1
|
Flores-Opazo M, Kopinke D, Helmbacher F, Fernández-Verdejo R, Tuñón-Suárez M, Lynch GS, Contreras O. Fibro-adipogenic progenitors in physiological adipogenesis and intermuscular adipose tissue remodeling. Mol Aspects Med 2024; 97:101277. [PMID: 38788527 DOI: 10.1016/j.mam.2024.101277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 04/27/2024] [Accepted: 05/13/2024] [Indexed: 05/26/2024]
Abstract
Excessive accumulation of intermuscular adipose tissue (IMAT) is a common pathological feature in various metabolic and health conditions and can cause muscle atrophy, reduced function, inflammation, insulin resistance, cardiovascular issues, and unhealthy aging. Although IMAT results from fat accumulation in muscle, the mechanisms underlying its onset, development, cellular components, and functions remain unclear. IMAT levels are influenced by several factors, such as changes in the tissue environment, muscle type and origin, extent and duration of trauma, and persistent activation of fibro-adipogenic progenitors (FAPs). FAPs are a diverse and transcriptionally heterogeneous population of stromal cells essential for tissue maintenance, neuromuscular stability, and tissue regeneration. However, in cases of chronic inflammation and pathological conditions, FAPs expand and differentiate into adipocytes, resulting in the development of abnormal and ectopic IMAT. This review discusses the role of FAPs in adipogenesis and how they remodel IMAT. It highlights evidence supporting FAPs and FAP-derived adipocytes as constituents of IMAT, emphasizing their significance in adipose tissue maintenance and development, as well as their involvement in metabolic disorders, chronic pathologies and diseases. We also investigated the intricate molecular pathways and cell interactions governing FAP behavior, adipogenesis, and IMAT accumulation in chronic diseases and muscle deconditioning. Finally, we hypothesize that impaired cellular metabolic flexibility in dysfunctional muscles impacts FAPs, leading to IMAT. A deeper understanding of the biology of IMAT accumulation and the mechanisms regulating FAP behavior and fate are essential for the development of new therapeutic strategies for several debilitating conditions.
Collapse
Affiliation(s)
| | - Daniel Kopinke
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, 32610, FL, USA; Myology Institute, University of Florida College of Medicine, Gainesville, FL, USA.
| | | | - Rodrigo Fernández-Verdejo
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA; Laboratorio de Fisiología Del Ejercicio y Metabolismo (LABFEM), Escuela de Kinesiología, Facultad de Medicina, Universidad Finis Terrae, Chile.
| | - Mauro Tuñón-Suárez
- Laboratorio de Fisiología Del Ejercicio y Metabolismo (LABFEM), Escuela de Kinesiología, Facultad de Medicina, Universidad Finis Terrae, Chile.
| | - Gordon S Lynch
- Centre for Muscle Research, Department of Anatomy and Physiology, The University of Melbourne, Melbourne, Victoria, Parkville 3010, Australia.
| | - Osvaldo Contreras
- Developmental and Regenerative Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia; School of Clinical Medicine, UNSW Sydney, Kensington, NSW 2052, Australia.
| |
Collapse
|
2
|
Yin A, Fu W, Elengickal A, Kim J, Liu Y, Bigot A, Mamchaoui K, Call JA, Yin H. Chronic hypoxia impairs skeletal muscle repair via HIF-2α stabilization. J Cachexia Sarcopenia Muscle 2024; 15:631-645. [PMID: 38333911 PMCID: PMC10995261 DOI: 10.1002/jcsm.13436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 11/28/2023] [Accepted: 01/02/2024] [Indexed: 02/10/2024] Open
Abstract
BACKGROUND Chronic hypoxia and skeletal muscle atrophy commonly coexist in patients with COPD and CHF, yet the underlying physio-pathological mechanisms remain elusive. Muscle regeneration, driven by muscle stem cells (MuSCs), holds therapeutic potential for mitigating muscle atrophy. This study endeavours to investigate the influence of chronic hypoxia on muscle regeneration, unravel key molecular mechanisms, and explore potential therapeutic interventions. METHODS Experimental mice were exposed to prolonged normobaric hypoxic air (15% pO2, 1 atm, 2 weeks) to establish a chronic hypoxia model. The impact of chronic hypoxia on body composition, muscle mass, muscle strength, and the expression levels of hypoxia-inducible factors HIF-1α and HIF-2α in MuSC was examined. The influence of chronic hypoxia on muscle regeneration, MuSC proliferation, and the recovery of muscle mass and strength following cardiotoxin-induced injury were assessed. The muscle regeneration capacities under chronic hypoxia were compared between wildtype mice, MuSC-specific HIF-2α knockout mice, and mice treated with HIF-2α inhibitor PT2385, and angiotensin converting enzyme (ACE) inhibitor lisinopril. Transcriptomic analysis was performed to identify hypoxia- and HIF-2α-dependent molecular mechanisms. Statistical significance was determined using analysis of variance (ANOVA) and Mann-Whitney U tests. RESULTS Chronic hypoxia led to limb muscle atrophy (EDL: 17.7%, P < 0.001; Soleus: 11.5% reduction in weight, P < 0.001) and weakness (10.0% reduction in peak-isometric torque, P < 0.001), along with impaired muscle regeneration characterized by diminished myofibre cross-sectional areas, increased fibrosis (P < 0.001), and incomplete strength recovery (92.3% of pre-injury levels, P < 0.05). HIF-2α stabilization in MuSC under chronic hypoxia hindered MuSC proliferation (26.1% reduction of MuSC at 10 dpi, P < 0.01). HIF-2α ablation in MuSC mitigated the adverse effects of chronic hypoxia on muscle regeneration and MuSC proliferation (30.9% increase in MuSC numbers at 10 dpi, P < 0.01), while HIF-1α ablation did not have the same effect. HIF-2α stabilization under chronic hypoxia led to elevated local ACE, a novel direct target of HIF-2α. Notably, pharmacological interventions with PT2385 or lisinopril enhanced muscle regeneration under chronic hypoxia (PT2385: 81.3% increase, P < 0.001; lisinopril: 34.6% increase in MuSC numbers at 10 dpi, P < 0.05), suggesting their therapeutic potential for alleviating chronic hypoxia-associated muscle atrophy. CONCLUSIONS Chronic hypoxia detrimentally affects skeletal muscle regeneration by stabilizing HIF-2α in MuSC and thereby diminishing MuSC proliferation. HIF-2α increases local ACE levels in skeletal muscle, contributing to hypoxia-induced regenerative deficits. Administration of HIF-2α or ACE inhibitors may prove beneficial to ameliorate chronic hypoxia-associated muscle atrophy and weakness by improving muscle regeneration under chronic hypoxia.
Collapse
Affiliation(s)
- Amelia Yin
- Center for Molecular MedicineThe University of GeorgiaAthensGAUSA
- Department of Biochemistry and Molecular BiologyThe University of GeorgiaAthensGAUSA
| | - Wenyan Fu
- Center for Molecular MedicineThe University of GeorgiaAthensGAUSA
- Department of Biochemistry and Molecular BiologyThe University of GeorgiaAthensGAUSA
| | - Anthony Elengickal
- Department of Biochemistry and Molecular BiologyThe University of GeorgiaAthensGAUSA
| | - Joonhee Kim
- Department of Biochemistry and Molecular BiologyThe University of GeorgiaAthensGAUSA
| | - Yang Liu
- Center for Molecular MedicineThe University of GeorgiaAthensGAUSA
- Department of Biochemistry and Molecular BiologyThe University of GeorgiaAthensGAUSA
| | - Anne Bigot
- Sorbonne Université, Inserm, Institut de MyologieCentre de Recherche en MyologieParisFrance
| | - Kamal Mamchaoui
- Sorbonne Université, Inserm, Institut de MyologieCentre de Recherche en MyologieParisFrance
| | - Jarrod A. Call
- Department of Physiology and PharmacologyThe University of GeorgiaAthensGAUSA
| | - Hang Yin
- Center for Molecular MedicineThe University of GeorgiaAthensGAUSA
- Department of Biochemistry and Molecular BiologyThe University of GeorgiaAthensGAUSA
| |
Collapse
|
3
|
Santocildes G, Viscor G, Pagès T, Torrella JR. Simulated altitude is medicine: intermittent exposure to hypobaric hypoxia and cold accelerates injured skeletal muscle recovery. J Physiol 2023. [PMID: 38153352 DOI: 10.1113/jp285398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 12/12/2023] [Indexed: 12/29/2023] Open
Abstract
Muscle injuries are the leading cause of sports casualties. Because of its high plasticity, skeletal muscle can respond to different stimuli to maintain and improve functionality. Intermittent hypobaric hypoxia (IHH) improves muscle oxygen delivery and utilization. Hypobaria coexists with cold in the biosphere, opening the possibility to consider the combined use of both environmental factors to achieve beneficial physiological adjustments. We studied the effects of IHH and cold exposure, separately and simultaneously, on muscle regeneration. Adult male rats were surgically injured in one gastrocnemius and randomly assigned to the following groups: (1) CTRL: passive recovery; (2) COLD: intermittently exposed to cold (4°C); (3) HYPO: submitted to IHH (4500 m); (4) COHY: exposed to intermittent simultaneous cold and hypoxia. Animals were subjected to these interventions for 4 h/day for 9 or 21 days. COLD and COHY rats showed faster muscle regeneration than CTRL, evidenced after 9 days at histological (dMHC-positive and centrally nucleated fibre reduction) and functional levels after 21 days. HYPO rats showed a full recovery from injury (at histological and functional levels) after 9 days, while COLD and COHY needed more time to induce a total functional recovery. IHH can be postulated as an anti-fibrotic treatment since it reduces collagen I deposition. The increase in the pSer473Akt/total Akt ratio observed after 9 days in COLD, HYPO and COHY, together with the increase in the pThr172AMPKα/total AMPKα ratio observed in the gastrocnemius of HYPO, provides clues to the molecular mechanisms involved in the improved muscle regeneration. KEY POINTS: Only intermittent hypobaric exposure accelerated muscle recovery as early as 9 days following injury at histological and functional levels. Injured muscles from animals treated with intermittent (4 h/day) cold, hypobaric hypoxia or a simultaneous combination of both stimuli regenerated histological structure and recovered muscle function 21 days after injury. The combination of cold and hypoxia showed a blunting effect as compared to hypoxia alone in the time course of the muscle recovery. The increased expression of the phosphorylated forms of Akt observed in all experimental groups could participate in the molecular cascade of events leading to a faster regeneration. The elevated levels of phosphorylated AMPKα in the HYPO group could play a key role in the modulation of the inflammatory response during the first steps of the muscle regeneration process.
Collapse
Affiliation(s)
- Garoa Santocildes
- Secció de Fisiologia, Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Ginés Viscor
- Secció de Fisiologia, Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Teresa Pagès
- Secció de Fisiologia, Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Joan Ramon Torrella
- Secció de Fisiologia, Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| |
Collapse
|
4
|
Cen H, Fan P, Ding Y, Luo B, Luo H, Chen M, Zhang Y. iPSCs ameliorate hypoxia-induced autophagy and atrophy in C2C12 myotubes via the AMPK/ULK1 pathway. Biol Res 2023; 56:29. [PMID: 37270528 DOI: 10.1186/s40659-023-00435-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 04/24/2023] [Indexed: 06/05/2023] Open
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) is an X-linked lethal genetic disorder for which there is no effective treatment. Previous studies have shown that stem cell transplantation into mdx mice can promote muscle regeneration and improve muscle function, however, the specific molecular mechanisms remain unclear. DMD suffers varying degrees of hypoxic damage during disease progression. This study aimed to investigate whether induced pluripotent stem cells (iPSCs) have protective effects against hypoxia-induced skeletal muscle injury. RESULTS In this study, we co-cultured iPSCs with C2C12 myoblasts using a Transwell nested system and placed them in a DG250 anaerobic workstation for oxygen deprivation for 24 h. We found that iPSCs reduced the levels of lactate dehydrogenase and reactive oxygen species and downregulated the mRNA and protein levels of BAX/BCL2 and LC3II/LC3I in hypoxia-induced C2C12 myoblasts. Meanwhile, iPSCs decreased the mRNA and protein levels of atrogin-1 and MuRF-1 and increased myotube width. Furthermore, iPSCs downregulated the phosphorylation of AMPKα and ULK1 in C2C12 myotubes exposed to hypoxic damage. CONCLUSIONS Our study showed that iPSCs enhanced the resistance of C2C12 myoblasts to hypoxia and inhibited apoptosis and autophagy in the presence of oxidative stress. Further, iPSCs improved hypoxia-induced autophagy and atrophy of C2C12 myotubes through the AMPK/ULK1 pathway. This study may provide a new theoretical basis for the treatment of muscular dystrophy in stem cells.
Collapse
Affiliation(s)
- Haimei Cen
- Department of Neurology, The First Affiliated Hospital, Jinan University, Guangzhou, 510630, Guangdong, China
| | - Pin Fan
- Department of Neurology, The First Affiliated Hospital, Jinan University, Guangzhou, 510630, Guangdong, China
| | - Yuting Ding
- Department of Neurology, The First Affiliated Hospital, Jinan University, Guangzhou, 510630, Guangdong, China
| | - Bin Luo
- Department of Neurology, The First Affiliated Hospital, Jinan University, Guangzhou, 510630, Guangdong, China
| | - Hong Luo
- Department of Neurology, Meizhou People's Hospital, Meizhou, 514000, Guangdong, China
| | - Menglong Chen
- Department of Neurology, The First Affiliated Hospital, Jinan University, Guangzhou, 510630, Guangdong, China.
| | - Yu Zhang
- Department of Neurology, The First Affiliated Hospital, Jinan University, Guangzhou, 510630, Guangdong, China.
| |
Collapse
|
5
|
Mendelson AA, Erickson D, Villar R. The role of the microcirculation and integrative cardiovascular physiology in the pathogenesis of ICU-acquired weakness. Front Physiol 2023; 14:1170429. [PMID: 37234410 PMCID: PMC10206327 DOI: 10.3389/fphys.2023.1170429] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Skeletal muscle dysfunction after critical illness, defined as ICU-acquired weakness (ICU-AW), is a complex and multifactorial syndrome that contributes significantly to long-term morbidity and reduced quality of life for ICU survivors and caregivers. Historically, research in this field has focused on pathological changes within the muscle itself, without much consideration for their in vivo physiological environment. Skeletal muscle has the widest range of oxygen metabolism of any organ, and regulation of oxygen supply with tissue demand is a fundamental requirement for locomotion and muscle function. During exercise, this process is exquisitely controlled and coordinated by the cardiovascular, respiratory, and autonomic systems, and also within the skeletal muscle microcirculation and mitochondria as the terminal site of oxygen exchange and utilization. This review highlights the potential contribution of the microcirculation and integrative cardiovascular physiology to the pathogenesis of ICU-AW. An overview of skeletal muscle microvascular structure and function is provided, as well as our understanding of microvascular dysfunction during the acute phase of critical illness; whether microvascular dysfunction persists after ICU discharge is currently not known. Molecular mechanisms that regulate crosstalk between endothelial cells and myocytes are discussed, including the role of the microcirculation in skeletal muscle atrophy, oxidative stress, and satellite cell biology. The concept of integrated control of oxygen delivery and utilization during exercise is introduced, with evidence of physiological dysfunction throughout the oxygen delivery pathway - from mouth to mitochondria - causing reduced exercise capacity in patients with chronic disease (e.g., heart failure, COPD). We suggest that objective and perceived weakness after critical illness represents a physiological failure of oxygen supply-demand matching - both globally throughout the body and locally within skeletal muscle. Lastly, we highlight the value of standardized cardiopulmonary exercise testing protocols for evaluating fitness in ICU survivors, and the application of near-infrared spectroscopy for directly measuring skeletal muscle oxygenation, representing potential advancements in ICU-AW research and rehabilitation.
Collapse
Affiliation(s)
- Asher A. Mendelson
- Section of Critical Care Medicine, Department of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Dustin Erickson
- Section of Critical Care Medicine, Department of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Rodrigo Villar
- Faculty of Kinesiology and Recreation Management, University of Manitoba, Winnipeg, MB, Canada
| |
Collapse
|
6
|
Zhang L, Voss JG, Soulakova JN, St Pierre Schneider B. Effects of hypobaric hypoxia during a simulated ultra-long-haul flight on inflammation and regeneration after muscle trauma and muscle trauma-hemorrhagic shock. Muscle Nerve 2023; 67:320-329. [PMID: 36747325 DOI: 10.1002/mus.27795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 02/01/2023] [Accepted: 02/01/2023] [Indexed: 02/08/2023]
Abstract
INTRODUCTION/AIMS Because wounded warfighters or trauma victims may receive en route care to the closest medical facility via airplane transport, we investigated the effects of extended mild hypobaric hypoxia (HB), the environmental milieu of most airplanes, on inflammation and regeneration after muscle trauma or monotrauma (MT) and muscle trauma-hemorrhagic shock or polytrauma (PT). METHODS Male C57BL/6N mice were assigned to one of six groups pertaining to injury (control/uninjured, MT, and PT) and atmospheric pressure exposure (HB and normobaric normoxia, NB). Body mass, blood and muscle leukocyte number by flow cytometry, immunohistochemistry, or both, and the muscle relative mRNA level of selected genes involved in inflammation and muscle regeneration were examined at ~1.7, 4, 8, and 14 days post trauma (dpt). At 14 dpt, the proportion of smaller- and larger-sized myofibers at the regenerating site of MT mice was determined. RESULTS Greater body mass loss, an increased number of blood and muscle leukocytes, and differential muscle relative mRNA levels were observed in MT and PT groups compared to controls. The MT+HB or PT+HB mice demonstrated more body mass loss and altered relative mRNA level than the corresponding NB mice. Additionally, a subgroup of MT+HB mice demonstrated a greater proportion of smaller myofibers (250 to 500 μm2 ) than MT+NB mice at 14 dpt. DISCUSSION HB exposure after muscle trauma alone may prolong regeneration. Following HB exposure, therapies that promote oxygenation may be needed during this muscle recovery.
Collapse
Affiliation(s)
- Liyuan Zhang
- College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, Texas, USA
| | - Joachim G Voss
- Frances Payne Bolton School of Nursing, Case Western Reserve University, Cleveland, Ohio, USA
| | - Julia N Soulakova
- Department of Population Health Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | | |
Collapse
|
7
|
Makar D, Nazemi A, Gong SG, Bhardwaj N, De Guzman R, Sessle BJ, Cioffi I. Development of a model to investigate the effects of prolonged ischaemia on the muscles of mastication of male Sprague Dawley rats. Arch Oral Biol 2023; 146:105602. [PMID: 36543038 DOI: 10.1016/j.archoralbio.2022.105602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 12/02/2022] [Accepted: 12/04/2022] [Indexed: 12/12/2022]
Abstract
OBJECTIVE The aims of this study were to develop a novel rodent model of masticatory muscle ischaemia via unilateral ligation of the external carotid artery (ECA), and to undertake a preliminary investigation to characterize its downstream effects on mechanosensitivity and cellular features of the masseter and temporalis muscles. DESIGN The right ECA of 18 male Sprague-Dawley rats was ligated under general anaesthesia. Mechanical detection thresholds (MDTs) at the masseter and temporalis bilaterally were measured immediately before ECA ligation and after euthanasia at 10-, 20-, and 35-days (n = 6 rats/timepoint). Tissue samples from both muscles and sides were harvested for histological analyses and for assessing changes in the expression of markers of hypoxia and muscle degeneration (Hif-1α, VegfA, and Fbxo32) via real time PCR. Data were analyzed using mixed effect models and non-parametric tests. Statistical significance was set at p < 0.05. RESULTS MDTs were higher in the right than left hemiface (p = 0.009) after 20 days. Histological changes indicative of muscle degeneration and fibrosis were observed in the right muscles. Hif-1α, VegfA, and Fbxo32 were more highly expressed in the masseter than temporalis muscles (all p < 0.05). Hif-1α and, VegfA did not change significantly with time in all muscles (all p > 0.05). Fbxo32 expression gradually increased in the right masseter (p = 0.024) and left temporalis (p = 0.05). CONCLUSIONS ECA ligation in rats induced hyposensitivity in the homolateral hemiface after 20 days accompanied by tissue degenerative changes. Our findings support the use of this model to study pathophysiologic mechanisms of masticatory muscle ischaemia in larger investigations.
Collapse
Affiliation(s)
- D Makar
- University of Toronto, Faculty of Dentistry, Centre for Multimodal Sensorimotor and Pain Research, Toronto, ON, Canada; University of Toronto, Faculty of Dentistry, Graduate Orthodontics, Toronto, ON, Canada
| | - A Nazemi
- University of Toronto, Faculty of Dentistry, Centre for Multimodal Sensorimotor and Pain Research, Toronto, ON, Canada
| | - S G Gong
- University of Toronto, Faculty of Dentistry, Graduate Orthodontics, Toronto, ON, Canada
| | - N Bhardwaj
- University of Toronto, Faculty of Medicine, Department of Comparative Medicine, Toronto, ON, Canada; Peter Gilgan Centre for Research and Learning, Sickkids Hospital, Toronto, ON, Canada
| | - R De Guzman
- University of Toronto, Faculty of Medicine, Department of Comparative Medicine, Toronto, ON, Canada
| | - B J Sessle
- University of Toronto, Faculty of Dentistry, Toronto, ON, Canada; University of Toronto, Faculty of Medicine, Department of Physiology, Toronto, ON, Canada
| | - I Cioffi
- University of Toronto, Faculty of Dentistry, Centre for Multimodal Sensorimotor and Pain Research, Toronto, ON, Canada; Mount Sinai Hospital, Department of Dentistry, Toronto, ON, Canada; University of Toronto, Faculty of Dentistry, Graduate Orthodontics, Toronto, ON, Canada.
| |
Collapse
|
8
|
Amorese AJ, Minchew EC, Tarpey MD, Readyoff AT, Williamson NC, Schmidt CA, McMillin SL, Goldberg EJ, Terwilliger ZS, Spangenburg QA, Witczak CA, Brault JJ, Abel ED, McClung JM, Fisher-Wellman KH, Spangenburg EE. Hypoxia Resistance Is an Inherent Phenotype of the Mouse Flexor Digitorum Brevis Skeletal Muscle. FUNCTION 2023; 4:zqad012. [PMID: 37168496 PMCID: PMC10165545 DOI: 10.1093/function/zqad012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/10/2023] [Accepted: 03/13/2023] [Indexed: 05/13/2023] Open
Abstract
The various functions of skeletal muscle (movement, respiration, thermogenesis, etc.) require the presence of oxygen (O2). Inadequate O2 bioavailability (ie, hypoxia) is detrimental to muscle function and, in chronic cases, can result in muscle wasting. Current therapeutic interventions have proven largely ineffective to rescue skeletal muscle from hypoxic damage. However, our lab has identified a mammalian skeletal muscle that maintains proper physiological function in an environment depleted of O2. Using mouse models of in vivo hindlimb ischemia and ex vivo anoxia exposure, we observed the preservation of force production in the flexor digitorum brevis (FDB), while in contrast the extensor digitorum longus (EDL) and soleus muscles suffered loss of force output. Unlike other muscles, we found that the FDB phenotype is not dependent on mitochondria, which partially explains the hypoxia resistance. Muscle proteomes were interrogated using a discovery-based approach, which identified significantly greater expression of the transmembrane glucose transporter GLUT1 in the FDB as compared to the EDL and soleus. Through loss-and-gain-of-function approaches, we determined that GLUT1 is necessary for the FDB to survive hypoxia, but overexpression of GLUT1 was insufficient to rescue other skeletal muscles from hypoxic damage. Collectively, the data demonstrate that the FDB is uniquely resistant to hypoxic insults. Defining the mechanisms that explain the phenotype may provide insight towards developing approaches for preventing hypoxia-induced tissue damage.
Collapse
Affiliation(s)
| | | | - Michael D Tarpey
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
| | - Andrew T Readyoff
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC 27834, USA
| | - Nicholas C Williamson
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
| | - Cameron A Schmidt
- Department of Biology, East Carolina University, Greenville, NC 27834, USA
| | - Shawna L McMillin
- Department of Kinesiology, East Carolina University, Greenville, NC 27858, USA
| | - Emma J Goldberg
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
| | - Zoe S Terwilliger
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
| | - Quincy A Spangenburg
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
| | - Carol A Witczak
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indianapolis, IN 46202, USA
- Indiana Center for Diabetes and Metabolic Diseases, Indianapolis, IN 46202, USA
| | - Jeffrey J Brault
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Musculoskeletal Health, Indianapolis, IN 46202, USA
| | - E Dale Abel
- David Geffen School of Medicine, Department of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Joseph M McClung
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
- Department of Cardiovascular Sciences, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC 27834, USA
| | - Kelsey H Fisher-Wellman
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
- Department of Cardiovascular Sciences, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA
| | | |
Collapse
|
9
|
Moberg M, Apró W, Horwath O, Hall G, Blackwood SJ, Katz A. Acute normobaric hypoxia blunts contraction-mediated mTORC1- and JNK-signaling in human skeletal muscle. Acta Physiol (Oxf) 2022; 234:e13771. [PMID: 34984845 PMCID: PMC9285439 DOI: 10.1111/apha.13771] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 09/28/2021] [Accepted: 01/01/2022] [Indexed: 12/26/2022]
Abstract
Aim Hypoxia has been shown to reduce resistance exercise‐induced stimulation of protein synthesis and long‐term gains in muscle mass. However, the mechanism whereby hypoxia exerts its effect is not clear. Here, we examine the effect of acute hypoxia on the activity of several signalling pathways involved in the regulation of muscle growth following a bout of resistance exercise. Methods Eight men performed two sessions of leg resistance exercise in normoxia or hypoxia (12% O2) in a randomized crossover fashion. Muscle biopsies were obtained at rest and 0, 90,180 minutes after exercise. Muscle analyses included levels of signalling proteins and metabolites associated with energy turnover. Results Exercise during normoxia induced a 5‐10‐fold increase of S6K1Thr389 phosphorylation throughout the recovery period, but hypoxia blunted the increases by ~50%. Phosphorylation of JNKThr183/Tyr185 and the JNK target SMAD2Ser245/250/255 was increased by 30‐ to 40‐fold immediately after the exercise in normoxia, but hypoxia blocked almost 70% of the activation. Throughout recovery, phosphorylation of JNK and SMAD2 remained elevated following the exercise in normoxia, but the effect of hypoxia was lost at 90‐180 minutes post‐exercise. Hypoxia had no effect on exercise‐induced Hippo or autophagy signalling and ubiquitin‐proteasome related protein levels. Nor did hypoxia alter the changes induced by exercise in high‐energy phosphates, glucose 6‐P, lactate or phosphorylation of AMPK or ACC. Conclusion We conclude that acute severe hypoxia inhibits resistance exercise‐induced mTORC1‐ and JNK signalling in human skeletal muscle, effects that do not appear to be mediated by changes in the degree of metabolic stress in the muscle.
Collapse
Affiliation(s)
- Marcus Moberg
- Åstrand Laboratory Department of Physiology, Nutrition and Biomechanics Swedish School of Sport and Health Sciences Stockholm Sweden
- Department of Physiology and Pharmacology Karolinska Institute Stockholm Sweden
| | - William Apró
- Åstrand Laboratory Department of Physiology, Nutrition and Biomechanics Swedish School of Sport and Health Sciences Stockholm Sweden
- Department of Clinical Science, Intervention and Technology Karolinska Institute Stockholm Sweden
| | - Oscar Horwath
- Åstrand Laboratory Department of Physiology, Nutrition and Biomechanics Swedish School of Sport and Health Sciences Stockholm Sweden
| | - Gerrit Hall
- Department of Biomedical Sciences Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
- Clinical Metabolomics Core Facility, Clinical Biochemistry Rigshospitalet Copenhagen Denmark
| | - Sarah Joan Blackwood
- Åstrand Laboratory Department of Physiology, Nutrition and Biomechanics Swedish School of Sport and Health Sciences Stockholm Sweden
| | - Abram Katz
- Åstrand Laboratory Department of Physiology, Nutrition and Biomechanics Swedish School of Sport and Health Sciences Stockholm Sweden
| |
Collapse
|
10
|
Horiike M, Ogawa Y, Kawada S. Effects of hyperoxia and hypoxia on the proliferation of C2C12 myoblasts. Am J Physiol Regul Integr Comp Physiol 2021; 321:R572-R587. [PMID: 34431403 DOI: 10.1152/ajpregu.00269.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Hyperoxic conditions are known to accelerate skeletal muscle regeneration after injuries. In the early phase of regeneration, macrophages invade the injured area and subsequently secrete various growth factors, which regulate myoblast proliferation and differentiation. Although hyperoxic conditions accelerate muscle regeneration, it is unknown whether this effect is indirectly mediated by macrophages. Here, using C2C12 cells, we show that not only hyperoxia but also hypoxia enhance myoblast proliferation directly, without accelerating differentiation into myotubes. Under hyperoxic conditions (95% O2 + 5% CO2), the cell membrane was damaged because of lipid oxidization, and a disrupted cytoskeletal structure, resulting in suppressed cell proliferation. However, a culture medium containing vitamin C (VC), an antioxidant, prevented this lipid oxidization and cytoskeletal disruption, resulting in enhanced proliferation in response to hyperoxia exposure of ≤4 h/day. In contrast, exposure to hypoxic conditions (95% N2 + 5% CO2) for ≤8 h/day enhanced cell proliferation. Hyperoxia did not promote cell differentiation into myotubes, regardless of whether the culture medium contained VC. Similarly, hypoxia did not accelerate cell differentiation. These results suggest that regardless of hyperoxia or hypoxia, changes in oxygen tension can enhance cell proliferation directly, but do not influence differentiation efficiency in C2C12 cells. Moreover, excess oxidative stress abrogated the enhancement of myoblast proliferation induced by hyperoxia. This research will contribute to basic data for applying the effects of hyperoxia or hypoxia to muscle regeneration therapy.
Collapse
Affiliation(s)
- Misa Horiike
- Department of Sport and Medical Science, Faculty of Medical Technology, Teikyo University, Tokyo, Japan
| | - Yoshiko Ogawa
- Department of Sport and Medical Science, Faculty of Medical Technology, Teikyo University, Tokyo, Japan
| | - Shigeo Kawada
- Department of Sport and Medical Science, Faculty of Medical Technology, Teikyo University, Tokyo, Japan
| |
Collapse
|
11
|
Rathor R, Suryakumar G, Singh SN. Diet and redox state in maintaining skeletal muscle health and performance at high altitude. Free Radic Biol Med 2021; 174:305-320. [PMID: 34352371 DOI: 10.1016/j.freeradbiomed.2021.07.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 07/14/2021] [Accepted: 07/19/2021] [Indexed: 01/07/2023]
Abstract
High altitude exposure leads to compromised physical performance with considerable weight loss. The major stressor at high altitude is hypobaric hypoxia which leads to disturbance in redox homeostasis. Oxidative stress is a well-known trigger for many high altitude illnesses and regulates several key signaling pathways under stressful conditions. Altered redox homeostasis is considered the prime culprit of high altitude linked skeletal muscle atrophy. Hypobaric hypoxia disturbs redox homeostasis through increased RONS production and compromised antioxidant system. Increased RONS disturbs the cellular homeostasis via multiple ways such as inflammation generation, altered protein anabolic pathways, redox remodeling of RyR1 that contributed to dysregulated calcium homeostasis, enhanced protein degradation pathways via activation calcium-regulated protein, calpain, and apoptosis. Ultimately, all the cellular signaling pathways aggregately result in skeletal muscle atrophy. Dietary supplementation of phytochemicals could become a safe and effective intervention to ameliorate skeletal muscle atrophy and enhance the physical performance of the personnel who are staying at high altitude regions. The present evidence-based review explores few dietary supplementations which regulate several signaling mechanisms and ameliorate hypobaric hypoxia induced muscle atrophy and enhances physical performance. However, a clinical research trial is required to establish proof-of-concept.
Collapse
Affiliation(s)
- Richa Rathor
- Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, New Delhi, 110054, India.
| | - Geetha Suryakumar
- Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, New Delhi, 110054, India
| | - Som Nath Singh
- Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, New Delhi, 110054, India
| |
Collapse
|
12
|
Nguyen TH, Conotte S, Belayew A, Declèves AE, Legrand A, Tassin A. Hypoxia and Hypoxia-Inducible Factor Signaling in Muscular Dystrophies: Cause and Consequences. Int J Mol Sci 2021; 22:7220. [PMID: 34281273 PMCID: PMC8269128 DOI: 10.3390/ijms22137220] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 12/29/2022] Open
Abstract
Muscular dystrophies (MDs) are a group of inherited degenerative muscle disorders characterized by a progressive skeletal muscle wasting. Respiratory impairments and subsequent hypoxemia are encountered in a significant subgroup of patients in almost all MD forms. In response to hypoxic stress, compensatory mechanisms are activated especially through Hypoxia-Inducible Factor 1 α (HIF-1α). In healthy muscle, hypoxia and HIF-1α activation are known to affect oxidative stress balance and metabolism. Recent evidence has also highlighted HIF-1α as a regulator of myogenesis and satellite cell function. However, the impact of HIF-1α pathway modifications in MDs remains to be investigated. Multifactorial pathological mechanisms could lead to HIF-1α activation in patient skeletal muscles. In addition to the genetic defect per se, respiratory failure or blood vessel alterations could modify hypoxia response pathways. Here, we will discuss the current knowledge about the hypoxia response pathway alterations in MDs and address whether such changes could influence MD pathophysiology.
Collapse
Affiliation(s)
- Thuy-Hang Nguyen
- Laboratory of Respiratory Physiology, Pathophysiology and Rehabilitation, Research Institute for Health Sciences and Technology, University of Mons, 7000 Mons, Belgium; (T.-H.N.); (S.C.); (A.B.); (A.L.)
| | - Stephanie Conotte
- Laboratory of Respiratory Physiology, Pathophysiology and Rehabilitation, Research Institute for Health Sciences and Technology, University of Mons, 7000 Mons, Belgium; (T.-H.N.); (S.C.); (A.B.); (A.L.)
| | - Alexandra Belayew
- Laboratory of Respiratory Physiology, Pathophysiology and Rehabilitation, Research Institute for Health Sciences and Technology, University of Mons, 7000 Mons, Belgium; (T.-H.N.); (S.C.); (A.B.); (A.L.)
| | - Anne-Emilie Declèves
- Department of Metabolic and Molecular Biochemistry, Research Institute for Health Sciences and Technology, University of Mons, 7000 Mons, Belgium;
| | - Alexandre Legrand
- Laboratory of Respiratory Physiology, Pathophysiology and Rehabilitation, Research Institute for Health Sciences and Technology, University of Mons, 7000 Mons, Belgium; (T.-H.N.); (S.C.); (A.B.); (A.L.)
| | - Alexandra Tassin
- Laboratory of Respiratory Physiology, Pathophysiology and Rehabilitation, Research Institute for Health Sciences and Technology, University of Mons, 7000 Mons, Belgium; (T.-H.N.); (S.C.); (A.B.); (A.L.)
| |
Collapse
|
13
|
Lu Y, Mao J, Han X, Zhang W, Li Y, Liu Y, Li Q. Downregulated hypoxia-inducible factor 1α improves myoblast differentiation under hypoxic condition in mouse genioglossus. Mol Cell Biochem 2021; 476:1351-1364. [PMID: 33389500 DOI: 10.1007/s11010-020-03995-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 08/01/2020] [Indexed: 10/22/2022]
Abstract
The treatment of obstructive sleep apnea-hypopnea syndrome targets the narrow anatomic structure of the upper airway (UA) and lacks an effective therapy for UA dilator muscle dysfunction. Long-term hypoxia can cause damage to UA dilator muscles and trigger a vicious cycle. We previously confirmed that hypoxia-inducible factor 1α (HIF-1α) upregulation mediates muscle fatigue in hypoxia condition, but the underlying mechanism remains to be determined. The present study investigated the intrinsic mechanisms and related pathways of HIF-1α that affect myoblast differentiation, with an aim to search for compounds that have protective effects in hypoxic condition. Differentiation of myoblasts was induced under hypoxia, and we found that hypoxia significantly inhibits the differentiation of myoblasts, damages the ultrastructure of mitochondria, and reduces the expression of myogenin, PGC-1β and pAMPKα1. HIF-1α has a negative regulation effect on AMPK. Downregulation of HIF-1α increases the expression of the abovementioned proteins, promotes the differentiation of myoblasts, and protects mitochondrial integrity. In addition, mitochondrial biogenesis occurs during myogenic differentiation. Inhibition of the AMPK pathway inhibits mitochondrial biogenesis, decreases the level of PGC-1β, and increases apoptosis. Resveratrol dimer can reverse the mitochondrial damage induced by AMPK pathway inhibition and decrease myoblast apoptosis. Our results provided a regulatory mechanism for hypoxic injury in genioglossus which may contribute to the pathogenesis and treatment of OSAHS.
Collapse
Affiliation(s)
- Yun Lu
- Department of Orthodontics, Shanghai Stomatological Hospital, Fudan University, No.356 East Beijing Road, Shanghai, 200001, China
- Oral Biomedical Engineering Laboratory, Shanghai Stomatological Hospital, Fudan University, 2 Tianjin Road, Shanghai, 200001, China
| | - Jiaqi Mao
- Oral Biomedical Engineering Laboratory, Shanghai Stomatological Hospital, Fudan University, 2 Tianjin Road, Shanghai, 200001, China
- Department of Endodontics, Stomatological Hospital, Hebei Medical University, 383 East Zhongshan Road, Shijiazhuang, 050017, China
| | - Xinxin Han
- Oral Biomedical Engineering Laboratory, Shanghai Stomatological Hospital, Fudan University, 2 Tianjin Road, Shanghai, 200001, China
| | - Weihua Zhang
- Department of Orthodontics, Shanghai Stomatological Hospital, Fudan University, No.356 East Beijing Road, Shanghai, 200001, China
- Oral Biomedical Engineering Laboratory, Shanghai Stomatological Hospital, Fudan University, 2 Tianjin Road, Shanghai, 200001, China
| | - Yuanyuan Li
- Oral Biomedical Engineering Laboratory, Shanghai Stomatological Hospital, Fudan University, 2 Tianjin Road, Shanghai, 200001, China
- Department of Pediatric Dentistry, Shanghai Stomatological Hospital, Fudan University, 356 East Beijing Road, Shanghai, 200001, China
| | - Yuehua Liu
- Department of Orthodontics, Shanghai Stomatological Hospital, Fudan University, No.356 East Beijing Road, Shanghai, 200001, China.
- Oral Biomedical Engineering Laboratory, Shanghai Stomatological Hospital, Fudan University, 2 Tianjin Road, Shanghai, 200001, China.
| | - Qiang Li
- Department of Orthodontics, Shanghai Stomatological Hospital, Fudan University, No.356 East Beijing Road, Shanghai, 200001, China.
- Oral Biomedical Engineering Laboratory, Shanghai Stomatological Hospital, Fudan University, 2 Tianjin Road, Shanghai, 200001, China.
| |
Collapse
|
14
|
Hyldahl RD, Peake JM. Combining cooling or heating applications with exercise training to enhance performance and muscle adaptations. J Appl Physiol (1985) 2020; 129:353-365. [PMID: 32644914 DOI: 10.1152/japplphysiol.00322.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Athletes use cold water immersion, cryotherapy chambers, or icing in the belief that these strategies improve postexercise recovery and promote greater adaptations to training. A number of studies have systematically investigated how regular cold water immersion influences long-term performance and muscle adaptations. The effects of regular cold water immersion after endurance or high-intensity interval training on aerobic capacity, lactate threshold, power output, and time trial performance are equivocal. Evidence for changes in angiogenesis and mitochondrial biogenesis in muscle in response to regular cold water immersion is also mixed. More consistent evidence is available that regular cold water immersion after strength training attenuates gains in muscle mass and strength. These effects are attributable to reduced activation of satellite cells, ribosomal biogenesis, anabolic signaling, and muscle protein synthesis. Athletes use passive heating to warm up before competition or improve postexercise recovery. Emerging evidence indicates that regular exposure to ambient heat, wearing garments perfused with hot water, or microwave diathermy can mimic the effects of endurance training by stimulating angiogenesis and mitochondrial biogenesis in muscle. Some passive heating applications may also mitigate muscle atrophy through their effects on mitochondrial biogenesis and muscle fiber hypertrophy. More research is needed to consolidate these findings, however. Future research in this field should focus on 1) the optimal modality, temperature, duration, and frequency of cooling and heating to enhance long-term performance and muscle adaptations and 2) whether molecular and morphological changes in muscle in response to cooling and heating applications translate to improvements in exercise performance.
Collapse
Affiliation(s)
- Robert D Hyldahl
- Department of Exercise Sciences, Brigham Young University, Provo, Utah
| | - Jonathan M Peake
- Queensland University of Technology, School of Biomedical Sciences and Institute of Health and Biomedical Innovation, Brisbane, Queensland, Australia.,Sport Performance Innovation and Knowledge Excellence, Queensland Academy of Sport, Brisbane, Queensland, Australia
| |
Collapse
|
15
|
Valle-Tenney R, Rebolledo D, Acuña MJ, Brandan E. HIF-hypoxia signaling in skeletal muscle physiology and fibrosis. J Cell Commun Signal 2020; 14:147-158. [PMID: 32088838 DOI: 10.1007/s12079-020-00553-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 02/11/2020] [Indexed: 02/06/2023] Open
Abstract
Hypoxia refers to the decrease in oxygen tension in the tissues, and the central effector of the hypoxic response is the transcription factor Hypoxia-Inducible Factor α (HIF1-α). Transient hypoxia in acute events, such as exercising or regeneration after damage, play an important role in skeletal muscle physiology and homeostasis. However, sustained activation of hypoxic signaling is a feature of skeletal muscle injury and disease, which can be a consequence of chronic damage but can also increase the severity of the pathology and worsen its outcome. Here, we review evidence that supports the idea that hypoxia and HIF-1α can contribute to the establishment of fibrosis in skeletal muscle through its crosstalk with other profibrotic factors, such as Transforming growth factor β (TGF-β), the induction of profibrotic cytokines expression, as is the case of Connective Tissue Growth Factor (CTGF/CCN2), or being the target of the Renin-angiotensin system (RAS).
Collapse
Affiliation(s)
- Roger Valle-Tenney
- Centro de Envejecimiento y Regeneración, CARE Chile UC, Santiago, Chile.,Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Daniela Rebolledo
- Centro de Envejecimiento y Regeneración, CARE Chile UC, Santiago, Chile.,Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas, Chile.,Centro Integrativo de Biología y Química Aplicada (CIBQA), Universidad Bernardo O Higgins, Santiago, Chile
| | - María José Acuña
- Centro de Envejecimiento y Regeneración, CARE Chile UC, Santiago, Chile.,Centro Integrativo de Biología y Química Aplicada (CIBQA), Universidad Bernardo O Higgins, Santiago, Chile
| | - Enrique Brandan
- Centro de Envejecimiento y Regeneración, CARE Chile UC, Santiago, Chile. .,Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile. .,Fundación Ciencia & Vida, Santiago, Chile. .,Department Cell and Molecular Biology, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
| |
Collapse
|
16
|
Chiu CH, Chang SS, Chang GJ, Chen ACY, Cheng CY, Chen SC, Chan YS. The Effect of Hyperbaric Oxygen Treatment on Myoblasts and Muscles After Contusion Injury. J Orthop Res 2020; 38:329-335. [PMID: 31531986 DOI: 10.1002/jor.24478] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 09/13/2019] [Indexed: 02/04/2023]
Abstract
The recommended treatment varies depending on the severity of muscle injuries. The aim of this study was to evaluate the in vitro myoblast proliferation and the in vivo histologic and physiologic effects of hyperbaric oxygen treatment on muscle healing after contusion. Cells from the C2C12 myoblast cell line were exposed to 100% O2 for 25 min then to air for 5 min at 2.5 atmospheres absolute in a hyperbaric chamber for a total treatment duration of 90 min per 48 h at intervals of 2, 4, 6 and 8 days. Cell growth measurements and western blot analysis of myogenin and actin were performed. Then, 18 mice aged 8-10 weeks were used in the muscle contusion model. The histologic and physiologic effects and muscle regeneration after hyperbaric oxygen treatment were evaluated. The myoblast growth rate was significantly higher (p < 0.05) after hyperbaric oxygen treatment. Densitometric evaluation demonstrated a 39% (p < 0.05) and 25% (p < 0.05) increase in myogenin and actin protein levels, respectively, in the cells treated with 1 dose of hyperbaric oxygen. Similarly, the myogenin and actin protein levels increased for samples receiving multiple hyperbaric oxygen treatments when compared with the control. Physiologic evaluation of fast twitch and tetanus strength revealed a significant difference between the control group and the 14-day hyperbaric oxygen group. In conclusion, hyperbaric oxygen treatment increases the myoblast growth rate and myogenin and actin production. Better histologic and physiologic performance were found after hyperbaric oxygen treatment in animal contusion model. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:329-335, 2020.
Collapse
Affiliation(s)
- Chih-Hao Chiu
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Bone and Joint Research Center, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Shih-Sheng Chang
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Taoyuan, Taiwan
- Bone and Joint Research Center, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Gwo-Jyh Chang
- Graduate Institute of Clinical and Medicinal Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan
| | - Alvin Chao-Yu Chen
- Bone and Joint Research Center, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Chun-Ying Cheng
- Bone and Joint Research Center, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Su-Ching Chen
- Bone and Joint Research Center, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Yi-Sheng Chan
- Bone and Joint Research Center, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Linkou, Taiwan
| |
Collapse
|
17
|
Role of hypoxia in skeletal muscle fibrosis: Synergism between hypoxia and TGF-β signaling upregulates CCN2/CTGF expression specifically in muscle fibers. Matrix Biol 2019; 87:48-65. [PMID: 31669521 DOI: 10.1016/j.matbio.2019.09.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 09/23/2019] [Accepted: 09/25/2019] [Indexed: 02/06/2023]
Abstract
Several skeletal muscle diseases are characterized by fibrosis, the excessive accumulation of extracellular matrix. Transforming growth factor-β (TGF-β) and connective tissue growth factor (CCN2/CTGF) are two profibrotic factors augmented in fibrotic skeletal muscle, together with signs of reduced vasculature that implies a decrease in oxygen supply. We observed that fibrotic muscles are characterized by the presence of positive nuclei for hypoxia-inducible factor-1α (HIF-1α), a key mediator of the hypoxia response. However, it is not clear how a hypoxic environment could contribute to the fibrotic phenotype in skeletal muscle. We evaluated the role of hypoxia and TGF-β on CCN2 expression in vitro. Fibroblasts, myoblasts and differentiated myotubes were incubated with TGF-β1 under hypoxic conditions. Hypoxia and TGF-β1 induced CCN2 expression synergistically in myotubes but not in fibroblasts or undifferentiated muscle progenitors. This induction requires HIF-1α and the Smad-independent TGF-β signaling pathway. We performed in vivo experiments using pharmacological stabilization of HIF-1α or hypoxia-induced via hindlimb ischemia together with intramuscular injections of TGF-β1, and we found increased CCN2 expression. These observations suggest that hypoxic signaling together with TGF-β signaling, which are both characteristics of a fibrotic skeletal muscle environment, induce the expression of CCN2 in skeletal muscle fibers and myotubes.
Collapse
|
18
|
Wei X, Luo L, Chen J. Roles of mTOR Signaling in Tissue Regeneration. Cells 2019; 8:cells8091075. [PMID: 31547370 PMCID: PMC6769890 DOI: 10.3390/cells8091075] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 09/06/2019] [Accepted: 09/07/2019] [Indexed: 12/11/2022] Open
Abstract
The mammalian target of rapamycin (mTOR), is a serine/threonine protein kinase and belongs to the phosphatidylinositol 3-kinase (PI3K)-related kinase (PIKK) family. mTOR interacts with other subunits to form two distinct complexes, mTORC1 and mTORC2. mTORC1 coordinates cell growth and metabolism in response to environmental input, including growth factors, amino acid, energy and stress. mTORC2 mainly controls cell survival and migration through phosphorylating glucocorticoid-regulated kinase (SGK), protein kinase B (Akt), and protein kinase C (PKC) kinase families. The dysregulation of mTOR is involved in human diseases including cancer, cardiovascular diseases, neurodegenerative diseases, and epilepsy. Tissue damage caused by trauma, diseases or aging disrupt the tissue functions. Tissue regeneration after injuries is of significance for recovering the tissue homeostasis and functions. Mammals have very limited regenerative capacity in multiple tissues and organs, such as the heart and central nervous system (CNS). Thereby, understanding the mechanisms underlying tissue regeneration is crucial for tissue repair and regenerative medicine. mTOR is activated in multiple tissue injuries. In this review, we summarize the roles of mTOR signaling in tissue regeneration such as neurons, muscles, the liver and the intestine.
Collapse
Affiliation(s)
- Xiangyong Wei
- Laboratory of Molecular Developmental Biology, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China.
| | - Lingfei Luo
- Laboratory of Molecular Developmental Biology, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China.
| | - Jinzi Chen
- Laboratory of Molecular Developmental Biology, School of Life Sciences, Southwest University, Beibei, Chongqing 400715, China.
| |
Collapse
|
19
|
Rahar B, Chawla S, Tulswani R, Saxena S. Acute Hypobaric Hypoxia-Mediated Biochemical/Metabolic Shuffling and Differential Modulation of S1PR-SphK in Cardiac and Skeletal Muscles. High Alt Med Biol 2019; 20:78-88. [PMID: 30892968 DOI: 10.1089/ham.2018.0046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
AIM High altitude exposure alters biochemical, metabolic, and physiological features of heart and skeletal muscles, and hence has pathological consequences in these tissues. Central to these hypoxia-associated biochemical/metabolic shuffling are energy deficit accumulation of free radicals and ensuing oxidative damage in the tissue. Recent preclinical/clinical studies indicate sphingosine-1-phosphate (S1P) axis, comprising S1P G protein coupled receptors (S1PR1-5) and its synthesizing enzyme-sphingosine kinase (SphK) to have key regulatory roles in homeostatic cardiac and skeletal muscle biology. In view of this, the aim of the present study was to chart the initiation and progression of biochemical/metabolic shuffling and assess the coincident differential modulation of S1PR(1-5) expression and total SphK activity in cardiac and skeletal muscles from rats exposed to progressive hypobaric hypoxia (HH; 21,000 feet for 12, 24, and 48 hours). RESULTS HH-associated responses were evident as raised damage markers in plasma, oxidative stress, decreased total tissue protein, imbalance of intermediate metabolites, and aerobic/anaerobic enzyme activities in cardiac and skeletal muscles (gastrocnemius and soleus) culminating as energy deficit. CONCLUSION Cardiac and gastrocnemius muscles were more susceptible to hypoxic environment than soleus muscle. These differential responses were directly and indirectly coincident with temporal expression of S1PR(1-5) and SphK activity.
Collapse
Affiliation(s)
- Babita Rahar
- 1 Experimental Biology Division, Defense Institute of Physiology and Allied Sciences, Defense Research and Development Organization, Delhi, India
| | - Sonam Chawla
- 1 Experimental Biology Division, Defense Institute of Physiology and Allied Sciences, Defense Research and Development Organization, Delhi, India
| | - Rajkumar Tulswani
- 2 PACT Division, Defense Institute of Physiology and Allied Sciences, Defense Research and Development Organization, Delhi, India
| | - Shweta Saxena
- 3 Medicinal and Aromatic Plant Division, Defense Institute of High Altitude Research (DIHAR), Defense Research and Development Organization, Jammu and Kashmir, India
| |
Collapse
|
20
|
McDonnell AC, Eiken O, Frings-Meuthen P, Rittweger J, Mekjavic IB. The LunHab project: Muscle and bone alterations in male participants following a 10 day lunar habitat simulation. Exp Physiol 2019; 104:1250-1261. [PMID: 31273869 DOI: 10.1113/ep087482] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 05/07/2019] [Indexed: 12/24/2022]
Abstract
NEW FINDINGS What is the central question of this study? It is well established that muscle and bone atrophy in conditions of inactivity or unloading, but there is little information regarding the effect of a hypoxic environment on the time course of these deconditioning physiological systems. What is the main finding and its importance? The main finding is that a horizontal 10 day bed rest in normoxia results in typical muscle atrophy, which is not aggravated by hypoxia. Changes in bone mineral content or in metabolism were not detected after either normoxic or hypoxic bed rest. ABSTRACT Musculoskeletal atrophy constitutes a typical adaptation to inactivity and unloading of weightbearing bones. The reduced-gravity environment in future Moon and Mars habitats is likely to be hypobaric hypoxic, and there is an urgent need to understand the effect of hypoxia on the process of inactivity-induced musculoskeletal atrophy. This was the principal aim of the present study. Eleven males participated in three 10 day interventions: (i) hypoxic ambulatory confinement; (ii) hypoxic bed rest; and (iii) normoxic bed rest. Before and after the interventions, the muscle strength (isometric maximal voluntary contraction), mass (lean mass, by dual-energy X-ray absorptiometry), cross-sectional area and total bone mineral content (determined with peripheral quantitative computed tomography) of the participants were measured. Blood and urine samples were collected before and on the 1st, 4th and 10th day of the intervention and analysed for biomarkers of bone resorption and formation. There was a significant reduction in thigh and lower leg muscle mass and volume after both normoxic and hypoxic bed rests. Muscle strength loss was proportionately greater than the loss in muscle mass for both thigh and lower leg. There was no indication of bone loss. Furthermore, the biomarkers of resorption and formation were not affected by any of the interventions. There was no significant effect of hypoxia on the musculoskeletal variables. Short-term normoxic (10 day) bed rest resulted in muscular deconditioning, but not in the loss of bone mineral content or changes in bone metabolism. Hypoxia did not modify these results.
Collapse
Affiliation(s)
- Adam C McDonnell
- Department of Automation, Biocybernetics and Robotics, Institute Jozef Stefan, Ljubljana, Slovenia
| | - Ola Eiken
- Department of Environmental Physiology, School of Technology and Health, Royal Institute of Technology, Solna, Sweden
| | - Petra Frings-Meuthen
- Institute for Aerospace Medicine, German Aerospace Centre (DLR), Cologne, Germany
| | - Joern Rittweger
- Institute for Aerospace Medicine, German Aerospace Centre (DLR), Cologne, Germany.,Department of Paediatrics and Adolescent Medicine, University of Cologne, Cologne, Germany
| | - Igor B Mekjavic
- Department of Automation, Biocybernetics and Robotics, Institute Jozef Stefan, Ljubljana, Slovenia.,Department of Biomedical Sciences and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
| |
Collapse
|
21
|
Ross CI, Shute RJ, Ruby BC, Slivka DR. Skeletal Muscle mRNA Response to Hypobaric and Normobaric Hypoxia After Normoxic Endurance Exercise. High Alt Med Biol 2019; 20:141-149. [DOI: 10.1089/ham.2018.0147] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- Caleb I. Ross
- Exercise Physiology Lab, University of Nebraska at Omaha, Omaha, Nebraska
| | - Robert J. Shute
- Exercise Physiology Lab, University of Nebraska at Omaha, Omaha, Nebraska
| | - Brent C. Ruby
- Montana Center for Work Physiology and Exercise Metabolism, University of Montana, Missoula, Montana
| | - Dustin R. Slivka
- Exercise Physiology Lab, University of Nebraska at Omaha, Omaha, Nebraska
| |
Collapse
|
22
|
Cheng AJ, Allodi I, Chaillou T, Schlittler M, Ivarsson N, Lanner JT, Thams S, Hedlund E, Andersson DC. Intact single muscle fibres from SOD1
G93A
amyotrophic lateral sclerosis mice display preserved specific force, fatigue resistance and training‐like adaptations. J Physiol 2019; 597:3133-3146. [DOI: 10.1113/jp277456] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 04/26/2019] [Indexed: 12/15/2022] Open
Affiliation(s)
- Arthur J. Cheng
- Department of Physiology and PharmacologyKarolinska Institutet 171 77 Stockholm Sweden
- School of Kinesiology and Health SciencesYork University M3J 1P3 Toronto Canada
| | - Ilary Allodi
- Department of NeuroscienceKarolinska Institutet 171 77 Stockholm Sweden
| | - Thomas Chaillou
- Department of Physiology and PharmacologyKarolinska Institutet 171 77 Stockholm Sweden
- Department of Health SciencesÖrebro University 701 82 Örebro Sweden
| | - Maja Schlittler
- Department of Physiology and PharmacologyKarolinska Institutet 171 77 Stockholm Sweden
- Sports Science and Innovation InstituteLithuanian Sports University 44221 Kaunas Lithuania
| | - Niklas Ivarsson
- Department of Physiology and PharmacologyKarolinska Institutet 171 77 Stockholm Sweden
| | - Johanna T. Lanner
- Department of Physiology and PharmacologyKarolinska Institutet 171 77 Stockholm Sweden
| | - Sebastian Thams
- Department of Clinical NeuroscienceKarolinska Institutet 171 77 Stockholm Sweden
| | - Eva Hedlund
- Department of NeuroscienceKarolinska Institutet 171 77 Stockholm Sweden
| | - Daniel C. Andersson
- Department of Physiology and PharmacologyKarolinska Institutet 171 77 Stockholm Sweden
- Heart and Vascular Theme, Section for Heart FailureArrhythmia and GUCH, Karolinska University Hospital 171 76 Stockholm Sweden
| |
Collapse
|
23
|
High altitude mediated skeletal muscle atrophy: Protective role of curcumin. Biochimie 2019; 156:138-147. [DOI: 10.1016/j.biochi.2018.10.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 10/16/2018] [Indexed: 12/21/2022]
|
24
|
Role of altered proteostasis network in chronic hypobaric hypoxia induced skeletal muscle atrophy. PLoS One 2018; 13:e0204283. [PMID: 30240405 PMCID: PMC6150520 DOI: 10.1371/journal.pone.0204283] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 09/04/2018] [Indexed: 01/07/2023] Open
Abstract
Background High altitude associated hypobaric hypoxia is one of the cellular and environmental perturbation that alters proteostasis network and push the healthy cell towards loss of muscle mass. The present study has elucidated the robust proteostasis network and signaling mechanism for skeletal muscle atrophy under chronic hypobaric hypoxia (CHH). Methods Male Sprague Dawley rats were exposed to simulated hypoxia equivalent to a pressure of 282 torr for different durations (1, 3, 7 and 14 days). After CHH exposure, skeletal muscle tissue was excised from the hind limb of rats for biochemical analysis. Results Chronic hypobaric hypoxia caused a substantial increase in protein oxidation and exhibited a greater activation of ER chaperones, glucose-regulated protein-78 (GRP-78) and protein disulphide isomerase (PDI) till 14d of CHH. Presence of oxidized proteins triggered the proteolytic systems, 20S proteasome and calpain pathway which were accompanied by a marked increase in [Ca2+]. Upregulated Akt pathway was observed upto 07d of CHH which was also linked with enhanced glycogen synthase kinase-3β (GSk-3β) expression, a negative regulator of Akt. Muscle-derived cytokines, tumor necrosis factor-α (TNF-α), interferon-ϒ (IFN-©) and interleukin-1β (IL-1β) levels significantly increased from 07d onwards. CHH exposure also upregulated the expression of nuclear factor kappa-B (NF-κB) and E3 ligase, muscle atrophy F-box-1 (Mafbx-1/Atrogin-1) and MuRF-1 (muscle ring finger-1) on 07d and 14d. Further, severe hypoxia also lead to increase expression of ER-associated degradation (ERAD) CHOP/ GADD153, Ub-proteasome and apoptosis pathway. Conclusions The disrupted proteostasis network was tightly coupled to degradative pathways, altered anabolic signaling, inflammation, and apoptosis under chronic hypoxia. Severe and prolonged hypoxia exposure affected the protein homeostasis which overwhelms the muscular system and tends towards skeletal muscle atrophy.
Collapse
|
25
|
Rahar B, Chawla S, Pandey S, Bhatt AN, Saxena S. Sphingosine-1-phosphate pretreatment amends hypoxia-induced metabolic dysfunction and impairment of myogenic potential in differentiating C2C12 myoblasts by stimulating viability, calcium homeostasis and energy generation. J Physiol Sci 2018; 68:137-151. [PMID: 28070865 PMCID: PMC10717551 DOI: 10.1007/s12576-016-0518-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 12/26/2016] [Indexed: 12/19/2022]
Abstract
Sphingosine-1-phosphate (S1P) has a role in transpiration in patho-physiological signaling in skeletal muscles. The present study evaluated the pre-conditioning efficacy of S1P in facilitating differentiation of C2C12 myoblasts under a normoxic/hypoxic cell culture environment. Under normoxia, exogenous S1P significantly promoted C2C12 differentiation as evident from morphometric descriptors and differentiation markers of the mature myotubes, but it could facilitate only partial recovery from hypoxia-induced compromised differentiation. Pretreatment of S1P optimized the myokine secretion, intracellular calcium release and energy generation by boosting the aerobic/anaerobic metabolism and mitochondrial mass. In the hypoxia-exposed cells, there was derangement of the S1PR1-3 expression patterns, while the same could be largely restored with S1P pretreatment. This is being proposed as a plausible underlying mechanism for the observed pro-myogenic efficacy of exogenous S1P preconditioning. The present findings are an invaluable addition to the existing knowledge on the pro-myogenic potential of S1P and may prove beneficial in the field of hypoxia-related myo-pathologies.
Collapse
Affiliation(s)
- Babita Rahar
- Experimental Biology Division, Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi, 110054, India
| | - Sonam Chawla
- Experimental Biology Division, Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi, 110054, India
| | - Sanjay Pandey
- Division of Metabolic and Cell Signaling Research, Institute of Nuclear Medicine and Allied Sciences (INMAS), Defence Research and Development Organization (DRDO), Brig. S.K. Mazumdar Road, Delhi, 110054, India
| | - Anant Narayan Bhatt
- Division of Metabolic and Cell Signaling Research, Institute of Nuclear Medicine and Allied Sciences (INMAS), Defence Research and Development Organization (DRDO), Brig. S.K. Mazumdar Road, Delhi, 110054, India
| | - Shweta Saxena
- Medicinal and Aromatic Plant Division, Defence Institute of High Altitude Research (DIHAR), Defence Research and Development Organization (DRDO), Ministry of Defence, Leh-Ladakh, 194101, Jammu and Kashmir, India.
| |
Collapse
|
26
|
Sfyri P, Matsakas A. Crossroads between peripheral atherosclerosis, western-type diet and skeletal muscle pathophysiology: emphasis on apolipoprotein E deficiency and peripheral arterial disease. J Biomed Sci 2017; 24:42. [PMID: 28688452 PMCID: PMC5502081 DOI: 10.1186/s12929-017-0346-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 06/07/2017] [Indexed: 12/16/2022] Open
Abstract
Atherosclerosis is a chronic inflammatory process that, in the presence of hyperlipidaemia, promotes the formation of atheromatous plaques in large vessels of the cardiovascular system. It also affects peripheral arteries with major implications for a number of other non-vascular tissues such as the skeletal muscle, the liver and the kidney. The aim of this review is to critically discuss and assimilate current knowledge on the impact of peripheral atherosclerosis and its implications on skeletal muscle homeostasis. Accumulating data suggests that manifestations of peripheral atherosclerosis in skeletal muscle originates in a combination of increased i)-oxidative stress, ii)-inflammation, iii)-mitochondrial deficits, iv)-altered myofibre morphology and fibrosis, v)-chronic ischemia followed by impaired oxygen supply, vi)-reduced capillary density, vii)- proteolysis and viii)-apoptosis. These structural, biochemical and pathophysiological alterations impact on skeletal muscle metabolic and physiologic homeostasis and its capacity to generate force, which further affects the individual's quality of life. Particular emphasis is given on two major areas representing basic and applied science respectively: a)-the abundant evidence from a well-recognised atherogenic model; the Apolipoprotein E deficient mouse and the role of a western-type diet and b)-on skeletal myopathy and oxidative stress-induced myofibre damage from human studies on peripheral arterial disease. A significant source of reactive oxygen species production and oxidative stress in cardiovascular disease is the family of NADPH oxidases that contribute to several pathologies. Finally, strategies targeting NADPH oxidases in skeletal muscle in an attempt to attenuate cellular oxidative stress are highlighted, providing a better understanding of the crossroads between peripheral atherosclerosis and skeletal muscle pathophysiology.
Collapse
Affiliation(s)
- Peggy Sfyri
- Molecular Physiology Laboratory, Centre for Atherothrombotic & Metabolic Disease, Hull York Medical School, University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom
| | - Antonios Matsakas
- Molecular Physiology Laboratory, Centre for Atherothrombotic & Metabolic Disease, Hull York Medical School, University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom.
| |
Collapse
|
27
|
Martin NRW, Aguilar-Agon K, Robinson GP, Player DJ, Turner MC, Myers SD, Lewis MP. Hypoxia Impairs Muscle Function and Reduces Myotube Size in Tissue Engineered Skeletal Muscle. J Cell Biochem 2017; 118:2599-2605. [PMID: 28294416 PMCID: PMC5518201 DOI: 10.1002/jcb.25982] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 02/21/2017] [Indexed: 12/21/2022]
Abstract
Contemporary tissue engineered skeletal muscle models display a high degree of physiological accuracy compared with native tissue, and therefore may be excellent platforms to understand how various pathologies affect skeletal muscle. Chronic obstructive pulmonary disease (COPD) is a lung disease which causes tissue hypoxia and is characterized by muscle fiber atrophy and impaired muscle function. In the present study we exposed engineered skeletal muscle to varying levels of oxygen (O2; 21–1%) for 24 h in order to see if a COPD like muscle phenotype could be recreated in vitro, and if so, at what degree of hypoxia this occurred. Maximal contractile force was attenuated in hypoxia compared to 21% O2; with culture at 5% and 1% O2 causing the most pronounced effects with 62% and 56% decrements in force, respectively. Furthermore at these levels of O2, myotubes within the engineered muscles displayed significant atrophy which was not seen at higher O2 levels. At the molecular level we observed increases in mRNA expression of MuRF‐1 only at 1% O2 whereas MAFbx expression was elevated at 10%, 5%, and 1% O2. In addition, p70S6 kinase phosphorylation (a downstream effector of mTORC1) was reduced when engineered muscle was cultured at 1% O2, with no significant changes seen above this O2 level. Overall, these data suggest that engineered muscle exposed to O2 levels of ≤5% adapts in a manner similar to that seen in COPD patients, and thus may provide a novel model for further understanding muscle wasting associated with tissue hypoxia. J. Cell. Biochem. 118: 2599–2605, 2017. © 2017 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Neil R W Martin
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Kathyrn Aguilar-Agon
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - George P Robinson
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Darren J Player
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Mark C Turner
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Stephen D Myers
- Department of Sport and Exercise Sciences, University of Chichester, Chichester, UK
| | - Mark P Lewis
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| |
Collapse
|
28
|
Rizo-Roca D, Ríos-Kristjánsson JG, Núñez-Espinosa C, Santos-Alves E, Gonçalves IO, Magalhães J, Ascensão A, Pagès T, Viscor G, Torrella JR. Intermittent hypobaric hypoxia combined with aerobic exercise improves muscle morphofunctional recovery after eccentric exercise to exhaustion in trained rats. J Appl Physiol (1985) 2016; 122:580-592. [PMID: 27765844 DOI: 10.1152/japplphysiol.00501.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 09/27/2016] [Accepted: 10/13/2016] [Indexed: 01/07/2023] Open
Abstract
Unaccustomed eccentric exercise leads to muscle morphological and functional alterations, including microvasculature damage, the repair of which is modulated by hypoxia. We present the effects of intermittent hypobaric hypoxia and exercise on recovery from eccentric exercise-induced muscle damage (EEIMD). Soleus muscles from trained rats were excised before (CTRL) and 1, 3, 7, and 14 days after a double session of EEIMD protocol. A recovery treatment consisting of one of the following protocols was applied 1 day after the EEIMD: passive normobaric recovery (PNR), a 4-h daily exposure to passive hypobaric hypoxia at 4,000 m (PHR), or hypobaric hypoxia exposure followed by aerobic exercise (AHR). EEIMD produced an increase in the percentage of abnormal fibers compared with CTRL, and it affected the microvasculature by decreasing capillary density (CD, capillaries per mm2) and the capillary-to-fiber ratio (CF). After 14 days, AHR exhibited CD and CF values similar to those of CTRL animals (789 and 3.30 vs. 746 and 3.06) and significantly higher than PNR (575 and 2.62) and PHR (630 and 2.92). Furthermore, VEGF expression showed a significant 43% increase in AHR when compared with PNR. Moreover, after 14 days, the muscle fibers in AHR had a more oxidative phenotype than the other groups, with significantly smaller cross-sectional areas (AHR, 3,745; PNR, 4,502; and PHR, 4,790 µm2), higher citrate synthase activity (AHR, 14.8; PNR, 13.1; and PHR, 12 µmol·min-1·mg-1) and a significant 27% increment in PGC-1α levels compared with PNR. Our data show that hypoxia combined with exercise attenuates or reverses the morphofunctional alterations induced by EEIMD.NEW & NOTEWORTHY Our study provides new insights into the use of intermittent hypobaric hypoxia combined with exercise as a strategy to recover muscle damage induced by eccentric exercise. We analyzed the effects of hypobaric exposure combined with aerobic exercise on histopathological features of muscle damage, fiber morphofunctionality, capillarization, angiogenesis, and the oxidative capacity of damaged soleus muscle. Most of these parameters were improved after a 2-wk protocol of intermittent hypobaric hypoxia combined with aerobic exercise.
Collapse
Affiliation(s)
- D Rizo-Roca
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; and
| | - J G Ríos-Kristjánsson
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; and
| | - C Núñez-Espinosa
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; and
| | - E Santos-Alves
- Research Center in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
| | - I O Gonçalves
- Research Center in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
| | - J Magalhães
- Research Center in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
| | - A Ascensão
- Research Center in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
| | - T Pagès
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; and
| | - G Viscor
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; and
| | - J R Torrella
- Departament de Biologia Cel·lular, Fisiologia i Immunologia, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain; and
| |
Collapse
|
29
|
Chaillou T, Lanner JT. Regulation of myogenesis and skeletal muscle regeneration: effects of oxygen levels on satellite cell activity. FASEB J 2016; 30:3929-3941. [PMID: 27601440 DOI: 10.1096/fj.201600757r] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/15/2016] [Indexed: 12/11/2022]
Abstract
Reduced oxygen (O2) levels (hypoxia) are present during embryogenesis and exposure to altitude and in pathologic conditions. During embryogenesis, myogenic progenitor cells reside in a hypoxic microenvironment, which may regulate their activity. Satellite cells are myogenic progenitor cells localized in a local environment, suggesting that the O2 level could affect their activity during muscle regeneration. In this review, we present the idea that O2 levels regulate myogenesis and muscle regeneration, we elucidate the molecular mechanisms underlying myogenesis and muscle regeneration in hypoxia and depict therapeutic strategies using changes in O2 levels to promote muscle regeneration. Severe hypoxia (≤1% O2) appears detrimental for myogenic differentiation in vitro, whereas a 3-6% O2 level could promote myogenesis. Hypoxia impairs the regenerative capacity of injured muscles. Although it remains to be explored, hypoxia may contribute to the muscle damage observed in patients with pathologies associated with hypoxia (chronic obstructive pulmonary disease, and peripheral arterial disease). Hypoxia affects satellite cell activity and myogenesis through mechanisms dependent and independent of hypoxia-inducible factor-1α. Finally, hyperbaric oxygen therapy and transplantation of hypoxia-conditioned myoblasts are beneficial procedures to enhance muscle regeneration in animals. These therapies may be clinically relevant to treatment of patients with severe muscle damage.-Chaillou, T. Lanner, J. T. Regulation of myogenesis and skeletal muscle regeneration: effects of oxygen levels on satellite cell activity.
Collapse
Affiliation(s)
- Thomas Chaillou
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Johanna T Lanner
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
30
|
D'Hulst G, Ferri A, Naslain D, Bertrand L, Horman S, Francaux M, Bishop DJ, Deldicque L. Fifteen days of 3,200 m simulated hypoxia marginally regulates markers for protein synthesis and degradation in human skeletal muscle. HYPOXIA 2016; 4:1-14. [PMID: 27800505 PMCID: PMC5085286 DOI: 10.2147/hp.s101133] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Chronic hypoxia leads to muscle atrophy. The molecular mechanisms responsible for this phenomenon are not well defined in vivo. We sought to determine how chronic hypoxia regulates molecular markers of protein synthesis and degradation in human skeletal muscle and whether these regulations were related to the regulation of the hypoxia-inducible factor (HIF) pathway. Eight young male subjects lived in a normobaric hypoxic hotel (FiO2 14.1%, 3,200 m) for 15 days in well-controlled conditions for nutrition and physical activity. Skeletal muscle biopsies were obtained in the musculus vastus lateralis before (PRE) and immediately after (POST) hypoxic exposure. Intramuscular hypoxia-inducible factor-1 alpha (HIF-1α) protein expression decreased (-49%, P=0.03), whereas hypoxia-inducible factor-2 alpha (HIF-2α) remained unaffected from PRE to POST hypoxic exposure. Also, downstream HIF-1α target genes VEGF-A (-66%, P=0.006) and BNIP3 (-24%, P=0.002) were downregulated, and a tendency was measured for neural precursor cell expressed, developmentally Nedd4 (-47%, P=0.07), suggesting lowered HIF-1α transcriptional activity after 15 days of exposure to environmental hypoxia. No difference was found on microtubule-associated protein 1 light chain 3 type II/I (LC3b-II/I) ratio, and P62 protein expression tended to increase (+45%, P=0.07) compared to PRE exposure levels, suggesting that autophagy was not modulated after chronic hypoxia. The mammalian target of rapamycin complex 1 pathway was not altered as Akt, mammalian target of rapamycin, S6 kinase 1, and 4E-binding protein 1 phosphorylation did not change between PRE and POST. Finally, myofiber cross-sectional area was unchanged between PRE and POST. In summary, our data indicate that moderate chronic hypoxia differentially regulates HIF-1α and HIF-2α, marginally affects markers of protein degradation, and does not modify markers of protein synthesis or myofiber cross-sectional area in human skeletal muscle.
Collapse
Affiliation(s)
- Gommaar D'Hulst
- Department of Kinesiology, Exercise Physiology Research Group, FaBeR, KU Leuven, Leuven, Belgium
| | - Alessandra Ferri
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia; Department of Health Sciences, University of Milano-Bicocca, Monza, Italy
| | - Damien Naslain
- Institute of Neuroscience, Université catholique de Louvain, Louvain-la-Neuve
| | - Luc Bertrand
- Institut de Recherche Expérimentale et Clinique, Pôle de Recherche Cardiovasculaire, Université catholique de Louvain, Brussels, Belgium
| | - Sandrine Horman
- Institut de Recherche Expérimentale et Clinique, Pôle de Recherche Cardiovasculaire, Université catholique de Louvain, Brussels, Belgium
| | - Marc Francaux
- Institute of Neuroscience, Université catholique de Louvain, Louvain-la-Neuve
| | - David J Bishop
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
| | - Louise Deldicque
- Department of Kinesiology, Exercise Physiology Research Group, FaBeR, KU Leuven, Leuven, Belgium; Institute of Neuroscience, Université catholique de Louvain, Louvain-la-Neuve
| |
Collapse
|
31
|
Favier FB, Britto FA, Freyssenet DG, Bigard XA, Benoit H. HIF-1-driven skeletal muscle adaptations to chronic hypoxia: molecular insights into muscle physiology. Cell Mol Life Sci 2015; 72:4681-96. [PMID: 26298291 PMCID: PMC11113128 DOI: 10.1007/s00018-015-2025-9] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Revised: 08/14/2015] [Accepted: 08/18/2015] [Indexed: 12/12/2022]
Abstract
Skeletal muscle is a metabolically active tissue and the major body protein reservoir. Drop in ambient oxygen pressure likely results in a decrease in muscle cells oxygenation, reactive oxygen species (ROS) overproduction and stabilization of the oxygen-sensitive hypoxia-inducible factor (HIF)-1α. However, skeletal muscle seems to be quite resistant to hypoxia compared to other organs, probably because it is accustomed to hypoxic episodes during physical exercise. Few studies have observed HIF-1α accumulation in skeletal muscle during ambient hypoxia probably because of its transient stabilization. Nevertheless, skeletal muscle presents adaptations to hypoxia that fit with HIF-1 activation, although the exact contribution of HIF-2, I kappa B kinase and activating transcription factors, all potentially activated by hypoxia, needs to be determined. Metabolic alterations result in the inhibition of fatty acid oxidation, while activation of anaerobic glycolysis is less evident. Hypoxia causes mitochondrial remodeling and enhanced mitophagy that ultimately lead to a decrease in ROS production, and this acclimatization in turn contributes to HIF-1α destabilization. Likewise, hypoxia has structural consequences with muscle fiber atrophy due to mTOR-dependent inhibition of protein synthesis and transient activation of proteolysis. The decrease in muscle fiber area improves oxygen diffusion into muscle cells, while inhibition of protein synthesis, an ATP-consuming process, and reduction in muscle mass decreases energy demand. Amino acids released from muscle cells may also have protective and metabolic effects. Collectively, these results demonstrate that skeletal muscle copes with the energetic challenge imposed by O2 rarefaction via metabolic optimization.
Collapse
Affiliation(s)
- F B Favier
- INRA, UMR 866 Dynamique Musculaire et Métabolisme, 34060, Montpellier, France.
- Université de Montpellier, 34090, Montpellier, France.
| | - F A Britto
- INRA, UMR 866 Dynamique Musculaire et Métabolisme, 34060, Montpellier, France
- Université de Montpellier, 34090, Montpellier, France
| | - D G Freyssenet
- Laboratoire de Physiologie de l'Exercice EA 4338, Université de Lyon, Université Jean Monnet, 42000, Saint Etienne, France
| | - X A Bigard
- Agence Française de Lutte contre le Dopage, 75007, Paris, France
| | - H Benoit
- INSERM, U1042 Hypoxie Physio-Pathologie, 38000, Grenoble, France
- Université Joseph Fourier, 38000, Grenoble, France
| |
Collapse
|
32
|
Effects of Transient Hypoxia versus Prolonged Hypoxia on Satellite Cell Proliferation and Differentiation In Vivo. Stem Cells Int 2015; 2015:961307. [PMID: 25788948 PMCID: PMC4348605 DOI: 10.1155/2015/961307] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 01/22/2015] [Indexed: 12/17/2022] Open
Abstract
The microenvironment of the injury site can have profound effects on wound healing. Muscle injury results in ischemia leading to short-term local hypoxia, but there are conflicting reports on the role of hypoxia on the myogenic program in vivo and in vitro. In our rat model of mitochondrial restoration (MR), temporary upregulation of mitochondrial activity by a cocktail of organelle-encoded RNAs results in satellite cell proliferation and initiation of myogenesis. We now report that MR leads to a transient hypoxic response in situ. Inhibition of hypoxia by lowering mitochondrial O2 consumption, either by respiratory electron transport inhibitors, or by NO-mediated inhibition of O2 binding to cytochrome c oxidase, resulted in exacerbation of inflammation. Lentivirus-mediated knockdown of hypoxia-inducible factor 1α (HIF1α) or of Notch signaling components had a similar effect, and pharmacologic inhibition of HIF or Notch reduced the number of proliferating Pax7+ cells. In contrast, a prolonged hypoxic response induced either by uncoupling of respiration from oxidative phosphorylation or through HIF stabilization by dimethyloxalylglycine (DMOG) had an immediate anti-inflammatory effect. Although significant satellite cell proliferation occurred in presence of DMOG, expression of differentiation markers was affected. These results emphasize the importance of transient hypoxia as opposed to prolonged hypoxia for myogenesis.
Collapse
|
33
|
Fujita N, Ono M, Tomioka T, Deie M. Effects of hyperbaric oxygen at 1.25 atmospheres absolute with normal air on macrophage number and infiltration during rat skeletal muscle regeneration. PLoS One 2014; 9:e115685. [PMID: 25531909 PMCID: PMC4274106 DOI: 10.1371/journal.pone.0115685] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 12/01/2014] [Indexed: 12/17/2022] Open
Abstract
Use of mild hyperbaric oxygen less than 2 atmospheres absolute (2026.54 hPa) with normal air is emerging as a common complementary treatment for severe muscle injury. Although hyperbaric oxygen at over 2 atmospheres absolute with 100% O2 promotes healing of skeletal muscle injury, it is not clear whether mild hyperbaric oxygen is equally effective. The purpose of the present study was to investigate the impact of hyperbaric oxygen at 1.25 atmospheres absolute (1266.59 hPa) with normal air on muscle regeneration. The tibialis anterior muscle of male Wistar rats was injured by injection of bupivacaine hydrochloride, and rats were randomly assigned to a hyperbaric oxygen experimental group or to a non-hyperbaric oxygen control group. Immediately after the injection, rats were exposed to hyperbaric oxygen, and the treatment was continued for 28 days. The cross-sectional area of centrally nucleated muscle fibers was significantly larger in rats exposed to hyperbaric oxygen than in controls 5 and 7 days after injury. The number of CD68- or CD68- and CD206-positive cells was significantly higher in rats exposed to hyperbaric oxygen than in controls 24 h after injury. Additionally, tumor necrosis factor-α and interleukin-10 mRNA expression levels were significantly higher in rats exposed to hyperbaric oxygen than in controls 24 h after injury. The number of Pax7- and MyoD- or MyoD- and myogenin-positive nuclei per mm2 and the expression levels of these proteins were significantly higher in rats exposed to hyperbaric oxygen than in controls 5 days after injury. These results suggest that mild hyperbaric oxygen promotes skeletal muscle regeneration in the early phase after injury, possibly due to reduced hypoxic conditions leading to accelerated macrophage infiltration and phenotype transition. In conclusion, mild hyperbaric oxygen less than 2 atmospheres absolute with normal air is an appropriate support therapy for severe muscle injuries.
Collapse
Affiliation(s)
- Naoto Fujita
- Graduate School of Biomedicine and Health Sciences, Hiroshima University, Hiroshima City, Hiroshima, Japan
- Faculty of Medicine, Hiroshima University, Hiroshima City, Hiroshima, Japan
- * E-mail:
| | - Miharu Ono
- Graduate School of Biomedicine and Health Sciences, Hiroshima University, Hiroshima City, Hiroshima, Japan
| | - Tomoka Tomioka
- Graduate School of Biomedicine and Health Sciences, Hiroshima University, Hiroshima City, Hiroshima, Japan
| | - Masataka Deie
- Graduate School of Biomedicine and Health Sciences, Hiroshima University, Hiroshima City, Hiroshima, Japan
- Faculty of Medicine, Hiroshima University, Hiroshima City, Hiroshima, Japan
| |
Collapse
|
34
|
Chaillou T, Koulmann N, Meunier A, Chapot R, Serrurier B, Beaudry M, Bigard X. Effect of hypoxia exposure on the recovery of skeletal muscle phenotype during regeneration. Mol Cell Biochem 2014; 390:31-40. [PMID: 24385110 DOI: 10.1007/s11010-013-1952-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 12/19/2013] [Indexed: 11/26/2022]
Abstract
Hypoxia impairs the muscle fibre-type shift from fast-to-slow during post-natal development; however, this adaptation could be a consequence of the reduced voluntary physical activity associated with hypoxia exposure rather than the result of hypoxia per se. Moreover, muscle oxidative capacity could be reduced in hypoxia, particularly when hypoxia is combined with additional stress. Here, we used a model of muscle regeneration to mimic the fast-to-slow fibre-type conversion observed during post-natal development. We hypothesised that hypoxia would impair the recovery of the myosin heavy chain (MHC) profile and oxidative capacity during muscle regeneration. To test this hypothesis, the soleus muscle of female rats was injured by notexin and allowed to recover for 3, 7, 14 and 28 days under normoxia or hypobaric hypoxia (5,500 m altitude) conditions. Ambient hypoxia did not impair the recovery of the slow MHC profile during muscle regeneration. However, hypoxia moderately decreased the oxidative capacity (assessed from the activity of citrate synthase) of intact muscle and delayed its recovery in regenerated muscle. Hypoxia transiently increased in both regenerated and intact muscles the content of phosphorylated AMPK and Pgc-1α mRNA, two regulators involved in mitochondrial biogenesis, while it transiently increased in intact muscle the mRNA level of the mitophagic factor BNIP3. In conclusion, hypoxia does not act to impair the fast-to-slow MHC isoform transition during regeneration. Hypoxia alters the oxidative capacity of intact muscle and delays its recovery in regenerated muscle; however, this adaptation to hypoxia was independent of the studied regulators of mitochondrial turn-over.
Collapse
Affiliation(s)
- Thomas Chaillou
- Département Environnements opérationnels, Institut de Recherche Biomédicale des Armées, antenne de La Tronche, BP 87, 38702, La Tronche Cedex, France,
| | | | | | | | | | | | | |
Collapse
|