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Maunder E, King A, Rothschild JA, Brick MJ, Leigh WB, Hedges CP, Merry TL, Kilding AE. Locally applied heat stress during exercise training may promote adaptations to mitochondrial enzyme activities in skeletal muscle. Pflugers Arch 2024:10.1007/s00424-024-02939-8. [PMID: 38446167 DOI: 10.1007/s00424-024-02939-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 01/22/2024] [Accepted: 03/01/2024] [Indexed: 03/07/2024]
Abstract
There is some evidence for temperature-dependent stimulation of mitochondrial biogenesis; however, the role of elevated muscle temperature during exercise in mitochondrial adaptation to training has not been studied in humans in vivo. The purpose of this study was to determine the role of elevating muscle temperature during exercise in temperate conditions through the application of mild, local heat stress on mitochondrial adaptations to endurance training. Eight endurance-trained males undertook 3 weeks of supervised cycling training, during which mild (~ 40 °C) heat stress was applied locally to the upper-leg musculature of one leg during all training sessions (HEAT), with the contralateral leg serving as the non-heated, exercising control (CON). Vastus lateralis microbiopsies were obtained from both legs before and after the training period. Training-induced increases in complex I (fold-change, 1.24 ± 0.33 vs. 1.01 ± 0.49, P = 0.029) and II (fold-change, 1.24 ± 0.33 vs. 1.01 ± 0.49, P = 0.029) activities were significantly larger in HEAT than CON. No significant effects of training, or interactions between local heat stress application and training, were observed for complex I-V or HSP70 protein expressions. Our data provides partial evidence to support the hypothesis that elevating local muscle temperature during exercise augments training-induced adaptations to mitochondrial enzyme activity.
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Affiliation(s)
- Ed Maunder
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand.
| | - Andrew King
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
| | - Jeffrey A Rothschild
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
| | - Matthew J Brick
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
- Orthosports North Harbour, AUT Millennium, Auckland, New Zealand
| | - Warren B Leigh
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
- Orthosports North Harbour, AUT Millennium, Auckland, New Zealand
| | - Christopher P Hedges
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Troy L Merry
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Andrew E Kilding
- Sports Performance Research Institute New Zealand, Auckland University of Technology, Auckland, New Zealand
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2
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D'Souza RF, Figueiredo VC, Markworth JF, Zeng N, Hedges CP, Roberts LA, Raastad T, Coombes JS, Peake JM, Mitchell CJ, Cameron‐Smith D. Cold water immersion in recovery following a single bout resistance exercise suppresses mechanisms of miRNA nuclear export and maturation. Physiol Rep 2023; 11:e15784. [PMID: 37549955 PMCID: PMC10406566 DOI: 10.14814/phy2.15784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 07/17/2023] [Accepted: 07/19/2023] [Indexed: 08/09/2023] Open
Abstract
Cold water immersion (CWI) following intense exercise is a common athletic recovery practice. However, CWI impacts muscle adaptations to exercise training, with attenuated muscle hypertrophy and increased angiogenesis. Tissue temperature modulates the abundance of specific miRNA species and thus CWI may affect muscle adaptations via modulating miRNA expression following a bout of exercise. The current study focused on the regulatory mechanisms involved in cleavage and nuclear export of mature miRNA, including DROSHA, EXPORTIN-5, and DICER. Muscle biopsies were obtained from the vastus lateralis of young males (n = 9) at rest and at 2, 4, and 48 h of recovery from an acute bout of resistance exercise, followed by either 10 min of active recovery (ACT) at ambient temperature or CWI at 10°C. The abundance of key miRNA species in the regulation of intracellular anabolic signaling (miR-1 and miR-133a) and angiogenesis (miR-15a and miR-126) were measured, along with several gene targets implicated in satellite cell dynamics (NCAM and PAX7) and angiogenesis (VEGF and SPRED-1). When compared to ACT, CWI suppressed mRNA expression of DROSHA (24 h p = 0.025 and 48 h p = 0.017), EXPORTIN-5 (24 h p = 0.008), and DICER (24 h p = 0.0034). Of the analyzed miRNA species, miR-133a (24 h p < 0.001 and 48 h p = 0.007) and miR-126 (24 h p < 0.001 and 48 h p < 0.001) remained elevated at 24 h post-exercise in the CWI trial only. Potential gene targets of these miRNA, however, did not differ between trials. CWI may therefore impact miRNA abundance in skeletal muscle, although the precise physiological relevance needs further investigation.
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Affiliation(s)
- Randall F. D'Souza
- Liggins InstituteThe University of AucklandAucklandNew Zealand
- Discipline of NutritionThe University of AucklandAucklandNew Zealand
- Maurice Wilkins Centre for Molecular BiodiscoveryThe University of AucklandAucklandNew Zealand
| | - Vandre C. Figueiredo
- Liggins InstituteThe University of AucklandAucklandNew Zealand
- Department of Biological SciencesOakland UniversityRochesterMichiganUSA
| | - James F. Markworth
- Liggins InstituteThe University of AucklandAucklandNew Zealand
- Department of Animal SciencePurdue UniversityWest LafayetteIndianaUSA
| | - Nina Zeng
- Liggins InstituteThe University of AucklandAucklandNew Zealand
- Department of PhysiologyThe University of AucklandAucklandNew Zealand
| | - Christopher P. Hedges
- Discipline of NutritionThe University of AucklandAucklandNew Zealand
- Maurice Wilkins Centre for Molecular BiodiscoveryThe University of AucklandAucklandNew Zealand
| | - Llion A. Roberts
- School of Human Movement and Nutrition SciencesUniversity of QueenslandBrisbaneQueenslandAustralia
- Sports Performance Innovation and Knowledge ExcellenceQueensland Academy of SportBrisbaneQueenslandAustralia
- School of Health Sciences and Social WorkGriffith UniversityGold CoastQueenslandAustralia
| | - Truls Raastad
- Department of Physical PerformanceNorwegian School of Sport SciencesOsloNorway
| | - Jeff S. Coombes
- School of Human Movement and Nutrition SciencesUniversity of QueenslandBrisbaneQueenslandAustralia
| | - Jonathan M. Peake
- Sports Performance Innovation and Knowledge ExcellenceQueensland Academy of SportBrisbaneQueenslandAustralia
- School of Biomedical SciencesQueensland University of TechnologyBrisbaneQueenslandAustralia
| | - Cameron J. Mitchell
- Liggins InstituteThe University of AucklandAucklandNew Zealand
- School of KinesiologyUniversity of British ColombiaVancouverBritish ColumbiaCanada
| | - David Cameron‐Smith
- Liggins InstituteThe University of AucklandAucklandNew Zealand
- College of Engineering, Science and EnvironmentUniversity of NewcastleCallaghanNew South WalesAustralia
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Masson SWC, Dissanayake WC, Broome SC, Hedges CP, Peeters WM, Gram M, Rowlands DS, Shepherd PR, Merry TL. A role for β-catenin in diet-induced skeletal muscle insulin resistance. Physiol Rep 2023; 11:e15536. [PMID: 36807886 PMCID: PMC9937784 DOI: 10.14814/phy2.15536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 11/15/2022] [Accepted: 11/20/2022] [Indexed: 02/19/2023] Open
Abstract
A central characteristic of insulin resistance is the impaired ability for insulin to stimulate glucose uptake into skeletal muscle. While insulin resistance can occur distal to the canonical insulin receptor-PI3k-Akt signaling pathway, the signaling intermediates involved in the dysfunction are yet to be fully elucidated. β-catenin is an emerging distal regulator of skeletal muscle and adipocyte insulin-stimulated GLUT4 trafficking. Here, we investigate its role in skeletal muscle insulin resistance. Short-term (5-week) high-fat diet (HFD) decreased skeletal muscle β-catenin protein expression 27% (p = 0.03), and perturbed insulin-stimulated β-cateninS552 phosphorylation 21% (p = 0.009) without affecting insulin-stimulated Akt phosphorylation relative to chow-fed controls. Under chow conditions, mice with muscle-specific β-catenin deletion had impaired insulin responsiveness, whereas under HFD, both mice exhibited similar levels of insulin resistance (interaction effect of genotype × diet p < 0.05). Treatment of L6-GLUT4-myc myocytes with palmitate lower β-catenin protein expression by 75% (p = 0.02), and attenuated insulin-stimulated β-catenin phosphorylationS552 and actin remodeling (interaction effect of insulin × palmitate p < 0.05). Finally, β-cateninS552 phosphorylation was 45% lower in muscle biopsies from men with type 2 diabetes while total β-catenin expression was unchanged. These findings suggest that β-catenin dysfunction is associated with the development of insulin resistance.
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Affiliation(s)
- Stewart W. C. Masson
- Discipline of Nutrition, Faculty of Medical and Health SciencesThe University of AucklandAucklandNew Zealand
| | - Waruni C. Dissanayake
- Maurice Wilkins Centre for Molecular BiodiscoveryThe University of AucklandAucklandNew Zealand,Department of Molecular Medicine and Pathology, Faculty of Medical and Health SciencesThe University of AucklandAucklandNew Zealand
| | - Sophie C. Broome
- Discipline of Nutrition, Faculty of Medical and Health SciencesThe University of AucklandAucklandNew Zealand
| | - Christopher P. Hedges
- Discipline of Nutrition, Faculty of Medical and Health SciencesThe University of AucklandAucklandNew Zealand,Maurice Wilkins Centre for Molecular BiodiscoveryThe University of AucklandAucklandNew Zealand
| | - Wouter M. Peeters
- School of Sport, Exercise and NutritionMassey UniversityAucklandNew Zealand,Faculty of Medical SciencesNewcastle UniversityNewcastleUK
| | - Martin Gram
- School of Sport, Exercise and NutritionMassey UniversityAucklandNew Zealand
| | - David S. Rowlands
- School of Sport, Exercise and NutritionMassey UniversityAucklandNew Zealand
| | - Peter R. Shepherd
- Maurice Wilkins Centre for Molecular BiodiscoveryThe University of AucklandAucklandNew Zealand,Department of Molecular Medicine and Pathology, Faculty of Medical and Health SciencesThe University of AucklandAucklandNew Zealand
| | - Troy L. Merry
- Discipline of Nutrition, Faculty of Medical and Health SciencesThe University of AucklandAucklandNew Zealand,Maurice Wilkins Centre for Molecular BiodiscoveryThe University of AucklandAucklandNew Zealand
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4
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Hedges CP, Shetty B, Broome SC, MacRae C, Koutsifeli P, Buckels EJ, MacIndoe C, Boix J, Tsiloulis T, Matthews BG, Sinha S, Arendse M, Jaiswal JK, Mellor KM, Hickey AJR, Shepherd PR, Merry TL. Dietary supplementation of clinically utilized PI3K p110α inhibitor extends the lifespan of male and female mice. Nat Aging 2023; 3:162-172. [PMID: 37118113 DOI: 10.1038/s43587-022-00349-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 12/02/2022] [Indexed: 04/30/2023]
Abstract
Diminished insulin and insulin-like growth factor-1 signaling extends the lifespan of invertebrates1-4; however, whether it is a feasible longevity target in mammals is less clear5-12. Clinically utilized therapeutics that target this pathway, such as small-molecule inhibitors of phosphoinositide 3-kinase p110α (PI3Ki), provide a translatable approach to studying the impact of these pathways on aging. Here, we provide evidence that dietary supplementation with the PI3Ki alpelisib from middle age extends the median and maximal lifespan of mice, an effect that was more pronounced in females. While long-term PI3Ki treatment was well tolerated and led to greater strength and balance, negative impacts on common human aging markers, including reductions in bone mass and mild hyperglycemia, were also evident. These results suggest that while pharmacological suppression of insulin receptor (IR)/insulin-like growth factor receptor (IGFR) targets could represent a promising approach to delaying some aspects of aging, caution should be taken in translation to humans.
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Affiliation(s)
- C P Hedges
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - B Shetty
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - S C Broome
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - C MacRae
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - P Koutsifeli
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - E J Buckels
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
- Molecular Medicine and Pathology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - C MacIndoe
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - J Boix
- Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | - T Tsiloulis
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - B G Matthews
- Molecular Medicine and Pathology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - S Sinha
- Department of Pathology, Waikato Hospital, Hamilton, New Zealand
| | - M Arendse
- Department of Pathology, Waikato Hospital, Hamilton, New Zealand
| | - J K Jaiswal
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
- Auckland Cancer Society Research Centre, University of Auckland, Auckland, New Zealand
| | - K M Mellor
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - A J R Hickey
- Applied Surgery and Metabolism Laboratory, School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - P R Shepherd
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
- Molecular Medicine and Pathology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - T L Merry
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand.
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand.
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5
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D'Souza RF, Masson SWC, Woodhead JST, James SL, MacRae C, Hedges CP, Merry TL. α1-Antitrypsin A treatment attenuates neutrophil elastase accumulation and enhances insulin sensitivity in adipose tissue of mice fed a high-fat diet. Am J Physiol Endocrinol Metab 2021; 321:E560-E570. [PMID: 34486403 DOI: 10.1152/ajpendo.00181.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Neutrophils accumulate in insulin-sensitive tissues during obesity and may play a role in impairing insulin sensitivity. The major serine protease expressed by neutrophils is neutrophil elastase (NE), which is inhibited endogenously by α1-antitrypsin A (A1AT). We investigated the effect of exogenous (A1AT) treatment on diet-induced metabolic dysfunction. Male C57Bl/6j mice fed a chow or a high-fat diet (HFD) were randomized to receive intraperitoneal injections three times weekly of either Prolastin (human A1AT; 2 mg) or vehicle (PBS) for 10 wk. Prolastin treatment did not affect plasma NE concentration, body weight, glucose tolerance, or insulin sensitivity in chow-fed mice. In contrast, Prolastin treatment attenuated HFD-induced increases in plasma and white adipose tissue (WAT) NE without affecting circulatory neutrophil levels or increases in body weight. Prolastin-treated mice fed a HFD had improved insulin sensitivity, as assessed by insulin tolerance test, and this was associated with higher insulin-dependent IRS-1 (insulin receptor substrate) and AktSer473 phosphorylation, and reduced inflammation markers in WAT but not liver or muscle. In 3T3-L1 adipocytes, Prolastin reversed recombinant NE-induced impairment of insulin-stimulated glucose uptake and IRS-1 phosphorylation. Furthermore, PDGF mediated p-AktSer473 activation and glucose uptake (which is independent of IRS-1) was not affected by recombinant NE treatment. Collectively, our findings suggest that NE infiltration of WAT during metabolic overload contributes to insulin resistance by impairing insulin-induced IRS-1 signaling.NEW & NOTEWORTHY Neutrophils accumulate in peripheral tissues during obesity and are critical coordinators of tissue inflammatory responses. Here, we provide evidence that inhibition of the primary neutrophil protease, neutrophil elastase, with α1-antitrypsin A (A1AT) can improve insulin sensitivity and glucose homeostasis of mice fed a high-fat diet. This was attributed to improved insulin-induced IRS-1 phosphorylation in white adipose tissue and provides further support for a role of neutrophils in mediating diet-induced peripheral tissue insulin resistance.
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Affiliation(s)
- Randall F D'Souza
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Stewart W C Masson
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Jonathan S T Woodhead
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Samuel L James
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Caitlin MacRae
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Christopher P Hedges
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Troy L Merry
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
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Ferri A, Yan X, Kuang J, Granata C, Oliveira RSF, Hedges CP, Lima-Silva AE, Billaut F, Bishop DJ. Fifteen days of moderate normobaric hypoxia does not affect mitochondrial function, and related genes and proteins, in healthy men. Eur J Appl Physiol 2021; 121:2323-2336. [PMID: 33988746 DOI: 10.1007/s00421-021-04706-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 04/28/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE To investigate within the one study potential molecular and cellular changes associated with mitochondrial biogenesis following 15 days of exposure to moderate hypoxia. METHODS Eight males underwent a muscle biopsy before and after 15 days of hypoxia exposure (FiO2 = 0.140-0.154; ~ 2500-3200 m) in a hypoxic hotel. Mitochondrial respiration, citrate synthase (CS) activity, and the content of genes and proteins associated with mitochondrial biogenesis were investigated. RESULTS Our main findings were the absence of significant changes in the mean values of CS activity, mitochondrial respiration in permeabilised fibers, or the content of genes and proteins associated with mitochondrial biogenesis, after 15 days of moderate normobaric hypoxia. CONCLUSION Our data provide evidence that 15 days of moderate normobaric hypoxia have negligible influence on skeletal muscle mitochondrial content and function, or genes and proteins content associated with mitochondrial biogenesis, in young recreationally active males. However, the increase in mitochondrial protease LON content after hypoxia exposure suggests the possibility of adaptations to optimise respiratory chain function under conditions of reduced O2 availability.
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Affiliation(s)
- Alessandra Ferri
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia
| | - Xu Yan
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia
| | - Jujiao Kuang
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia
| | - Cesare Granata
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia.,Department of Diabetes, Central Clinical School, Monash University, Alfred Medical Research and Education Precinct, Melbourne, VIC, Australia
| | | | | | - Adriano E Lima-Silva
- Human Performance Research Group, Federal University of Technology-Parana (UTFPR), Curitiba, Brazil
| | - Francois Billaut
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia.,Département de Kinésiologie, Université Laval, Québec, Canada
| | - David J Bishop
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia.
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Hedges CP, Boix J, Jaiswal JK, Shetty B, Shepherd PR, Merry TL. Efficacy of Providing the PI3K p110α Inhibitor BYL719 (Alpelisib) to Middle-Aged Mice in Their Diet. Biomolecules 2021; 11:biom11020150. [PMID: 33503847 PMCID: PMC7911305 DOI: 10.3390/biom11020150] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/12/2021] [Accepted: 01/19/2021] [Indexed: 12/20/2022] Open
Abstract
BYL719 (alpelisib) is a small molecule inhibitor of PI3K p110α developed for cancer therapy. Targeted suppression of PI3K has led to lifespan extension in rodents and model organisms. If PI3K inhibitors are to be considered as an aging therapeutic, it is important to understand the potential consequences of long-term exposure, and the most practical way to achieve this is through diet administration. Here, we investigated the pharmacokinetics of BYL719 delivered in diet and the efficacy of BYL719 to suppress insulin signaling when administered in the diet of 8-month-old male and female mice. Compared to oral gavage, diet incorporation resulted in a lower peak plasma BYL719 (3.6 vs. 9.2 μM) concentration but similar half-life (~1.5 h). Consuming BYL719 resulted in decreased insulin signaling in liver and muscle within 72 h, and mice still showed impaired glucose tolerance and insulin sensitivity following 6 weeks of access to a diet containing 0.3 g/kg BYL719. However, consuming BYL719 did not affect food intake, body mass, muscle function (rotarod and hang time performance) or cognitive behaviors. This provides evidence that BYL719 has long-term efficacy without major toxicity or side effects, and suggests that administering BYL719 in diet is suitable for studying the effect of pharmacological suppression of PI3K p110α on aging and metabolic function.
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Affiliation(s)
- Christopher P. Hedges
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland 1023, New Zealand; (C.P.H.); (B.S.)
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland 1023, New Zealand; (J.K.J.); (P.R.S.)
| | - Jordi Boix
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand;
| | - Jagdish K. Jaiswal
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland 1023, New Zealand; (J.K.J.); (P.R.S.)
- Auckland Cancer Society Research Centre, University of Auckland, Auckland 1023, New Zealand
| | - Bhoopika Shetty
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland 1023, New Zealand; (C.P.H.); (B.S.)
| | - Peter R. Shepherd
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland 1023, New Zealand; (J.K.J.); (P.R.S.)
- Molecular Medicine and Pathology, School of Medical Sciences, University of Auckland, Auckland 1023, New Zealand
| | - Troy L. Merry
- Discipline of Nutrition, School of Medical Sciences, University of Auckland, Auckland 1023, New Zealand; (C.P.H.); (B.S.)
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland 1023, New Zealand; (J.K.J.); (P.R.S.)
- Correspondence: ; Tel.: +64-9-923-6372
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8
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Woodhead JST, D'Souza RF, Hedges CP, Wan J, Berridge MV, Cameron-Smith D, Cohen P, Hickey AJR, Mitchell CJ, Merry TL. High-intensity interval exercise increases humanin, a mitochondrial encoded peptide, in the plasma and muscle of men. J Appl Physiol (1985) 2020; 128:1346-1354. [PMID: 32271093 PMCID: PMC7717117 DOI: 10.1152/japplphysiol.00032.2020] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/03/2020] [Accepted: 04/04/2020] [Indexed: 12/19/2022] Open
Abstract
Humanin is a small regulatory peptide encoded within the 16S ribosomal RNA gene (MT-RNR2) of the mitochondrial genome that has cellular cyto- and metabolo-protective properties similar to that of aerobic exercise training. Here we investigated whether acute high-intensity interval exercise or short-term high-intensity interval training (HIIT) impacted skeletal muscle and plasma humanin levels. Vastus lateralis muscle biopsies and plasma samples were collected from young healthy untrained men (n = 10, 24.5 ± 3.7 yr) before, immediately following, and 4 h following the completion of 10 × 60 s cycle ergometer bouts at V̇o2peak power output (untrained). Resting and postexercise sampling was also performed after six HIIT sessions (trained) completed over 2 wk. Humanin protein abundance in muscle and plasma were increased following an acute high-intensity exercise bout. HIIT trended (P = 0.063) to lower absolute humanin plasma levels, without effecting the response in muscle or plasma to acute exercise. A similar response in the plasma was observed for the small humanin-like peptide 6 (SHLP6), but not SHLP2, indicating selective regulation of peptides encoded by MT-RNR2 gene. There was a weak positive correlation between muscle and plasma humanin levels, and contraction of isolated mouse EDL muscle increased humanin levels ~4-fold. The increase in muscle humanin levels with acute exercise was not associated with MT-RNR2 mRNA or humanin mRNA levels (which decreased following acute exercise). Overall, these results suggest that humanin is an exercise-sensitive mitochondrial peptide and acute exercise-induced humanin responses in muscle are nontranscriptionally regulated and may partially contribute to the observed increase in plasma concentrations.NEW & NOTEWORTHY Small regulatory peptides encoded within the mitochondrial genome (mitochondrial derived peptides) have been shown to have cellular cyto- and metabolo-protective roles that parallel those of exercise. Here we provide evidence that humanin and SHLP6 are exercise-sensitive mitochondrial derived peptides. Studies to determine whether mitochondrial derived peptides play a role in regulating exercise-induced adaptations are warranted.
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Affiliation(s)
- Jonathan S T Woodhead
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Randall F D'Souza
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Christopher P Hedges
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Junxiang Wan
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, California
| | | | - David Cameron-Smith
- Liggins Institute, The University of Auckland, Auckland, New Zealand
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Innovation, Singapore
| | - Pinchas Cohen
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, California
| | - Anthony J R Hickey
- School of Biological Sciences, Faculty of Science, The University of Auckland, Auckland, New Zealand
| | - Cameron J Mitchell
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Troy L Merry
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
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9
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D'Souza RF, Woodhead JST, Hedges CP, Zeng N, Wan J, Kumagai H, Lee C, Cohen P, Cameron-Smith D, Mitchell CJ, Merry TL. Increased expression of the mitochondrial derived peptide, MOTS-c, in skeletal muscle of healthy aging men is associated with myofiber composition. Aging (Albany NY) 2020; 12:5244-5258. [PMID: 32182209 PMCID: PMC7138593 DOI: 10.18632/aging.102944] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Accepted: 03/09/2020] [Indexed: 02/06/2023]
Abstract
Mitochondria putatively regulate the aging process, in part, through the small regulatory peptide, mitochondrial open reading frame of the 12S rRNA-c (MOTS-c) that is encoded by the mitochondrial genome. Here we investigated the regulation of MOTS-c in the plasma and skeletal muscle of healthy aging men. Circulating MOTS-c reduced with age, but older (70-81 y) and middle-aged (45-55 y) men had ~1.5-fold higher skeletal muscle MOTS-c expression than young (18-30 y). Plasma MOTS-c levels only correlated with plasma in young men, was associated with markers of slow-type muscle, and associated with improved muscle quality in the older group (maximal leg-press load relative to thigh cross-sectional area). Using small mRNA assays we provide evidence that MOTS-c transcription may be regulated independently of the full length 12S rRNA gene in which it is encoded, and expression is not associated with antioxidant response element (ARE)-related genes as previously seen in culture. Our results suggest that plasma and muscle MOTS-c are differentially regulated with aging, and the increase in muscle MOTS-c expression with age is consistent with fast-to-slow type muscle fiber transition. Further research is required to determine the molecular targets of endogenous MOTS-c in human muscle but they may relate to factors that maintain muscle quality.
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Affiliation(s)
- Randall F D'Souza
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Jonathan S T Woodhead
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Christopher P Hedges
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Nina Zeng
- Liggins Institute, The University of Auckland, Auckland, New Zealand.,Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Junxiang Wan
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA
| | - Hiroshi Kumagai
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA.,Japan Society for the Promotion of Science, Tokyo, Japan.,Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan
| | - Changhan Lee
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA.,USC Norris Comprehensive Cancer Center, Los Angeles, CA 90033, USA.,Biomedical Science, Graduate School, Ajou University, Suwon, Korea
| | - Pinchas Cohen
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA 90089, USA
| | | | - Cameron J Mitchell
- Liggins Institute, The University of Auckland, Auckland, New Zealand.,School of Kinesiology, University of British Colombia, Vancouver, BC V6T 1Z1, Canada
| | - Troy L Merry
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
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10
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Merry TL, MacRae C, Pham T, Hedges CP, Ristow M. Deficiency in ROS-sensing nuclear factor erythroid 2-like 2 causes altered glucose and lipid homeostasis following exercise training. Am J Physiol Cell Physiol 2019; 318:C337-C345. [PMID: 31774701 DOI: 10.1152/ajpcell.00426.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Oxidative stress induced by acute exercise may regulate exercise training-induced adaptations that improve metabolic health. One of the central transcription regulatory targets of reactive oxygen species (ROS) is Nrf2 (nuclear factor erythroid-derived 2-like 2, or NFE2L2). Here, we investigated whether global deficiency of Nrf2 in mice would impact exercise training-induced changes in glucose and lipid homeostasis. We report that following 6 wk of treadmill exercise training, Nrf2-deficient mice have elevated fasting plasma triglycerides and free fatty acids and higher blood glucose levels following a meal despite having a similar fat mass to wild-type controls. This impaired glucose homeostasis appears to be related to reduced insulin sensitivity primarily in adipose and liver tissue, and although a clear mechanism was not evident, Nrf2-deficient mice had increased markers of hepatic oxidative stress and stress-related kinase activation in white adipose tissue (WAT) without overt inflammation alteration in WAT or modulation of hepatic and WAT fibroblast growth factor 21 gene expression. Our results suggest that Nrf2 facilitates exercise training-induced improvements in glucose homeostasis; however, further research is required to determine whether this occurs through direct regulation of exercise adaptations or via the maintenance of redox balance during training.
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Affiliation(s)
- Troy L Merry
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand.,Energy Metabolism Laboratory, Institute for Translational Medicines, Department of Health Sciences and Technology, Swiss Federal Institute of Technology Zurich, Schwerzenbach, Switzerland
| | - Caitlin MacRae
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Toan Pham
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Christopher P Hedges
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Michael Ristow
- Energy Metabolism Laboratory, Institute for Translational Medicines, Department of Health Sciences and Technology, Swiss Federal Institute of Technology Zurich, Schwerzenbach, Switzerland
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11
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D'Souza RF, Zeng N, Markworth JF, Figueiredo VC, Hedges CP, Petersen AC, Della Gatta PA, Cameron-Smith D, Mitchell CJ. Whey Protein Supplementation Post Resistance Exercise in Elderly Men Induces Changes in Muscle miRNA's Compared to Resistance Exercise Alone. Front Nutr 2019; 6:91. [PMID: 31249834 PMCID: PMC6582369 DOI: 10.3389/fnut.2019.00091] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 05/24/2019] [Indexed: 12/17/2022] Open
Abstract
Progressive muscle loss with aging results in decreased physical function, frailty, and impaired metabolic health. Deficits in anabolic signaling contribute to an impaired ability for aged skeletal muscle to adapt in response to exercise and protein feeding. One potential contributing mechanism could be exerted by dysregulation of microRNAs (miRNAs). Therefore, the aim of this study was to determine if graded protein doses consumed after resistance exercise altered muscle miRNA expression in elderly men. Twenty-three senior men (67.9 ± 0.9 years) performed a bout of resistance exercise and were randomized to consume either a placebo, 20 or 40 g of whey protein (n = 8, n = 7, and n = 8, respectively). Vastus lateralis biopsies were collected before, 2 and 4 h after exercise. Expression of 19 miRNAs, previously identified to influence muscle phenotype, were measured via RT-PCR. Of these, miR-16-5p was altered with exercise in all groups (p = 0.032). Expression of miR-15a and-499a increased only in the placebo group 4 h after exercise and miR-451a expression increased following exercise only in the 40 g whey supplementation group. Changes in p-P70S6KThr389 and p-AktSer473 following exercise were correlated with alterations in miR-208a and-499a and-206 expression, irrespective of protein dose, suggesting a possible role for miRNA in the regulation of acute phosphorylation events during early hours of exercise recovery.
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Affiliation(s)
- Randall F D'Souza
- Liggins Institute, The University of Auckland, Auckland, New Zealand.,Discipline of Nutrition, The University of Auckland, Auckland, New Zealand
| | - Nina Zeng
- Liggins Institute, The University of Auckland, Auckland, New Zealand
| | - James F Markworth
- Liggins Institute, The University of Auckland, Auckland, New Zealand.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
| | - Vandre C Figueiredo
- Liggins Institute, The University of Auckland, Auckland, New Zealand.,College of Health Sciences, University of Kentucky, Lexington, KY, United States
| | - Christopher P Hedges
- Applied Surgery and Metabolism Laboratory, School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Aaron C Petersen
- Institute for Health and Sport (iHeS), Victoria University, Melbourne, VIC, Australia
| | - Paul A Della Gatta
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | - David Cameron-Smith
- Liggins Institute, The University of Auckland, Auckland, New Zealand.,Food and Bio-based Products, AgResearch Grasslands, Palmerston North, New Zealand.,The Riddet Institute, Massey University, Palmerston North, New Zealand
| | - Cameron J Mitchell
- Liggins Institute, The University of Auckland, Auckland, New Zealand.,School of Kinesiology, University of British Colombia, Vancouver, BC, Canada
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12
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Hedges CP, Wilkinson RT, Devaux JB, Hickey AJ. Hymenoptera flight muscle mitochondrial function: Increasing metabolic power increases oxidative stress. Comp Biochem Physiol A Mol Integr Physiol 2019; 230:115-121. [DOI: 10.1016/j.cbpa.2019.01.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 01/02/2019] [Indexed: 11/26/2022]
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13
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Devaux JBL, Hedges CP, Birch N, Herbert N, Renshaw GMC, Hickey AJR. Acidosis Maintains the Function of Brain Mitochondria in Hypoxia-Tolerant Triplefin Fish: A Strategy to Survive Acute Hypoxic Exposure? Front Physiol 2019; 9:1941. [PMID: 30713504 PMCID: PMC6346031 DOI: 10.3389/fphys.2018.01941] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 12/22/2018] [Indexed: 11/13/2022] Open
Abstract
The vertebrate brain is generally very sensitive to acidosis, so a hypoxia-induced decrease in pH is likely to have an effect on brain mitochondria (mt). Mitochondrial respiration (JO2) is required to generate an electrical gradient (ΔΨm) and a pH gradient to power ATP synthesis, yet the impact of pH modulation on brain mt function remains largely unexplored. As intertidal fishes within rock pools routinely experience hypoxia and reoxygenation, they would most likely experience changes in cellular pH. We hence compared four New Zealand triplefin fish species ranging from intertidal hypoxia-tolerant species (HTS) to subtidal hypoxia-sensitive species (HSS). We predicted that HTS would tolerate acidosis better than HSS in terms of sustaining mt structure and function. Using respirometers coupled to fluorimeters and pH electrodes, we titrated lactic-acid to decrease the pH of the media, and simultaneously recorded JO2, ΔΨm, and H+ buffering capacities within permeabilized brain and swelling of mt isolated from non-permeabilized brains. We then measured ATP synthesis rates in the most HTS (Bellapiscus medius) and the HSS (Forsterygion varium) at pH 7.25 and 6.65. Mitochondria from HTS brain did have greater H+ buffering capacities than HSS mt (∼10 mU pH.mgprotein -1). HTS mt swelled by 40% when exposed to a decrease of 1.5 pH units, and JO2 was depressed by up to 15% in HTS. However, HTS were able to maintain ΔΨm near -120 mV. Estimates of work, in terms of charges moved across the mt inner-membrane, suggested that with acidosis, HTS mt may in part harness extra-mt H+ to maintain ΔΨm, and could therefore support ATP production. This was confirmed with elevated ATP synthesis rates and enhanced P:O ratios at pH 6.65 relative to pH 7.25. In contrast, mt volumes and ΔΨm decreased downward pH 6.9 in HSS mt and paradoxically, JO2 increased (∼25%) but ATP synthesis and P:O ratios were depressed at pH 6.65. This indicates a loss of coupling in the HSS with acidosis. Overall, the mt of these intertidal fish have adaptations that enhance ATP synthesis efficiency under acidic conditions such as those that occur in hypoxic or reoxygenated brain.
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Affiliation(s)
- Jules B L Devaux
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Christopher P Hedges
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Nigel Birch
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Neill Herbert
- Institute of Marine Science, The University Auckland, Auckland, New Zealand
| | - Gillian M C Renshaw
- School of Allied Health Sciences, Griffith University, Gold Coast, QLD, Australia
| | - Anthony J R Hickey
- School of Biological Sciences, The University of Auckland, Auckland, New Zealand
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14
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Hedges CP, Bishop DJ, Hickey AJR. Voluntary wheel running prevents the acidosis-induced decrease in skeletal muscle mitochondrial reactive oxygen species emission. FASEB J 2018; 33:4996-5004. [PMID: 30596520 DOI: 10.1096/fj.201801870r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Decreases in pH (acidosis) in vitro can alter skeletal muscle mitochondrial function [respiration and reactive oxygen species (ROS) emission]. However, because skeletal muscles readily adapt to exercise, the effects of acidosis may be different on sedentary vs. trained muscle. The aim of this work was to compare the effects of pH on skeletal muscle mitochondrial function between sedentary vs. exercise-trained male Sprague-Dawley rats ( n = 10 in each cohort). Rates of mitochondrial respiration and ROS emission were determined from the soleus muscle of both cohorts over a physiologic range of pH values (pH 6.2-7.1). Exercise-trained rats had 14% higher mean muscle buffering capacities; 46 and 40% greater enzyme activity of citrate synthase and lactate dehydrogenase, respectively; and greater activity of respiratory complexes I-IV. ADP-stimulated respiration with complex I and II substrates was ∼25% greater in exercise-trained rats but was unaffected by pH in either cohort. In both cohorts, lowering pH decreased respiration only in complex I- and complex II-supported nonphosphorylating (leak) state. However, as pH decreased, ROS emissions in complex I- and complex II-supported leak state decreased only in sedentary rats; in exercise-trained rats, ROS emissions in this state remained constant. We hypothesize that this effect may result from modulation at complex III, which declined 47% per unit pH in sedentary rats, in comparison to 23% in exercise-trained rats. Taken together, these data suggest that pH regulates mitochondrial respiratory complexes and that exercise training can decrease the effects of pH on skeletal muscle mitochondrial function.-Hedges, C. P., Bishop, D. J., Hickey, A. J. R. Voluntary wheel running prevents the acidosis-induced decrease in skeletal muscle mitochondrial reactive oxygen species emission.
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Affiliation(s)
- Christopher P Hedges
- Applied Surgery and Metabolism Laboratory, School of Biological Sciences, The University of Auckland, Auckland, New Zealand.,Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia; and
| | - David J Bishop
- Institute for Health and Sport, Victoria University, Melbourne, Victoria, Australia; and.,School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
| | - Anthony J R Hickey
- Applied Surgery and Metabolism Laboratory, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
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15
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Pileggi CA, Hedges CP, D'Souza RF, Durainayagam BR, Markworth JF, Hickey AJR, Mitchell CJ, Cameron-Smith D. Exercise recovery increases skeletal muscle H 2O 2 emission and mitochondrial respiratory capacity following two-weeks of limb immobilization. Free Radic Biol Med 2018; 124:241-248. [PMID: 29909291 DOI: 10.1016/j.freeradbiomed.2018.06.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/10/2018] [Accepted: 06/11/2018] [Indexed: 01/11/2023]
Abstract
Extended periods of skeletal muscle disuse result in muscle atrophy. Following limb immobilization, increased mitochondrial reactive oxygen species (ROS) production may contribute to atrophy through increases in skeletal muscle protein degradation. However, the effect of skeletal muscle disuse on mitochondrial ROS production remains unclear. This study investigated the effect of immobilization, followed by two subsequent periods of restored physical activity, on mitochondrial H2O2 emissions in adult male skeletal muscle. Middle-aged men (n = 30, 49.7 ± 3.84 y) completed two weeks of unilateral lower-limb immobilization, followed by two weeks of baseline-matched activity, consisting of 10,000 steps a day, then completed two weeks of three times weekly supervised resistance training. Vastus lateralis biopsies were taken at baseline, post-immobilization, post-ambulatory recovery, and post-resistance-training. High-resolution respirometry was used simultaneously with fluorometry to determine mitochondrial respiration and hydrogen peroxide (H2O2) production in permeabilized muscle fibres. Mitochondrial H2O2 emission with complex I and II substrates, in the absence of ADP, was greater following immobilization, however, there was no effect on mitochondrial respiration. Both ambulatory recovery and resistance training, following the period of immobilization, increased in mitochondrial H2O2 emissions. These data demonstrated that 2 weeks of immobilization increases mitochondrial H2O2 emissions, but subsequent retraining periods of ambulatory recovery and resistance training also led to in robust increases in mitochondrial H2O2 emissions in skeletal muscle.
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Affiliation(s)
- Chantal A Pileggi
- Liggins Institute, The University of Auckland, Auckland, New Zealand
| | - Christopher P Hedges
- College of Sport and Exercise Science, Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia; Applied Surgery and Metabolism Laboratory, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | - Randall F D'Souza
- Liggins Institute, The University of Auckland, Auckland, New Zealand
| | | | - James F Markworth
- Liggins Institute, The University of Auckland, Auckland, New Zealand
| | - Anthony J R Hickey
- Applied Surgery and Metabolism Laboratory, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
| | | | - David Cameron-Smith
- Liggins Institute, The University of Auckland, Auckland, New Zealand; Food & Bio-based Products Group, AgResearch, Palmerston North, New Zealand; Riddet Institute, Palmerston North, New Zealand.
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16
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Wyckelsma VL, Levinger I, Murphy RM, Petersen AC, Perry BD, Hedges CP, Anderson MJ, McKenna MJ. Intense interval training in healthy older adults increases skeletal muscle [ 3H]ouabain-binding site content and elevates Na +,K +-ATPase α 2 isoform abundance in Type II fibers. Physiol Rep 2017; 5:5/7/e13219. [PMID: 28373411 PMCID: PMC5392511 DOI: 10.14814/phy2.13219] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 02/27/2017] [Indexed: 12/12/2022] Open
Abstract
Young adults typically adapt to intense exercise training with an increased skeletal muscle Na+,K+-ATPase (NKA) content, concomitant with reduced extracellular potassium concentration [K+] during exercise and enhanced exercise performance. Whether these changes with longitudinal training occur in older adults is unknown and was investigated here. Fifteen older adults (69.4 ± 3.5 years, mean ± SD) were randomized to either 12 weeks of intense interval training (4 × 4 min at 90-95% peak heart rate), 3 days/week (IIT, n = 8); or no exercise controls (n = 7). Before and after training, participants completed an incremental cycle ergometer exercise test until a rating of perceived exertion of 17 (very hard) on a 20-point scale was attained, with measures of antecubital venous [K+]v Participants underwent a resting muscle biopsy prior to and at 48-72 h following the final training session. After IIT, the peak exercise work rate (25%), oxygen uptake (16%) and heart rate (6%) were increased (P < 0.05). After IIT, the peak exercise plasma [K+]v tended to rise (P = 0.07), while the rise in plasma [K+]v relative to work performed (nmol.L-1J-1) was unchanged. Muscle NKA content increased by 11% after IIT (P < 0.05). Single fiber measurements, increased in NKA α2 isoform in Type II fibers after IIT (30%, P < 0.05), with no changes to the other isoforms in single fibers or homogenate. Thus, intense exercise training in older adults induced an upregulation of muscle NKA, with a fiber-specific increase in NKA α2 abundance in Type II fibers, coincident with increased muscle NKA content and enhanced exercise performance.
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Affiliation(s)
- Victoria L Wyckelsma
- Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living (ISEAL), Victoria, Australia
| | - Itamar Levinger
- Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living (ISEAL), Victoria, Australia
| | - Robyn M Murphy
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Victoria, Australia
| | - Aaron C Petersen
- Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living (ISEAL), Victoria, Australia
| | - Ben D Perry
- Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living (ISEAL), Victoria, Australia.,Renal Division, Department of Medicine, Emory University, Atlanta, Georgia
| | - Christopher P Hedges
- Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living (ISEAL), Victoria, Australia
| | - Mitchell J Anderson
- Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living (ISEAL), Victoria, Australia.,Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Michael J McKenna
- Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living (ISEAL), Victoria, Australia
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17
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Masson SWC, Hedges CP, Devaux JBL, James CS, Hickey AJR. Mitochondrial glycerol 3-phosphate facilitates bumblebee pre-flight thermogenesis. Sci Rep 2017; 7:13107. [PMID: 29026172 PMCID: PMC5638826 DOI: 10.1038/s41598-017-13454-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 09/22/2017] [Indexed: 11/27/2022] Open
Abstract
Bumblebees (Bombus terrestris) fly at low ambient temperatures where other insects cannot, and to do so they must pre-warm their flight muscles. While some have proposed mechanisms, none fully explain how pre-flight thermogenesis occurs. Here, we present a novel hypothesis based on the less studied mitochondrial glycerol 3-phosphate dehydrogenase pathway (mGPDH). Using calorimetry, and high resolution respirometry coupled with fluorimetry, we report substrate oxidation by mGPDH in permeabilised flight muscles operates, in vitro, at a high flux, even in the absence of ADP. This may be facilitated by an endogenous, mGPDH-mediated uncoupling of mitochondria. This uncoupling increases ETS activity, which results in increased heat release. Furthermore, passive regulation of this mechanism is achieved via dampened temperature sensitivity of mGPDH relative to other respiratory pathways, and subsequent consumption of its substrate, glycerol 3-phosphate (G3P), at low temperatures. Mitochondrial GPDH may therefore facilitate pre-flight thermogenesis through poor mitochondrial coupling. We calculate this can occur at a sufficient rate to warm flight muscles until shivering commences, and until flight muscle function is adequate for bumblebees to fly in the cold.
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Affiliation(s)
- Stewart W C Masson
- School of Biological Sciences, University of Auckland, 3a Symonds St, Auckland, 1010, New Zealand
| | - Christopher P Hedges
- School of Biological Sciences, University of Auckland, 3a Symonds St, Auckland, 1010, New Zealand.,Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, VIC, Australia
| | - Jules B L Devaux
- School of Biological Sciences, University of Auckland, 3a Symonds St, Auckland, 1010, New Zealand
| | - Crystal S James
- School of Biological Sciences, University of Auckland, 3a Symonds St, Auckland, 1010, New Zealand
| | - Anthony J R Hickey
- School of Biological Sciences, University of Auckland, 3a Symonds St, Auckland, 1010, New Zealand.
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18
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Pileggi CA, Hedges CP, Segovia SA, Markworth JF, Durainayagam BR, Gray C, Zhang XD, Barnett MPG, Vickers MH, Hickey AJR, Reynolds CM, Cameron-Smith D. Maternal High Fat Diet Alters Skeletal Muscle Mitochondrial Catalytic Activity in Adult Male Rat Offspring. Front Physiol 2016; 7:546. [PMID: 27917127 PMCID: PMC5114294 DOI: 10.3389/fphys.2016.00546] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 10/28/2016] [Indexed: 12/29/2022] Open
Abstract
A maternal high-fat (HF) diet during pregnancy can lead to metabolic compromise, such as insulin resistance in adult offspring. Skeletal muscle mitochondrial dysfunction is one mechanism contributing to metabolic impairments in insulin resistant states. Therefore, the present study aimed to investigate whether mitochondrial dysfunction is evident in metabolically compromised offspring born to HF-fed dams. Sprague-Dawley dams were randomly assigned to receive a purified control diet (CD; 10% kcal from fat) or a high fat diet (HFD; 45% kcal from fat) for 10 days prior to mating, throughout pregnancy and during lactation. From weaning, all male offspring received a standard chow diet and soleus muscle was collected at day 150. Expression of the mitochondrial transcription factors nuclear respiratory factor-1 (NRF1) and mitochondrial transcription factor A (mtTFA) were downregulated in HF offspring. Furthermore, genes encoding the mitochondrial electron transport system (ETS) respiratory complex subunits were suppressed in HF offspring. Moreover, protein expression of the complex I subunit, NDUFB8, was downregulated in HF offspring (36%), which was paralleled by decreased maximal catalytic linked activity of complex I and III (40%). Together, these results indicate that exposure to a maternal HF diet during development may elicit lifelong mitochondrial alterations in offspring skeletal muscle.
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Affiliation(s)
| | - Christopher P Hedges
- College of Sport and Exercise Science, Institute of Sport, Exercise and Active Living, Victoria UniversityMelbourne, VIC, Australia; Applied Surgery and Metabolism Laboratory, School of Biological Sciences, University of AucklandAuckland, New Zealand
| | - Stephanie A Segovia
- Liggins Institute, University of AucklandAuckland, New Zealand; Gravida: National Centre for Growth and Development, University of AucklandAuckland, New Zealand
| | | | | | - Clint Gray
- Liggins Institute, University of AucklandAuckland, New Zealand; Gravida: National Centre for Growth and Development, University of AucklandAuckland, New Zealand
| | - Xiaoyuan D Zhang
- Liggins Institute, University of AucklandAuckland, New Zealand; Gravida: National Centre for Growth and Development, University of AucklandAuckland, New Zealand
| | - Matthew P G Barnett
- Food Nutrition and Health Team, Food and Bio-based Products Group, AgResearch Grasslands Palmerston North, New Zealand
| | - Mark H Vickers
- Liggins Institute, University of AucklandAuckland, New Zealand; Gravida: National Centre for Growth and Development, University of AucklandAuckland, New Zealand
| | - Anthony J R Hickey
- Applied Surgery and Metabolism Laboratory, School of Biological Sciences, University of Auckland Auckland, New Zealand
| | - Clare M Reynolds
- Liggins Institute, University of AucklandAuckland, New Zealand; Gravida: National Centre for Growth and Development, University of AucklandAuckland, New Zealand
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19
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Hedges CP, Pileggi CA, Mitchell CJ. Retirees, rest, respiration and ROS: does age or inactivity drive mitochondrial dysfunction? J Physiol 2015; 593:5037-8. [PMID: 26627711 DOI: 10.1113/jp271499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Christopher P Hedges
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Australia.,Applied Surgery and Metabolism Laboratory, School of Biological Sciences, University of Auckland, Auckland, New Zealand
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20
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Kontos GJ, Hedges CP, Rost MC, Nussbaum DK, Hanson JW. Postintubation tracheal stenosis: diagnosis and management. S D J Med 1993; 46:323-5. [PMID: 8256133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Postintubation damage is a potential hazard in any patient intubated with an oral or nasal endotracheal tube or with a tracheostomy tube for ventilatory support. Postintubation tracheal stenosis may be fatal unless it is recognized and treated promptly. This paper reviews the important features of diagnosis and treatment of postintubation tracheal stenosis.
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Affiliation(s)
- G J Kontos
- Midwest Cardiovascular Center, Sioux Falls, SD
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