1
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Gharibans AA, Hayes TCL, Carson DA, Calder S, Varghese C, Du P, Yarmut Y, Waite S, Keane C, Woodhead JST, Andrews CN, O'Grady G. A novel scalable electrode array and system for non-invasively assessing gastric function using flexible electronics. Neurogastroenterol Motil 2023; 35:e14418. [PMID: 35699340 PMCID: PMC10078595 DOI: 10.1111/nmo.14418] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/29/2022] [Accepted: 05/05/2022] [Indexed: 02/02/2023]
Abstract
BACKGROUND Disorders of gastric function are highly prevalent, but diagnosis often remains symptom-based and inconclusive. Body surface gastric mapping is an emerging diagnostic solution, but current approaches lack scalability and are cumbersome and clinically impractical. We present a novel scalable system for non-invasively mapping gastric electrophysiology in high-resolution (HR) at the body surface. METHODS The system comprises a custom-designed stretchable high-resolution "peel-and-stick" sensor array (8 × 8 pre-gelled Ag/AgCl electrodes at 2 cm spacing; area 225 cm2 ), wearable data logger with custom electronics incorporating bioamplifier chips, accelerometer and Bluetooth synchronized in real-time to an App with cloud connectivity. Automated algorithms filter and extract HR biomarkers including propagation (phase) mapping. The system was tested in a cohort of 24 healthy subjects to define reliability and characterize features of normal gastric activity (30 m fasting, standardized meal, and 4 h postprandial). KEY RESULTS Gastric mapping was successfully achieved non-invasively in all cases (16 male; 8 female; aged 20-73 years; BMI 24.2 ± 3.5). In all subjects, gastric electrophysiology and meal responses were successfully captured and quantified non-invasively (mean frequency 2.9 ± 0.3 cycles per minute; peak amplitude at mean 60 m postprandially with return to baseline in <4 h). Spatiotemporal mapping showed regular and consistent wave activity of mean direction 182.7° ± 73 (74.7% antegrade, 7.8% retrograde, 17.5% indeterminate). CONCLUSIONS AND INFERENCES BSGM is a new diagnostic tool for assessing gastric function that is scalable and ready for clinical applications, offering several biomarkers that are improved or new to gastroenterology practice.
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Affiliation(s)
- Armen A Gharibans
- Department of Surgery, University of Auckland, Auckland, New Zealand.,Alimetry Ltd, Auckland, New Zealand.,Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Tommy C L Hayes
- Department of Surgery, University of Auckland, Auckland, New Zealand
| | - Daniel A Carson
- Department of Surgery, University of Auckland, Auckland, New Zealand
| | | | - Chris Varghese
- Department of Surgery, University of Auckland, Auckland, New Zealand
| | - Peng Du
- Alimetry Ltd, Auckland, New Zealand.,Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | | | | | - Celia Keane
- Department of Surgery, University of Auckland, Auckland, New Zealand.,Alimetry Ltd, Auckland, New Zealand
| | - Jonathan S T Woodhead
- Alimetry Ltd, Auckland, New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Christopher N Andrews
- Alimetry Ltd, Auckland, New Zealand.,Department of Medicine, University of Calgary, NB Calgary, Alberta, Canada
| | - Greg O'Grady
- Department of Surgery, University of Auckland, Auckland, New Zealand.,Alimetry Ltd, Auckland, New Zealand
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2
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Calder S, Schamberg G, Varghese C, Waite S, Sebaratnam G, Woodhead JST, Du P, Andrews C, O'Grady G, Gharibans AA. An automated artifact detection and rejection system for body surface gastric mapping. Neurogastroenterol Motil 2022; 34:e14421. [PMID: 35699347 PMCID: PMC9786272 DOI: 10.1111/nmo.14421] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 05/09/2022] [Accepted: 05/18/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND Body surface gastric mapping (BSGM) is a new clinical tool for gastric motility diagnostics, providing high-resolution data on gastric myoelectrical activity. Artifact contamination was a key challenge to reliable test interpretation in traditional electrogastrography. This study aimed to introduce and validate an automated artifact detection and rejection system for clinical BSGM applications. METHODS Ten patients with chronic gastric symptoms generated a variety of artifacts according to a standardized protocol (176 recordings) using a commercial BSGM system (Alimetry, New Zealand). An automated artifact detection and rejection algorithm was developed, and its performance was compared with a reference standard comprising consensus labeling by 3 analysis experts, followed by comparison with 6 clinicians (3 untrained and 3 trained in artifact detection). Inter-rater reliability was calculated using Fleiss' kappa. KEY RESULTS Inter-rater reliability was 0.84 (95% CI:0.77-0.90) among experts, 0.76 (95% CI:0.68-0.83) among untrained clinicians, and 0.71 (95% CI:0.62-0.79) among trained clinicians. The sensitivity and specificity of the algorithm against experts was 96% (95% CI:91%-100%) and 95% (95% CI:90%-99%), respectively, vs 77% (95% CI:68%-85%) and 99% (95% CI:96%-100%) against untrained clinicians, and 97% (95% CI:92%-100%) and 88% (95% CI:82%-94%) against trained clinicians. CONCLUSIONS & INFERENCES An automated artifact detection and rejection algorithm was developed showing >95% sensitivity and specificity vs expert markers. This algorithm overcomes an important challenge in the clinical translation of BSGM and is now being routinely implemented in patient test interpretations.
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Affiliation(s)
| | | | - Chris Varghese
- Department of SurgeryThe University of AucklandAucklandNew Zealand
| | | | | | | | - Peng Du
- Auckland Bioengineering InstituteThe University of AucklandAucklandNew Zealand
| | - Christopher N. Andrews
- Alimetry LtdAucklandNew Zealand,Division of GastroenterologyUniversity of CalgaryCalgaryAlbertaCanada
| | - Greg O'Grady
- Alimetry LtdAucklandNew Zealand,Department of SurgeryThe University of AucklandAucklandNew Zealand,Auckland Bioengineering InstituteThe University of AucklandAucklandNew Zealand
| | - Armen A. Gharibans
- Alimetry LtdAucklandNew Zealand,Department of SurgeryThe University of AucklandAucklandNew Zealand,Auckland Bioengineering InstituteThe University of AucklandAucklandNew Zealand
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3
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Xirouchaki CE, Jia Y, McGrath MJ, Greatorex S, Tran M, Merry TL, Hong D, Eramo MJ, Broome SC, Woodhead JST, D’souza RF, Gallagher J, Salimova E, Huang C, Schittenhelm RB, Sadoshima J, Watt MJ, Mitchell CA, Tiganis T. Skeletal muscle NOX4 is required for adaptive responses that prevent insulin resistance. Sci Adv 2021; 7:eabl4988. [PMID: 34910515 PMCID: PMC8673768 DOI: 10.1126/sciadv.abl4988] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 10/26/2021] [Indexed: 05/27/2023]
Abstract
Reactive oxygen species (ROS) generated during exercise are considered integral for the health-promoting effects of exercise. However, the precise mechanisms by which exercise and ROS promote metabolic health remain unclear. Here, we demonstrate that skeletal muscle NADPH oxidase 4 (NOX4), which is induced after exercise, facilitates ROS-mediated adaptive responses that promote muscle function, maintain redox balance, and prevent the development of insulin resistance. Conversely, reductions in skeletal muscle NOX4 in aging and obesity contribute to the development of insulin resistance. NOX4 deletion in skeletal muscle compromised exercise capacity and antioxidant defense and promoted oxidative stress and insulin resistance in aging and obesity. The abrogated adaptive mechanisms, oxidative stress, and insulin resistance could be corrected by deleting the H2O2-detoxifying enzyme GPX-1 or by treating mice with an agonist of NFE2L2, the master regulator of antioxidant defense. These findings causally link NOX4-derived ROS in skeletal muscle with adaptive responses that promote muscle function and insulin sensitivity.
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Affiliation(s)
- Chrysovalantou E. Xirouchaki
- Monash Biomedicine Discovery Institute, Monash
University, Clayton, Victoria 3800, Australia
- Department of Biochemistry and Molecular Biology,
Monash University, Clayton, Victoria 3800, Australia
| | - Yaoyao Jia
- Monash Biomedicine Discovery Institute, Monash
University, Clayton, Victoria 3800, Australia
- Department of Biochemistry and Molecular Biology,
Monash University, Clayton, Victoria 3800, Australia
| | - Meagan J. McGrath
- Monash Biomedicine Discovery Institute, Monash
University, Clayton, Victoria 3800, Australia
- Department of Biochemistry and Molecular Biology,
Monash University, Clayton, Victoria 3800, Australia
| | - Spencer Greatorex
- Monash Biomedicine Discovery Institute, Monash
University, Clayton, Victoria 3800, Australia
- Department of Biochemistry and Molecular Biology,
Monash University, Clayton, Victoria 3800, Australia
| | - Melanie Tran
- Monash Biomedicine Discovery Institute, Monash
University, Clayton, Victoria 3800, Australia
- Department of Biochemistry and Molecular Biology,
Monash University, Clayton, Victoria 3800, Australia
| | - Troy L. Merry
- Monash Biomedicine Discovery Institute, Monash
University, Clayton, Victoria 3800, Australia
- Department of Biochemistry and Molecular Biology,
Monash University, Clayton, Victoria 3800, Australia
- Discipline of Nutrition, Faculty of Medical and
Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Dawn Hong
- Monash Biomedicine Discovery Institute, Monash
University, Clayton, Victoria 3800, Australia
- Department of Biochemistry and Molecular Biology,
Monash University, Clayton, Victoria 3800, Australia
| | - Matthew J. Eramo
- Monash Biomedicine Discovery Institute, Monash
University, Clayton, Victoria 3800, Australia
- Department of Biochemistry and Molecular Biology,
Monash University, Clayton, Victoria 3800, Australia
| | - Sophie C. Broome
- Discipline of Nutrition, Faculty of Medical and
Health Sciences, 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
| | - Randall F. D’souza
- Discipline of Nutrition, Faculty of Medical and
Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Jenny Gallagher
- Monash Biomedicine Discovery Institute, Monash
University, Clayton, Victoria 3800, Australia
- Department of Biochemistry and Molecular Biology,
Monash University, Clayton, Victoria 3800, Australia
| | - Ekaterina Salimova
- Monash Biomedical Imaging, Monash University,
Clayton, Victoria 3800, Australia
| | - Cheng Huang
- Monash Biomedicine Discovery Institute, Monash
University, Clayton, Victoria 3800, Australia
- Department of Biochemistry and Molecular Biology,
Monash University, Clayton, Victoria 3800, Australia
- Monash Proteomics and Metabolomics Facility, Monash
University, Clayton, Victoria 3800, Australia
| | - Ralf B. Schittenhelm
- Monash Biomedicine Discovery Institute, Monash
University, Clayton, Victoria 3800, Australia
- Department of Biochemistry and Molecular Biology,
Monash University, Clayton, Victoria 3800, Australia
- Monash Proteomics and Metabolomics Facility, Monash
University, Clayton, Victoria 3800, Australia
| | - Junichi Sadoshima
- Department of Cell Biology and Molecular Medicine,
Cardiovascular Research Institute, Rutgers New Jersey Medical School, Newark, NJ
07103, USA
| | - Matthew J. Watt
- Monash Biomedicine Discovery Institute, Monash
University, Clayton, Victoria 3800, Australia
- Department of Physiology, Monash University, Clayton,
Victoria 3800, Australia
| | - Christina A. Mitchell
- Monash Biomedicine Discovery Institute, Monash
University, Clayton, Victoria 3800, Australia
- Department of Biochemistry and Molecular Biology,
Monash University, Clayton, Victoria 3800, Australia
| | - Tony Tiganis
- Monash Biomedicine Discovery Institute, Monash
University, Clayton, Victoria 3800, Australia
- Department of Biochemistry and Molecular Biology,
Monash University, Clayton, Victoria 3800, Australia
- Monash Metabolic Phenotyping Facility, Monash
University, Clayton, Victoria 3800, Australia
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4
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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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5
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Woodhead JST, Merry TL. Mitochondrial-derived peptides and exercise. Biochim Biophys Acta Gen Subj 2021; 1865:130011. [PMID: 34520826 DOI: 10.1016/j.bbagen.2021.130011] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/05/2021] [Accepted: 09/07/2021] [Indexed: 01/07/2023]
Abstract
Acute exercise, and in particular aerobic exercise, increases skeletal muscle energy demand causing mitochondrial stress, and mitochondrial-related adaptations which are a hallmark of exercise training. Given that mitochondria are central players in the exercise response, it is imperative that they have networks that can communicate their status both intra- and inter-cellularly. Peptides encoded by short open-reading frames within mitochondrial DNA, mitochondrial-derived peptides (MDPs), have been suggested to form a newly recognised branch of this retrograde signalling cascade that contribute to coordinating the adaptive response to regular exercise. Here we summarise the recent evidence that acute high intensity exercise in humans can increase concentrations of the MDPs humanin and MOTS-c in skeletal muscle and plasma, and speculate on the mechanisms controlling MDP responses to exercise stress. Evidence that exercise training results in chronic changes in MDP expression within tissues and the circulation is conflicting and may depend on the mode, duration, intensity of training plan and participant characteristics. Further research is required to define the effect of these variables on MDPs and to determine whether MDPs other than MOTS-c have exercise mimetic properties. MOTS-c treatment of young and aged mice improves exercise capacity/performance and leads to adaptions that are similar to that of being physically active (weight loss, increased antioxidant capacity and improved insulin sensitivity), however, studies utilising a MOTS-c inactivating genetic variant or combination of exercise + MOTS-c treatment in mice suggest that there are distinct and overlapping pathways through which exercise and MOTS-c evoke metabolic benefits. Overall, MOTS-c, and potentially other MDPs, may be exercise-sensitive myokines and further work is required to define inter- and intra-tissue targets in an exercise context.
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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
| | - 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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6
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Sequeira IR, Woodhead JST, Chan A, D'Souza RF, Wan J, Hollingsworth KG, Plank LD, Cohen P, Poppitt SD, Merry TL. Plasma mitochondrial derived peptides MOTS-c and SHLP2 positively associate with android and liver fat in people without diabetes. Biochim Biophys Acta Gen Subj 2021; 1865:129991. [PMID: 34419510 DOI: 10.1016/j.bbagen.2021.129991] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/10/2021] [Accepted: 08/17/2021] [Indexed: 12/15/2022]
Abstract
Mitochondrial-derived peptides (MDPs) are encoded by the mitochondrial genome and hypothesised to form part of a retrograde signalling network that modulates adaptive responses to metabolic stress. To understand how metabolic stress regulates MDPs in humans we assessed the association between circulating MOTS-c and SHLP2 and components of metabolic syndrome (MS), as well as depot-specific fat mass in participants without overt type 2 diabetes or cardiovascular disease. One-hundred and twenty-five Chinese participants (91 male, 34 female) had anthropometry, whole body dual-energy X-ray absorptiometry scans and fasted blood samples analysed. Chinese female participants and an additional 34 European Caucasian female participants also underwent magnetic resonance imaging and spectroscopy (MRI/S) for visceral, pancreatic and liver fat quantification. In Chinese participants (age = 41 ± 1 years, BMI = 27.8 ± 3.9 kg/m2), plasma MOTS-c (315 ± 27 pg/ml) and SHLP2 (1393 ± 82 pg/ml) were elevated in those with MS (n = 26). While multiple components of the MS sequelae positively associated with both MOTS-c and SHLP2, including blood pressure, fasting plasma glucose and triglycerides, the most significant of these was waist circumference (p < 0.0001). Android fat had a greater effect on increasing plasma MOTS-c (p < 0.004) and SHLP2 (p < 0.009) relative to whole body fat. Associations with MRI/S parameters corrected for total body fat mass revealed that liver fat positively associated with plasma MOTS-c and SHLP2 and visceral fat with SHLP2. Consistent with hepatic stress being a driver of circulating MDP concentrations, plasma MOTS-c and SHLP2 were higher in participants with elevated liver damage markers and in male C57Bl/6j mice fed a diet that induces hepatic lipid accumulation and damage. Our findings provide evidence that in the absence of overt type 2 diabetes, components of the MS positively associated with levels of MOTS-c and SHLP2 and that android fat, in particular liver fat, is a primary driver of these associations. MOTS-c and SHLP2 have previously been shown to have cyto- and metabolo-protective properties, therefore we suggest that liver stress may be a mitochondrial peptide signal, and that mitochondrial peptides are part of a hepatic centric-hormetic response intended to restore metabolic balance.
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Affiliation(s)
- Ivana R Sequeira
- Human Nutrition Unit, School of Biological Sciences, University of Auckland, Auckland, New Zealand; High Value Nutrition National Science Challenge, New Zealand
| | - Jonathan S T Woodhead
- Discipline of Nutrition, School of Medical Sciences, The University of Auckland, Auckland, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Alex Chan
- Discipline of Nutrition, School of Medical 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, School of Medical 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, CA, USA
| | - Kieren G Hollingsworth
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Lindsay D Plank
- Department of Surgery, University of Auckland, Auckland, New Zealand
| | - Pinchas Cohen
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Sally D Poppitt
- Human Nutrition Unit, School of Biological Sciences, University of Auckland, Auckland, New Zealand; High Value Nutrition National Science Challenge, New Zealand; Riddet CoRE for Food and Nutrition, Massey University, New Zealand
| | - Troy L Merry
- Discipline of Nutrition, School of Medical 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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7
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Masson SWC, Woodhead JST, D'Souza RF, Broome SC, MacRae C, Cho HC, Atiola RD, Futi T, Dent JR, Shepherd PR, Merry TL. β-Catenin is required for optimal exercise- and contraction-stimulated skeletal muscle glucose uptake. J Physiol 2021; 599:3897-3912. [PMID: 34180063 DOI: 10.1113/jp281352] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 06/22/2021] [Indexed: 01/14/2023] Open
Abstract
KEY POINTS Loss of β-catenin impairs in vivo and isolated muscle exercise/contraction-stimulated glucose uptake. β-Catenin is required for exercise-induced skeletal muscle actin cytoskeleton remodelling. β-Catenin675 phosphorylation during exercise may be intensity dependent. ABSTRACT The conserved structural protein β-catenin is an emerging regulator of vesicle trafficking in multiple tissues and supports insulin-stimulated glucose transporter 4 (GLUT4) translocation in skeletal muscle by facilitating cortical actin remodelling. Actin remodelling may be a convergence point between insulin and exercise/contraction-stimulated glucose uptake. Here we investigated whether β-catenin is involved in regulating exercise/contraction-stimulated glucose uptake. We report that the muscle-specific deletion of β-catenin induced in adult mice (BCAT-mKO) impairs both exercise- and contraction (isolated muscle)-induced glucose uptake without affecting running performance or canonical exercise signalling pathways. Furthermore, high intensity exercise in mice and contraction of myotubes and isolated muscles led to the phosphorylation of β-cateninS675 , and this was impaired by Rac1 inhibition. Moderate intensity exercise in control and Rac1 muscle-specific knockout mice did not induce muscle β-cateninS675 phosphorylation, suggesting exercise intensity-dependent regulation of β-cateninS675 . Introduction of a non-phosphorylatable S675A mutant of β-catenin into myoblasts impaired GLUT4 translocation and actin remodelling stimulated by carbachol, a Rac1 and RhoA activator. Exercise-induced increases in cross-sectional phalloidin staining (F-actin marker) of gastrocnemius muscle was impaired in muscle from BCAT-mKO mice. Collectively our findings suggest that β-catenin is required for optimal glucose transport in muscle during exercise/contraction, potentially via facilitating actin cytoskeleton remodelling.
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Affiliation(s)
- Stewart W C Masson
- 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
| | - Jonathan S T Woodhead
- 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
| | - Randall F D'Souza
- 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
| | - Sophie C Broome
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Caitlin MacRae
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Hyun C Cho
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Robert D Atiola
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Tumanu Futi
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Jessica R Dent
- Department of Surgery, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Peter R Shepherd
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand.,Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - 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
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8
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Merry TL, Chan A, Woodhead JST, Reynolds JC, Kumagai H, Kim SJ, Lee C. Mitochondrial-derived peptides in energy metabolism. Am J Physiol Endocrinol Metab 2020; 319:E659-E666. [PMID: 32776825 PMCID: PMC7750512 DOI: 10.1152/ajpendo.00249.2020] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/05/2020] [Accepted: 08/05/2020] [Indexed: 12/23/2022]
Abstract
Mitochondrial-derived peptides (MDPs) are small bioactive peptides encoded by short open-reading frames (sORF) in mitochondrial DNA that do not necessarily have traditional hallmarks of protein-coding genes. To date, eight MDPs have been identified, all of which have been shown to have various cyto- or metaboloprotective properties. The 12S ribosomal RNA (MT-RNR1) gene harbors the sequence for MOTS-c, whereas the other seven MDPs [humanin and small humanin-like peptides (SHLP) 1-6] are encoded by the 16S ribosomal RNA gene. Here, we review the evidence that endogenous MDPs are sensitive to changes in metabolism, showing that metabolic conditions like obesity, diabetes, and aging are associated with lower circulating MDPs, whereas in humans muscle MDP expression is upregulated in response to stress that perturbs the mitochondria like exercise, some mtDNA mutation-associated diseases, and healthy aging, which potentially suggests a tissue-specific response aimed at restoring cellular or mitochondrial homeostasis. Consistent with this, treatment of rodents with humanin, MOTS-c, and SHLP2 can enhance insulin sensitivity and offer protection against a range of age-associated metabolic disorders. Furthermore, assessing how mtDNA variants alter the functions of MDPs is beginning to provide evidence that MDPs are metabolic signal transducers in humans. Taken together, MDPs appear to form an important aspect of a retrograde signaling network that communicates mitochondrial status with the wider cell and to distal tissues to modulate adaptative responses to metabolic stress. It remains to be fully determined whether the metaboloprotective properties of MDPs can be harnessed into therapies for metabolic disease.
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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
| | - Alex Chan
- Discipline of Nutrition, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Jonathan S T Woodhead
- 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
| | - Joseph C Reynolds
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, California
| | - Hiroshi Kumagai
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, California
- Japan Society for the Promotion of Science, Tokyo, Japan
- Graduate School of Health and Sports Science, Juntendo University, Chiba, Japan
| | - Su-Jeong Kim
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, California
| | - Changhan Lee
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, California
- University of Southern California Norris Comprehensive Cancer Center, Los Angeles, California
- Biomedical Science, Graduate School, Ajou University, Suwon, South Korea
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9
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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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10
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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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11
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D'Souza RF, Woodhead JST, Zeng N, Blenkiron C, Merry TL, Cameron-Smith D, Mitchell CJ. Circulatory exosomal miRNA following intense exercise is unrelated to muscle and plasma miRNA abundances. Am J Physiol Endocrinol Metab 2018; 315:E723-E733. [PMID: 29969318 DOI: 10.1152/ajpendo.00138.2018] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
MicroRNAs (miRNAs) regulate gene expression via transcript degradation and translational inhibition, and they may also function as long distance signaling molecules. Circulatory miRNAs are either protein-bound or packaged within vesicles (exosomes). Ten young men (24.6 ± 4.0 yr) underwent a single bout of high-intensity interval cycling exercise. Vastus lateralis biopsies and plasma were collected immediately before and after exercise, as well as 4 h following the exercise bout. Twenty-nine miRNAs previously reported to be regulated by acute exercise were assessed within muscle, venous plasma, and enriched circulatory exosomes via qRT-PCR. Of the 29 targeted miRNAs, 11 were altered in muscle, 8 in plasma, and 9 in the exosome fraction. Although changes in muscle and plasma expression were bidirectional, all regulated exosomal miRNAs increased following exercise. Three miRNAs were altered in all three sample pools (miR-1-3p, -16-5p, and -222-3p), three in both muscle and plasma (miR-21-5p, -134-3p, and -107), three in both muscle and exosomes (miR-23a-3p, -208a-3p, and -150-5p), and three in both plasma and exosomes (miR-486-5p, -126-3p, and -378a-5p). There was a marked discrepancy between the observed alterations between sample pools. A subset of exosomal miRNAs increased in abundance following exercise, suggesting an exercise-induced release of exosomes enriched in specific miRNAs. The uniqueness of the exosomal miRNA response suggests its relevance as a sample pool that needs to be further explored in better understanding biological functions.
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Affiliation(s)
| | - Jonathan S T Woodhead
- Discipline of Nutrition, School of Medical Sciences, The University of Auckland , New Zealand
| | - Nina Zeng
- Liggins Institute, The University of Auckland , New Zealand
| | - Cherie Blenkiron
- Department of Molecular Medicine and Pathology, The University of Auckland , New Zealand
- Department of Obstetrics and Gynaeocology, The University of Auckland , New Zealand
| | - Troy L Merry
- Discipline of Nutrition, School of Medical Sciences, The University of Auckland , New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland , New Zealand
| | - David Cameron-Smith
- Liggins Institute, The University of Auckland , New Zealand
- Food & Bio-based Products Group, AgResearch, Palmerston North , New Zealand
- Riddet Institute , Palmerston North , New Zealand
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12
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Broome SC, Woodhead JST, Merry TL. Mitochondria-Targeted Antioxidants and Skeletal Muscle Function. Antioxidants (Basel) 2018; 7:antiox7080107. [PMID: 30096848 PMCID: PMC6116009 DOI: 10.3390/antiox7080107] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 08/06/2018] [Accepted: 08/07/2018] [Indexed: 02/06/2023] Open
Abstract
One of the main sources of reactive oxygen species (ROS) in skeletal muscle is the mitochondria. Prolonged or very high ROS exposure causes oxidative damage, which can be deleterious to muscle function, and as such, there is growing interest in targeting antioxidants to the mitochondria in an effort to prevent or treat muscle dysfunction and damage associated with disease and injury. Paradoxically, however, ROS also act as important signalling molecules in controlling cellular homeostasis, and therefore caution must be taken when supplementing with antioxidants. It is possible that mitochondria-targeted antioxidants may limit oxidative stress without suppressing ROS from non-mitochondrial sources that might be important for cell signalling. Therefore, in this review, we summarise literature relating to the effect of mitochondria-targeted antioxidants on skeletal muscle function. Overall, mitochondria-targeted antioxidants appear to exert beneficial effects on mitochondrial capacity and function, insulin sensitivity and age-related declines in muscle function. However, it seems that this is dependent on the type of mitochondrial-trageted antioxidant employed, and its specific mechanism of action, rather than simply targeting to the mitochondria.
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Affiliation(s)
- Sophie C Broome
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand.
| | - Jonathan S T Woodhead
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand.
| | - Troy L Merry
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand.
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1023, New Zealand.
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