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Murgia M, Ciciliot S, Nagaraj N, Reggiani C, Schiaffino S, Franchi MV, Pišot R, Šimunič B, Toniolo L, Blaauw B, Sandri M, Biolo G, Flück M, Narici MV, Mann M. Signatures of muscle disuse in spaceflight and bed rest revealed by single muscle fiber proteomics. PNAS Nexus 2022; 1:pgac086. [PMID: 36741463 PMCID: PMC9896895 DOI: 10.1093/pnasnexus/pgac086] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/07/2022] [Indexed: 02/07/2023]
Abstract
Astronauts experience dramatic loss of muscle mass, decreased strength, and insulin resistance, despite performing daily intense physical exercise that would lead to muscle growth on Earth. Partially mimicking spaceflight, prolonged bed rest causes muscle atrophy, loss of force, and glucose intolerance. To unravel the underlying mechanisms, we employed highly sensitive single fiber proteomics to detail the molecular remodeling caused by unloading and inactivity during bed rest and changes of the muscle proteome of astronauts before and after a mission on the International Space Station. Muscle focal adhesions, involved in fiber-matrix interaction and insulin receptor stabilization, are prominently downregulated in both bed rest and spaceflight and restored upon reloading. Pathways of antioxidant response increased strongly in slow but not in fast muscle fibers. Unloading alone upregulated markers of neuromuscular damage and the pathway controlling EIF5A hypusination. These proteomic signatures of mechanical unloading in muscle fiber subtypes contribute to disentangle the effect of microgravity from the pleiotropic challenges of spaceflight.
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Affiliation(s)
| | - Stefano Ciciliot
- Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padua, Italy,Department of Molecular Medicine, University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
| | | | - Carlo Reggiani
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi, 58/B, 35131 Padua, Italy,Science and Research Center Koper, Institute for Kinesiology Research, Garibaldijeva Street 1, 6000 Koper, Slovenia
| | | | - Martino V Franchi
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi, 58/B, 35131 Padua, Italy
| | - Rado Pišot
- Science and Research Center Koper, Institute for Kinesiology Research, Garibaldijeva Street 1, 6000 Koper, Slovenia
| | - Boštjan Šimunič
- Science and Research Center Koper, Institute for Kinesiology Research, Garibaldijeva Street 1, 6000 Koper, Slovenia
| | - Luana Toniolo
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi, 58/B, 35131 Padua, Italy
| | - Bert Blaauw
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi, 58/B, 35131 Padua, Italy,Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padua, Italy
| | - Marco Sandri
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi, 58/B, 35131 Padua, Italy,Veneto Institute of Molecular Medicine, Via Orus 2, 35129 Padua, Italy
| | - Gianni Biolo
- Clinical Department of Medical, Surgical and Health Sciences, Strada di Fiume 447, 34149 Trieste, Italy
| | - Martin Flück
- Department of Medicine, University of Fribourg, Chemin du Musee 5, 1700 Fribourg, Switzerland
| | - Marco V Narici
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi, 58/B, 35131 Padua, Italy,Science and Research Center Koper, Institute for Kinesiology Research, Garibaldijeva Street 1, 6000 Koper, Slovenia,CIR-MYO Myology Center, Viale G Colombo 3, 35121 Padua, Italy
| | - Matthias Mann
- Max-Planck-Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany,NNF Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3B, Building 6.1, 2200 Copenhagen, Denmark
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Contini M, Altman D, Cornachione A, Rassier DE, Bagni MA. An increase in force after stretch of diaphragm fibers and myofibrils is accompanied by an increase in sarcomere length non-uniformities and Ca 2+ sensitivity. Am J Physiol Cell Physiol 2022; 323:C14-C28. [PMID: 35613356 DOI: 10.1152/ajpcell.00394.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
When muscle fibers from limb muscles are stretched while activated, the force increases to a steady-state level that is higher than that produced during isometric contractions at a corresponding sarcomere length, a phenomenon known as residual force enhancement (RFE). The mechanisms responsible for the RFE are an increased stiffness of titin molecules which may lead to an increased Ca2+ sensitivity of the contractile apparatus,and the development of sarcomere length non-uniformities. RFE is not observed in cardiac muscles, which makes this phenomenon specific to certain preparations. The aim of this study was to investigate if the RFE is present in the diaphragm, and its potential association with an increased Ca2+ sensitivity and the development of sarcomere length non-uniformities. We used two preparations: single intact fibers and myofibrils isolated from the diaphragm from mice. We investigated RFE in a variety of lengths across the force-length relationship. RFE was observed in both preparations at all lengths investigated, and was larger with increasing magnitudes of stretch. RFE was accompanied by an increased Ca2+ sensitivity as shown by a change in the force-pCa2+-curve, and increased sarcomere length non-uniformities. Therefore, RFE is a phenomenon commonly observed in skeletal muscles, with mechanisms that are similar across preparations.
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Affiliation(s)
- Massimo Contini
- Department of Experimental and Clinical Medicine, University of Florence, Italy
| | - David Altman
- Department of Physics, Willamette University, Salem, OR, United States
| | - Anabelle Cornachione
- Department of Physiological Sciences, Federal University of São Carlos, São Paulo, Brazil
| | | | - Maria Angela Bagni
- Department of Experimental and Clinical Medicine, University of Florence, Italy
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Pollmann C, Haug M, Reischl B, Prölß G, Pöschel T, Rupitsch SJ, Clemen CS, Schröder R, Friedrich O. Growing Old Too Early: Skeletal Muscle Single Fiber Biomechanics in Ageing R349P Desmin Knock-in Mice Using the MyoRobot Technology. Int J Mol Sci 2020; 21:ijms21155501. [PMID: 32752098 PMCID: PMC7432536 DOI: 10.3390/ijms21155501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/21/2020] [Accepted: 07/28/2020] [Indexed: 11/16/2022] Open
Abstract
Muscle biomechanics relies on active motor protein assembly and passive strain transmission through cytoskeletal structures. The desmin filament network aligns myofibrils at the z-discs, provides nuclear–sarcolemmal anchorage and may also serve as memory for muscle repositioning following large strains. Our previous analyses of R349P desmin knock-in mice, an animal model for the human R350P desminopathy, already depicted pre-clinical changes in myofibrillar arrangement and increased fiber bundle stiffness. As the effect of R349P desmin on axial biomechanics in fully differentiated single muscle fibers is unknown, we used our MyoRobot to compare passive visco-elasticity and active contractile biomechanics in single fibers from fast- and slow-twitch muscles from adult to senile mice, hetero- or homozygous for the R349P desmin mutation with wild type littermates. We demonstrate that R349P desmin presence predominantly increased axial stiffness in both muscle types with a pre-aged phenotype over wild type fibers. Axial viscosity and Ca2+-mediated force were largely unaffected. Mutant single fibers showed tendencies towards faster unloaded shortening over wild type fibers. Effects of aging seen in the wild type appeared earlier in the mutant desmin fibers. Our single-fiber experiments, free of extracellular matrix, suggest that compromised muscle biomechanics is not exclusively attributed to fibrosis but also originates from an impaired intermediate filament network.
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Affiliation(s)
- Charlotte Pollmann
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Bavaria, Germany; (C.P.); (B.R.); (G.P.); (O.F.)
| | - Michael Haug
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Bavaria, Germany; (C.P.); (B.R.); (G.P.); (O.F.)
- Graduate School in Advanced Optical Technologies, Paul-Gordan-Str. 6, 91052 Erlangen, Bavaria, Germany
- School of Medical Sciences, University of New South Wales, Wallace Wurth Building, 18 High St, Sydney, NSW 2052, Australia
- Correspondence:
| | - Barbara Reischl
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Bavaria, Germany; (C.P.); (B.R.); (G.P.); (O.F.)
| | - Gerhard Prölß
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Bavaria, Germany; (C.P.); (B.R.); (G.P.); (O.F.)
| | - Thorsten Pöschel
- Institute of Multi Scale Simulation of Particulate Systems, Friedrich-Alexander-University Erlangen-Nürnberg, Nägelbachstr. 49b, 91052 Erlangen, Bavaria, Germany;
| | - Stefan J Rupitsch
- Institute of Sensor Technology, Friedrich-Alexander-University Erlangen-Nürnberg, Paul-Gordan-Str. 3/5, 91052 Erlangen, Bavaria, Germany;
| | - Christoph S Clemen
- German Aerospace Center (DLR), Institute of Aerospace Medicine, Linder Höhe, 51147 Cologne, North Rhine-Westphalia, Germany;
- Institute of Neuropathology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen, Bavaria, Germany;
- Insitute of Vegetative Physiology, Medical Faculty, University of Cologne, Center of Physiology and Pathophysiology, Robert-Koch-Street 39, 50931 Cologne, North Rhine-Westphalia, Germany
| | - Rolf Schröder
- Institute of Neuropathology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen, Bavaria, Germany;
- Muscle Research Center Erlangen (MURCE), Friedrich-Alexander-University Erlangen-Nürnberg, 91054 Erlangen, Bavaria, Germany
| | - Oliver Friedrich
- Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Bavaria, Germany; (C.P.); (B.R.); (G.P.); (O.F.)
- Graduate School in Advanced Optical Technologies, Paul-Gordan-Str. 6, 91052 Erlangen, Bavaria, Germany
- School of Medical Sciences, University of New South Wales, Wallace Wurth Building, 18 High St, Sydney, NSW 2052, Australia
- Muscle Research Center Erlangen (MURCE), Friedrich-Alexander-University Erlangen-Nürnberg, 91054 Erlangen, Bavaria, Germany
- Victor Chang Cardiac Research Institute, Lowy Packer Building, 405 Liverpool St, Sydney, NSW 2010, Australia
- Optical Imaging Centre Erlangen OICE, Cauerstr. 3, 91058 Erlangen, Bavaria, Germany
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Abstract
A substantial intracellular localization of matrix metalloproteinase 2 (MMP2) has been reported in cardiomyocytes, where it plays a role in the degradation of the contractile apparatus following ischemia-reperfusion injury. Whether MMP2 may have a similar function in skeletal muscle is unknown. This study determined that the absolute amount of MMP2 is similar in rat skeletal and cardiac muscle and human muscle (~10-18 nmol/kg muscle wet wt) but is ~50- to 100-fold less than the amount of calpain-1. We compared mechanically skinned muscle fibers, where the extracellular matrix (ECM) is completely removed, with intact fiber segments and found that ~30% of total MMP2 was associated with the ECM, whereas ~70% was inside the muscle fibers. Concordant with whole muscle fractionation, further separation of skinned fiber segments into cytosolic, membranous, and cytoskeletal and nuclear compartments indicated that ~57% of the intracellular MMP2 was freely diffusible, ~6% was associated with the membrane, and ~37% was bound within the fiber. Under native zymography conditions, only 10% of MMP2 became active upon prolonged (17 h) exposure to 20 μM Ca2+, a concentration that would fully activate calpain-1 in seconds to minutes; full activation of MMP2 would require ~1 mM Ca2+. Given the prevalence of intracellular MMP2 in skeletal muscle, it is necessary to investigate its function using physiological conditions, including isolation of any potential functional relevance of MMP2 from that of the abundant protease calpain-1.
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Affiliation(s)
- Xiaoyu Ren
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Graham D Lamb
- School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia
| | - Robyn M Murphy
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
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Murgia M, Toniolo L, Nagaraj N, Ciciliot S, Vindigni V, Schiaffino S, Reggiani C, Mann M. Single Muscle Fiber Proteomics Reveals Fiber-Type-Specific Features of Human Muscle Aging. Cell Rep 2018; 19:2396-2409. [PMID: 28614723 DOI: 10.1016/j.celrep.2017.05.054] [Citation(s) in RCA: 169] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 04/10/2017] [Accepted: 05/17/2017] [Indexed: 12/20/2022] Open
Abstract
Skeletal muscle is a key tissue in human aging, which affects different muscle fiber types unequally. We developed a highly sensitive single muscle fiber proteomics workflow to study human aging and show that the senescence of slow and fast muscle fibers is characterized by diverging metabolic and protein quality control adaptations. Whereas mitochondrial content declines with aging in both fiber types, glycolysis and glycogen metabolism are upregulated in slow but downregulated in fast muscle fibers. Aging mitochondria decrease expression of the redox enzyme monoamine oxidase A. Slow fibers upregulate a subset of actin and myosin chaperones, whereas an opposite change happens in fast fibers. These changes in metabolism and sarcomere quality control may be related to the ability of slow, but not fast, muscle fibers to maintain their mass during aging. We conclude that single muscle fiber analysis by proteomics can elucidate pathophysiology in a sub-type-specific manner.
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Affiliation(s)
- Marta Murgia
- Max-Planck-Institute of Biochemistry, Martinsried 82152, Germany; Department of Biomedical Science, University of Padova, Padua 35121, Italy.
| | - Luana Toniolo
- Department of Biomedical Science, University of Padova, Padua 35121, Italy
| | | | - Stefano Ciciliot
- Venetian Institute of Molecular Medicine, Padua 35129, Italy; Department of Medicine, University of Padua, Padua 35128, Italy
| | - Vincenzo Vindigni
- Department of Neurosciences, University of Padova, Padua 35128, Italy
| | | | - Carlo Reggiani
- Department of Biomedical Science, University of Padova, Padua 35121, Italy
| | - Matthias Mann
- Max-Planck-Institute of Biochemistry, Martinsried 82152, Germany.
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Wette SG, Smith HK, Lamb GD, Murphy RM. Characterization of muscle ankyrin repeat proteins in human skeletal muscle. Am J Physiol Cell Physiol 2017; 313:C327-C339. [PMID: 28615162 DOI: 10.1152/ajpcell.00077.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/06/2017] [Accepted: 06/13/2017] [Indexed: 12/23/2022]
Abstract
Muscle ankyrin repeat proteins (MARPs) are a family of titin-associated, stress-response molecules and putative transducers of stretch-induced signaling in skeletal muscle. In cardiac muscle, cardiac ankyrin repeat protein (CARP) and diabetes-related ankyrin repeat protein (DARP) reportedly redistribute from binding sites on titin to the nucleus following a prolonged stretch. However, it is unclear whether ankyrin repeat domain protein 2 (Ankrd 2) shows comparable stretch-induced redistribution to the nucleus. We measured the following in rested human skeletal muscle: 1) the absolute amount of MARPs and 2) the distribution of Ankrd 2 and DARP in both single fibers and whole muscle preparations. In absolute amounts, Ankrd 2 is the most abundant MARP in human skeletal muscle, there being ~3.1 µmol/kg, much greater than DARP and CARP (~0.11 and ~0.02 µmol/kg, respectively). All DARP was found to be tightly bound at cytoskeletal (or possibly nuclear) sites. In contrast, ~70% of the total Ankrd 2 is freely diffusible in the cytosol [including virtually all of the phosphorylated (p)Ankrd 2-Ser99 form], ~15% is bound to non-nuclear membranes, and ~15% is bound at cytoskeletal sites, likely at the N2A region of titin. These data are not consistent with the proposal that Ankrd 2, per se, or pAnkrd 2-Ser99 mediates stretch-induced signaling in skeletal muscle, dissociating from titin and translocating to the nucleus, because the majority of these forms of Ankrd 2 are already free in the cytosol. It will be necessary to show that the titin-associated Ankrd 2 is modified by stretch in some as-yet-unidentified way, distinct from the diffusible pool, if it is to act as a stretch-sensitive signaling molecule.
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Affiliation(s)
- Stefan G Wette
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Heather K Smith
- Department of Exercise Sciences, The University of Auckland, Auckland, New Zealand
| | - Graham D Lamb
- School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia; and
| | - Robyn M Murphy
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia;
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Rassier DE, Minozzo FC. Length-dependent Ca2+ activation in skeletal muscle fibers from mammalians. Am J Physiol Cell Physiol 2016; 311:C201-11. [PMID: 27225655 DOI: 10.1152/ajpcell.00046.2016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/23/2016] [Indexed: 11/22/2022]
Abstract
We tested the hypotheses that 1) a decrease in activation of skeletal muscles at short sarcomere lengths (SLs) is caused by an inhibition of Ca(2+) release from the sarcoplasmic reticulum (SR), and 2) the decrease in Ca(2+) would be caused by an inhibition of action potential conduction from the periphery to the core of the fibers. Intact, single fibers dissected from the flexor digitorum brevis from mice were activated at different SLs, and intracellular Ca(2+) was imaged with confocal microscopy. Force decreased at SLs shorter than 2.1 μm, while Ca(2+) concentration decreased at SLs below 1.9 μm. The concentration of Ca(2+) at short SL was lower at the core than at the peripheries of the fiber. When the external concentration of Na(+) was decreased in the experimental media, impairing action potential conduction, Ca(2+) gradients were observed in all SLs. When caffeine was used in the experimental media, the gradients of Ca(2+) were abolished. We concluded that there is an inhibition of Ca(2+) release from the sarcoplasmic reticulum (SR) at short SLs, which results from a decreased conduction of action potential from the periphery to the core of the fibers.
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Affiliation(s)
- Dilson E Rassier
- Departments of Kinesiology and Physical Education, McGill University, Montreal, Canada; Department of Physics, McGill University, Montreal Canada; Department of Physiology, McGill University, Montreal, Canada; and
| | - Fábio C Minozzo
- Departments of Kinesiology and Physical Education, McGill University, Montreal, Canada; McGill Health Centre Research Institute, Montreal, Canada
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Wyckelsma VL, McKenna MJ, Serpiello FR, Lamboley CR, Aughey RJ, Stepto NK, Bishop DJ, Murphy RM. Single-fiber expression and fiber-specific adaptability to short-term intense exercise training of Na+-K+-ATPase α- and β-isoforms in human skeletal muscle. J Appl Physiol (1985) 2015; 118:699-706. [PMID: 25614596 DOI: 10.1152/japplphysiol.00419.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The Na(+)-K(+)-ATPase (NKA) plays a key role in muscle excitability, but little is known in human skeletal muscle about fiber-type-specific differences in NKA isoform expression or adaptability. A vastus lateralis muscle biopsy was taken in 17 healthy young adults to contrast NKA isoform protein relative abundance between type I and IIa fibers. We further investigated muscle fiber-type-specific NKA adaptability in eight of these adults following 4-wk repeated-sprint exercise (RSE) training, comprising three sets of 5 × 4-s sprints, 3 days/wk. Single fibers were separated, and myosin heavy chain (I and IIa) and NKA (α1-3 and β1-3) isoform abundance were determined via Western blotting. All six NKA isoforms were expressed in both type I and IIa fibers. No differences between fiber types were found for α1-, α2-, α3-, β1-, or β3-isoform abundances. The NKA β2-isoform was 27% more abundant in type IIa than type I fibers (P < 0.05), with no other fiber-type-specific trends evident. RSE training increased β1 in type IIa fibers (pretraining 0.70 ± 0.25, posttraining 0.84 ± 0.24 arbitrary units, 42%, P < 0.05). No training effects were found for other NKA isoforms. Thus human skeletal muscle expresses all six NKA isoforms and not in a fiber-type-specific manner; this points to their different functional roles in skeletal muscle cells. Detection of elevated NKA β1 after RSE training demonstrates the sensitivity of the single-fiber Western blotting technique for fiber-type-specific intervention effects.
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Affiliation(s)
- V L Wyckelsma
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia; and
| | - M J McKenna
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia; and
| | - F R Serpiello
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia; and
| | - C R Lamboley
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia; and
| | - R J Aughey
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia; and
| | - N K Stepto
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia; and
| | - D J Bishop
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia; and
| | - R M Murphy
- Department of Biochemistry, La Trobe University, Melbourne, Victoria, Australia
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Frankenberg NT, Lamb GD, Overgaard K, Murphy RM, Vissing K. Small heat shock proteins translocate to the cytoskeleton in human skeletal muscle following eccentric exercise independently of phosphorylation. J Appl Physiol (1985) 2014; 116:1463-72. [PMID: 24699855 DOI: 10.1152/japplphysiol.01026.2013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Small heat shock proteins (sHSPs) are a subgroup of the highly conserved family of HSPs that are stress inducible and confer resistance to cellular stress and injury. This study aimed to quantitatively examine whether type of contraction (concentric or eccentric) affects sHSPs, HSP27 and αB-crystallin, localization, and phosphorylation in human muscle. Vastus lateralis muscle biopsies from 11 healthy male volunteers were obtained pre- and 3 h, 24 h, and 7 days following concentric (CONC), eccentric (ECC1), and repeated bout eccentric (ECC2) exercise. No changes were apparent in a control group (n = 5) who performed no exercise. Eccentric exercise induced muscle damage, as evidenced by increased muscle force loss, perceived muscle soreness, and elevated plasma creatine kinase and myoglobin levels. Total HSP27 and αB-crystallin amounts did not change following any type of exercise. Following eccentric exercise (ECC1 and ECC2) phosphorylation of HSP27 at serine 15 (pHSP27-Ser15) was increased approximately 3- to 6-fold at 3 h, and pαB-crystallin-Ser59 increased ~10-fold at 3 h. Prior to exercise most of the sHSP and psHSP pools were present in the cytosolic compartment. Eccentric exercise resulted in partial redistribution of HSP27 (~23%) from the cytosol to the cytoskeletal fraction (~28% for pHSP27-Ser15 and ~7% for pHSP27-Ser82), with subsequent full reversal within 24 h. αB-crystallin also showed partial redistribution from the cytosolic to cytoskeletal fraction (~18% of total) 3 h post-ECC1, but not after ECC2. There was no redistribution or phosphorylation of sHSPs with CONC. Eccentric exercise results in increased sHSP phosphorylation and translocation to the cytoskeletal fraction, but the sHSP translocation is not dependent on their phosphorylation.
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Affiliation(s)
- Noni T Frankenberg
- Department of Zoology, La Trobe University, Melbourne, Victoria, Australia; and
| | - Graham D Lamb
- Department of Zoology, La Trobe University, Melbourne, Victoria, Australia; and
| | - Kristian Overgaard
- Section of Sport Science, Department of Public Health, Aarhus University, Aarhus, Denmark
| | - Robyn M Murphy
- Department of Zoology, La Trobe University, Melbourne, Victoria, Australia; and
| | - Kristian Vissing
- Section of Sport Science, Department of Public Health, Aarhus University, Aarhus, Denmark
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