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Lund J, Lähteenmäki E, Eklund T, Bakke HG, Thoresen GH, Pirinen E, Jauhiainen M, Rustan AC, Lehti M. Human HDL subclasses modulate energy metabolism in skeletal muscle cells. J Lipid Res 2024; 65:100481. [PMID: 38008260 PMCID: PMC10770614 DOI: 10.1016/j.jlr.2023.100481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 11/28/2023] Open
Abstract
In addition to its antiatherogenic role, HDL reportedly modulates energy metabolism at the whole-body level. HDL functionality is associated with its structure and composition, and functional activities can differ between HDL subclasses. Therefore, we studied if HDL2 and HDL3, the two major HDL subclasses, are able to modulate energy metabolism of skeletal muscle cells. Differentiated mouse and primary human skeletal muscle myotubes were used to investigate the influences of human HDL2 and HDL3 on glucose and fatty uptake and oxidation. HDL-induced changes in lipid distribution and mRNA expression of genes related to energy substrate metabolism, mitochondrial function, and HDL receptors were studied with human myotubes. Additionally, we examined the effects of apoA-I and discoidal, reconstituted HDL particles on substrate metabolism. In mouse myotubes, HDL subclasses strongly enhanced glycolysis upon high and low glucose concentrations. HDL3 caused a minor increase in ATP-linked respiration upon glucose conditioning but HDL2 improved complex I-mediated mitochondrial respiration upon fatty acid treatment. In human myotubes, glucose metabolism was attenuated but fatty acid uptake and oxidation were markedly increased by both HDL subclasses, which also increased mRNA expression of genes related to fatty acid metabolism and HDL receptors. Finally, both HDL subclasses induced incorporation of oleic acid into different lipid classes. These results, demonstrating that HDL subclasses enhance fatty acid oxidation in human myotubes but improve anaerobic metabolism in mouse myotubes, support the role of HDL as a circulating modulator of energy metabolism. Exact mechanisms and components of HDL causing the change, require further investigation.
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Affiliation(s)
- Jenny Lund
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Emilia Lähteenmäki
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
| | - Tiia Eklund
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - Hege G Bakke
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - G Hege Thoresen
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway; Department of Pharmacology, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Eija Pirinen
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Research Unit for Biomedicine and Internal Medicine, Faculty of Medicine, University of Oulu, Oulu, Finland; Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland; Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Matti Jauhiainen
- Department of Public Health and Welfare, Minerva Foundation Institute for Medical Research and Finnish Institute for Health and Welfare, Helsinki, Finland
| | - Arild C Rustan
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Maarit Lehti
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
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Irshad Z, Lund J, Sillars A, Løvsletten NG, Gharanei S, Salt IP, Freeman DJ, Gill JMR, Thoresen GH, Rustan AC, Zammit VA. The roles of DGAT1 and DGAT2 in human myotubes are dependent on donor patho-physiological background. FASEB J 2023; 37:e23209. [PMID: 37779421 PMCID: PMC10947296 DOI: 10.1096/fj.202300960rr] [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: 05/11/2023] [Revised: 09/01/2023] [Accepted: 09/06/2023] [Indexed: 10/03/2023]
Abstract
The roles of DGAT1 and DGAT2 in lipid metabolism and insulin responsiveness of human skeletal muscle were studied using cryosections and myotubes prepared from muscle biopsies from control, athlete, and impaired glucose regulation (IGR) cohorts of men. The previously observed increases in intramuscular triacylglycerol (IMTG) in athletes and IGR were shown to be related to an increase in lipid droplet (LD) area in type I fibers in athletes but, conversely, in type II fibers in IGR subjects. Specific inhibition of both diacylglycerol acyltransferase (DGAT) 1 and 2 decreased fatty acid (FA) uptake by myotubes, whereas only DGAT2 inhibition also decreased fatty acid oxidation. Fatty acid uptake in myotubes was negatively correlated with the lactate thresholds of the respective donors. DGAT2 inhibition lowered acetate uptake and oxidation in myotubes from all cohorts whereas DGAT1 inhibition had no effect. A positive correlation between acetate oxidation in myotubes and resting metabolic rate (RMR) from fatty acid oxidation in vivo was observed. Myotubes from athletes and IGR had higher rates of de novo lipogenesis from acetate that were normalized by DGAT2 inhibition. Moreover, DGAT2 inhibition in myotubes also resulted in increased insulin-induced Akt phosphorylation. The differential effects of DGAT1 and DGAT2 inhibition suggest that the specialized role of DGAT2 in esterifying nascent diacylglycerols and de novo synthesized FA is associated with synthesis of a pool of triacylglycerol, which upon hydrolysis results in effectors that promote mitochondrial fatty acid oxidation but decrease insulin signaling in skeletal muscle cells.
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Affiliation(s)
- Zehra Irshad
- Translational and Experimental Medicine, Warwick Medical SchoolUniversity of WarwickCoventryUK
| | - Jenny Lund
- Section for Pharmacology and Pharmaceutical Biosciences, Department of PharmacyUniversity of OsloOsloNorway
| | - Anne Sillars
- School of Cardiovascular and Metabolic Health, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Nils Gunnar Løvsletten
- Section for Pharmacology and Pharmaceutical Biosciences, Department of PharmacyUniversity of OsloOsloNorway
| | - Seley Gharanei
- Translational and Experimental Medicine, Warwick Medical SchoolUniversity of WarwickCoventryUK
- Warwickshire Institute for the Study of Diabetes, Endocrinology and Metabolism (WISDEM)University Hospitals Coventry and Warwickshire NHS TrustCoventryUK
| | - Ian P. Salt
- School of Molecular Biosciences, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Dilys J. Freeman
- School of Cardiovascular and Metabolic Health, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Jason M. R. Gill
- School of Cardiovascular and Metabolic Health, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - G. Hege Thoresen
- Section for Pharmacology and Pharmaceutical Biosciences, Department of PharmacyUniversity of OsloOsloNorway
- Department of Pharmacology, Institute of Clinical MedicineUniversity of OsloOsloNorway
| | - Arild C. Rustan
- Section for Pharmacology and Pharmaceutical Biosciences, Department of PharmacyUniversity of OsloOsloNorway
| | - Victor A. Zammit
- Translational and Experimental Medicine, Warwick Medical SchoolUniversity of WarwickCoventryUK
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Skagen C, Løvsletten NG, Asoawe L, Al-Karbawi Z, Rustan AC, Thoresen GH, Haugen F. Functional expression of the thermally activated transient receptor potential channels TRPA1 and TRPM8 in human myotubes. J Therm Biol 2023; 116:103623. [PMID: 37542841 DOI: 10.1016/j.jtherbio.2023.103623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/29/2023] [Accepted: 06/11/2023] [Indexed: 08/07/2023]
Abstract
Transient potential (TRP) ion channels expressed in primary sensory neurons act as the initial detectors of environmental cold and heat, information which controls muscle energy expenditure. We hypothesize that non-neuronal TRPs have direct cellular responses to thermal exposure, also affecting cellular metabolism. In the present study we show expression of TRPA1, TRPM8 and TRPV1 in rat skeletal muscle and human primary myotubes by qPCR. Effects of TRP activity on metabolism in human myotubes were studied using radiolabeled glucose. FURA-2 was used for Ca2+ imaging. TRPA1, TRPM8 and TRPV1 were expressed at low levels in primary human myotubes and in m. gastrocnemius, m. soleus, and m. trapezius from rat. Activation of TRPA1 by ligustilide resulted in an increased glucose uptake and oxidation in human myotubes, whereas activation of TRPM8 by menthol and icilin significantly decreased glucose uptake and oxidation. Activation of heat sensing TRPV1 by capsaicin had no effect on glucose metabolism. Agonist-induced increases in intracellular Ca2+ levels by ligustilide and icilin in human myotubes confirmed a direct activation of TRPA1 and TRPM8, respectively. The mRNA expression of some genes involved in thermogenesis, i.e. peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), uncoupling protein (UCP) 1 and UCP3, were downregulated in human myotubes following TRPA1 activation, while the mRNA expression of TRPM8 and TRPA1 were downregulated following TRPM8 activation by menthol and icilin, respectively. Cold exposure (18 °C) of cultured myotubes followed by a short recovery period had no effect on glucose uptake and oxidation in the basal situation, however when TRPA1 and TRPM8 channels were chemically inhibited a temperature-induced difference in glucose metabolism was found. In conclusion, mRNA of TRPA1, TRPM8 and TRPV1 are expressed in rat skeletal muscle and human skeletal muscle cells. Modulation of TRPA1 and TRPM8 by chemical agents induced changes in Ca2+ levels and glucose metabolism in human skeletal muscle cells, indicating functional receptors.
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Affiliation(s)
- Christine Skagen
- Division of Work Psychology and Physiology, National Institute of Occupational Health (STAMI), Oslo, Norway; Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Norway
| | - Nils Gunnar Løvsletten
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Norway
| | - Lucia Asoawe
- Division of Work Psychology and Physiology, National Institute of Occupational Health (STAMI), Oslo, Norway
| | - Zeineb Al-Karbawi
- Division of Work Psychology and Physiology, National Institute of Occupational Health (STAMI), Oslo, Norway; Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Norway
| | - Arild C Rustan
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Norway
| | - G Hege Thoresen
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Norway
| | - Fred Haugen
- Division of Work Psychology and Physiology, National Institute of Occupational Health (STAMI), Oslo, Norway.
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Giza S, Mojica‐Santiago JA, Parafati M, Malany LK, Platt D, Schmidt CE, Coen PM, Malany S. Microphysiological system for studying contractile differences in young, active, and old, sedentary adult derived skeletal muscle cells. Aging Cell 2022; 21:e13650. [PMID: 35653714 PMCID: PMC9282836 DOI: 10.1111/acel.13650] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 04/06/2022] [Accepted: 05/18/2022] [Indexed: 12/15/2022] Open
Abstract
Microphysiological systems (MPS), also referred to as tissue chips, incorporating 3D skeletal myobundles are a novel approach for physiological and pharmacological studies to uncover new medical treatments for sarcopenia. We characterize a MPS in which engineered skeletal muscle myobundles derived from donor-specific satellite cells that model aged phenotypes are encapsulated in a perfused tissue chip platform containing platinum electrodes. Our myobundles were derived from CD56+ myogenic cells obtained via percutaneous biopsy of the vastus lateralis from adults phenotyped by age and physical activity. Following 17 days differentiation including 5 days of a 3 V, 2 Hz electrical stimulation regime, the myobundles exhibited fused myotube alignment and upregulation of myogenic, myofiber assembly, signaling and contractile genes as demonstrated by gene array profiling and localization of key components of the sarcomere. Our results demonstrate that myobundles derived from the young, active (YA) group showed high intensity immunofluorescent staining of α-actinin proteins and responded to electrical stimuli with a ~1 μm displacement magnitude compared with non-stimulated myobundles. Myobundles derived from older sedentary group (OS) did not display a synchronous contraction response. Hypertrophic potential is increased in YA-derived myobundles in response to stimulation as shown by upregulation of insulin growth factor (IGF-1), α-actinin (ACTN3, ACTA1) and fast twitch troponin protein (TNNI2) compared with OS-derived myobundles. Our MPS mimics disease states of muscle decline and thus provides an aged system and experimental platform to investigate electrical stimulation mimicking exercise regimes and may be adapted to long duration studies of compound efficacy and toxicity for therapeutic evaluation against sarcopenia.
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Affiliation(s)
- Shelby Giza
- Department of Pharmacodynamics, College of PharmacyUniversity of FloridaGainesvilleFloridaUSA
| | - Jorge A. Mojica‐Santiago
- J. Crayton Pruitt Family Department of Biomedical Engineering, Herbert Wertheim College of EngineeringUniversity of FloridaGainesvilleFloridaUSA
| | - Maddalena Parafati
- Department of Pharmacodynamics, College of PharmacyUniversity of FloridaGainesvilleFloridaUSA
| | | | - Don Platt
- Micro Aerospace SolutionsMelbourneFloridaUSA
| | - Christine E. Schmidt
- J. Crayton Pruitt Family Department of Biomedical Engineering, Herbert Wertheim College of EngineeringUniversity of FloridaGainesvilleFloridaUSA
| | - Paul M. Coen
- Translational Research InstituteAdventHealthOrlandoFloridaUSA
| | - Siobhan Malany
- Department of Pharmacodynamics, College of PharmacyUniversity of FloridaGainesvilleFloridaUSA
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Skagen C, Nyman TA, Peng XR, O'Mahony G, Kase ET, Rustan AC, Thoresen GH. Chronic treatment with terbutaline increases glucose and oleic acid oxidation and protein synthesis in cultured human myotubes. CURRENT RESEARCH IN PHARMACOLOGY AND DRUG DISCOVERY 2021; 2:100039. [PMID: 34909668 PMCID: PMC8663959 DOI: 10.1016/j.crphar.2021.100039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 05/28/2021] [Accepted: 06/02/2021] [Indexed: 12/04/2022] Open
Abstract
Objective In vivo studies have reported several beneficial metabolic effects of β-adrenergic receptor agonist administration in skeletal muscle, including increased glucose uptake, fatty acid metabolism, lipolysis and mitochondrial biogenesis. Although these effects have been widely studied in vivo, the in vitro data are limited to mouse and rat cell lines. Therefore, we sought to discover the effects of the β2-adrenergic receptor agonist terbutaline on metabolism and protein synthesis in human primary skeletal muscle cells. Methods Human cultured myotubes were exposed to terbutaline in various concentrations (0.01–30 μM) for 4 or 96 h. Thereafter uptake of [14C]deoxy-D-glucose, oxydation of [14C]glucose and [14C]oleic acid were measured. Incorporation of [14C]leucine, gene expression by qPCR and proteomics analyses by mass spectrometry by the STAGE-TIP method were performed after 96 h exposure to 1 and 10 μM of terbutaline. Results The results showed that 4 h treatment with terbutaline in concentrations up to 1 μM increased glucose uptake in human myotubes, but also decreased both glucose and oleic acid oxidation along with oleic acid uptake in concentrations of 10–30 μM. Moreover, administration of terbutaline for 96 h increased glucose uptake (in terbutaline concentrations up to 1 μM) and oxidation (1 μM), as well as oleic acid oxidation (0.1–30 μM), leucine incorporation into cellular protein (1–10 μM) and upregulated several pathways related to mitochondrial metabolism (1 μM). Data are available via ProteomeXchange with identifier PXD024063. Conclusion These results suggest that β2-adrenergic receptor have direct effects in human skeletal muscle affecting fuel metabolism and net protein synthesis, effects that might be favourable for both type 2 diabetes and muscle wasting disorders. The metabolic effects of terbutaline were studied in human primary myotubes. Acute treatment with terbutaline increased glucose uptake. Chronic treatment with terbutaline increased glucose and oleic acid oxidation. Chronic treatment with terbutaline increased protein synthesis. Proteomics analysis revealed an increase in mitochondrial proteins.
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Affiliation(s)
- Christine Skagen
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Norway
| | - Tuula A Nyman
- Department of Immunology, Institute of Clinical Medicine, University of Oslo and Oslo University Hospital, Norway
| | - Xiao-Rong Peng
- Bioscience Metabolism, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Gavin O'Mahony
- Medicinal Chemsitry, Research and Early Development Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Eili Tranheim Kase
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Norway
| | - Arild Chr Rustan
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Norway
| | - G Hege Thoresen
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Norway.,Department of Pharmacology, Institute of Clinical Medicine, University of Oslo, Norway
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6
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Mengeste AM, Rustan AC, Lund J. Skeletal muscle energy metabolism in obesity. Obesity (Silver Spring) 2021; 29:1582-1595. [PMID: 34464025 DOI: 10.1002/oby.23227] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/29/2021] [Accepted: 04/06/2021] [Indexed: 01/22/2023]
Abstract
Comparing energy metabolism in human skeletal muscle and primary skeletal muscle cells in obesity, while focusing on glucose and fatty acid metabolism, shows many common changes. Insulin-mediated glucose uptake in skeletal muscle and primary myotubes is decreased by obesity, whereas differences in basal glucose metabolism are inconsistent among studies. With respect to fatty acid metabolism, there is an increased uptake and storage of fatty acids and a reduced complete lipolysis, suggesting alterations in lipid turnover. In addition, fatty acid oxidation is decreased, probably at the level of complete oxidation, as β -oxidation may be enhanced in obesity, which indicates mitochondrial dysfunction. Metabolic changes in skeletal muscle with obesity promote metabolic inflexibility, ectopic lipid accumulation, and formation of toxic lipid intermediates. Skeletal muscle also acts as an endocrine organ, secreting myokines that participate in interorgan cross talk. This review highlights interventions and some possible targets for treatment through action on skeletal muscle energy metabolism. Effects of exercise in vivo on obesity have been compared with simulation of endurance exercise in vitro on myotubes (electrical pulse stimulation). Possible pharmaceutical targets, including signaling pathways and drug candidates that could modify lipid storage and turnover or increase mitochondrial function or cellular energy expenditure through adaptive thermogenic mechanisms, are discussed.
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Affiliation(s)
- Abel M Mengeste
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Arild C Rustan
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Jenny Lund
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
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Krapf S, Schjølberg T, Asoawe L, Honkanen SK, Kase ET, Thoresen GH, Haugen F. Novel methods for cold exposure of skeletal muscle in vivo and in vitro show temperature-dependent myokine production. J Therm Biol 2021; 98:102930. [PMID: 34016352 DOI: 10.1016/j.jtherbio.2021.102930] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 03/17/2021] [Accepted: 03/29/2021] [Indexed: 11/29/2022]
Abstract
Proteins secreted from skeletal muscle serving a signalling role have been termed myokines. Many of the myokines are exercise factors, produced and released in response to muscle activity. Cold exposures affecting muscle may occur in recreational, occupational and therapeutic settings. Whether muscle temperature independently affects myokine profile, is still to be elucidated. We hypothesized that manipulating muscle temperature by means of external cooling would change myokine production and release. In the present study we have established new models for cold exposure of muscle in vivo and in vitro where rat hind limb or cultured human myotubes were cooled to 18 °C. After a recovery period, muscle tissue, cells and culture media were harvested for further analysis by qPCR and immunoassays. Expression of several myokine genes were significantly increased after cold exposure in both models: in rat muscle, mRNA levels of CCL2 (p = 0.04), VEGFA (p = 0.02), CXCL1 (p = 0.02) and RBM3 (p = 0.02) increased while mRNA levels of IL-6 (p = 0.03) were decreased; in human myotubes, mRNA levels of IL6 (p = 0.01), CXCL8 (p = 0.04), VEGFA (p = 0.03) and CXCL1 (p < 0.01) were significantly increased, as well as intracellular protein levels of IL-8 (CXCL8 gene product; p < 0.01). The corresponding effect on myokine secretion was not observed, on the contrary, IL-8 (p = 0.02) and VEGF (VEGFA gene product) p < 0.01) concentrations in culture media were reduced after cold exposure in vitro. In conclusion, cold exposure of muscle in vivo and in vitro had an effect on the production and release of several known exercise-related myokines. Myokine expression at the level of mRNA and protein was increased by cold exposure, whereas secretion tended to be decreased.
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Affiliation(s)
- Solveig Krapf
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | | | - Lucia Asoawe
- National Institute of Occupational Health, Oslo, Norway
| | | | - Eili Tranheim Kase
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - G Hege Thoresen
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway; Department of Pharmacology, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Fred Haugen
- National Institute of Occupational Health, Oslo, Norway.
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8
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Mitochondrial DNA from osteoarthritic patients drives functional impairment of mitochondrial activity: a study on transmitochondrial cybrids. Cytotherapy 2021; 23:399-410. [PMID: 33727013 DOI: 10.1016/j.jcyt.2020.08.010] [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: 08/21/2019] [Revised: 06/05/2020] [Accepted: 08/20/2020] [Indexed: 11/23/2022]
Abstract
With the redefinition of osteoarthritis (OA) and the understanding that the joint behaves as an organ, OA is now considered a systemic illness with a low grade of chronic inflammation. Mitochondrial dysfunction is well documented in OA and has the capacity to alter chondrocyte and synoviocyte function. Transmitochondrial cybrids are suggested as a useful cellular model to study mitochondrial biology in vitro, as they carry different mitochondrial variants with the same nuclear background. The aim of this work was to study mitochondrial and metabolic function of cybrids with mitochondrial DNA from healthy (N) and OA donors. In this work, the authors demonstrate that cybrids from OA patients behave differently from cybrids from N donors in several mitochondrial parameters. Furthermore, OA cybrids behave similarly to OA chondrocytes. These results enhance our understanding of the role of mitochondria in the degeneration process of OA and present cybrids as a useful model to study OA pathogenesis.
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9
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Aas V, Thoresen GH, Rustan AC, Lund J. Substrate oxidation in primary human skeletal muscle cells is influenced by donor age. Cell Tissue Res 2020; 382:599-608. [PMID: 32897419 PMCID: PMC7683494 DOI: 10.1007/s00441-020-03275-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 08/07/2020] [Indexed: 12/21/2022]
Abstract
Primary human myotubes represent an alternative system to intact skeletal muscle for the study of human diseases related to changes in muscle energy metabolism. This work aimed to study if fatty acid and glucose metabolism in human myotubes in vitro were related to muscle of origin, donor gender, age, or body mass index (BMI). Myotubes from a total of 82 donors were established from three different skeletal muscles, i.e., musculus vastus lateralis, musculus obliquus internus abdominis, and musculi interspinales, and cellular energy metabolism was evaluated. Multiple linear regression analyses showed that donor age had a significant effect on glucose and oleic acid oxidation after correcting for gender, BMI, and muscle of origin. Donor BMI was the only significant contributor to cellular oleic acid uptake, whereas cellular glucose uptake did not rely on any of the variables examined. Despite the effect of age on substrate oxidation, cellular mRNA expression of pyruvate dehydrogenase kinase 4 (PDK4) and peroxisome proliferator–activated receptor gamma coactivator 1 alpha (PPARGC1A) did not correlate with donor age. In conclusion, donor age significantly impacts substrate oxidation in cultured human myotubes, whereas donor BMI affects cellular oleic acid uptake.
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Affiliation(s)
- Vigdis Aas
- Department of Life Sciences and Health, Faculty of Health Sciences, OsloMet - Oslo Metropolitan University, Oslo, Norway
| | - G Hege Thoresen
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Blindern, P.O. Box 1068, 0316, Oslo, Norway.,Department of Pharmacology, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Arild C Rustan
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Blindern, P.O. Box 1068, 0316, Oslo, Norway
| | - Jenny Lund
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Blindern, P.O. Box 1068, 0316, Oslo, Norway.
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10
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Baugh ME, Bowser SM, McMillan RP, Davy BM, Essenmacher LA, Neilson AP, Hulver MW, Davy KP. Postprandial skeletal muscle metabolism following a high-fat diet in sedentary and endurance-trained males. J Appl Physiol (1985) 2020; 128:872-883. [PMID: 32163335 DOI: 10.1152/japplphysiol.00576.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Our objective was to determine the influence of a high-fat diet (HFD) on fasting and postprandial skeletal muscle substrate metabolism in endurance-trained (ET) compared with sedentary (SED) humans. SED (n = 17) and ET (n = 7) males were control-fed a 10-day moderate-fat diet followed by a 5-day isocaloric HFD (55% fat, 30% carbohydrate). Skeletal muscle biopsies were taken in the fasted condition and 4 h after a high-fat meal (820 kcals; 63% fat and 25% carbohydrate). Palmitate-induced suppression of pyruvate oxidation, an indication of substrate preference, and oxidation of fat and glucose were measured in homogenized skeletal muscle in fasted and fed states. Postprandial responses were calculated as percent changes from fasting to fed states. Postprandial suppression of pyruvate oxidation was maintained after the HFD in ET, but not SED skeletal muscle, suggesting greater adaptability to dietary intake changes in the former. Fasting total fat oxidation increased due to the HFD in ET skeletal muscle (P = 0.006), which was driven by incomplete fat oxidation (P = 0.008). Fasting fat oxidation remained unchanged in skeletal muscle of SED individuals. Yet, postprandial fat oxidation was similar between groups. Fasting glucose oxidation was elevated after the HFD in ET (P = 0.036), but not SED, skeletal muscle. Postprandial glucose oxidation was reduced due to the HFD in SED (P = 0.002), but not ET, skeletal muscle. These findings provide insight into differing substrate metabolism responses between SED and ET individuals and highlight the role that the prevailing diet may play in modulating fasting and postprandial metabolic responses in skeletal muscle.NEW & NOTEWORTHY The relationship between high dietary fat intake and physical activity level and their combined effect on skeletal muscle substrate metabolism remains unclear. We assessed the influence of the prevailing diet in modulating substrate oxidation in skeletal muscle of endurance-trained compared with sedentary humans during a high-fat challenge meal. Collectively, our findings demonstrate the adaptability of skeletal muscle in endurance-trained individuals to high dietary fat intake.
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Affiliation(s)
- Mary Elizabeth Baugh
- Section on Gerontology and Geriatric Medicine, Sticht Center for Healthy Aging and Alzheimer's Prevention, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Suzanne M Bowser
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, Netherlands
| | - Ryan P McMillan
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, Blacksburg, Virginia.,Metabolic Phenotyping Core, Virginia Tech, Blacksburg, Virginia
| | - Brenda M Davy
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, Blacksburg, Virginia.,Translational Obesity Research Interdisciplinary Graduate Education Program, Virginia Tech, Blacksburg, Virginia
| | | | - Andrew P Neilson
- Plants for Human Health Institute, Department of Food, Bioprocessing, and Nutrition Sciences, North Carolina State University, Kannapolis, North Carolina
| | - Matthew W Hulver
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, Blacksburg, Virginia.,Metabolic Phenotyping Core, Virginia Tech, Blacksburg, Virginia.,Translational Obesity Research Interdisciplinary Graduate Education Program, Virginia Tech, Blacksburg, Virginia
| | - Kevin P Davy
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, Blacksburg, Virginia.,Metabolic Phenotyping Core, Virginia Tech, Blacksburg, Virginia.,Translational Obesity Research Interdisciplinary Graduate Education Program, Virginia Tech, Blacksburg, Virginia
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Løvsletten NG, Vu H, Skagen C, Lund J, Kase ET, Thoresen GH, Zammit VA, Rustan AC. Treatment of human skeletal muscle cells with inhibitors of diacylglycerol acyltransferases 1 and 2 to explore isozyme-specific roles on lipid metabolism. Sci Rep 2020; 10:238. [PMID: 31937853 PMCID: PMC6959318 DOI: 10.1038/s41598-019-57157-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 12/19/2019] [Indexed: 12/30/2022] Open
Abstract
Diacylglycerol acyltransferases (DGAT) 1 and 2 catalyse the final step in triacylglycerol (TAG) synthesis, the esterification of fatty acyl-CoA to diacylglycerol. Despite catalysing the same reaction and being present in the same cell types, they exhibit different functions on lipid metabolism in various tissues. Yet, their roles in skeletal muscle remain poorly defined. In this study, we investigated how selective inhibitors of DGAT1 and DGAT2 affected lipid metabolism in human primary skeletal muscle cells. The results showed that DGAT1 was dominant in human skeletal muscle cells utilizing fatty acids (FAs) derived from various sources, both exogenously supplied FA, de novo synthesised FA, or FA derived from lipolysis, to generate TAG, as well as being involved in de novo synthesis of TAG. On the other hand, DGAT2 seemed to be specialised for de novo synthesis of TAG from glycerol-3-posphate only. Interestingly, DGAT activities were also important for regulating FA oxidation, indicating a key role in balancing FAs between storage in TAG and efficient utilization through oxidation. Finally, we observed that inhibition of DGAT enzymes could potentially alter glucose-FA interactions in skeletal muscle. In summary, treatment with DGAT1 or DGAT2 specific inhibitors resulted in different responses on lipid metabolism in human myotubes, indicating that the two enzymes play distinct roles in TAG metabolism in skeletal muscle.
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Affiliation(s)
- Nils G Løvsletten
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Helene Vu
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Christine Skagen
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Jenny Lund
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Eili T Kase
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - G Hege Thoresen
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Victor A Zammit
- Division of Translational and Experimental medicine, Warwick Medical School, University of Warwick, Coventry, UK
| | - Arild C Rustan
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway.
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12
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Lund J, Ouwens DM, Wettergreen M, Bakke SS, Thoresen GH, Aas V. Increased Glycolysis and Higher Lactate Production in Hyperglycemic Myotubes. Cells 2019; 8:cells8091101. [PMID: 31540443 PMCID: PMC6770141 DOI: 10.3390/cells8091101] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 12/22/2022] Open
Abstract
Previous studies have shown that chronic hyperglycemia impairs glucose and fatty acid oxidation in cultured human myotubes. To further study the hyperglycemia-induced suppression of oxidation, lactate oxidation, mitochondrial function and glycolytic rate were evaluated. Further, we examined the intracellular content of reactive oxygen species (ROS), production of lactate and conducted pathway-ANOVA analysis on microarray data. In addition, the roles of the pentose phosphate pathway (PPP) and the hexosamine pathway were evaluated. Lactic acid oxidation was suppressed in hyperglycemic versus normoglycaemic myotubes. No changes in mitochondrial function or ROS concentration were observed. Pathway-ANOVA analysis indicated several upregulated pathways in hyperglycemic cells, including glycolysis and PPP. Functional studies showed that glycolysis and lactate production were higher in hyperglycemic than normoglycaemic cells. However, there were no indications of involvement of PPP or the hexosamine pathway. In conclusion, hyperglycemia reduced substrate oxidation while increasing glycolysis and lactate production in cultured human myotubes.
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Affiliation(s)
- Jenny Lund
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, 0316 Oslo, Norway.
| | - D Margriet Ouwens
- German Diabetes Center (DDZ), Leibniz Center for Diabetes Research, Heinrich Heine University, Medical Faculty, 40225 Düsseldorf, Germany.
- German Center for Diabetes Research (DZD), 85764 Munich-Neuherberg, Germany.
- Department of Endocrinology, Ghent University Hospital, B-9000 Ghent, Belgium.
| | - Marianne Wettergreen
- Department of Life Sciences and Health, Faculty of Health Sciences, OsloMet - Oslo Metropolitan University, 0130 Oslo, Norway.
| | - Siril S Bakke
- Center of Molecular Inflammation Research and Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
| | - G Hege Thoresen
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, 0316 Oslo, Norway.
- Department of Pharmacology, Institute of Clinical Medicine, University of Oslo, 0316 Oslo, Norway.
| | - Vigdis Aas
- Department of Life Sciences and Health, Faculty of Health Sciences, OsloMet - Oslo Metropolitan University, 0130 Oslo, Norway.
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13
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Lund J, Helle SA, Li Y, Løvsletten NG, Stadheim HK, Jensen J, Kase ET, Thoresen GH, Rustan AC. Higher lipid turnover and oxidation in cultured human myotubes from athletic versus sedentary young male subjects. Sci Rep 2018; 8:17549. [PMID: 30510272 PMCID: PMC6277406 DOI: 10.1038/s41598-018-35715-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 11/07/2018] [Indexed: 12/19/2022] Open
Abstract
In this study we compared fatty acid (FA) metabolism in myotubes established from athletic and sedentary young subjects. Six healthy sedentary (maximal oxygen uptake (VO2max) ≤ 46 ml/kg/min) and six healthy athletic (VO2max > 60 ml/kg/min) young men were included. Myoblasts were cultured and differentiated to myotubes from satellite cells isolated from biopsy of musculus vastus lateralis. FA metabolism was studied in myotubes using [14C]oleic acid. Lipid distribution was assessed by thin layer chromatography, and FA accumulation, lipolysis and re-esterification were measured by scintillation proximity assay. Gene and protein expressions were studied. Myotubes from athletic subjects showed lower FA accumulation, lower incorporation of FA into total lipids, triacylglycerol (TAG), diacylglycerol and cholesteryl ester, higher TAG-related lipolysis and re-esterification, and higher complete oxidation and incomplete β-oxidation of FA compared to myotubes from sedentary subjects. mRNA expression of the mitochondrial electron transport chain complex III gene UQCRB was higher in cells from athletic compared to sedentary. Myotubes established from athletic subjects have higher lipid turnover and oxidation compared to myotubes from sedentary subjects. Our findings suggest that cultured myotubes retain some of the phenotypic traits of their donors.
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Affiliation(s)
- Jenny Lund
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway.
| | - Siw A Helle
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
| | - Yuchuan Li
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Nils G Løvsletten
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
| | - Hans K Stadheim
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Jørgen Jensen
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
| | - Eili T Kase
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
| | - G Hege Thoresen
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway.,Department of Pharmacology, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Arild C Rustan
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
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14
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Metabolic Responses to Carbohydrate Ingestion during Exercise: Associations between Carbohydrate Dose and Endurance Performance. Nutrients 2018; 10:nu10010037. [PMID: 29301367 PMCID: PMC5793265 DOI: 10.3390/nu10010037] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 12/20/2017] [Accepted: 12/25/2017] [Indexed: 11/17/2022] Open
Abstract
Carbohydrate (CHO) ingestion during exercise lasting less than three hours improves endurance exercise performance but there is still debate about the optimal dose. We utilised stable isotopes and blood metabolite profiles to further examine metabolic responses to CHO (glucose only) ingestion in the 20–64 g·h−1 range, and to determine the association with performance outcome. In a double-blind, randomized cross-over design, male cyclists (n = 20, mean ± SD, age 34 ± 10 years, mass 75.8 ± 9 kg, peak power output 394 ± 36 W, VO2max 62 ± 9 mL·kg−1·min−1) completed four main experimental trials. Each trial involved a two-hour constant load ride (185 ± 25 W) followed by a time trial, where one of three CHO beverages, or a control (water), were administered every 15 min, providing 0, 20, 39 or 64 g CHO·h−1. Dual glucose tracer techniques, indirect calorimetry and blood analyses were used to determine glucose kinetics, exogenous CHO oxidation (EXO), endogenous CHO and fat oxidation; and metabolite responses. Regression analysis revealed that total exogenous CHO oxidised in the second hour of exercise, and suppression of serum NEFA concentration provided the best prediction model of performance outcome. However, the model could only explain ~19% of the variance in performance outcome. The present data demonstrate that consuming ~40 g·h−1 of CHO appears to be the minimum ingestion rate required to induce metabolic effects that are sufficient to impact upon performance outcome. These data highlight a lack of performance benefit and few changes in metabolic outcomes beyond an ingestion rate of 39 g·h−1. Further work is required to explore dose-response effects of CHO feeding and associations between multiple metabolic parameters and subsequent performance outcome.
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