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Lenardič A, Domenig SA, Zvick J, Bundschuh N, Tarnowska-Sengül M, Furrer R, Noé FJ, Trautmann CLL, Ghosh A, Bacchin G, Gjonlleshaj P, Qabrati X, Masschelein E, De Bock K, Handschin C, Bar-Nur O. Generation of allogenic and xenogeneic functional muscle stem cells for intramuscular transplantation. J Clin Invest 2024:e166998. [PMID: 38713532 DOI: 10.1172/jci166998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2024] Open
Abstract
Satellite cells, the stem cells of skeletal muscle tissue, hold a remarkable regeneration capacity and therapeutic potential in regenerative medicine. However, low satellite cell yield from autologous or donor-derived muscles hinders the adoption of satellite cell transplantation for the treatment of muscle diseases, including Duchenne muscular dystrophy (DMD). To address this limitation, here we investigated whether satellite cells can be derived in allogeneic or xenogeneic animal hosts. First, injection of CRISPR/Cas9-corrected mouse DMD-induced pluripotent stem cells (iPSCs) into mouse blastocysts carrying an ablation system of host satellite cells gave rise to intraspecies chimeras exclusively carrying iPSC-derived satellite cells. Furthermore, injection of genetically corrected DMD-iPSCs into rat blastocysts resulted in the formation of interspecies rat-mouse chimeras harboring mouse satellite cells. Remarkably, iPSC-derived satellite cells or derivative myoblasts produced in intraspecies or interspecies chimeras restored dystrophin expression in DMD mice following intramuscular transplantation, and contributed to the satellite cell pool. Collectively, this study demonstrates the feasibility of producing therapeutically competent stem cells across divergent animal species, raising the possibility of generating human muscle stem cells in large animals for regenerative medicine purposes.
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Affiliation(s)
- Ajda Lenardič
- Laboratory of Regenerative and Movement Biology, ETH Zurich (Swiss Federal Institute of Technology Zurich), Schwerzenbach, Switzerland
| | - Seraina A Domenig
- Laboratory of Regenerative and Movement Biology, ETH Zurich (Swiss Federal Institute of Technology Zurich), Schwerzenbach, Switzerland
| | - Joel Zvick
- Laboratory of Regenerative and Movement Biology, ETH Zurich (Swiss Federal Institute of Technology Zurich), Schwerzenbach, Switzerland
| | - Nicola Bundschuh
- Laboratory of Regenerative and Movement Biology, ETH Zurich (Swiss Federal Institute of Technology Zurich), Schwerzenbach, Switzerland
| | - Monika Tarnowska-Sengül
- Laboratory of Regenerative and Movement Biology, ETH Zurich (Swiss Federal Institute of Technology Zurich), Schwerzenbach, Switzerland
| | | | - Falko J Noé
- Laboratory of Regenerative and Movement Biology, ETH Zurich (Swiss Federal Institute of Technology Zurich), Schwerzenbach, Switzerland
| | - Christine Ling Li Trautmann
- Laboratory of Regenerative and Movement Biology, ETH Zurich (Swiss Federal Institute of Technology Zurich), Schwerzenbach, Switzerland
| | - Adhideb Ghosh
- Laboratory of Regenerative and Movement Biology, ETH Zurich (Swiss Federal Institute of Technology Zurich), Schwerzenbach, Switzerland
| | - Giada Bacchin
- Laboratory of Regenerative and Movement Biology, ETH Zurich (Swiss Federal Institute of Technology Zurich), Schwerzenbach, Switzerland
| | - Pjeter Gjonlleshaj
- Laboratory of Regenerative and Movement Biology, ETH Zurich (Swiss Federal Institute of Technology Zurich), Schwerzenbach, Switzerland
| | - Xhem Qabrati
- Laboratory of Regenerative and Movement Biology, ETH Zurich (Swiss Federal Institute of Technology Zurich), Schwerzenbach, Switzerland
| | - Evi Masschelein
- Laboratory of Exercise and Health, ETH Zurich (Swiss Federal Institute of Technology Zurich), Schwerzenbach, Switzerland
| | - Katrien De Bock
- Laboratory of Exercise and Health, ETH Zurich (Swiss Federal Institute of Technology Zurich), Schwerzenbach, Switzerland
| | | | - Ori Bar-Nur
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
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Abstract
OBJECTIVE Exercise enhances the sensitivity of mammalian target of rapamycin complex 1 (mTORC1) to amino acids, in particular leucine. How long this enhanced sensitivity lasts, and which mechanisms control enhanced leucine-mediated mTORC1 activation following exercise is currently unknown. METHODS C57BL/6J mice were exercised for one night in a resistance-braked running wheel after a 12-day acclimatization period. Mice were gavaged with a submaximal dose of l-leucine or saline acutely or 48 h after exercise cessation, following 3 h food withdrawal. Muscles were excised 30 min after leucine administration. To study the contribution of mTORC1, we repeated those experiments but blocked mTORC1 activation using rapamycin immediately before the overnight running bout and one hour before the first dose of leucine. mTORC1 signaling, muscle protein synthesis and amino acid sensing machinery were assessed using immunoblot and qPCR. Leucine uptake was measured using L-[14C(U)]-leucine tracer labeling. RESULTS When compared to sedentary conditions, leucine supplementation more potently activated mTORC1 and protein synthesis in acutely exercised muscle. This effect was observed in m. soleus but not in m. tibialis anterior nor m. plantaris. The synergistic effect in m. soleus was long-lasting as key downstream markers of mTORC1 as well as protein synthesis remained higher when leucine was administered 48 h after exercise. We found that exercise enhanced the expression of amino acid transporters and promoted uptake of leucine into the muscle, leading to higher free intramuscular leucine levels. This coincided with increased expression of activating transcription factor 4 (ATF4), a main transcriptional regulator of amino acid uptake and metabolism, and downstream activation of amino acid genes as well as leucyl-tRNA synthetase (LARS), a putative leucine sensor. Finally, blocking mTORC1 using rapamycin did not reduce expression and activation of ATF4, suggesting that the latter does not act downstream of mTORC1. Rather, we found a robust increase in eukaryotic initiation factor 2α (eIF2α) phosphorylation, suggesting that the integrated stress response pathway, rather than exercise-induced mTORC1 activation, drives long-term ATF4 expression in skeletal muscle after exercise. CONCLUSIONS The enhanced sensitivity of mTORC1 to leucine is maintained at least 48 h after exercise. This shows that the anabolic window of opportunity for protein ingestion is not restricted to the first hours immediately following exercise. Increased mTORC1 sensitivity to leucine coincided with enhanced leucine influx into muscle and higher expression of genes involved in leucine sensing and amino acid metabolism. Also, exercise induced an increase in ATF4 protein expression. Altogether, these data suggest that muscular contractions switch on a coordinated program to enhance amino acid uptake as well as intramuscular sensing of key amino acids involved in mTORC1 activation and the stimulation of muscle protein synthesis.
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Affiliation(s)
- Gommaar D'Hulst
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zurich, Zürich, Switzerland
| | - Evi Masschelein
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zurich, Zürich, Switzerland
| | - Katrien De Bock
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zurich, Zürich, Switzerland.
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Masschelein E, De Smet S, Denhaerynck K, Ceulemans LJ, Monbaliu D, De Geest S. Patient-reported outcomes evaluation and assessment of facilitators and barriers to physical activity in the Transplantoux aerobic exercise intervention. PLoS One 2022; 17:e0273497. [PMID: 36288368 PMCID: PMC9605336 DOI: 10.1371/journal.pone.0273497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 08/09/2022] [Indexed: 11/06/2022] Open
Abstract
Background Transplantoux’s MVT exercise intervention prepares organ transplant recipients to cycle or hike up France’s Mont Ventoux. We aimed to assess (i) MVT’s effects on patient-reported outcomes (PROs) and (ii) perceived barriers and facilitators to physical activity. Methods Using a hybrid design, a convenience sample of transplant recipients participating in MVT (n = 47 cycling (TxCYC); n = 18 hiking (TxHIK)), matched control transplant recipients (TxCON, n = 213), and healthy MVT participants (HCON, n = 91) completed surveys to assess physical activity (IPAQ), health-related quality of life (HRQOL; SF-36 and EuroQol VAS), mental health (GHQ-12), and depressive symptomatology, anxiety, and stress (DASS-21) at baseline, then after 3, 6 (Mont Ventoux climb), 9, and 12 months. TxCYC and TxHIK participated in a 6-month intervention of individualized home-based cycling/hiking exercise and a series of supervised group training sessions. Barriers and facilitators to physical activity (Barriers and Motivators Questionnaire) were measured at 12 months. Results Regarding PROs, except for reducing TxHIK stress levels, MVT induced no substantial intervention effects. For both TxCYC and TxHIK, between-group comparisons at baseline showed that physical activity, HRQOL, mental health, depressive symptomatology and stress were similar to those of HCON. In contrast, compared to TxCYC, TxHIK, and HCON, physical activity, HRQOL and mental health were lower in TxCON. TxCON also reported greater barriers, lower facilitators, and different priority rankings concerning physical activity barriers and facilitators. Conclusion Barely any of the PROs assessed in the present study responded to Transplantoux’s MVT exercise intervention. TxCON reported distinct and unfavorable profiles regarding PROs and barriers and facilitators to physical activity. These findings can assist tailored physical activity intervention development. Trial registration Clinical trial notation: The study was approved by the University Hospitals Leuven’s Institutional Review Board (B322201523602).
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Affiliation(s)
- Evi Masschelein
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, ETH Zürich, Zurich, Switzerland
| | - Stefan De Smet
- Abdominal Transplantation, Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
- Transplantoux Foundation, Leuven, Belgium
| | - Kris Denhaerynck
- Institute of Nursing Science, Department Public Health, Faculty of Medicine, University of Basel, Basel, Switzerland
| | - Laurens J. Ceulemans
- Thoracic Surgery, University Hospitals Leuven, Leuven, Belgium
- Chronic Diseases and Metabolism, Laboratory of Respiratory Diseases and Thoracic Surgery (BREATHE), KU Leuven, Leuven, Belgium
| | - Diethard Monbaliu
- Abdominal Transplantation, Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium
- Transplantoux Foundation, Leuven, Belgium
- Department of Abdominal Transplant Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Sabina De Geest
- Institute of Nursing Science, Department Public Health, Faculty of Medicine, University of Basel, Basel, Switzerland
- Academic Centre for Nursing and Midwifery, Department of Public Health and Primary Care, KU Leuven, Leuven, Belgium
- * E-mail:
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Fan Z, Turiel G, Ardicoglu R, Ghobrial M, Masschelein E, Kocijan T, Zhang J, Tan G, Fitzgerald G, Gorski T, Alvarado-Diaz A, Gilardoni P, Adams CM, Ghesquière B, De Bock K. Exercise-induced angiogenesis is dependent on metabolically primed ATF3/4 + endothelial cells. Cell Metab 2021; 33:1793-1807.e9. [PMID: 34358431 PMCID: PMC8432967 DOI: 10.1016/j.cmet.2021.07.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 05/18/2021] [Accepted: 07/14/2021] [Indexed: 12/21/2022]
Abstract
Exercise is a powerful driver of physiological angiogenesis during adulthood, but the mechanisms of exercise-induced vascular expansion are poorly understood. We explored endothelial heterogeneity in skeletal muscle and identified two capillary muscle endothelial cell (mEC) populations that are characterized by differential expression of ATF3/4. Spatial mapping showed that ATF3/4+ mECs are enriched in red oxidative muscle areas while ATF3/4low ECs lie adjacent to white glycolytic fibers. In vitro and in vivo experiments revealed that red ATF3/4+ mECs are more angiogenic when compared with white ATF3/4low mECs. Mechanistically, ATF3/4 in mECs control genes involved in amino acid uptake and metabolism and metabolically prime red (ATF3/4+) mECs for angiogenesis. As a consequence, supplementation of non-essential amino acids and overexpression of ATF4 increased proliferation of white mECs. Finally, deleting Atf4 in ECs impaired exercise-induced angiogenesis. Our findings illustrate that spatial metabolic angiodiversity determines the angiogenic potential of muscle ECs.
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Affiliation(s)
- Zheng Fan
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zürich 8603, Switzerland
| | - Guillermo Turiel
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zürich 8603, Switzerland
| | - Raphaela Ardicoglu
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zürich 8603, Switzerland; Laboratory of Molecular and Behavioral Neuroscience, Department of Health Sciences and Technology, ETH Zürich, Zürich 8057, Switzerland
| | - Moheb Ghobrial
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zürich 8603, Switzerland; Group Brain Vasculature and Perivascular Niche, Division of Experimental and Translational Neuroscience, Krembil Brain Institute, Krembil Research Institute, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON M5T 2S8, Canada
| | - Evi Masschelein
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zürich 8603, Switzerland
| | - Tea Kocijan
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zürich 8603, Switzerland
| | - Jing Zhang
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zürich 8603, Switzerland
| | - Ge Tan
- Functional Genomics Center Zürich, ETH/University of Zürich, Zürich 8093, Switzerland
| | - Gillian Fitzgerald
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zürich 8603, Switzerland
| | - Tatiane Gorski
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zürich 8603, Switzerland
| | - Abdiel Alvarado-Diaz
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zürich 8603, Switzerland
| | - Paola Gilardoni
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zürich 8603, Switzerland
| | - Christopher M Adams
- Division of Endocrinology, Metabolism and Nutrition, Mayo Clinic, Rochester, MN 55905, USA
| | - Bart Ghesquière
- Metabolomics Expertise Center, VIB Center for Cancer Biology, VIB, Leuven, Belgium; Metabolomics Expertise Center, Department of Oncology, Cancer Institute, KU Leuven, Leuven, Belgium
| | - Katrien De Bock
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH Zürich), Zürich 8603, Switzerland.
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Cappelle M, Masschelein E, Vos R, Van Remoortel H, Smets S, Vanbekbergen J, Verreydt J, Troosters T, Goetschalckx K, Gosselink R, Monbaliu D. High-Intensity Training for 6 Months Safely, but Only Temporarily, Improves Exercise Capacity in Selected Solid Organ Transplant Recipients. Transplant Proc 2021; 53:1836-1845. [PMID: 34049699 DOI: 10.1016/j.transproceed.2021.03.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 03/10/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND Organ transplantation is a life-saving intervention that improves quality of life of patients with irreversible organ failure. Although exercise training immediately after transplantation has been suggested to be beneficial, such interventions remain rare in stable transplant recipients, whereas effects of high-intensity training (HIT) are even less frequently investigated. Moreover, sustainability of such interventions has not yet been reported. We investigated the effects of a 6-month, cycling-based HIT program on physical performance in long-term stable solid organ transplant (SOT) recipients, with follow-up evaluation after 6 months. METHODS Forty-two adult, stable, and selected SOT recipients participated in a 6-month individualized home- and group-based HIT program. Exercise capacity (VO2max), maximal power (Wmax), and body mass index were measured before, at the end, and 6 months after completion of the intervention. RESULTS The study comprised 12 heart, 7 lung, 8 liver, and 15 kidney recipients (mean age, 41.4 ± 11.1 years; median time posttransplant, 3.4 [1.7-8.0] years). For 6 months, VO2max increased in the heart, lung, and kidney groups, Wmax increased in the heart group, and body mass index decreased in the liver group. Six months after the HIT program, the achieved gain in exercise capacity had disappeared in all groups. CONCLUSION Despite voluntary participation selection bias, our observations indicate that HIT is safe and may result in a beneficial effect on physical performance in selected, stable SOT recipients. However, there was no sustained beneficial effect once training stopped. Larger scale and longer term studies are still required to investigate longevity of improvement and overall beneficial effects on clinical outcomes.
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Affiliation(s)
- Marie Cappelle
- Department of Microbiology, Immunology, and Transplantation, Laboratory of Abdominal Transplantation, KU Leuven, Leuven, Belgium; Department of Abdominal Transplant Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Evi Masschelein
- Department of Microbiology, Immunology, and Transplantation, Laboratory of Abdominal Transplantation, KU Leuven, Leuven, Belgium; Department of Abdominal Transplant Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Robin Vos
- Department CHROMETA, BREATHE, KU Leuven, Leuven, Belgium; Department of Respiratory Diseases, University Hospitals Leuven, Leuven, Belgium
| | - Hans Van Remoortel
- Department of Rehabilitation Sciences, KU Leuven, University of Leuven, Leuven, Belgium
| | - Sven Smets
- Department of Nephrology, Sint Trudo Hospital, Sint-Truiden, Belgium
| | - Jonas Vanbekbergen
- Department of Microbiology, Immunology, and Transplantation, Laboratory of Abdominal Transplantation, KU Leuven, Leuven, Belgium; Department of Abdominal Transplant Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Joris Verreydt
- Department of Microbiology, Immunology, and Transplantation, Laboratory of Abdominal Transplantation, KU Leuven, Leuven, Belgium; Department of Abdominal Transplant Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Thierry Troosters
- Department of Rehabilitation Sciences, KU Leuven, University of Leuven, Leuven, Belgium
| | - Kaatje Goetschalckx
- Department of Cardiovascular Diseases, University Hospitals Leuven, Leuven, Belgium
| | - Rik Gosselink
- Department of Rehabilitation Sciences, KU Leuven, University of Leuven, Leuven, Belgium
| | - Diethard Monbaliu
- Department of Microbiology, Immunology, and Transplantation, Laboratory of Abdominal Transplantation, KU Leuven, Leuven, Belgium; Department of Abdominal Transplant Surgery, University Hospitals Leuven, Leuven, Belgium.
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D’Hulst G, Masschelein E, De Bock K. Dampened Muscle mTORC1 Response Following Ingestion of High-Quality Plant-Based Protein and Insect Protein Compared to Whey. Nutrients 2021; 13:1396. [PMID: 33919313 PMCID: PMC8143359 DOI: 10.3390/nu13051396] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/09/2021] [Accepted: 04/14/2021] [Indexed: 12/19/2022] Open
Abstract
Increased amino acid availability acutely stimulates protein synthesis partially via activation of mechanistic target of rapamycin complex 1 (mTORC1). Plant-and insect-based protein sources matched for total protein and/or leucine to animal proteins induce a lower postprandial rise in amino acids, but their effects on mTOR activation in muscle are unknown. C57BL/6J mice were gavaged with different protein solutions: whey, a pea-rice protein mix matched for total protein or leucine content to whey, worm protein matched for total protein, or saline. Blood was drawn 30, 60, 105 and 150 min after gavage and muscle samples were harvested 60 min and 150 min after gavage to measure key components of the mTORC1 pathway. Ingestion of plant-based proteins induced a lower rise in blood leucine compared to whey, which coincided with a dampened mTORC1 activation, both acutely and 150 min after administration. Matching total leucine content to whey did not rescue the reduced rise in plasma amino acids, nor the lower increase in mTORC1 compared to whey. Insect protein elicits a similar activation of downstream mTORC1 kinases as plant-based proteins, despite lower postprandial aminoacidemia. The mTORC1 response following ingestion of high-quality plant-based and insect proteins is dampened compared to whey in mouse skeletal muscle.
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Affiliation(s)
- Gommaar D’Hulst
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zurich, 8603 Zurich, Switzerland; (E.M.); (K.D.B.)
- Laboratory of Regenerative and Movement Biology, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zurich, 8093 Zurich, Switzerland
| | - Evi Masschelein
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zurich, 8603 Zurich, Switzerland; (E.M.); (K.D.B.)
| | - Katrien De Bock
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zurich, 8603 Zurich, Switzerland; (E.M.); (K.D.B.)
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Scheuren AC, D'Hulst G, Kuhn GA, Masschelein E, Wehrle E, De Bock K, Müller R. Hallmarks of frailty and osteosarcopenia in prematurely aged PolgA (D257A/D257A) mice. J Cachexia Sarcopenia Muscle 2020; 11:1121-1140. [PMID: 32596975 PMCID: PMC7432580 DOI: 10.1002/jcsm.12588] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 02/14/2020] [Accepted: 02/24/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Frailty is a geriatric syndrome characterized by increased susceptibility to adverse health outcomes. One major determinant thereof is the gradual weakening of the musculoskeletal system and the associated osteosarcopenia. To improve our understanding of the underlying pathophysiology and, more importantly, to test potential interventions aimed at counteracting frailty, suitable animal models are needed. METHODS To evaluate the relevance of prematurely aged PolgA(D257A/D257A) mice as a model for frailty and osteosarcopenia, we quantified the clinical mouse frailty index in PolgA(D257A/D257A) and wild-type littermates (PolgA(+/+) , WT) with age and concertedly assessed the quantity and quality of bone and muscle tissue. Lastly, the anabolic responsiveness of skeletal muscle, muscle progenitors, and bone was assessed. RESULTS PolgA(D257A/D257A) accumulated health deficits at a higher rate compared with WT, resulting in a higher frailty index at 40 and 46 weeks of age (+166%, +278%, P < 0.0001), respectively, with no differences between genotypes at 34 weeks. Concomitantly, PolgA(D257A/D257A) displayed progressive musculoskeletal deterioration such as reduced bone and muscle mass as well as impaired functionality thereof. In addition to lower muscle weights (-14%, P < 0.05, -23%, P < 0.0001) and fibre area (-20%, P < 0.05, -22%, P < 0.0001) at 40 and 46 weeks, respectively, PolgA(D257A/D257A) showed impairments in grip strength and concentric muscle forces (P < 0.05). PolgA(D257A/D257A) mutation altered the acute response to various anabolic stimuli in skeletal muscle and muscle progenitors. While PolgA(D257A/D257A) muscles were hypersensitive to eccentric contractions as well as leucine administration, shown by larger downstream signalling response of the mechanistic target of rapamycin complex 1, myogenic progenitors cultured in vitro showed severe anabolic resistance to leucine and robust impairments in cell proliferation. Longitudinal micro-computed tomography analysis of the sixth caudal vertebrae showed that PolgA(D257A/D257A) had lower bone morphometric parameters (e.g. bone volume fraction, trabecular, and cortical thickness, P < 0.05) as well as reduced remodelling activities (e.g. bone formation and resorption rate, P < 0.05) compared with WT. When subjected to 4 weeks of cyclic loading, young but not aged PolgA(D257A/D257A) caudal vertebrae showed load-induced bone adaptation, suggesting reduced mechanosensitivity with age. CONCLUSIONS PolgA(D257A/D257A) mutation leads to hallmarks of age-related frailty and osteosarcopenia and provides a powerful model to better understand the relationship between frailty and the aging musculoskeletal system.
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Affiliation(s)
| | - Gommaar D'Hulst
- Laboratory of Exercise and HealthETH ZurichZurichSwitzerland
| | | | - Evi Masschelein
- Laboratory of Exercise and HealthETH ZurichZurichSwitzerland
| | - Esther Wehrle
- Institute for BiomechanicsETH ZurichZurichSwitzerland
| | - Katrien De Bock
- Laboratory of Exercise and HealthETH ZurichZurichSwitzerland
| | - Ralph Müller
- Institute for BiomechanicsETH ZurichZurichSwitzerland
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Masschelein E, D'Hulst G, Zvick J, Hinte L, Soro-Arnaiz I, Gorski T, von Meyenn F, Bar-Nur O, De Bock K. Exercise promotes satellite cell contribution to myofibers in a load-dependent manner. Skelet Muscle 2020; 10:21. [PMID: 32646489 PMCID: PMC7346400 DOI: 10.1186/s13395-020-00237-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [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: 03/27/2020] [Accepted: 06/15/2020] [Indexed: 01/07/2023] Open
Abstract
Background Satellite cells (SCs) are required for muscle repair following injury and are involved in muscle remodeling upon muscular contractions. Exercise stimulates SC accumulation and myonuclear accretion. To what extent exercise training at different mechanical loads drive SC contribution to myonuclei however is unknown. Results By performing SC fate tracing experiments, we show that 8 weeks of voluntary wheel running increased SC contribution to myofibers in mouse plantar flexor muscles in a load-dependent, but fiber type-independent manner. Increased SC fusion however was not exclusively linked to muscle hypertrophy as wheel running without external load substantially increased SC fusion in the absence of fiber hypertrophy. Due to nuclear propagation, nuclear fluorescent fate tracing mouse models were inadequate to quantify SC contribution to myonuclei. Ultimately, by performing fate tracing at the DNA level, we show that SC contribution mirrors myonuclear accretion during exercise. Conclusions Collectively, mechanical load during exercise independently promotes SC contribution to existing myofibers. Also, due to propagation of nuclear fluorescent reporter proteins, our data warrant caution for the use of existing reporter mouse models for the quantitative evaluation of satellite cell contribution to myonuclei.
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Affiliation(s)
- Evi Masschelein
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Gommaar D'Hulst
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Joel Zvick
- Department Health Sciences and Technology, Laboratory of Regenerative and Movement Biology, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Laura Hinte
- Department Health Sciences and Technology, Laboratory of Nutrition and Metabolic Epigenetics, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Inés Soro-Arnaiz
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Tatiane Gorski
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Ferdinand von Meyenn
- Department Health Sciences and Technology, Laboratory of Nutrition and Metabolic Epigenetics, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Ori Bar-Nur
- Department Health Sciences and Technology, Laboratory of Regenerative and Movement Biology, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Katrien De Bock
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland.
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D’Hulst G, Masschelein E, Palmer A, Bar-Nur O, De Bock K. Exercise promotes satellite cell contribution to myofibers in a load‐dependent manner. FASEB J 2020. [DOI: 10.1096/fasebj.2020.34.s1.09179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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D'Hulst G, Soro-Arnaiz I, Masschelein E, Veys K, Fitzgerald G, Smeuninx B, Kim S, Deldicque L, Blaauw B, Carmeliet P, Breen L, Koivunen P, Zhao SM, De Bock K. PHD1 controls muscle mTORC1 in a hydroxylation-independent manner by stabilizing leucyl tRNA synthetase. Nat Commun 2020; 11:174. [PMID: 31924757 PMCID: PMC6954236 DOI: 10.1038/s41467-019-13889-6] [Citation(s) in RCA: 237] [Impact Index Per Article: 59.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 12/06/2019] [Indexed: 02/08/2023] Open
Abstract
mTORC1 is an important regulator of muscle mass but how it is modulated by oxygen and nutrients is not completely understood. We show that loss of the prolyl hydroxylase domain isoform 1 oxygen sensor in mice (PHD1KO) reduces muscle mass. PHD1KO muscles show impaired mTORC1 activation in response to leucine whereas mTORC1 activation by growth factors or eccentric contractions was preserved. The ability of PHD1 to promote mTORC1 activity is independent of its hydroxylation activity but is caused by decreased protein content of the leucyl tRNA synthetase (LRS) leucine sensor. Mechanistically, PHD1 interacts with and stabilizes LRS. This interaction is promoted during oxygen and amino acid depletion and protects LRS from degradation. Finally, elderly subjects have lower PHD1 levels and LRS activity in muscle from aged versus young human subjects. In conclusion, PHD1 ensures an optimal mTORC1 response to leucine after episodes of metabolic scarcity. mTORC1 is an important regulator of muscle mass. Here, the authors show that the PHD1 controls muscle mass in a hydroxylation-independent manner. PHD1 prevents the degradation of leucine sensor LRS during oxygen and amino acid depletion to ensure effective mTORC1 activation in response to leucine.
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Affiliation(s)
- Gommaar D'Hulst
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Inés Soro-Arnaiz
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Evi Masschelein
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Koen Veys
- Laboratory of Angiogenesis and Vascular Metabolism, VIB Center for Cancer Biology (CCB), VIB, Leuven, Belgium.,Laboratory of Angiogenesis and Vascular Metabolism, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Gillian Fitzgerald
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Benoit Smeuninx
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.,MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Sunghoon Kim
- Medicinal Bioconvergence Research Center, College of Pharmacy, Seoul National University, Gwanak-gu, Seoul, South Korea
| | - Louise Deldicque
- Institute of Neuroscience, Université catholique de Louvain, Louvain-La-Neuve, Belgium
| | - Bert Blaauw
- Department of Biomedical Sciences, Venetian Institute of Molecular Medicine, University of Padova, Padova, Italy
| | - Peter Carmeliet
- Laboratory of Angiogenesis and Vascular Metabolism, VIB Center for Cancer Biology (CCB), VIB, Leuven, Belgium.,Laboratory of Angiogenesis and Vascular Metabolism, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Leigh Breen
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.,MRC Arthritis Research UK Centre for Musculoskeletal Ageing Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Peppi Koivunen
- Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, Oulu Center for Cell-Matrix Research, University of Oulu, Oulu, Finland
| | - Shi-Min Zhao
- Obstetrics and Gynaecology Hospital of Fudan University, State Key Lab of Genetic Engineering, School of Life Sciences and Institutes of Biomedical Sciences, Shanghai, P. R. China.,Institute of Biomedical Science, Fudan University, Shanghai, P. R. China.,Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, P. R. China
| | - Katrien De Bock
- Department Health Sciences and Technology, Laboratory of Exercise and Health, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland.
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D'Hulst G, Palmer AS, Masschelein E, Bar-Nur O, De Bock K. Voluntary Resistance Running as a Model to Induce mTOR Activation in Mouse Skeletal Muscle. Front Physiol 2019; 10:1271. [PMID: 31636571 PMCID: PMC6787551 DOI: 10.3389/fphys.2019.01271] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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: 07/01/2019] [Accepted: 09/19/2019] [Indexed: 12/30/2022] Open
Abstract
Long-term voluntary resistance running has been shown to be a valid model to induce muscle growth in rodents. Moreover, the mammalian target of rapamycin complex 1 (mTORC1) is a key signaling complex regulating exercise/nutrient-induced alterations in muscle protein synthesis. How acute resistance running affects mTORC1 signaling in muscle and if resistance applied to the wheel can modulate mTORC1 activation has not yet been fully elucidated. Here, we show that both acute resistance running and acute free running activated mTORC1 signaling in the m. gastrocnemius, m. soleus, and m. plantaris, but not in m. tibialis anterior of mice when compared to sedentary controls. Furthermore, only the low threshold oxidative part in the m. gastrocnemius showed increased mTORC1 signaling upon running and acute heavy-load resistance running evoked higher downstream mTORC1 signaling in both m. soleus and m. plantaris than free running without resistance, pointing toward mechanical load as an important independent regulator of mTORC1. Collectively, in this study, we show that voluntary resistance running is an easy-to-use, time-efficient and low stress model to study acute alterations in mTORC1 signaling upon high-load muscular contractions in mice.
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Affiliation(s)
- Gommaar D'Hulst
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Andrew S Palmer
- Laboratory of Regenerative and Movement Biology, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Evi Masschelein
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Ori Bar-Nur
- Laboratory of Regenerative and Movement Biology, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
| | - Katrien De Bock
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zurich, Zurich, Switzerland
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12
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Van Thienen R, Masschelein E, D'Hulst G, Thomis M, Hespel P. Twin Resemblance in Muscle HIF-1α Responses to Hypoxia and Exercise. Front Physiol 2017; 7:676. [PMID: 28149279 PMCID: PMC5241297 DOI: 10.3389/fphys.2016.00676] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [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: 09/15/2016] [Accepted: 12/20/2016] [Indexed: 12/21/2022] Open
Abstract
Hypoxia-inducible factor-1 (HIF-1) is a master regulator of myocellular adaptation to exercise and hypoxia. However, the role of genetic factors in regulation of HIF-1 responses to exercise and hypoxia is unknown. We hypothesized that hypoxia at rest and during exercise stimulates the HIF-1 pathway and its downstream targets in energy metabolism regulation in a genotype-dependent manner. Eleven monozygotic twin (MZ) pairs performed an experimental trial in both normoxia and hypoxia (FiO2 10.7%). Biopsies were taken from m. vastus lateralis before and after a 20-min submaximal cycling bout @~30% of sea-level VO2max. Key-markers of the HIF-1 pathway and glycolytic and oxidative metabolism were analyzed using real-time PCR and Western Blot. Hypoxia increased HIF-1α protein expression by ~120% at rest vs. +150% during exercise (p < 0.05). Furthermore, hypoxia but not exercise increased muscle mRNA content of HIF-1α (+50%), PHD2 (+45%), pVHL (+45%; p < 0.05), PDK4 (+1200%), as well as PFK-M (+20%) and PPAR-γ1 (+60%; p < 0.05). Neither hypoxia nor exercise altered PHD1, LDH-A, PDH-A1, COX-4, and CS mRNA expressions. The hypoxic, but not normoxic exercise-induced increment of muscle HIF-1α mRNA content was about 10-fold more similar within MZ twins than between the twins (p < 0.05). Furthermore, in resting muscle the hypoxia-induced increments of muscle HIF-1α protein content, and HIF-1α and PDK4 mRNA content were about 3-4-fold more homogeneous within than between the twins pairs (p < 0.05). The present observations in monozygotic twins for the first time clearly indicate that the HIF-1α protein as well as mRNA responses to submaximal exercise in acute hypoxia are at least partly regulated by genetic factors.
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Affiliation(s)
- Ruud Van Thienen
- Exercise Physiology Research Group, Department of Kinesiology, KU Leuven Leuven, Belgium
| | - Evi Masschelein
- Exercise Physiology Research Group, Department of Kinesiology, KU Leuven Leuven, Belgium
| | - Gommaar D'Hulst
- Exercise Physiology Research Group, Department of Kinesiology, KU Leuven Leuven, Belgium
| | - Martine Thomis
- Physical Activity, Sports and Health Research Group, Department of Kinesiology, KU Leuven Leuven, Belgium
| | - Peter Hespel
- Exercise Physiology Research Group, Department of Kinesiology, KU Leuven Leuven, Belgium
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13
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Abstract
PURPOSE Physiological responses to hypoxia vary between individuals, and genetic factors are conceivably involved. Using a monozygotic twin design, we investigated the role of genetic factors in physiological responses to acute hypoxia. METHODS Thirteen pairs of monozygotic twin brothers participated in two experimental sessions in a normobaric hypoxic facility with a 2-wk interval. In one session, fraction of inspired O2 (FiO2) was gradually reduced to 10.7% (approximately 5300 m altitude) over 5 h. During the next 3 h at 10.7%, FiO2 subjects performed a 20-min submaximal exercise bout (EXSUB, 1.2 W·kg) and a maximal incremental exercise test (EXMAX). An identical control experiment was done in normoxia. Cardiorespiratory measurements were continuously performed, and 8-h urine output was collected. RESULTS Compared with normoxia, hypoxia decreased (P < 0.05) arterial O2 saturation (%SpO2) at rest (-22%) and during exercise (-28%). Furthermore, V˙O2max (-39%), HRmax (HR, -8%), maximal pulmonary ventilation (V˙Emax, -11%), and urinary norepinephrine excretion (-31%) were reduced (P < 0.05) whereas HR at rest (25%) and during EXSUB (16%) and V˙E at rest (38%) and during EXSUB (70%) were increased (P < 0.05). However, hypoxia-induced changes (Δ) were not randomly distributed between subjects. Between-pair variance was substantially larger than within-pair variance (P < 0.05) for Δ%SpO2 at rest (approximately threefold) and during exercise (approximately fourfold), ΔV˙O2max (approximately fourfold), ΔHR during exercise (approximately seven- to eightfold), hypoxic ventilatory response (approximately sixfold), and Δ urinary norepinephrine output (approximately threefold). Incidence of acute mountain sickness (AMS) also yielded significant twin similarity (P < 0.05). AMS subjects showed approximately 50% greater drop in urinary norepinephrine and lower hypoxic ventilator response than AMS individuals. CONCLUSIONS Our data suggest that genetic factors regulate cardiorespiratory responses, exercise tolerance, and pathogenesis of AMS symptoms in acute severe hypoxia. Hypoxia-induced sympathetic downregulation was associated with AMS.
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Affiliation(s)
- Evi Masschelein
- 1Exercise Physiology Research Group, Department of Kinesiology, KU Leuven, Leuven, BELGIUM; and 2Physical Activity, Sports and Health Research Group, Department of Kinesiology, KU Leuven, Leuven, BELGIUM
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14
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Masschelein E, Puype J, Broos S, Van Thienen R, Deldicque L, Lambrechts D, Hespel P, Thomis M. A genetic predisposition score associates with reduced aerobic capacity in response to acute normobaric hypoxia in lowlanders. High Alt Med Biol 2015; 16:34-42. [PMID: 25761120 DOI: 10.1089/ham.2014.1083] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Given the high inter-individual variability in the sensitivity to high altitude, we hypothesize the presence of underlying genetic factors. The aim of this study was to construct a genetic predisposition score based on previously identified high-altitude gene variants to explain the inter-individual variation in the reduced maximal O2 uptake (ΔVo2max) in response to acute hypoxia. Ninety-six healthy young male Belgian lowlanders were included. In both normobaric normoxia (Fio2=20.9%) and acute normobaric hypoxia (Fio2=10.7%-12.5%) Vo2max was measured. Forty-one SNPs in 21 genes were genotyped. A stepwise regression analysis was applied to detect a subset of SNPs to be associated with ΔVo2max. This subset of SNPs was included in the genetic predisposition score. A general linear model and regression analysis with age, weight, height, hypoxic protocol group, and Vo2max in normoxia as covariates were used to test the explained variance of the genetic predisposition score. A ROC analysis was performed to discriminate between the low- and high ΔVo2max subgroups. A stepwise regression analysis revealed a subset of SNPs [rs833070 (VEGFA), rs4253778 (PPARA), rs6735530 (EPAS1), rs4341 (ACE), rs1042713 (ADRB2), and rs1042714 (ADRB2)] to be associated with ΔVo2max. The genetic predisposition score was found to be an independent predictive variable with a partial explained variance of 23% (p<0.0001). A ROC analysis showed significant discriminating accuracy (AUC=0.78, 95% confidence interval=0.64-0.91) between the low- and high ΔVo2max subgroups. This six-SNP based genetic predisposition score showed a significantly predictive value for ΔVo2max.
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Affiliation(s)
- Evi Masschelein
- 1 Exercise Physiology Research Group , KU Leuven, Leuven, Belgium
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15
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Deldicque L, Masschelein E, Van Thienen R, D'Hulst G, Hespel P, Thomis M. Acute environmental hypoxia activates autophagy in human skeletal muscle (1167.2). FASEB J 2014. [DOI: 10.1096/fasebj.28.1_supplement.1167.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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16
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Masschelein E, Van Thienen R, D'Hulst G, Hespel P, Thomis M, Deldicque L. Acute environmental hypoxia induces LC3 lipidation in a genotype-dependent manner. FASEB J 2013; 28:1022-34. [PMID: 24200883 DOI: 10.1096/fj.13-239863] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Hypoxia-induced muscle wasting is a phenomenon often described with prolonged stays at high altitude, which has been attributed to altered protein metabolism. We hypothesized that acute normobaric hypoxia would induce a negative net protein balance by repressing anabolic and activating proteolytic signaling pathways at rest and postexercise and that those changes could be partially genetically determined. Eleven monozygotic twins participated in an experimental trial in normoxia and hypoxia (10.7% O2). Muscle biopsy samples were obtained before and after a 20-min moderate cycling exercise. In hypoxia at rest, autophagic flux was increased, as indicated by an increased microtubule-associated protein 1 light chain 3 type II/I (LC3-II/I) ratio (+25%) and LC3-II expression (+60%) and decreased p62/SQSTM1 expression (-25%; P<0.05), whereas exercise reversed those changes to a level similar to that with normoxia except for p62/SQSTM1, which was further decreased (P<0.05). Hypoxia also increased Bnip3 (+34%) and MAFbx (+18%) mRNA levels as well as REDD1 expression (+439%) and AMP-activated protein kinase phosphorylation (+22%; P<0.05). Among the molecular responses to hypoxia and/or exercise, high monozygotic similarity was found for REDD1, LC3-II, and LC3-II/I (P<0.05). Our results indicate that environmental hypoxia modulates protein metabolism at rest and after moderate exercise by primarily increasing markers of protein breakdown and, more specifically, markers of the autophagy-lysosomal system, with a modest genetic contribution.
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Affiliation(s)
- Evi Masschelein
- 1Exercise Physiology Research Group, Department of Kinesiology, KU Leuven, Tervuursevest 101, B-3001 Leuven, Belgium.
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Masschelein E, Van Thienen R, Wang X, Van Schepdael A, Thomis M, Hespel P. Dietary nitrate improves muscle but not cerebral oxygenation status during exercise in hypoxia. J Appl Physiol (1985) 2012; 113:736-45. [DOI: 10.1152/japplphysiol.01253.2011] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Exercise tolerance is impaired in hypoxia, and it has recently been shown that dietary nitrate supplementation can reduce the oxygen (O2) cost of muscle contractions. Therefore, we investigated the effect of dietary nitrate supplementation on arterial, muscle, and cerebral oxygenation status, symptoms of acute mountain sickness (AMS), and exercise tolerance at simulated 5,000 m altitude. Fifteen young, healthy volunteers participated in three experimental sessions according to a crossover study design. From 6 days prior to each session, subjects received either beetroot (BR) juice delivering 0.07 mmol nitrate/kg body wt/day or a control drink (CON). One session was in normoxia with CON (NORCON); the two other sessions were in hypoxia (11% O2), with either CON (HYPCON) or BR (HYPBR). Subjects first cycled for 20 min at 45% of peak O2 consumption (VO2peak; EX45%) and thereafter, performed a maximal incremental exercise test (EXmax). Whole-body VO2, arterial O2 saturation (%SpO2) via pulsoximetry, and tissue oxygenation index of both muscle (TOIM) and cerebral (TOIC) tissue by near-infrared spectroscopy were measured. Hypoxia per se substantially reduced VO2peak, %SpO2, TOIM, and TOIC (NORCON vs. HYPCON, P < 0.05). Compared with HYPCON, VO2 at rest and during EX45% was lower in HYPBR ( P < 0.05), whereas %SpO2 was higher ( P < 0.05). TOIM was ∼4-5% higher in HYPBR than in HYPCON both at rest and during EX45% and EXmax ( P < 0.05). TOIC as well as the incidence of AMS symptoms were similar between HYPCON and HYPBR at any time. Hypoxia reduced time to exhaustion in EXmax by 36% ( P < 0.05), but this ergolytic effect was partly negated by BR (+5%, P < 0.05). Short-term dietary nitrate supplementation improves arterial and muscle oxygenation status but not cerebral oxygenation status during exercise in severe hypoxia. This is associated with improved exercise tolerance against the background of a similar incidence of AMS.
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Affiliation(s)
- Evi Masschelein
- Research Center for Exercise and Health, Department of Biomedical Kinesiology, KU Leuven, Leuven, Belgium; and
| | - Ruud Van Thienen
- Research Center for Exercise and Health, Department of Biomedical Kinesiology, KU Leuven, Leuven, Belgium; and
| | - Xu Wang
- Laboratory for Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, KU Leuven, Leuven, Belgium
| | - Ann Van Schepdael
- Laboratory for Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, KU Leuven, Leuven, Belgium
| | - Martine Thomis
- Research Center for Exercise and Health, Department of Biomedical Kinesiology, KU Leuven, Leuven, Belgium; and
| | - Peter Hespel
- Research Center for Exercise and Health, Department of Biomedical Kinesiology, KU Leuven, Leuven, Belgium; and
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Vincent B, Windelinckx A, Van Proeyen K, Masschelein E, Nielens H, Ramaekers M, Van Leemputte M, Hespel P, Thomis M. Alpha-actinin-3 deficiency does not significantly alter oxidative enzyme activity in fast human muscle fibres. Acta Physiol (Oxf) 2012; 204:555-61. [PMID: 21933355 DOI: 10.1111/j.1748-1716.2011.02366.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
AIM In Western European populations, about 18% of all individuals have a complete deficiency of the alpha-actinin-3 protein owing to homozygosity for a stop codon mutation (R577X) in the ACTN3 gene. Actn3(-/-) knock-out mice show increased activity of multiple enzymes in the aerobic metabolic pathway in fast muscle fibres. Whether this observation is also present in human XX genotype carriers compared to RR carriers has not been studied in a fibre-type-specific approach in humans. The purpose of this study was therefore to compare fibre-type-specific oxidative enzyme activity in humans with a different ACTN3 R577X genotype. METHODS Vastus lateralis muscle biopsy samples of 17 XX and 16 RR subjects were used to measure markers of oxidative capacity [cytochrome c oxidase (CYTOX) and succinate dehydrogenase (SDH)] in a fibre-type-specific assay using enzyme histochemistry. RESULTS Cytochrome c oxidase staining showed no significant genotype group differences in type I or type II muscle fibres. Also, we found no significant differences in SDH staining of fast fibres comparing XX and RR carriers. CONCLUSION In conclusion, the increase in oxidative enzyme activity of fast muscle fibres, as reported in an Actn3(-/-) knock-out mouse, was not observed in our human samples. Known differences in metabolic characteristics of muscle fibres in rodents compared to humans may in part explain this discrepancy in findings.
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Affiliation(s)
- B Vincent
- Research Centre for Exercise and Health, Department of Biomedical Kinesiology, Faculty of Kinesiology and Rehabilitation Sciences, K. U. Leuven, Belgium
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Wang X, Masschelein E, Hespel P, Adams E, Van Schepdael A. Simultaneous determination of nitrite and nitrate in human plasma by on‐capillary preconcentration with field‐amplified sample stacking. Electrophoresis 2011; 33:402-5. [DOI: 10.1002/elps.201100285] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 07/20/2011] [Accepted: 08/29/2011] [Indexed: 12/21/2022]
Affiliation(s)
- Xu Wang
- Laboratory for Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, K.U. Leuven, Leuven, Belgium
| | - Evi Masschelein
- Research Centre for Exercise and Health, Faculty of Kinesiology and Rehabilitation Sciences, K.U. Leuven, Leuven, Belgium
| | - Peter Hespel
- Research Centre for Exercise and Health, Faculty of Kinesiology and Rehabilitation Sciences, K.U. Leuven, Leuven, Belgium
| | - Erwin Adams
- Laboratory for Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, K.U. Leuven, Leuven, Belgium
| | - Ann Van Schepdael
- Laboratory for Pharmaceutical Analysis, Faculty of Pharmaceutical Sciences, K.U. Leuven, Leuven, Belgium
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