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Chun Y, Jo JH, Park JW. Effects of physical activity levels on characteristic pain in temporomandibular dysfunctions: a cross-sectional study. Head Face Med 2024; 20:6. [PMID: 38238755 PMCID: PMC10795209 DOI: 10.1186/s13005-024-00407-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 01/04/2024] [Indexed: 01/22/2024] Open
Abstract
BACKGROUND Physical activity is known to influence the symptoms of a variety of pain disorders including fibromyalgia and osteoarthritis although the underlying mechanism is not fully understood. In spite of the high prevalence of temporomandibular disorders (TMD), no previous study has objectively evaluated the relationship between TMD and general physical activity. This study aims to investigate the influence of physical activity on pain and disability from TMD, considering various confounders including sleep, systemic inflammation, psychosocial disturbances, and widespread pain. METHODS This observational cross-sectional study is based on consecutive samples of 100 TMD patients (22 with high pain disability and 78 with low pain disability level). Physical activity levels were assessed with actigraph. Level of pain and disability were evaluated using the Graded Chronic Pain Scale. Hematologic examinations including inflammatory biomarkers were assessed and comorbidities were investigated with validated questionnaires. Differences were analyzed according to disability level. RESULTS Patients with high disability level spent significantly more time doing both moderate (p = 0.033) and vigorous (p = 0.039) level physical activity. Light physical activity, on the other hand, was associated with low disability but the difference did not reach statistical significance. Time spent in light physical activity was significantly associated with high levels of pain and disability (p = 0.026, β = -0.001) and time spent in vigorous physical activity had significant predictive power (cutoff value 2.5 min per week, AUC 0.643, p = 0.041). Scores of the Jaw Function Limitation Score-20 (p = 0.001), present McGill Pain Score (p = 0.010), and number of people potentially diagnosed with fibromyalgia (p = 0.033) were significantly higher in the high disability group. CONCLUSIONS Moderate or vigorous physical activity is associated with worse TMD symptoms while light physical activity may be beneficial. Further research related to the amount and frequency of physical activity is necessary to establish clinical guidelines for TMD. TRIAL REGISTRATION clinical trial registration of the Clinical Research Information Service of Republic of Korea (number KCT0007107).
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Affiliation(s)
- Youngwoo Chun
- Department of Oral Medicine, Seoul National University Dental Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, South Korea
- Department of Oral Medicine and Oral Diagnosis, School of Dentistry, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea
| | - Jung Hwan Jo
- Department of Oral Medicine, Seoul National University Dental Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, South Korea
- Department of Oral Medicine and Oral Diagnosis, School of Dentistry, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea
| | - Ji Woon Park
- Department of Oral Medicine, Seoul National University Dental Hospital, 101, Daehak-ro, Jongno-gu, Seoul, 03080, South Korea.
- Department of Oral Medicine and Oral Diagnosis, School of Dentistry, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea.
- Dental Research Institute, Seoul National University, 101 Daehak-ro, Jongno-gu, Seoul, 03080, South Korea.
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2
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Ishii S, Oyama K, Kobirumaki-Shimozawa F, Nakanishi T, Nakahara N, Suzuki M, Ishiwata S, Fukuda N. Myosin and tropomyosin-troponin complementarily regulate thermal activation of muscles. J Gen Physiol 2023; 155:e202313414. [PMID: 37870863 PMCID: PMC10591409 DOI: 10.1085/jgp.202313414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 09/04/2023] [Accepted: 10/03/2023] [Indexed: 10/24/2023] Open
Abstract
Contraction of striated muscles is initiated by an increase in cytosolic Ca2+ concentration, which is regulated by tropomyosin and troponin acting on actin filaments at the sarcomere level. Namely, Ca2+-binding to troponin C shifts the "on-off" equilibrium of the thin filament state toward the "on" state, promoting actomyosin interaction; likewise, an increase in temperature to within the body temperature range shifts the equilibrium to the on state, even in the absence of Ca2+. Here, we investigated the temperature dependence of sarcomere shortening along isolated fast skeletal myofibrils using optical heating microscopy. Rapid heating (25 to 41.5°C) within 2 s induced reversible sarcomere shortening in relaxing solution. Further, we investigated the temperature-dependence of the sliding velocity of reconstituted fast skeletal or cardiac thin filaments on fast skeletal or β-cardiac myosin in an in vitro motility assay within the body temperature range. We found that (a) with fast skeletal thin filaments on fast skeletal myosin, the temperature dependence was comparable to that obtained for sarcomere shortening in fast skeletal myofibrils (Q10 ∼8), (b) both types of thin filaments started to slide at lower temperatures on fast skeletal myosin than on β-cardiac myosin, and (c) cardiac thin filaments slid at lower temperatures compared with fast skeletal thin filaments on either type of myosin. Therefore, the mammalian striated muscle may be fine-tuned to contract efficiently via complementary regulation of myosin and tropomyosin-troponin within the body temperature range, depending on the physiological demands of various circumstances.
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Affiliation(s)
- Shuya Ishii
- Foundational Quantum Technology Research Directorate, National Institutes for Quantum Science and Technology, Gunma, Japan
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Kotaro Oyama
- Foundational Quantum Technology Research Directorate, National Institutes for Quantum Science and Technology, Gunma, Japan
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
| | | | - Tomohiro Nakanishi
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
- Department of Anesthesiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Naoya Nakahara
- Department of Molecular Physiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Madoka Suzuki
- Institute for Protein Research, Osaka University, Osaka, Japan
| | - Shin’ichi Ishiwata
- Department of Physics, Faculty of Science and Engineering, Waseda University, Tokyo, Japan
| | - Norio Fukuda
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
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3
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Idoux R, Exbrayat-Héritier C, Sohm F, Jaque-Fernandez F, Vaganay E, Berthier C, Bretaud S, Jacquemond V, Ruggiero F, Allard B. A mechano- and heat-gated two-pore domain K + channel controls excitability in adult zebrafish skeletal muscle. Proc Natl Acad Sci U S A 2023; 120:e2305959120. [PMID: 37903280 PMCID: PMC10636360 DOI: 10.1073/pnas.2305959120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 09/26/2023] [Indexed: 11/01/2023] Open
Abstract
TRAAK channels are mechano-gated two-pore-domain K+ channels. Up to now, activity of these channels has been reported in neurons but not in skeletal muscle, yet an archetype of tissue challenged by mechanical stress. Using patch clamp methods on isolated skeletal muscle fibers from adult zebrafish, we show here that single channels sharing properties of TRAAK channels, i.e., selective to K+ ions, of 56 pS unitary conductance in the presence of 5 mM external K+, activated by membrane stretch, heat, arachidonic acid, and internal alkaline pH, are present in enzymatically isolated fast skeletal muscle fibers from adult zebrafish. The kcnk4b transcript encoding for TRAAK channels was cloned and found, concomitantly with activity of mechano-gated K+ channels, to be absent in zebrafish fast skeletal muscles at the larval stage but arising around 1 mo of age. The transfer of the kcnk4b gene in HEK cells and in the adult mouse muscle, that do not express functional TRAAK channels, led to expression and activity of mechano-gated K+ channels displaying properties comparable to native zebrafish TRAAK channels. In whole-cell voltage-clamp and current-clamp conditions, membrane stretch and heat led to activation of macroscopic K+ currents and to acceleration of the repolarization phase of action potentials respectively, suggesting that heat production and membrane deformation associated with skeletal muscle activity can control muscle excitability through TRAAK channel activation. TRAAK channels may represent a teleost-specific evolutionary product contributing to improve swimming performance for escaping predators and capturing prey at a critical stage of development.
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Affiliation(s)
- Romane Idoux
- Physiopathologie et Génétique du Neurone et du Muscle, Université Claude Bernard Lyon 1, CNRS UMR 5261, INSERM U1315, Faculté de Médecine Rockefeller, Lyon69008, France
| | - Chloé Exbrayat-Héritier
- Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, Lyon69007, France
| | - Frédéric Sohm
- Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, Lyon69007, France
| | - Francisco Jaque-Fernandez
- Physiopathologie et Génétique du Neurone et du Muscle, Université Claude Bernard Lyon 1, CNRS UMR 5261, INSERM U1315, Faculté de Médecine Rockefeller, Lyon69008, France
| | - Elisabeth Vaganay
- Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, Lyon69007, France
| | - Christine Berthier
- Physiopathologie et Génétique du Neurone et du Muscle, Université Claude Bernard Lyon 1, CNRS UMR 5261, INSERM U1315, Faculté de Médecine Rockefeller, Lyon69008, France
| | - Sandrine Bretaud
- Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, Lyon69007, France
| | - Vincent Jacquemond
- Physiopathologie et Génétique du Neurone et du Muscle, Université Claude Bernard Lyon 1, CNRS UMR 5261, INSERM U1315, Faculté de Médecine Rockefeller, Lyon69008, France
| | - Florence Ruggiero
- Institut de Génomique Fonctionnelle de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5242, Université Claude Bernard Lyon 1, Lyon69007, France
| | - Bruno Allard
- Physiopathologie et Génétique du Neurone et du Muscle, Université Claude Bernard Lyon 1, CNRS UMR 5261, INSERM U1315, Faculté de Médecine Rockefeller, Lyon69008, France
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4
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Quedan D, Singh R, Akel A, Bernardino AL, Thang C, Bhaskaruni M, Haldankar A, Tanner BCW, Root DD. Cooperative & competitive binding of anti-myosin tail antibodies revealed by super-resolution microscopy. Arch Biochem Biophys 2023; 747:109753. [PMID: 37714251 DOI: 10.1016/j.abb.2023.109753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 09/08/2023] [Accepted: 09/11/2023] [Indexed: 09/17/2023]
Abstract
The MF30 monoclonal antibody, which binds to the myosin subfragment-2 (S2), was found to increase the extent of myofibril shortening. Yet, previous observations found no effect of this antibody on actin sliding over myosin during in vitro motility assays with purified proteins in which myosin binding protein C (MyBPC) was absent. MF30 is hypothesized to enhance the availability of myosin heads (subfragment-1 or S1) to bind actin by destabilizing the myosin S2 coiled-coil and sterically blocking S2 from binding S1. The mechanism of action likely includes MF30's substantial size, thereby inhibiting S1 heads and MyBPC from binding S2. Hypothetically, MF30 should enhance the ON state of myosin, thereby increasing muscle contraction. Our findings indicate that MF30 binds preferentially to the unfolded heavy chains of S2, displaying positive cooperativity. However, the dose-response curve of MF30's enhancement of myofibril shortening did not suggest complex interactions with S2. Single, double, and triple-stained myofibrils with increasing amounts of antibodies against myosin rods indicate a possible competition with MyBPC. Additional assays revealed decreased fluorescence intensity at the C-zone (central zone in the sarcomere, where MyBPC is located), where MyBPC may inhibit MF30 binding. Another monoclonal antibody named MF20, which binds to the light meromyosin (LMM) without affecting myofibril contraction, showed less reduction in fluorescence intensity at the C-zone in expansion microscopy than MF30. Expansion microscopy images of myofibrils labeled with MF20 revealed labeling of the A-band (anisotropic band) and a slight reduction in the labeling at the C-zone. The staining pattern obtained from the expansion microscopy image was consistent with images from photolocalization microscopy which required the synthesis of unique photoactivatable quantum dots, and Zeiss Airyscan imaging as well as alternative expansion microscopy digestion methods. Consistent with the hypothesis that MF30 competes with MyBPC binding to S2, cardiac tissue from MyBPC knockout mice was stained more intensely, especially in the C-zone, by MF30 compared to the wild type.
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Affiliation(s)
- Dua'a Quedan
- Department of Biological Sciences, Division of Biochemistry and Molecular Biology, University of North Texas, Denton, TX, 76203, USA
| | - Rohit Singh
- Department of Biological Sciences, Division of Biochemistry and Molecular Biology, University of North Texas, Denton, TX, 76203, USA
| | - Amal Akel
- Department of Biological Sciences, Division of Biochemistry and Molecular Biology, University of North Texas, Denton, TX, 76203, USA
| | - Andrea L Bernardino
- Department of Biological Sciences, Division of Biochemistry and Molecular Biology, University of North Texas, Denton, TX, 76203, USA
| | - Christopher Thang
- Department of Biological Sciences, Division of Biochemistry and Molecular Biology, University of North Texas, Denton, TX, 76203, USA
| | - Mithilesh Bhaskaruni
- Department of Biological Sciences, Division of Biochemistry and Molecular Biology, University of North Texas, Denton, TX, 76203, USA
| | - Anushka Haldankar
- Department of Biological Sciences, Division of Biochemistry and Molecular Biology, University of North Texas, Denton, TX, 76203, USA
| | - Bertrand C W Tanner
- Department of Integrative Physiology & Neuroscience, Washington State University, Pullman, WA, 99164, USA
| | - Douglas D Root
- Department of Biological Sciences, Division of Biochemistry and Molecular Biology, University of North Texas, Denton, TX, 76203, USA.
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5
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Pertici I, Bongini L, Caremani M, Reconditi M, Linari M, Piazzesi G, Lombardi V, Bianco P. Matching Mechanics and Energetics of Muscle Contraction Suggests Unconventional Chemomechanical Coupling during the Actin-Myosin Interaction. Int J Mol Sci 2023; 24:12324. [PMID: 37569700 PMCID: PMC10418673 DOI: 10.3390/ijms241512324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/18/2023] [Accepted: 07/27/2023] [Indexed: 08/13/2023] Open
Abstract
The mechanical performances of the vertebrate skeletal muscle during isometric and isotonic contractions are interfaced with the corresponding energy consumptions to define the coupling between mechanical and biochemical steps in the myosin-actin energy transduction cycle. The analysis is extended to a simplified synthetic nanomachine in which eight HMM molecules purified from fast mammalian skeletal muscle are brought to interact with an actin filament in the presence of 2 mM ATP, to assess the emergent properties of a minimum number of motors working in ensemble without the effects of both the higher hierarchical levels of striated muscle organization and other sarcomeric, regulatory and cytoskeleton proteins. A three-state model of myosin-actin interaction is able to predict the known relationships between energetics and transient and steady-state mechanical properties of fast skeletal muscle either in vivo or in vitro only under the assumption that during shortening a myosin motor can interact with two actin sites during one ATP hydrolysis cycle. Implementation of the molecular details of the model should be achieved by exploiting kinetic and structural constraints present in the transients elicited by stepwise perturbations in length or force superimposed on the isometric contraction.
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Affiliation(s)
| | | | | | | | | | | | - Vincenzo Lombardi
- PhysioLab, University of Florence, 50019 Sesto Fiorentino, Italy; (I.P.); (L.B.); (M.C.); (M.R.); (M.L.); (G.P.); (P.B.)
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6
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James RS, Seebacher F, Tallis J. Can animals tune tissue mechanics in response to changing environments caused by anthropogenic impacts? J Exp Biol 2023; 226:287009. [PMID: 36779312 DOI: 10.1242/jeb.245109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Anthropogenic climate change and pollution are impacting environments across the globe. This Review summarises the potential impact of such anthropogenic effects on animal tissue mechanics, given the consequences for animal locomotor performance and behaviour. More specifically, in light of current literature, this Review focuses on evaluating the acute and chronic effects of temperature on the mechanical function of muscle tissues. For ectotherms, maximal muscle performance typically occurs at temperatures approximating the natural environment of the species. However, species vary in their ability to acclimate to chronic changes in temperature, which is likely to have longer-term effects on species range. Some species undergo periods of dormancy to avoid extreme temperature or drought. Whilst the skeletal muscle of such species generally appears to be adapted to minimise muscle atrophy and maintain performance for emergence from dormancy, the increased occurrence of extreme climatic conditions may reduce the survival of individuals in such environments. This Review also considers the likely impact of anthropogenic pollutants, such as hormones and heavy metals, on animal tissue mechanics, noting the relative paucity of literature directly investigating this key area. Future work needs to determine the direct effects of anthropogenic environmental changes on animal tissues and related changes in locomotor performance and behaviour, including accounting for currently unknown interactions between environmental factors, e.g. temperature and pollutants.
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Affiliation(s)
- Rob S James
- Faculty of Life Sciences, University of Bradford, Bradford BD7 1DP, UK
| | - Frank Seebacher
- School of Life and Environmental Sciences A08, University of Sydney, Sydney, NSW 2006, Australia
| | - Jason Tallis
- Research Centre for Sport, Exercise and Life Sciences, Coventry University, Priory Street, Coventry CV1 5FB, UK
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7
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Ranatunga KW, Geeves MA. Effects of Hydrostatic-Pressure on Muscle Contraction: A Look Back on Some Experimental Findings. Int J Mol Sci 2023; 24:5031. [PMID: 36902460 PMCID: PMC10003533 DOI: 10.3390/ijms24055031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 03/08/2023] Open
Abstract
Findings from experiments that used hydrostatic pressure changes to analyse the process of skeletal muscle contraction are re-examined. The force in resting muscle is insensitive to an increase in hydrostatic pressure from 0.1 MPa (atmospheric) to 10 MPa, as also found for force in rubber-like elastic filaments. The force in rigour muscle rises with increased pressure, as shown experimentally for normal elastic fibres (e.g., glass, collagen, keratin, etc.). In submaximal active contractions, high pressure leads to tension potentiation. The force in maximally activated muscle decreases with increased pressure: the extent of this force decrease in maximal active muscle is sensitive to the concentration of products of ATP hydrolysis (Pi-inorganic phosphate and ADP-adenosine diphosphate) in the medium. When the increased hydrostatic pressure is rapidly decreased, the force recovered to the atmospheric level in all cases. Thus, the resting muscle force remained the same: the force in the rigour muscle decreased in one phase and that in active muscle increased in two phases. The rate of rise of active force on rapid pressure release increased with the concentration of Pi in the medium, indicating that it is coupled to the Pi release step in the ATPase-driven crossbridge cycle in muscle. Pressure experiments on intact muscle illustrate possible underlying mechanisms of tension potentiation and causes of muscle fatigue.
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Affiliation(s)
- K. W. Ranatunga
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol BS8 1TD, UK
| | - M. A. Geeves
- Department of Biosciences, University of Kent, Kent, Canterbury CT2 7NJ, UK
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8
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Ogorodnik E, Karsai A, Liu YX, Di Lucente J, Huang Y, Keel T, Haudenschild DR, Jin LW, Liu GY. Mechanical Cues for Triggering and Regulating Cellular Movement Selectively at the Single-Cell Level. J Phys Chem B 2023; 127:866-873. [PMID: 36652348 DOI: 10.1021/acs.jpcb.2c06461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Cell motility plays important roles in many biophysical and physiological processes ranging from in vitro biomechanics, wound healing, to cancer metastasis. This work introduces a new means to trigger and regulate motility individually using transient mechanical stimulus applied to designated cells. Using BV2 microglial cells, our investigations indicate that motility can be reproducibly and reliably initiated using mechanical compression of the cells. The location and magnitude of the applied force impact the movement of the cell. Based on observations from this investigation and current knowledge of BV2 cellular motility, new physical insights are revealed into the underlying mechanism of force-induced single cellular movement. The process involves high degrees of myosin activation to repair actin cortex breakages induced by the initial mechanical compression, which leads to focal adhesion degradation, lamellipodium detachment, and finally, cell polarization and movement. Modern technology enables accurate control over force magnitude and location of force delivery, thus bringing us closer to programming cellular movement at the single-cell level. This approach is of generic importance to other cell types beyond BV2 cells and has the intrinsic advantages of being transient, non-toxic, and non-destructive, thus exhibiting high translational potentials including mechano-based therapy.
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Affiliation(s)
- Evgeny Ogorodnik
- Biophysics Graduate Group, University of California, Davis, California 95616, United States
| | - Arpad Karsai
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Ying X Liu
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Jacopo Di Lucente
- M.I.N.D. Institute, Department of Pathology and Laboratory Medicine, University of California Davis Medical Center, Sacramento, California 95817, United States
| | - Yuqi Huang
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Terell Keel
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Dominik R Haudenschild
- Department of Orthopedic Surgery, University of California Davis School of Medicine, Sacramento, California 95817, United States
| | - Lee-Way Jin
- M.I.N.D. Institute, Department of Pathology and Laboratory Medicine, University of California Davis Medical Center, Sacramento, California 95817, United States
| | - Gang-Yu Liu
- Biophysics Graduate Group, University of California, Davis, California 95616, United States.,Department of Chemistry, University of California, Davis, California 95616, United States
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9
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Richard NA, Koehle MS. Influence and Mechanisms of Action of Environmental Stimuli on Work Near and Above the Severe Domain Boundary (Critical Power). SPORTS MEDICINE - OPEN 2022; 8:42. [PMID: 35347469 PMCID: PMC8960528 DOI: 10.1186/s40798-022-00430-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 02/26/2022] [Indexed: 11/10/2022]
Abstract
Abstract
The critical power (CP) concept represents the uppermost rate of steady state aerobic metabolism during work. Work above CP is limited by a fixed capacity (W′) with exercise intensity being an accelerant of its depletion rate. Exercise at CP is a considerable insult to homeostasis and any work done above it will rapidly become intolerable. Humans live and exercise in situations of hypoxia, heat, cold and air pollution all of which impose a new environmental stress in addition to that of exercise. Hypoxia disrupts the oxygen cascade and consequently aerobic energy production, whereas heat impacts the circulatory system’s ability to solely support exercise performance. Cold lowers efficiency and increases the metabolic cost of exercise, whereas air pollution negatively impacts the respiratory system. This review will examine the effects imposed by environmental conditions on CP and W′ and describe the key physiological mechanisms which are affected by the environment.
Graphical Abstract
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10
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Hinks A, Jacob K, Mashouri P, Medak KD, Franchi MV, Wright DC, Brown SHM, Power GA. Influence of weighted downhill running training on serial sarcomere number and work loop performance in the rat soleus. Biol Open 2022; 11:276077. [PMID: 35876382 PMCID: PMC9346294 DOI: 10.1242/bio.059491] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 06/23/2022] [Indexed: 12/16/2022] Open
Abstract
Increased serial sarcomere number (SSN) has been observed in rats following downhill running training due to the emphasis on active lengthening contractions; however, little is known about the influence on dynamic contractile function. Therefore, we employed 4 weeks of weighted downhill running training in rats, then assessed soleus SSN and work loop performance. We hypothesised trained rats would produce greater net work output during work loops due to a greater SSN. Thirty-one Sprague-Dawley rats were assigned to a training or sedentary control group. Weight was added during downhill running via a custom-made vest, progressing from 5–15% body mass. Following sacrifice, the soleus was dissected, and a force-length relationship was constructed. Work loops (cyclic muscle length changes) were then performed about optimal muscle length (LO) at 1.5–3-Hz cycle frequencies and 1–7-mm length changes. Muscles were then fixed in formalin at LO. Fascicle lengths and sarcomere lengths were measured to calculate SSN. Intramuscular collagen content and crosslinking were quantified via a hydroxyproline content and pepsin-solubility assay. Trained rats had longer fascicle lengths (+13%), greater SSN (+8%), and a less steep passive force-length curve than controls (P<0.05). There were no differences in collagen parameters (P>0.05). Net work output was greater (+78–209%) in trained than control rats for the 1.5-Hz work loops at 1 and 3-mm length changes (P<0.05), however, net work output was more related to maximum specific force (R2=0.17-0.48, P<0.05) than SSN (R2=0.03-0.07, P=0.17-0.86). Therefore, contrary to our hypothesis, training-induced sarcomerogenesis likely contributed little to the improvements in work loop performance. This article has an associated First Person interview with the first author of the paper. Summary: An investigation of adaptations in mechanical function induced by a novel method of weighted downhill running training in rats, and the connections to adaptations in muscle architecture.
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Affiliation(s)
- Avery Hinks
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Kaitlyn Jacob
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Parastoo Mashouri
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Kyle D Medak
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Martino V Franchi
- Department of Biomedical Sciences, Neuromuscular Physiology Laboratory, University of Padua, Padua 35122, Italy
| | - David C Wright
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada.,School of Kinesiology, Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Stephen H M Brown
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
| | - Geoffrey A Power
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, 50 Stone Road East, Guelph, ON N1G 2W1, Canada
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11
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Weidner S, Tomalka A, Rode C, Siebert T. How velocity impacts eccentric force generation of fully activated skinned skeletal muscle fibers in long stretches. J Appl Physiol (1985) 2022; 133:223-233. [PMID: 35652830 DOI: 10.1152/japplphysiol.00735.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Eccentric muscle contractions are fundamental to everyday life. They occur markedly in jumping, running, and accidents. Following an initial force rise, stretching of a fully activated muscle can result in a phase of decreasing force ('Give') followed by force redevelopment. However, how the stretch velocity affects 'Give' and force redevelopment remains largely unknown. We investigated the force produced by fully activated single skinned fibers of rat extensor digitorum longus muscles during long stretches. Fibers were pulled from length .85 to 1.3 optimal fiber length at a rate of 1, 10 and 100% of the estimated maximum shortening velocity. 'Give' was absent in slow stretches. Medium and fast stretches yielded a clear 'Give'. After the initial force peak, forces decreased by 11.2% and 27.8% relative to the initial peak force before rising again. During the last half of the stretch (from 1.07 to 1.3 optimal fiber length, which is within the range of the expected descending limb of the force-length relationship), the linear force slope tripled from slow to medium stretch and increased further by 60% from medium to fast stretch. These results are compatible with forcible cross-bridge detachment and re-development of a cross-bridge distribution, and a viscoelastic titin contribution to fiber force. Accounting for these results can improve muscle models and predictions of multi-body simulations.
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Affiliation(s)
- Sven Weidner
- nstitute of Sport and Movement Science, Department of Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany
| | - André Tomalka
- nstitute of Sport and Movement Science, Department of Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany
| | - Christian Rode
- nstitute of Sport Science, Department of Biomechanics, University of Rostock, Rostock, Germany
| | - Tobias Siebert
- nstitute of Sport and Movement Science, Department of Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany.,Stuttgart Center of Simulation Science, University of Stuttgart, Stuttgart, Germany
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12
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Tallis J, James RS, Emma LJE, Cox VM, Hurst J. High-fat diet affects measures of skeletal muscle contractile performance in a temperature specific manner but does not influence regional thermal sensitivity. J Exp Biol 2022; 225:275327. [PMID: 35363265 DOI: 10.1242/jeb.244178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 03/25/2022] [Indexed: 11/20/2022]
Abstract
The present study examined if 20-weeks high-fat diet (HFD) consumption had a temperature specific effect on the contractile performance and regional thermal sensitivity of isolated mouse soleus (SOL) and diaphragm (DIA) muscle. Four-week-old female CD-1 mice were randomly selected to consume either a standard laboratory diet or a standard laboratory diet in conjunction with a HFD for 20-weeks. Peripheral SOL and core DIA were isolated from each animal and maximal isometric force and work loop power were assessed at 20⁰C, 28⁰C, 35⁰C and 40⁰C. Increasing temperature to 35⁰C resulted in greater isometric stress, lower activation and relaxation time and higher work loop power in both muscles. A further increase in temperature to 40⁰C did not affect isometric force but increased work loop power output of the SOL. Conversely, isometric force of the DIA was reduced and work loop power maintained when temperature was increased to 40⁰C. HFD consumption resulted in greater isometric force and absolute work loop power of the SOL and reduced isometric stress of the DIA, effects that were less apparent at lower temperatures. When the relationship between temperature and each measure of contractile function was examined by linear regression, there was no difference in slope between the control or HFD groups for either SOL or DIA. These results indicate that whilst contractile function initially increases with temperature, the temperature to elicit maximal performance is muscle and contractile mode-specific. Furthermore, HFD effects on contractile function are temperature specific, but HFD does not influence the relationship between temperature and performance.
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Affiliation(s)
- Jason Tallis
- Research Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, UK
| | - Rob S James
- Research Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, UK
| | - L J Eyre Emma
- Research Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, UK
| | - Val M Cox
- Research Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, UK
| | - Josh Hurst
- Research Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, UK
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13
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Opto-thermal technologies for microscopic analysis of cellular temperature-sensing systems. Biophys Rev 2021; 14:41-54. [PMID: 35340595 PMCID: PMC8921355 DOI: 10.1007/s12551-021-00854-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 10/12/2021] [Indexed: 12/15/2022] Open
Abstract
AbstractCould enzymatic activities and their cooperative functions act as cellular temperature-sensing systems? This review introduces recent opto-thermal technologies for microscopic analyses of various types of cellular temperature-sensing system. Optical microheating technologies have been developed for local and rapid temperature manipulations at the cellular level. Advanced luminescent thermometers visualize the dynamics of cellular local temperature in space and time during microheating. An optical heater and thermometer can be combined into one smart nanomaterial that demonstrates hybrid function. These technologies have revealed a variety of cellular responses to spatial and temporal changes in temperature. Spatial temperature gradients cause asymmetric deformations during mitosis and neurite outgrowth. Rapid changes in temperature causes imbalance of intracellular Ca2+ homeostasis and membrane potential. Among those responses, heat-induced muscle contractions are highlighted. It is also demonstrated that the short-term heating hyperactivates molecular motors to exceed their maximal activities at optimal temperatures. We discuss future prospects for opto-thermal manipulation of cellular functions and contributions to obtain a deeper understanding of the mechanisms of cellular temperature-sensing systems.
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14
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Effects of temperature on the locomotor performance and contraction properties of skeletal muscle from two Phrynocephalus lizards at high and low altitude. J Comp Physiol B 2021; 191:907-916. [PMID: 34341847 DOI: 10.1007/s00360-021-01391-9] [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: 01/13/2021] [Revised: 04/16/2021] [Accepted: 07/01/2021] [Indexed: 01/31/2023]
Abstract
Locomotor performance and skeletal muscle contraction are critical for animals and are susceptible to changes in the external thermal environment, especially for ectotherms. Phrynocephalus erythrurus, which is endemic to the Qinghai-Tibetan plateau, is known for living at the highest elevation among all reptiles in the world (4500-5300 m). In this study, which compares P. erythrurus with the lowland Phrynocephalus przewalskii, we evaluated the locomotor performance at different body temperatures, the effects of temperature and oxygen partial pressure (PO2) on the contractile properties of iliofibularis (IF) muscle in vitro, ATPase activity of IF muscle at different temperatures, and the fiber types of IF muscle. Lowland P. przewalskii runs significantly faster than highland P. erythrurus at all test body temperatures. Almost all contractile properties of the IF muscle of P. przewalskii were better than that of P. erythrurus under all test temperatures and PO2. However, P. erythrurus could achieve both optimal isometric (e.g., dPo/dt) and optimal isotonic (e.g., Vmax) contraction at a lower temperature compared with P. przewalskii. Multi-factor analysis further revealed that temperature has a significant effect on the contractile properties of IF muscle for both species. Although the proportion of fibers types and ATPase activities of IF muscle have no significant interspecies difference, the changing pattern of ATPase activities with temperature is consistent with certain contractile properties and locomotor performance. The interspecies differences in locomotor ability and contractile properties of skeletal muscle in high- and low-altitude lizards may be the results of long-term adaptation to the local environment.
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15
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Fenwick AJ, Lin DC, Tanner BCW. Myosin cross-bridge kinetics slow at longer muscle lengths during isometric contractions in intact soleus from mice. Proc Biol Sci 2021; 288:20202895. [PMID: 33975478 DOI: 10.1098/rspb.2020.2895] [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] [Indexed: 11/12/2022] Open
Abstract
Muscle contraction results from force-generating cross-bridge interactions between myosin and actin. Cross-bridge cycling kinetics underlie fundamental contractile properties, such as active force production and energy utilization. Factors that influence cross-bridge kinetics at the molecular level propagate through the sarcomeres, cells and tissue to modulate whole-muscle function. Conversely, movement and changes in the muscle length can influence cross-bridge kinetics on the molecular level. Reduced, single-molecule and single-fibre experiments have shown that increasing the strain on cross-bridges may slow their cycling rate and prolong their attachment duration. However, whether these strain-dependent cycling mechanisms persist in the intact muscle tissue, which encompasses more complex organization and passive elements, remains unclear. To investigate this multi-scale relationship, we adapted traditional step-stretch protocols for use with mouse soleus muscle during isometric tetanic contractions, enabling novel estimates of length-dependent cross-bridge kinetics in the intact skeletal muscle. Compared to rates at the optimal muscle length (Lo), we found that cross-bridge detachment rates increased by approximately 20% at 90% of Lo (shorter) and decreased by approximately 20% at 110% of Lo (longer). These data indicate that cross-bridge kinetics vary with whole-muscle length during intact, isometric contraction, which could intrinsically modulate force generation and energetics, and suggests a multi-scale feedback pathway between whole-muscle function and cross-bridge activity.
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Affiliation(s)
- Axel J Fenwick
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA.,Washington Center for Muscle Biology, Washington State University, Pullman, WA 99164, USA
| | - David C Lin
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA.,Washington Center for Muscle Biology, Washington State University, Pullman, WA 99164, USA.,The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164, USA
| | - Bertrand C W Tanner
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164, USA.,Washington Center for Muscle Biology, Washington State University, Pullman, WA 99164, USA
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16
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Hurr C. Acute Local Cooling to the Lower Body during Recovery Does Not Improve Repeated Vertical Jump Performance. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18095026. [PMID: 34068730 PMCID: PMC8126198 DOI: 10.3390/ijerph18095026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 04/15/2021] [Accepted: 05/05/2021] [Indexed: 12/03/2022]
Abstract
BACKGROUND: Local cooling, or cryotherapy, has received attention due to its effects on athlete recovery before or after strenuous exercise. This study seeks to verify the effectiveness of 3 min applications of acute local cooling to the lower extremities between sets of a repeated vertical jump exercise. METHODS: Using a randomized crossover design, twelve subjects performed a total of 3 sets of 30 consecutive maximal vertical jumps and were allowed a recovery period of 5 min after each set. In the recovery period, subjects rested with or without a cooling suit worn on their lower legs. Changes in heart rate, blood lactate, and rate of perceived exertion were assessed. RESULTS: Vertical jump performance steadily decreased during 30 consecutive vertical jumps in all 3 sets; however, no differences in jump performance were observed among the groups. Heart rate, blood lactate, and rate of perceived exertion tended to be lower in the cooling recovery group relative to the control group. CONCLUSION: The current study provides evidence that acute local cooling recovery after a vertical jump exercise may not add any performance benefits but may provide a psychological benefit. The effectiveness of acute local cooling in other functional performances should be addressed in further research.
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Affiliation(s)
- Chansol Hurr
- Integrative Exercise Physiology Laboratory, Department of Physical Education, Jeonbuk National University, 567 Baekje-daero, Jeollabuk-do, Jeonju-si 54896, Korea
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17
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Hessel AL, Monroy JA, Nishikawa KC. Non-cross Bridge Viscoelastic Elements Contribute to Muscle Force and Work During Stretch-Shortening Cycles: Evidence From Whole Muscles and Permeabilized Fibers. Front Physiol 2021; 12:648019. [PMID: 33854441 PMCID: PMC8039322 DOI: 10.3389/fphys.2021.648019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 03/08/2021] [Indexed: 12/27/2022] Open
Abstract
The sliding filament-swinging cross bridge theory of skeletal muscle contraction provides a reasonable description of muscle properties during isometric contractions at or near maximum isometric force. However, it fails to predict muscle force during dynamic length changes, implying that the model is not complete. Mounting evidence suggests that, along with cross bridges, a Ca2+-sensitive viscoelastic element, likely the titin protein, contributes to muscle force and work. The purpose of this study was to develop a multi-level approach deploying stretch-shortening cycles (SSCs) to test the hypothesis that, along with cross bridges, Ca2+-sensitive viscoelastic elements in sarcomeres contribute to force and work. Using whole soleus muscles from wild type and mdm mice, which carry a small deletion in the N2A region of titin, we measured the activation- and phase-dependence of enhanced force and work during SSCs with and without doublet stimuli. In wild type muscles, a doublet stimulus led to an increase in peak force and work per cycle, with the largest effects occurring for stimulation during the lengthening phase of SSCs. In contrast, mdm muscles showed neither doublet potentiation features, nor phase-dependence of activation. To further distinguish the contributions of cross bridge and non-cross bridge elements, we performed SSCs on permeabilized psoas fiber bundles activated to different levels using either [Ca2+] or [Ca2+] plus the myosin inhibitor 2,3-butanedione monoxime (BDM). Across activation levels ranging from 15 to 100% of maximum isometric force, peak force, and work per cycle were enhanced for fibers in [Ca2+] plus BDM compared to [Ca2+] alone at a corresponding activation level, suggesting a contribution from Ca2+-sensitive, non-cross bridge, viscoelastic elements. Taken together, our results suggest that a tunable viscoelastic element such as titin contributes to: (1) persistence of force at low [Ca2+] in doublet potentiation; (2) phase- and length-dependence of doublet potentiation observed in wild type muscles and the absence of these effects in mdm muscles; and (3) increased peak force and work per cycle in SSCs. We conclude that non-cross bridge viscoelastic elements, likely titin, contribute substantially to muscle force and work, as well as the phase-dependence of these quantities, during dynamic length changes.
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Affiliation(s)
- Anthony L Hessel
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - Jenna A Monroy
- W.M. Keck Science Department, Claremont Colleges, Claremont, CA, United States
| | - Kiisa C Nishikawa
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, United States
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18
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Pertici I, Bianchi G, Bongini L, Lombardi V, Bianco P. A Myosin II-Based Nanomachine Devised for the Study of Ca 2+-Dependent Mechanisms of Muscle Regulation. Int J Mol Sci 2020; 21:ijms21197372. [PMID: 33036217 PMCID: PMC7583892 DOI: 10.3390/ijms21197372] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/01/2020] [Accepted: 10/02/2020] [Indexed: 02/03/2023] Open
Abstract
The emergent properties of the array arrangement of the molecular motor myosin II in the sarcomere of the striated muscle, the generation of steady force and shortening, can be studied in vitro with a synthetic nanomachine made of an ensemble of eight heavy-meromyosin (HMM) fragments of myosin from rabbit psoas muscle, carried on a piezoelectric nanopositioner and brought to interact with a properly oriented actin filament attached via gelsolin (a Ca2+-regulated actin binding protein) to a bead trapped by dual laser optical tweezers. However, the application of the original version of the nanomachine to investigate the Ca2+-dependent regulation mechanisms of the other sarcomeric (regulatory or cytoskeleton) proteins, adding them one at a time, was prevented by the impossibility to preserve [Ca2+] as a free parameter. Here, the nanomachine is implemented by assembling the bead-attached actin filament with the Ca2+-insensitive gelsolin fragment TL40. The performance of the nanomachine is determined both in the absence and in the presence of Ca2+ (0.1 mM, the concentration required for actin attachment to the bead with gelsolin). The nanomachine exhibits a maximum power output of 5.4 aW, independently of [Ca2+], opening the possibility for future studies of the Ca2+-dependent function/dysfunction of regulatory and cytoskeletal proteins.
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19
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Special Issue: The Actin-Myosin Interaction in Muscle: Background and Overview. Int J Mol Sci 2019; 20:ijms20225715. [PMID: 31739584 PMCID: PMC6887992 DOI: 10.3390/ijms20225715] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 10/15/2019] [Indexed: 12/12/2022] Open
Abstract
Muscular contraction is a fundamental phenomenon in all animals; without it life as we know it would be impossible. The basic mechanism in muscle, including heart muscle, involves the interaction of the protein filaments myosin and actin. Motility in all cells is also partly based on similar interactions of actin filaments with non-muscle myosins. Early studies of muscle contraction have informed later studies of these cellular actin-myosin systems. In muscles, projections on the myosin filaments, the so-called myosin heads or cross-bridges, interact with the nearby actin filaments and, in a mechanism powered by ATP-hydrolysis, they move the actin filaments past them in a kind of cyclic rowing action to produce the macroscopic muscular movements of which we are all aware. In this special issue the papers and reviews address different aspects of the actin-myosin interaction in muscle as studied by a plethora of complementary techniques. The present overview provides a brief and elementary introduction to muscle structure and function and the techniques used to study it. It goes on to give more detailed descriptions of what is known about muscle components and the cross-bridge cycle using structural biology techniques, particularly protein crystallography, electron microscopy and X-ray diffraction. It then has a quick look at muscle mechanics and it summarises what can be learnt about how muscle works based on the other studies covered in the different papers in the special issue. A picture emerges of the main molecular steps involved in the force-producing process; steps that are also likely to be seen in non-muscle myosin interactions with cellular actin filaments. Finally, the remarkable advances made in studying the effects of mutations in the contractile assembly in causing specific muscle diseases, particularly those in heart muscle, are outlined and discussed.
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20
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Ishii S, Oyama K, Arai T, Itoh H, Shintani SA, Suzuki M, Kobirumaki-Shimozawa F, Terui T, Fukuda N, Ishiwata S. Microscopic heat pulses activate cardiac thin filaments. J Gen Physiol 2019; 151:860-869. [PMID: 31010810 PMCID: PMC6572001 DOI: 10.1085/jgp.201812243] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 02/20/2019] [Accepted: 03/31/2019] [Indexed: 11/30/2022] Open
Abstract
During the excitation-contraction coupling of the heart, sarcomeres are activated via thin filament structural changes (i.e., from the "off" state to the "on" state) in response to a release of Ca2+ from the sarcoplasmic reticulum. This process involves chemical reactions that are highly dependent on ambient temperature; for example, catalytic activity of the actomyosin ATPase rises with increasing temperature. Here, we investigate the effects of rapid heating by focused infrared (IR) laser irradiation on the sliding of thin filaments reconstituted with human α-tropomyosin and bovine ventricular troponin in an in vitro motility assay. We perform high-precision analyses measuring temperature by the fluorescence intensity of rhodamine-phalloidin-labeled F-actin coupled with a fluorescent thermosensor sheet containing the temperature-sensitive dye Europium (III) thenoyltrifluoroacetonate trihydrate. This approach enables a shift in temperature from 25°C to ∼46°C within 0.2 s. We find that in the absence of Ca2+ and presence of ATP, IR laser irradiation elicits sliding movements of reconstituted thin filaments with a sliding velocity that increases as a function of temperature. The heating-induced acceleration of thin filament sliding likewise occurs in the presence of Ca2+ and ATP; however, the temperature dependence is more than twofold less pronounced. These findings could indicate that in the mammalian heart, the on-off equilibrium of the cardiac thin filament state is partially shifted toward the on state in diastole at physiological body temperature, enabling rapid and efficient myocardial dynamics in systole.
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Affiliation(s)
- Shuya Ishii
- Department of Physics, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Kotaro Oyama
- Department of Physics, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
- Quantum Beam Science Research Directorate, National Institutes for Quantum and Radiological Science and Technology, Gunma, Japan
- PRESTO, Japan Science and Technology Agency, Saitama, Japan
| | - Tomomi Arai
- Department of Physics, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Hideki Itoh
- Department of Physics, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
- Epithelial Biology Laboratory, Institute of Medical Biology, Agency for Science, Technology and Research, Singapore, Singapore
| | | | - Madoka Suzuki
- PRESTO, Japan Science and Technology Agency, Saitama, Japan
- Institute for Protein Research, Osaka University, Osaka, Japan
| | | | - Takako Terui
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
- Department of Anesthesiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Norio Fukuda
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Shin'ichi Ishiwata
- Department of Physics, Faculty of Science and Engineering, Waseda University, Tokyo, Japan
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21
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Ikegami R, Eshima H, Mashio T, Ishiguro T, Hoshino D, Poole DC, Kano Y. Accumulation of intramyocyte TRPV1-mediated calcium during heat stress is inhibited by concomitant muscle contractions. J Appl Physiol (1985) 2019; 126:691-698. [PMID: 30676872 DOI: 10.1152/japplphysiol.00668.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Heat stress promotes intramyocyte calcium concentration ([Ca2+]i) accumulation via transient receptor potential vanilloid 1 (TRPV1) channels. We tested the hypothesis that muscle contractile activity concomitant with heat stress would accelerate the increase in [Ca2+]i via TRPV1, further impairing [Ca2+]i homeostasis. Spinotrapezius muscles of adult Wistar rats were exteriorized in vivo and loaded with the fluorescent Ca2+ probe fura 2-AM. Heat stress (muscle surface temperature 40°C) was used as TRPV1 activator. An isometric contraction (100 Hz, 5-10 V, 30 s) was induced electrically concomitant with heat stress. [Ca2+]i was determined for 20 min using in vivo fluorescence microscopy, and the phosphorylation response of TRPV1 was determined by Western blotting. Heat stress induced a significant [Ca2+]i increase of 18.5 ± 8.1% at 20 min and TRPV1 phosphorylation (+231%), which was inhibited by addition of the TRPV1 inhibitor (capsazepine). However, contrary to expectations, the heat stress and isometric contraction condition almost completely inhibited TRPV1 phosphorylation and the consequent [Ca2+]i elevation (<2.8% accumulation during heat stress, P > 0.05). In conclusion, this in vivo physiological model demonstrated that isometric muscle contraction(s) can suppress the phosphorylation response of TRPV1 and maintain [Ca2+]i homeostasis during heat stress. NEW & NOTEWORTHY This investigation is the first document the dynamics of intramyocyte calcium concentration ([Ca2+]i) increase in the myoplasm of skeletal muscle fibers in response to heat stress where the muscle blood flow is preserved. Heat stress at 40°C drives a myoplasmic [Ca2+]i accumulation in concert with transient receptor potential vanilloid 1 (TRPV1) phosphorylation. However, muscle contraction caused TRPV1 channel deactivation by dephosphorylation of TRPV1. TRPV1 inactivation via isometric contraction(s) permits maintenance of [Ca2+]i homeostasis even under high imposed muscle temperature.
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Affiliation(s)
- Ryo Ikegami
- Department of Engineering Science, Bioscience, and Technology Program, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo , Japan
| | - Hiroaki Eshima
- Department of Nutrition and Integrative Physiology, University of Utah School of Medicine , Salt Lake City, Utah
| | - Takuro Mashio
- Department of Engineering Science, Bioscience, and Technology Program, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo , Japan
| | - Tomosada Ishiguro
- Department of Engineering Science, Bioscience, and Technology Program, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo , Japan
| | - Daisuke Hoshino
- Department of Engineering Science, Bioscience, and Technology Program, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo , Japan
| | - David C Poole
- Departments of Anatomy and Physiology and Kinesiology, Kansas State University , Manhattan, Kansas
| | - Yutaka Kano
- Department of Engineering Science, Bioscience, and Technology Program, The University of Electro-Communications, Chofugaoka, Chofu, Tokyo , Japan
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22
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James RS, Tallis J. The likely effects of thermal climate change on vertebrate skeletal muscle mechanics with possible consequences for animal movement and behaviour. CONSERVATION PHYSIOLOGY 2019; 7:coz066. [PMID: 31687144 PMCID: PMC6822537 DOI: 10.1093/conphys/coz066] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 07/26/2019] [Accepted: 08/12/2019] [Indexed: 05/05/2023]
Abstract
Climate change can involve alteration in the local temperature that an animal is exposed to, which in turn may affect skeletal muscle temperature. The underlying effects of temperature on the mechanical performance of skeletal muscle can affect organismal performance in key activities, such as locomotion and fitness-related behaviours, including prey capture and predator avoidance. The contractile performance of skeletal muscle is optimized within a specific thermal range. An increased muscle temperature can initially cause substantial improvements in force production, faster rates of force generation, relaxation, shortening, and production of power output. However, if muscle temperature becomes too high, then maximal force production and power output can decrease. Any deleterious effects of temperature change on muscle mechanics could be exacerbated by other climatic changes, such as drought, altered water, or airflow regimes that affect the environment the animal needs to move through. Many species will change their location on a daily, or even seasonal basis, to modulate the temperature that they are exposed to, thereby improving the mechanical performance of their muscle. Some species undergo seasonal acclimation to optimize muscle mechanics to longer-term changes in temperature or undergo dormancy to avoid extreme climatic conditions. As local climate alters, species either cope with the change, adapt, avoid extreme climate, move, or undergo localized extinction events. Given that such outcomes will be determined by organismal performance within the thermal environment, the effects of climate change on muscle mechanics could have a major impact on the ability of a population to survive in a particular location.
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Affiliation(s)
- Rob S James
- Research Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, UK
- Corresponding author: Centre for Sport, Exercise and Life Sciences, Coventry University, Priory Street, CV1 5FB Coventry, UK.
| | - Jason Tallis
- Research Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, UK
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Do Actomyosin Single-Molecule Mechanics Data Predict Mechanics of Contracting Muscle? Int J Mol Sci 2018; 19:ijms19071863. [PMID: 29941816 PMCID: PMC6073448 DOI: 10.3390/ijms19071863] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 06/19/2018] [Accepted: 06/20/2018] [Indexed: 12/15/2022] Open
Abstract
In muscle, but not in single-molecule mechanics studies, actin, myosin and accessory proteins are incorporated into a highly ordered myofilament lattice. In view of this difference we compare results from single-molecule studies and muscle mechanics and analyze to what degree data from the two types of studies agree with each other. There is reasonable correspondence in estimates of the cross-bridge power-stroke distance (7–13 nm), cross-bridge stiffness (~2 pN/nm) and average isometric force per cross-bridge (6–9 pN). Furthermore, models defined on the basis of single-molecule mechanics and solution biochemistry give good fits to experimental data from muscle. This suggests that the ordered myofilament lattice, accessory proteins and emergent effects of the sarcomere organization have only minor modulatory roles. However, such factors may be of greater importance under e.g., disease conditions. We also identify areas where single-molecule and muscle data are conflicting: (1) whether force generation is an Eyring or Kramers process with just one major power-stroke or several sub-strokes; (2) whether the myofilaments and the cross-bridges have Hookean or non-linear elasticity; (3) if individual myosin heads slip between actin sites under certain conditions, e.g., in lengthening; or (4) if the two heads of myosin cooperate.
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