell method or slightly modified gel electrophoretic techniques. Over the last 40 years, the combined usage of isoelectric focusing in the first dimension and sodium dodecyl sulfate polyacrylamide slab gel electrophoresis in the second dimension has been successfully employed in several hundred published studies on gel-based skeletal muscle biochemistry. This review focuses on normal and physiologically challenged skeletal muscle tissues and outlines key findings from mass spectrometry-based muscle proteomics, which was instrumental in the identification of several thousand individual protein isoforms following gel electrophoretic separation. These muscle-associated protein species belong to the diverse group of regulatory and contractile proteins of the acto-myosin apparatus that forms the sarcomere, cytoskeletal proteins, metabolic enzymes and transporters, signaling proteins, ion-handling proteins, molecular chaperones and extracellular matrix proteins.
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Affiliation(s)
- Sandra Murphy
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare, Ireland.
| | - Paul Dowling
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare, Ireland.
| | - Kay Ohlendieck
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Co. Kildare, Ireland.
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Proteomic profiling of the dystrophin-deficient mdx phenocopy of dystrophinopathy-associated cardiomyopathy. BIOMED RESEARCH INTERNATIONAL 2014; 2014:246195. [PMID: 24772416 PMCID: PMC3977469 DOI: 10.1155/2014/246195] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 02/16/2014] [Indexed: 01/07/2023]
Abstract
Cardiorespiratory complications are frequent symptoms of Duchenne muscular dystrophy, a neuromuscular disorder caused by primary abnormalities in the dystrophin gene. Loss of cardiac dystrophin initially leads to changes in dystrophin-associated glycoproteins and subsequently triggers secondarily sarcolemmal disintegration, fibre necrosis, fibrosis, fatty tissue replacement, and interstitial inflammation. This results in progressive cardiac disease, which is the cause of death in a considerable number of patients afflicted with X-linked muscular dystrophy. In order to better define the molecular pathogenesis of this type of cardiomyopathy, several studies have applied mass spectrometry-based proteomics to determine proteome-wide alterations in dystrophinopathy-associated cardiomyopathy. Proteomic studies included both gel-based and label-free mass spectrometric surveys of dystrophin-deficient heart muscle from the established mdx animal model of dystrophinopathy. Comparative cardiac proteomics revealed novel changes in proteins associated with mitochondrial energy metabolism, glycolysis, signaling, iron binding, antibody response, fibre contraction, basal lamina stabilisation, and cytoskeletal organisation. This review summarizes the importance of studying cardiomyopathy within the field of muscular dystrophy research, outlines key features of the mdx heart and its suitability as a model system for studying cardiac pathogenesis, and discusses the impact of recent proteomic findings for exploring molecular and cellular aspects of cardiac abnormalities in inherited muscular dystrophies.
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Hölper S, Ruhs A, Krüger M. Stable isotope labeling for proteomic analysis of tissues in mouse. Methods Mol Biol 2014; 1188:95-106. [PMID: 25059607 DOI: 10.1007/978-1-4939-1142-4_8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Since the first metabolic labeling experiments with stable isotopes beginning of the last century, several approaches were pursued to monitor protein dynamics in living animals. Today, almost all model organisms from bacteria to rodents can be fully labeled with SILAC (stable isotope labeling of amino acids in cell culture) amino acids. The development of special media and diets containing the labeled amino acids provides an efficient way to metabolically label prokaryotic and eukaryotic organisms. Preferentially, the essential amino acid lysine ((13)C6-lysine) is used to label mice (Mus musculus) and after one generation the natural isotope is fully replaced by the stable (13)C6-lysine isotope. So far, the SILAC mouse approach has been used to analyze several transgenic and knockout mouse models. Spike-in of labeled proteins into non-labeled samples provides an accurate relative protein quantification method without any chemical modification. Here we describe how to establish a SILAC mouse colony and describe the analysis of skeletal muscle tissue with different metabolic and contractile profiles.
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Affiliation(s)
- Soraya Hölper
- Max Planck Institute for Heart and Lung Research, Lugwigstr. 43, 61231, Bad Nauheim, Germany
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Govoni A, Magri F, Brajkovic S, Zanetta C, Faravelli I, Corti S, Bresolin N, Comi GP. Ongoing therapeutic trials and outcome measures for Duchenne muscular dystrophy. Cell Mol Life Sci 2013; 70:4585-602. [PMID: 23775131 PMCID: PMC11113854 DOI: 10.1007/s00018-013-1396-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 05/28/2013] [Accepted: 05/30/2013] [Indexed: 01/13/2023]
Abstract
Muscular dystrophy is a heterogeneous group of genetic disorders characterised by progressive muscle tissue degeneration. No effective treatment has been discovered for these diseases. Preclinical and clinical studies aimed at the development of new therapeutic approaches have been carried out, primarily in subjects affected with dystrophinopathies (Duchenne and Becker muscular dystrophy). In this review, we outline the current therapeutic approaches and past and ongoing clinical trials, highlighting both the advantages and limits of each one. The experimental designs of these trials were based on different rationales, including immunomodulation, readthrough strategies, exon skipping, gene therapy, and cell therapy. We also provide an overview of available outcome measures, focusing on their reliability in estimating meaningful clinical improvement in order to aid in the design of future trials. This perspective is extremely relevant to the field considering the recent development of novel therapeutic approaches that will result in an increasing number of clinical studies over the next few years.
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Affiliation(s)
- Alessandra Govoni
- Neuroscience Section, Neurology Unit, Department of Pathophysiology and Transplantation (DEPT), Dino Ferrari Centre, University of Milan, IRCCS Foundation Ca’ Granda Ospedale Maggiore Policlinico, Italy Via Francesco Sforza 35, 20122 Milan, Italy
| | - Francesca Magri
- Neuroscience Section, Neurology Unit, Department of Pathophysiology and Transplantation (DEPT), Dino Ferrari Centre, University of Milan, IRCCS Foundation Ca’ Granda Ospedale Maggiore Policlinico, Italy Via Francesco Sforza 35, 20122 Milan, Italy
- IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Simona Brajkovic
- Neuroscience Section, Neurology Unit, Department of Pathophysiology and Transplantation (DEPT), Dino Ferrari Centre, University of Milan, IRCCS Foundation Ca’ Granda Ospedale Maggiore Policlinico, Italy Via Francesco Sforza 35, 20122 Milan, Italy
| | - Chiara Zanetta
- Neuroscience Section, Neurology Unit, Department of Pathophysiology and Transplantation (DEPT), Dino Ferrari Centre, University of Milan, IRCCS Foundation Ca’ Granda Ospedale Maggiore Policlinico, Italy Via Francesco Sforza 35, 20122 Milan, Italy
| | - Irene Faravelli
- Neuroscience Section, Neurology Unit, Department of Pathophysiology and Transplantation (DEPT), Dino Ferrari Centre, University of Milan, IRCCS Foundation Ca’ Granda Ospedale Maggiore Policlinico, Italy Via Francesco Sforza 35, 20122 Milan, Italy
| | - Stefania Corti
- Neuroscience Section, Neurology Unit, Department of Pathophysiology and Transplantation (DEPT), Dino Ferrari Centre, University of Milan, IRCCS Foundation Ca’ Granda Ospedale Maggiore Policlinico, Italy Via Francesco Sforza 35, 20122 Milan, Italy
| | - Nereo Bresolin
- Neuroscience Section, Neurology Unit, Department of Pathophysiology and Transplantation (DEPT), Dino Ferrari Centre, University of Milan, IRCCS Foundation Ca’ Granda Ospedale Maggiore Policlinico, Italy Via Francesco Sforza 35, 20122 Milan, Italy
- IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Giacomo P. Comi
- Neuroscience Section, Neurology Unit, Department of Pathophysiology and Transplantation (DEPT), Dino Ferrari Centre, University of Milan, IRCCS Foundation Ca’ Granda Ospedale Maggiore Policlinico, Italy Via Francesco Sforza 35, 20122 Milan, Italy
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Carberry S, Zweyer M, Swandulla D, Ohlendieck K. Comparative proteomic analysis of the contractile-protein-depleted fraction from normal versus dystrophic skeletal muscle. Anal Biochem 2013; 446:108-15. [PMID: 23954569 DOI: 10.1016/j.ab.2013.08.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 08/03/2013] [Accepted: 08/06/2013] [Indexed: 01/16/2023]
Abstract
In basic and applied myology, gel-based proteomics is routinely used for studying global changes in the protein constellation of contractile fibers during myogenesis, physiological adaptations, neuromuscular degeneration, and the natural aging process. Since the main proteins of the actomyosin apparatus and its auxiliary sarcomeric components often negate weak signals from minor muscle proteins during proteomic investigations, we have here evaluated whether a simple prefractionation step can be employed to eliminate certain aspects of this analytical obstacle. To remove a large portion of highly abundant contractile proteins from skeletal muscle homogenates without the usage of major manipulative steps, differential centrifugation was used to decisively reduce the sample complexity of crude muscle tissue extracts. The resulting protein fraction was separated by two-dimensional gel electrophoresis, and 2D-landmark proteins were identified by mass spectrometry. To evaluate the suitability of the contractile-protein-depleted fraction for comparative proteomics, normal versus dystrophic muscle preparations were examined. The mass spectrometric analysis of differentially expressed proteins, as determined by fluorescence difference in-gel electrophoresis, identified 10 protein species in dystrophic mdx hindlimb muscles. Interesting new biomarker candidates included Hsp70, transferrin, and ferritin, whereby their altered concentration levels in dystrophin-deficient muscle were confirmed by immunoblotting.
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Affiliation(s)
- Steven Carberry
- Department of Biology, National University of Ireland, Maynooth, Kildare, Ireland
| | - Margit Zweyer
- Department of Physiology II, University of Bonn, D-53115 Bonn, Germany
| | - Dieter Swandulla
- Department of Physiology II, University of Bonn, D-53115 Bonn, Germany
| | - Kay Ohlendieck
- Department of Biology, National University of Ireland, Maynooth, Kildare, Ireland.
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Matsumura CY, Menezes de Oliveira B, Durbeej M, Marques MJ. Isobaric Tagging-Based Quantification for Proteomic Analysis: A Comparative Study of Spared and Affected Muscles from mdx Mice at the Early Phase of Dystrophy. PLoS One 2013; 8:e65831. [PMID: 23823696 PMCID: PMC3688818 DOI: 10.1371/journal.pone.0065831] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 04/29/2013] [Indexed: 11/18/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is the most common childhood myopathy, characterized by muscle loss and cardiorespiratory failure. While the genetic basis of DMD is well established, secondary mechanisms associated with dystrophic pathophysiology are not fully clarified yet. In order to obtain new insights into the molecular mechanisms of muscle dystrophy during earlier stages of the disease, we performed a comparative proteomic profile of the spared extraocular muscles (EOM) vs. affected diaphragm from the mdx mice, using a label based shotgun proteomic approach. Out of the 857 identified proteins, 42 to 62 proteins had differential abundance of peptide ions. The calcium-handling proteins sarcalumenin and calsequestrin-1 were increased in control EOM compared with control DIA, reinforcing the view that constitutional properties of EOM are important for their protection against myonecrosis. The finding that galectin-1 (muscle regeneration), annexin A1 (anti-inflammatory) and HSP 47 (fibrosis) were increased in dystrophic diaphragm provides novel insights into the mechanisms through which mdx affected muscles are able to counteract dystrophy, during the early stage of the disease. Overall, the shotgun technique proved to be suitable to perform quantitative comparisons between distinct dystrophic muscles and allowed the suggestion of new potential biomarkers and drug targets for dystrophinopaties.
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Affiliation(s)
- Cintia Yuri Matsumura
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade de Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | | | - Madeleine Durbeej
- Muscle Biology Unit, Department of Experimental Medical Science, University of Lund, Lund, Sweden
| | - Maria Julia Marques
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade de Campinas (UNICAMP), Campinas, São Paulo, Brazil
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Rayavarapu S, Coley W, Cakir E, Jahnke V, Takeda S, Aoki Y, Grodish-Dressman H, Jaiswal JK, Hoffman EP, Brown KJ, Hathout Y, Nagaraju K. Identification of disease specific pathways using in vivo SILAC proteomics in dystrophin deficient mdx mouse. Mol Cell Proteomics 2013; 12:1061-73. [PMID: 23297347 DOI: 10.1074/mcp.m112.023127] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disorder caused by a mutation in the dystrophin gene. DMD is characterized by progressive weakness of skeletal, cardiac, and respiratory muscles. The molecular mechanisms underlying dystrophy-associated muscle weakness and damage are not well understood. Quantitative proteomics techniques could help to identify disease-specific pathways. Recent advances in the in vivo labeling strategies such as stable isotope labeling in mouse (SILAC mouse) with (13)C6-lysine or stable isotope labeling in mammals (SILAM) with (15)N have enabled accurate quantitative analysis of the proteomes of whole organs and tissues as a function of disease. Here we describe the use of the SILAC mouse strategy to define the underlying pathological mechanisms in dystrophin-deficient skeletal muscle. Differential SILAC proteome profiling was performed on the gastrocnemius muscles of 3-week-old (early stage) dystrophin-deficient mdx mice and wild-type (normal) mice. The generated data were further confirmed in an independent set of mdx and normal mice using a SILAC spike-in strategy. A total of 789 proteins were quantified; of these, 73 were found to be significantly altered between mdx and normal mice (p < 0.05). Bioinformatics analyses using Ingenuity Pathway software established that the integrin-linked kinase pathway, actin cytoskeleton signaling, mitochondrial energy metabolism, and calcium homeostasis are the pathways initially affected in dystrophin-deficient muscle at early stages of pathogenesis. The key proteins involved in these pathways were validated by means of immunoblotting and immunohistochemistry in independent sets of mdx mice and in human DMD muscle biopsies. The specific involvement of these molecular networks early in dystrophic pathology makes them potential therapeutic targets. In sum, our findings indicate that SILAC mouse strategy has uncovered previously unidentified pathological pathways in mouse models of human skeletal muscle disease.
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Affiliation(s)
- Sree Rayavarapu
- Research Center for Genetic Medicine, Children's National Medical Center, 111 Michigan Ave NW, Washington, DC, USA
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Abstract
Cellular aging is a fundamental biological process, and mass spectrometry-based proteomics has been widely used for the global identification of age-related changes in a variety of tissues. The proteomic profiling of senescent skeletal muscles has revealed a variety of alterations in proteins associated with the contractile apparatus, cell signaling, ion homeostasis, metabolism, and the cellular stress response. Here, we outline the two-dimensional gel electrophoretic separation and fluorescent labeling of the urea-soluble protein complement from aged diaphragm muscle. This chapter describes the various experimental steps involved in gel electrophoresis-based proteomics, including protein extraction, isoelectric focusing, slab gel electrophoresis, fluorescence labeling, image analysis, protein digestion, mass spectrometric identification of proteins and immunoblotting.
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Affiliation(s)
- Steven Carberry
- Department of Biology, National University of Ireland Maynooth, Maynooth, Kildare, Ireland
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Profiling of age-related changes in the tibialis anterior muscle proteome of the mdx mouse model of dystrophinopathy. J Biomed Biotechnol 2012; 2012:691641. [PMID: 23093855 PMCID: PMC3471022 DOI: 10.1155/2012/691641] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 06/13/2012] [Indexed: 12/22/2022] Open
Abstract
X-linked muscular dystrophy is a highly progressive disease of childhood and characterized by primary genetic abnormalities in the dystrophin gene. Senescent mdx specimens were used for a large-scale survey of potential age-related alterations in the dystrophic phenotype, because the established mdx animal model of dystrophinopathy exhibits progressive deterioration of muscle tissue with age. Since the mdx tibialis anterior muscle is a frequently used model system in muscular dystrophy research, we employed this particular muscle to determine global changes in the dystrophic skeletal muscle proteome. The comparison of mdx mice aged 8 weeks versus 22 months by mass-spectrometry-based proteomics revealed altered expression levels in 8 distinct protein species. Increased levels were shown for carbonic anhydrase, aldolase, and electron transferring flavoprotein, while the expressions of pyruvate kinase, myosin, tropomyosin, and the small heat shock protein Hsp27 were found to be reduced in aged muscle. Immunoblotting confirmed age-dependent changes in the density of key muscle proteins in mdx muscle. Thus, segmental necrosis in mdx tibialis anterior muscle appears to trigger age-related protein perturbations due to dystrophin deficiency. The identification of novel indicators of progressive muscular dystrophy might be useful for the establishment of a muscle subtype-specific biomarker signature of dystrophinopathy.
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Staunton L, Zweyer M, Swandulla D, Ohlendieck K. Mass spectrometry-based proteomic analysis of middle-aged vs. aged vastus lateralis reveals increased levels of carbonic anhydrase isoform 3 in senescent human skeletal muscle. Int J Mol Med 2012; 30:723-33. [PMID: 22797148 PMCID: PMC3573712 DOI: 10.3892/ijmm.2012.1056] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 05/31/2012] [Indexed: 12/21/2022] Open
Abstract
The age-related loss of skeletal muscle mass and associated progressive decline in contractile strength is a serious pathophysiological issue in the elderly. In order to investigate global changes in the skeletal muscle proteome after the fifth decade of life, this study analysed total extracts from human vastus lateralis muscle by fluorescence difference in-gel electrophoresis. Tissue specimens were derived from middle-aged (47-62 years) vs. aged (76-82 years) individuals and potential changes in the protein expression profiles were compared between these two age groups by a comprehensive gel electrophoresis-based survey. Age-dependent alterations in the concentration of 19 protein spots were revealed and mass spectrometry identified these components as being involved in the excitation-contraction-relaxation cycle, muscle metabolism, ion handling and the cellular stress response. This indicates a generally perturbed protein expression pattern in senescent human muscle. Increased levels of mitochondrial enzymes and isoform switching of the key contractile protein, actin, support the idea of glycolytic-to-oxidative and fast-to-slow transition processes during muscle aging. Importantly, the carbonic anhydrase (CA)3 isoform displayed an increased abundance during muscle aging, which was independently verified by immunoblotting of differently aged human skeletal muscle samples. Since the CA3 isoform is relatively muscle-specific and exhibits a fibre type-specific expression pattern, this enzyme may represent an interesting new biomarker of sarcopenia. Increased levels of CA are indicative of an increased demand of CO₂-removal in senescent muscle, and also suggest age-related fibre type shifting to slower-contracting muscles during human aging.
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Affiliation(s)
- Lisa Staunton
- Department of Biology, National University of Ireland, Maynooth, Kildare, Ireland
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