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Edman S, Jones RG, Jannig PR, Fernandez-Gonzalo R, Norrbom J, Thomas NT, Khadgi S, Koopmans PJ, Morena F, Peterson CS, Scott LN, Greene NP, Figueiredo VC, Fry CS, Zhengye L, Lanner JT, Wen Y, Alkner B, Murach KA, von Walden F. The 24-Hour Time Course of Integrated Molecular Responses to Resistance Exercise in Human Skeletal Muscle Implicates MYC as a Hypertrophic Regulator That is Sufficient for Growth. bioRxiv 2024:2024.03.26.586857. [PMID: 38586026 PMCID: PMC10996609 DOI: 10.1101/2024.03.26.586857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Molecular control of recovery after exercise in muscle is temporally dynamic. A time course of biopsies around resistance exercise (RE) combined with -omics is necessary to better comprehend the molecular contributions of skeletal muscle adaptation in humans. Vastus lateralis biopsies before and 30 minutes, 3-, 8-, and 24-hours after acute RE were collected. A time-point matched biopsy-only group was also included. RNA-sequencing defined the transcriptome while DNA methylomics and computational approaches complemented these data. The post-RE time course revealed: 1) DNA methylome responses at 30 minutes corresponded to upregulated genes at 3 hours, 2) a burst of translation- and transcription-initiation factor-coding transcripts occurred between 3 and 8 hours, 3) global gene expression peaked at 8 hours, 4) ribosome-related genes dominated the mRNA landscape between 8 and 24 hours, 5) methylation-regulated MYC was a highly influential transcription factor throughout the 24-hour recovery and played a primary role in ribosome-related mRNA levels between 8 and 24 hours. The influence of MYC in human muscle adaptation was strengthened by transcriptome information from acute MYC overexpression in mouse muscle. To test whether MYC was sufficient for hypertrophy, we generated a muscle fiber-specific doxycycline inducible model of pulsatile MYC induction. Periodic 48-hour pulses of MYC over 4 weeks resulted in higher muscle mass and fiber size in the soleus of adult female mice. Collectively, we present a temporally resolved resource for understanding molecular adaptations to RE in muscle and reveal MYC as a regulator of RE-induced mRNA levels and hypertrophy.
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Affiliation(s)
- Sebastian Edman
- Karolinska Institute, Division of Pediatric Neurology, Department of Women’s and Children’s Health, Stockholm, Sweden
| | - Ronald G. Jones
- University of Arkansas, Exercise Science Research Center, Department of Health, Human Performance, and Recreation, Fayetteville, AR, USA
| | - Paulo R. Jannig
- Karolinska Institute, Division of Pediatric Neurology, Department of Women’s and Children’s Health, Stockholm, Sweden
| | - Rodrigo Fernandez-Gonzalo
- Karolinska Institute, Division of Clinical Physiology, Department of Laboratory Medicine, Stockholm, Sweden
- Unit of Clinical Physiology, Karolinska University Hospital, Huddinge, Sweden
| | - Jessica Norrbom
- Karolinska Institute, Molecular Exercise Physiology Group, Department of Physiology and Pharmacology, Stockholm, Sweden
| | - Nicholas T. Thomas
- University of Kentucky, Center for Muscle Biology, Lexington, KY, USA
- University of Kentucky, Department of Athletic Training and Clinical Nutrition, Lexington, KY, USA
| | - Sabin Khadgi
- University of Arkansas, Exercise Science Research Center, Department of Health, Human Performance, and Recreation, Fayetteville, AR, USA
| | - Pieter Jan Koopmans
- University of Arkansas, Exercise Science Research Center, Department of Health, Human Performance, and Recreation, Fayetteville, AR, USA
- University of Arkansas, Cell and Molecular Biology Graduate Program, Fayetteville, AR, USA
| | - Francielly Morena
- University of Arkansas, Exercise Science Research Center, Department of Health, Human Performance, and Recreation, Fayetteville, AR, USA
| | - Calvin S. Peterson
- University of Arkansas, Exercise Science Research Center, Department of Health, Human Performance, and Recreation, Fayetteville, AR, USA
| | - Logan N. Scott
- University of Kentucky, Center for Muscle Biology, Lexington, KY, USA
- University of Kentucky, Department of Physiology, Lexington, KY, USA
- University of Kentucky, Department of Internal Medicine, Division of Biomedical Informatics, Lexington, KY, USA
| | - Nicholas P. Greene
- University of Arkansas, Exercise Science Research Center, Department of Health, Human Performance, and Recreation, Fayetteville, AR, USA
| | - Vandre C. Figueiredo
- University of Kentucky, Center for Muscle Biology, Lexington, KY, USA
- Oakland University, Department of Biological Sciences, Rochester Hills, MI, USA
| | - Christopher S. Fry
- University of Kentucky, Center for Muscle Biology, Lexington, KY, USA
- University of Kentucky, Department of Athletic Training and Clinical Nutrition, Lexington, KY, USA
| | - Liu Zhengye
- Karolinska Institute, Molecular Muscle Physiology & Pathophysiology Group, Department of Physiology & Pharmacology, Stockholm, Sweden
| | - Johanna T. Lanner
- Karolinska Institute, Molecular Muscle Physiology & Pathophysiology Group, Department of Physiology & Pharmacology, Stockholm, Sweden
| | - Yuan Wen
- University of Kentucky, Center for Muscle Biology, Lexington, KY, USA
- University of Kentucky, Department of Physiology, Lexington, KY, USA
- University of Kentucky, Department of Internal Medicine, Division of Biomedical Informatics, Lexington, KY, USA
| | - Björn Alkner
- Department of Orthopedics, Eksjö, Region Jönköping County and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Kevin A. Murach
- University of Arkansas, Exercise Science Research Center, Department of Health, Human Performance, and Recreation, Fayetteville, AR, USA
- University of Arkansas, Cell and Molecular Biology Graduate Program, Fayetteville, AR, USA
| | - Ferdinand von Walden
- Karolinska Institute, Division of Pediatric Neurology, Department of Women’s and Children’s Health, Stockholm, Sweden
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Edman S, Horwath O, Van der Stede T, Blackwood SJ, Moberg I, Strömlind H, Nordström F, Ekblom M, Katz A, Apró W, Moberg M. Pro-Brain-Derived Neurotrophic Factor (BDNF), but Not Mature BDNF, Is Expressed in Human Skeletal Muscle: Implications for Exercise-Induced Neuroplasticity. Function (Oxf) 2024; 5:zqae005. [PMID: 38706964 PMCID: PMC11065112 DOI: 10.1093/function/zqae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/15/2023] [Accepted: 01/24/2024] [Indexed: 05/07/2024] Open
Abstract
Exercise promotes brain plasticity partly by stimulating increases in mature brain-derived neurotrophic factor (mBDNF), but the role of the pro-BDNF isoform in the regulation of BDNF metabolism in humans is unknown. We quantified the expression of pro-BDNF and mBDNF in human skeletal muscle and plasma at rest, after acute exercise (+/- lactate infusion), and after fasting. Pro-BDNF and mBDNF were analyzed with immunoblotting, enzyme-linked immunosorbent assay, immunohistochemistry, and quantitative polymerase chain reaction. Pro-BDNF was consistently and clearly detected in skeletal muscle (40-250 pg mg-1 dry muscle), whereas mBDNF was not. All methods showed a 4-fold greater pro-BDNF expression in type I muscle fibers compared to type II fibers. Exercise resulted in elevated plasma levels of mBDNF (55%) and pro-BDNF (20%), as well as muscle levels of pro-BDNF (∼10%, all P < 0.05). Lactate infusion during exercise induced a significantly greater increase in plasma mBDNF (115%, P < 0.05) compared to control (saline infusion), with no effect on pro-BDNF levels in plasma or muscle. A 3-day fast resulted in a small increase in plasma pro-BDNF (∼10%, P < 0.05), with no effect on mBDNF. Pro-BDNF is highly expressed in human skeletal muscle, particularly in type I fibers, and is increased after exercise. While exercising with higher lactate augmented levels of plasma mBDNF, exercise-mediated increases in circulating mBDNF likely derive partly from release and cleavage of pro-BDNF from skeletal muscle, and partly from neural and other tissues. These findings have implications for preclinical and clinical work related to a wide range of neurological disorders such as Alzheimer's, clinical depression, and amyotrophic lateral sclerosis.
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Affiliation(s)
- Sebastian Edman
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
- Department of Women’s and Children’s Health, Karolinska Institute, Stockholm 171 77, Sweden
| | - Oscar Horwath
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
| | - Thibaux Van der Stede
- Department of Movement and Sport Sciences, Ghent University, Ghent 9000, Belgium
- The August Krogh Section for Human Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen 1172, Denmark
| | - Sarah Joan Blackwood
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
| | - Isabel Moberg
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
| | - Henrik Strömlind
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
| | - Fabian Nordström
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
| | - Maria Ekblom
- Department of Physical Activity and Health, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
- Department of Neuroscience, Karolinska Institute, Stockholm 171 77, Sweden
| | - Abram Katz
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
| | - William Apró
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
- Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm 171 77, Sweden
| | - Marcus Moberg
- Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, Stockholm 114 33, Sweden
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm 171 77, Sweden
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Edman S, Flockhart M, Larsen FJ, Apró W. Need for speed: Human fast-twitch mitochondria favor power over efficiency. Mol Metab 2024; 79:101854. [PMID: 38104652 PMCID: PMC10788296 DOI: 10.1016/j.molmet.2023.101854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 12/19/2023] Open
Abstract
OBJECTIVE Human skeletal muscle consists of a mixture of slow- and fast-twitch fibers with distinct capacities for contraction mechanics, fermentation, and oxidative phosphorylation. While the divergence in mitochondrial volume favoring slow-twitch fibers is well established, data on the fiber type-specific intrinsic mitochondrial function and morphology are highly limited with existing data mainly being generated in animal models. This highlights the need for more human data on the topic. METHODS Here, we utilized THRIFTY, a rapid fiber type identification protocol to detect, sort, and pool fast- and slow-twitch fibers within 6 h of muscle biopsy sampling. Respiration of permeabilized fast- and slow-twitch fiber pools was then analyzed with high-resolution respirometry. Using standardized western blot procedures, muscle fiber pools were subsequently analyzed for control proteins and key proteins related to respiratory capacity. RESULTS Maximal complex I+II respiration was 25% higher in human slow-twitch fibers compared to fast-twitch fibers. However, per mitochondrial volume, the respiratory rate of mitochondria in fast-twitch fibers was approximately 50% higher for complex I+II, which was primarily mediated through elevated complex II respiration. Furthermore, the abundance of complex II protein and proteins regulating cristae structure were disproportionally elevated in mitochondria of the fast-twitch fibers. The difference in intrinsic respiratory rate was not reflected in fatty acid-or complex I respiration. CONCLUSION Mitochondria of human fast-twitch muscle fibers compensate for their lack of volume by substantially elevating intrinsic respiratory rate through increased reliance on complex II.
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Affiliation(s)
- Sebastian Edman
- Department of Women's and Children's Health, Karolinska Institute, Stockholm, Sweden; The Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, The Swedish School of Sport and Health Sciences, Stockholm, Sweden.
| | - Mikael Flockhart
- The Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, The Swedish School of Sport and Health Sciences, Stockholm, Sweden; Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Filip J Larsen
- The Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, The Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - William Apró
- The Åstrand Laboratory, Department of Physiology, Nutrition and Biomechanics, The Swedish School of Sport and Health Sciences, Stockholm, Sweden; Department of Clinical Sciences, Intervention and Technology, Karolinska Institute, Stockholm, Sweden
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Ismaeel A, Thomas NT, McCashland M, Vechetti IJ, Edman S, Lanner JT, Figueiredo VC, Fry CS, McCarthy JJ, Wen Y, Murach KA, von Walden F. Coordinated Regulation of Myonuclear DNA Methylation, mRNA, and miRNA Levels Associates With the Metabolic Response to Rapid Synergist Ablation-Induced Skeletal Muscle Hypertrophy in Female Mice. Function (Oxf) 2023; 5:zqad062. [PMID: 38020067 PMCID: PMC10666992 DOI: 10.1093/function/zqad062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/16/2023] [Accepted: 11/01/2023] [Indexed: 12/01/2023] Open
Abstract
The central dogma of molecular biology dictates the general flow of molecular information from DNA that leads to a functional cellular outcome. In skeletal muscle fibers, the extent to which global myonuclear transcriptional alterations, accounting for epigenetic and post-transcriptional influences, contribute to an adaptive stress response is not clearly defined. In this investigation, we leveraged an integrated analysis of the myonucleus-specific DNA methylome and transcriptome, as well as myonuclear small RNA profiling to molecularly define the early phase of skeletal muscle fiber hypertrophy. The analysis of myonucleus-specific mature microRNA and other small RNA species provides new directions for exploring muscle adaptation and complemented the methylation and transcriptional information. Our integrated multi-omics interrogation revealed a coordinated myonuclear molecular landscape during muscle loading that coincides with an acute and rapid reduction of oxidative metabolism. This response may favor a biosynthesis-oriented metabolic program that supports rapid hypertrophic growth.
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Affiliation(s)
- Ahmed Ismaeel
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY 40508, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
| | - Nicholas T Thomas
- Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
- Department of Athletic Training and Clinical Nutrition, College of Health Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - Mariah McCashland
- Department of Nutrition and Health Sciences, University of Nebraska–Lincoln, Lincoln, NE 68583, USA
| | - Ivan J Vechetti
- Department of Nutrition and Health Sciences, University of Nebraska–Lincoln, Lincoln, NE 68583, USA
| | - Sebastian Edman
- Department of Women’s and Children’s Health, Karolinska Institutet, Solna 17177, Sweden
| | - Johanna T Lanner
- Department of Physiology and Pharmacology, Karolinska Institutet, Solna 17177, Sweden
| | - Vandré C Figueiredo
- Department of Biological Sciences, Oakland University, Rochester, MI 48309, USA
| | - Christopher S Fry
- Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
- Department of Athletic Training and Clinical Nutrition, College of Health Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - John J McCarthy
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY 40508, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
| | - Yuan Wen
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY 40508, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY 40536, USA
- Division of Biomedical Informatics, Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, KY 40536, USA
| | - Kevin A Murach
- Department of Health, Human Performance, and Recreation, Exercise Science Research Center, University of Arkansas, Fayetteville, AR 72701, USA
| | - Ferdinand von Walden
- Department of Women’s and Children’s Health, Karolinska Institutet, Solna 17177, Sweden
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Edman S, Horwath O, Apró W. THRIFTY-A High-throughput Single Muscle Fiber Typing Method Based on Immunofluorescence Detection. Bio Protoc 2023; 13:e4678. [PMID: 37251094 PMCID: PMC10213079 DOI: 10.21769/bioprotoc.4678] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 02/07/2023] [Accepted: 03/22/2023] [Indexed: 05/31/2023] Open
Abstract
Skeletal muscle consists of a mixture of fiber types with different functional and metabolic characteristics. The relative composition of these muscle fiber types has implications for muscle performance, whole-body metabolism, and health. However, analyses of muscle samples in a fiber type-dependent manner are very time consuming. Therefore, these are often neglected in favor of more time-efficient analyses on mixed muscle samples. Methods such as western blot and myosin heavy chain separation by SDS-PAGE have previously been utilized to fiber type-isolated muscle fibers. More recently, the introduction of the dot blot method significantly increased the speed of fiber typing. However, despite recent advancements, none of the current methodologies are feasible for large-scale investigations because of their time requirements. Here, we present the protocol for a new method, which we have named THRIFTY (high-THRoughput Immunofluorescence Fiber TYping), that enables rapid fiber type identification using antibodies towards the different myosin heavy chain (MyHC) isoforms of fast and slow twitch muscle fibers. First, a short segment (<1 mm) is cut off from isolated muscle fibers and mounted on a customized gridded microscope slide holding up to 200 fiber segments. Second, the fiber segments attached to the microscope slide are stained with MyHC-specific antibodies and then visualized using a fluorescence microscope. Lastly, the remaining pieces of the fibers can either be collected individually or pooled together with fibers of the same type for subsequent analyses. The THRIFTY protocol is approximately three times as fast as the dot blot method, which enables not only time-sensitive assays to be performed but also increases the feasibility to conduct large-scale investigations into fiber type specific physiology. Graphical Overview Graphical overview of the THRIFTY workflow. Cut off a small segment (0.5 mm) of an individually dissected muscle fiber and mount it onto the customized microscope slide containing a printed grid system. Using a Hamilton syringe, fixate the fiber segment by applying a small droplet of distilled water on the segment and let it fully dry (1A). The remaining large segment of the fiber should be placed in the corresponding square on a black A4 paper (1B). Once the microscope slide has been fully mounted with fiber segments, submerge the slide in a polypropylene slide mailer (illustrated as a Coplin jar in the figure) containing acetone to permeabilize the fiber segments. Thereafter, incubate the slide with primary antibodies targeting MyHC-I and MyHC-II. Following washes in PBS solution, incubate the slides with fluorescently labeled secondary antibodies, wash again, and mount with a cover glass and antifade reagent (2). Identification of fiber type can be performed using a digital fluorescence microscope (3), whereafter the remaining pieces of the fiber segments (large) are pooled together according to their fiber type or individually collected for experiments on single fibers (4). Image modified from Horwath et al. (2022).
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Affiliation(s)
- Sebastian Edman
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Oscar Horwath
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - William Apró
- Department of Physiology, Nutrition and Biomechanics, Åstrand Laboratory, Swedish School of Sport and Health Sciences, Stockholm, Sweden
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
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Horwath O, Edman S, Andersson A, Larsen FJ, Apró W. THRIFTY: a novel high-throughput method for rapid fibre type identification of isolated skeletal muscle fibres. J Physiol 2022; 600:4421-4438. [PMID: 36069036 PMCID: PMC9825974 DOI: 10.1113/jp282959] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 08/25/2022] [Indexed: 01/11/2023] Open
Abstract
Fibre type-specific analyses are required for broader understanding of muscle physiology, but such analyses are difficult to conduct due to the extreme time requirements of dissecting and fibre typing individual fibres. Investigations are often confined to a small number of fibres from few participants with low representativeness of the entire fibre population and the participant population. To increase the feasibility of conducting large-scale fibre type-specific studies, a valid and rapid method for high-throughput fibre typing of individually dissected fibres was developed and named THRIFTY (for high-THRoughput Immunofluorescence Fibre TYping). Employing THRIFTY, 400 fibre segments were fixed onto microscope slides with a pre-printed coordinated grid system, probed with antibodies against myosin heavy chain (MyHC)-I and MyHC-II and classified using a fluorescence microscope. The validity and speed of THRIFTY was compared to a previously validated protocol (dot blot) on a fibre-to-fibre basis. Fibre pool purity was evaluated using 'gold standard' SDS-PAGE and silver staining. A modified THRIFTY-protocol using fluorescence western blot equipment was also validated. THRIFTY displayed excellent agreement with the dot blot protocol, κ = 0.955 (95% CI: 0.928, 0.982), P < 0.001. Both the original and modified THRIFTY protocols generated type I and type II fibre pools of absolute purity. Using THRIFTY, 400 fibres were typed just under 11 h, which was approximately 3 times faster than dot blot. THRIFTY is a novel and valid method with high versatility for very rapid fibre typing of individual fibres. THRIFTY can therefore facilitate the generation of large fibre pools for more extensive mechanistic studies into skeletal muscle physiology. KEY POINTS: Skeletal muscle is composed of different fibre types, each with distinct physiological properties. To fully understand how skeletal muscle adapts to external cues such as exercise, nutrition and ageing, fibre type-specific investigations are required. Such investigations are very difficult to conduct due to the extreme time requirements related to classifying individually isolated muscle fibres. To bypass this issue, we have developed a rapid and reliable method named THRIFTY which is cheap as well as versatile and which can easily be implemented in most laboratories. THRIFTY increases the feasibility of conducting larger fibre type-specific studies and enables time-sensitive assays where measurements need to be carried out in close connection with tissue sampling. By using THRIFTY, new insights into fibre type-specific muscle physiology can be gained which may have broad implications in health and disease.
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Affiliation(s)
- Oscar Horwath
- Department of PhysiologyNutrition and BiomechanicsÅstrand LaboratorySwedish School of Sport and Health SciencesStockholmSweden
| | - Sebastian Edman
- Department of PhysiologyNutrition and BiomechanicsÅstrand LaboratorySwedish School of Sport and Health SciencesStockholmSweden
| | - Alva Andersson
- Department of PhysiologyNutrition and BiomechanicsÅstrand LaboratorySwedish School of Sport and Health SciencesStockholmSweden
| | - Filip J. Larsen
- Department of PhysiologyNutrition and BiomechanicsÅstrand LaboratorySwedish School of Sport and Health SciencesStockholmSweden
| | - William Apró
- Department of PhysiologyNutrition and BiomechanicsÅstrand LaboratorySwedish School of Sport and Health SciencesStockholmSweden,Department of Clinical ScienceIntervention and TechnologyKarolinska InstitutetStockholmSweden
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Edman S, Horwath O, Andersson A, Apró W. THRIFTY; A Novel Method For Rapid Fiber Type Identification Of Isolated Skeletal Muscle Fibers. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000876416.24394.9e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Valente-Silva P, Cervenka I, Ferreira DMS, Correia JC, Edman S, Horwath O, Heng B, Chow S, Jacobs KR, Guillemin GJ, Blomstrand E, Ruas JL. Effects of Tryptophan Supplementation and Exercise on the Fate of Kynurenine Metabolites in Mice and Humans. Metabolites 2021; 11:metabo11080508. [PMID: 34436450 PMCID: PMC8400416 DOI: 10.3390/metabo11080508] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 12/12/2022] Open
Abstract
The kynurenine pathway of tryptophan (TRP) degradation (KP) generates metabolites with effects on metabolism, immunity, and mental health. Endurance exercise training can change KP metabolites by changing the levels of KP enzymes in skeletal muscle. This leads to a metabolite pattern that favors energy expenditure and an anti-inflammatory immune cell profile and reduces neurotoxic metabolites. Here, we aimed to understand if TRP supplementation in untrained vs. trained subjects affects KP metabolite levels and biological effects. Our data show that chronic TRP supplementation in mice increases all KP metabolites in circulation, and that exercise reduces the neurotoxic branch of the pathway. However, in addition to increasing wheel running, we did not observe other effects of TRP supplementation on training adaptations, energy metabolism or behavior in mice. A similar increase in KP metabolites was seen in trained vs. untrained human volunteers that took a TRP drink while performing a bout of aerobic exercise. With this acute TRP administration, TRP and KYN were higher in the trained vs. the untrained group. Considering the many biological effects of the KP, which can lead to beneficial or deleterious effects to health, our data encourage future studies of the crosstalk between TRP supplementation and physical exercise.
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Affiliation(s)
- Paula Valente-Silva
- Department of Physiology and Pharmacology, Biomedicum Karolinska Institutet, 171 77 Stockholm, Sweden; (P.V.-S.); (I.C.); (D.M.S.F.); (J.C.C.)
| | - Igor Cervenka
- Department of Physiology and Pharmacology, Biomedicum Karolinska Institutet, 171 77 Stockholm, Sweden; (P.V.-S.); (I.C.); (D.M.S.F.); (J.C.C.)
| | - Duarte M. S. Ferreira
- Department of Physiology and Pharmacology, Biomedicum Karolinska Institutet, 171 77 Stockholm, Sweden; (P.V.-S.); (I.C.); (D.M.S.F.); (J.C.C.)
| | - Jorge C. Correia
- Department of Physiology and Pharmacology, Biomedicum Karolinska Institutet, 171 77 Stockholm, Sweden; (P.V.-S.); (I.C.); (D.M.S.F.); (J.C.C.)
| | - Sebastian Edman
- Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, 114 33 Stockholm, Sweden; (S.E.); (O.H.); (E.B.)
| | - Oscar Horwath
- Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, 114 33 Stockholm, Sweden; (S.E.); (O.H.); (E.B.)
| | - Benjamin Heng
- Neuroinflammation Group, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sidney, NSW 2109, Australia; (B.H.); (S.C.); (K.R.J.); (G.J.G.)
| | - Sharron Chow
- Neuroinflammation Group, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sidney, NSW 2109, Australia; (B.H.); (S.C.); (K.R.J.); (G.J.G.)
| | - Kelly R. Jacobs
- Neuroinflammation Group, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sidney, NSW 2109, Australia; (B.H.); (S.C.); (K.R.J.); (G.J.G.)
| | - Gilles J. Guillemin
- Neuroinflammation Group, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sidney, NSW 2109, Australia; (B.H.); (S.C.); (K.R.J.); (G.J.G.)
| | - Eva Blomstrand
- Department of Physiology, Nutrition and Biomechanics, Swedish School of Sport and Health Sciences, 114 33 Stockholm, Sweden; (S.E.); (O.H.); (E.B.)
| | - Jorge L. Ruas
- Department of Physiology and Pharmacology, Biomedicum Karolinska Institutet, 171 77 Stockholm, Sweden; (P.V.-S.); (I.C.); (D.M.S.F.); (J.C.C.)
- Correspondence:
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Edman S, Moberg M, Psilander N. Acute Signaling Responses To Resistance Exercise In Previously Trained And Untrained Skeletal Muscle. Med Sci Sports Exerc 2020. [DOI: 10.1249/01.mss.0000684440.32316.65] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Edman S, Söderlund K, Moberg M, Apró W, Blomstrand E. mTORC1 Signaling in Individual Human Muscle Fibers Following Resistance Exercise in Combination With Intake of Essential Amino Acids. Front Nutr 2019; 6:96. [PMID: 31294029 PMCID: PMC6603157 DOI: 10.3389/fnut.2019.00096] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 06/10/2019] [Indexed: 11/13/2022] Open
Abstract
Human muscles contain a mixture of type I and type II fibers with different contractile and metabolic properties. Little is presently known about the effect of anabolic stimuli, in particular nutrition, on the molecular responses of these different fiber types. Here, we examine the effect of resistance exercise in combination with intake of essential amino acids (EAA) on mTORC1 signaling in individual type I and type II human muscle fibers. Five strength-trained men performed two sessions of heavy leg press exercise. During exercise and recovery, the subjects ingested an aqueous solution of EAA (290 mg/kg) or flavored water (placebo). Muscle biopsies were taken from the vastus lateralis before and 90 min after exercise. The biopsies were freeze-dried and single fibers dissected out and weighed (range 0.95-8.1 μg). The fibers were homogenized individually and identified as type I or II by incubation with antibodies against the different isoforms of myosin. They were also analyzed for both the levels of protein as well as phosphorylation of proteins in the mTORC1 pathway using Western blotting. The levels of the S6K1 and eEF2 proteins were ~50% higher in type II than in type I fibers (P < 0.05), but no difference was found between fiber types with respect to the level of mTOR protein. Resistance exercise led to non-significant increases (2-3-fold) in mTOR and S6K1 phosphorylation as well as a 50% decrease (P < 0.05) in eEF2 phosphorylation in both fiber types. Intake of EAA caused a 2 and 6-fold higher (P < 0.05) elevation of mTOR and S6K1 phosphorylation, respectively, in both type I and type II fibers compared to placebo, with no effect on phosphorylation of eEF2. In conclusion, protein levels of S6K1 and eEF2 were significantly higher in type II than type I fibers suggesting higher capacity of the mTOR pathway in type II fibers. Ingestion of EAA enhanced the effect of resistance exercise on phosphorylation of mTOR and S6K1 in both fiber types, but with considerable variation between single fibers of both types.
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Affiliation(s)
- Sebastian Edman
- The Åstrand Laboratory, the Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Karin Söderlund
- The Åstrand Laboratory, the Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Marcus Moberg
- The Åstrand Laboratory, the Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - William Apró
- The Åstrand Laboratory, the Swedish School of Sport and Health Sciences, Stockholm, Sweden
| | - Eva Blomstrand
- The Åstrand Laboratory, the Swedish School of Sport and Health Sciences, Stockholm, Sweden.,Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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