101
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Wong HS, Monternier PA, Brand MD. S1QELs suppress mitochondrial superoxide/hydrogen peroxide production from site I Q without inhibiting reverse electron flow through Complex I. Free Radic Biol Med 2019; 143:545-559. [PMID: 31518685 DOI: 10.1016/j.freeradbiomed.2019.09.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 08/30/2019] [Accepted: 09/09/2019] [Indexed: 12/12/2022]
Abstract
Mitochondria are important sources of superoxide and hydrogen peroxide in cell signaling and disease. In particular, superoxide/hydrogen peroxide production during reverse electron transport from ubiquinol to NAD+ though Complex I is implicated in several physiological and pathological processes. S1QELs are small molecules that suppress superoxide/hydrogen peroxide production at Complex I without affecting forward electron transport. Their mechanism of action is disputed. To test different mechanistic models, we compared the effects of two inhibitors of Complex I electron transport (piericidin A and rotenone) and two S1QELs from different chemical families on superoxide/hydrogen peroxide production and electron transport by Complex I in isolated mitochondria. Piericidin A and rotenone (and S1QEL1.1 at higher concentrations) prevented superoxide/hydrogen peroxide production from sites IQ and IF in Complex I by inhibiting reverse electron transport into the complex. S1QELs decreased the potency of electron transport inhibition by piericidin A and rotenone, suggesting that S1QELs bind directly to Complex I. S1QEL2.1 (and S1QEL1.1 at lower concentrations) suppressed site IQ without affecting reverse electron transport or site IF, showing that sites IQ and IF are distinct, and that S1QELs do not work simply by decreasing reverse electron transport to site IF (or site IQ). S1QELs did not affect the reduction of NAD+ or the rate of site IF driven by reverse electron transport, therefore they do not alter the driving forces for reverse electron transport and that is not how they suppress site IQ. We conclude that S1QELs bind to Complex I to influence the conformation of the piericidin A and rotenone binding sites and directly suppress superoxide/hydrogen peroxide production at site IQ, which is a separate site from site IF.
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Affiliation(s)
- Hoi-Shan Wong
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94945, USA.
| | | | - Martin D Brand
- Buck Institute for Research on Aging, 8001 Redwood Blvd, Novato, CA, 94945, USA.
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102
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Havird JC, Noe GR, Link L, Torres A, Logan DC, Sloan DB, Chicco AJ. Do angiosperms with highly divergent mitochondrial genomes have altered mitochondrial function? Mitochondrion 2019; 49:1-11. [PMID: 31229574 PMCID: PMC6885534 DOI: 10.1016/j.mito.2019.06.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 06/07/2019] [Accepted: 06/17/2019] [Indexed: 02/06/2023]
Abstract
Angiosperm mitochondrial (mt) genes are generally slow-evolving, but multiple lineages have undergone dramatic accelerations in rates of nucleotide substitution and extreme changes in mt genome structure. While molecular evolution in these lineages has been investigated, very little is known about their mt function. Some studies have suggested altered respiration in individual taxa, although there are several reasons why mt variation might be neutral in others. Here, we develop a new protocol to characterize respiration in isolated plant mitochondria and apply it to species of Silene with mt genomes that are rapidly evolving, highly fragmented, and exceptionally large (~11 Mbp). This protocol, complemented with traditional measures of plant fitness, cytochrome c oxidase activity assays, and fluorescence microscopy, was also used to characterize inter- and intraspecific variation in mt function. Contributions of the individual "classic" OXPHOS complexes, the alternative oxidase, and external NADH dehydrogenases to overall mt respiratory flux were found to be similar to previously studied angiosperms with more typical mt genomes. Some differences in mt function could be explained by inter- and intraspecific variation. This study suggests that Silene species with peculiar mt genomes still show relatively normal mt respiration. This may be due to strong purifying selection on mt variants, coevolutionary responses in the nucleus, or a combination of both. Future experiments should explore such questions using a comparative framework and investigating other lineages with unusual mitogenomes.
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Affiliation(s)
- Justin C Havird
- Department of Biology, Colorado State University, Fort Collins, CO, USA; Department of Integrative Biology, The University of Texas, Austin, TX, USA.
| | - Gregory R Noe
- Department of Biology, Colorado State University, Fort Collins, CO, USA
| | - Luke Link
- Department of Biology, Colorado State University, Fort Collins, CO, USA
| | - Amber Torres
- Department of Biology, Colorado State University, Fort Collins, CO, USA.
| | - David C Logan
- IRHS, INRA, Université d'Angers, AGROCAMPUS-Ouest, SFR 4207 QUASAV, 49071 Beaucouzé cedex, France
| | - Daniel B Sloan
- Department of Biology, Colorado State University, Fort Collins, CO, USA.
| | - Adam J Chicco
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
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103
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Munro D, Pamenter ME. Comparative studies of mitochondrial reactive oxygen species in animal longevity: Technical pitfalls and possibilities. Aging Cell 2019; 18:e13009. [PMID: 31322803 PMCID: PMC6718592 DOI: 10.1111/acel.13009] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 06/03/2019] [Accepted: 06/30/2019] [Indexed: 11/30/2022] Open
Abstract
The mitochondrial oxidative theory of aging has been repeatedly investigated over the past 30 years by comparing the efflux of hydrogen peroxide (H2O2) from isolated mitochondria of long‐ and short‐lived species using horseradish peroxidase‐based assays. However, a clear consensus regarding the relationship between H2O2 production rates and longevity has not emerged. Concomitantly, novel insights into the mechanisms of reactive oxygen species (ROS) handling by mitochondria themselves should have raised concerns about the validity of this experimental approach. Here, we review pitfalls of the horseradish peroxidase/amplex red detection system for the measurement of mitochondrial ROS formation rates, with an emphasis on longevity studies. Importantly, antioxidant systems in the mitochondrial matrix are often capable of scavenging H2O2 faster than mitochondria produce it. As a consequence, as much as 84% of the H2O2 produced by mitochondria may be consumed before it diffuses into the reaction medium, where it can be detected by the horseradish peroxidase/amplex red system, this proportion is likely not consistent across species. Furthermore, previous studies often used substrates that elicit H2O2 formation at a much higher rate than in physiological conditions and at sites of secondary importance in vivo. Recent evidence suggests that the activity of matrix antioxidants may correlate with longevity instead of the rate of H2O2 formation. We conclude that past studies have been methodologically insufficient to address the putative relationship between longevity and mitochondrial ROS. Thus, novel methodological approaches are required that more accurately encompass mitochondrial ROS metabolism.
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Affiliation(s)
- Daniel Munro
- Department of Biology University of Ottawa Ottawa Ontario Canada
| | - Matthew E. Pamenter
- Department of Biology University of Ottawa Ottawa Ontario Canada
- University of Ottawa Brain and Mind Research Institute Ottawa Ontario Canada
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104
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Cardioprotective effects of idebenone do not involve ROS scavenging: Evidence for mitochondrial complex I bypass in ischemia/reperfusion injury. J Mol Cell Cardiol 2019; 135:160-171. [DOI: 10.1016/j.yjmcc.2019.08.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 08/20/2019] [Accepted: 08/21/2019] [Indexed: 12/20/2022]
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105
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Scavuzzo CJ, LeBlancq MJ, Nargang F, Lemieux H, Hamilton TJ, Dickson CT. The amnestic agent anisomycin disrupts intrinsic membrane properties of hippocampal neurons via a loss of cellular energetics. J Neurophysiol 2019; 122:1123-1135. [PMID: 31291154 PMCID: PMC6766744 DOI: 10.1152/jn.00370.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/08/2019] [Accepted: 07/08/2019] [Indexed: 12/20/2022] Open
Abstract
The nearly axiomatic idea that de novo protein synthesis is necessary for long-term memory consolidation is based heavily on behavioral studies using translational inhibitors such as anisomycin. Although inhibiting protein synthesis has been shown to disrupt the expression of memory, translational inhibitors also have been found to profoundly disrupt basic neurobiological functions, including the suppression of ongoing neural activity in vivo. In the present study, using transverse hippocampal brain slices, we monitored the passive and active membrane properties of hippocampal CA1 pyramidal neurons using intracellular whole cell recordings during a brief ~30-min exposure to fast-bath-perfused anisomycin. Anisomycin suppressed protein synthesis to 46% of control levels as measured using incorporation of radiolabeled amino acids and autoradiography. During its application, anisomycin caused a significant depolarization of the membrane potential, without any changes in apparent input resistance or membrane time constant. Anisomycin-treated neurons also showed significant decreases in firing frequencies and spike amplitudes, and showed increases in spike width across spike trains, without changes in spike threshold. Because these changes indicated a loss of cellular energetics contributing to maintenance of ionic gradients across the membrane, we confirmed that anisomycin impaired mitochondrial function by reduced staining with 2,3,5-triphenyltetrazolium chloride and also impaired cytochrome c oxidase (complex IV) activity as indicated through high-resolution respirometry. These findings emphasize that anisomycin-induced alterations in neural activity and metabolism are a likely consequence of cell-wide translational inhibition. Critical reevaluation of studies using translational inhibitors to promote the protein synthesis dependent idea of long-term memory is absolutely necessary.NEW & NOTEWORTHY Memory consolidation is thought to be dependent on the synthesis of new proteins because translational inhibitors produce amnesia when administered just after learning. However, these agents also disrupt basic neurobiological functions. We show that blocking protein synthesis disrupts basic membrane properties of hippocampal neurons that correspond to induced disruptions of mitochondrial function. It is likely that translational inhibitors cause amnesia through their disruption of neural activity as a result of dysfunction of intracellular energetics.
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Affiliation(s)
- C. J. Scavuzzo
- Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
| | - M. J. LeBlancq
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - F. Nargang
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - H. Lemieux
- Faculty Saint-Jean, Department of Medicine, Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada
| | - T. J. Hamilton
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Psychology, MacEwan University, Edmonton, Alberta, Canada
| | - C. T. Dickson
- Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
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106
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E6 Oncoproteins from High-Risk Human Papillomavirus Induce Mitochondrial Metabolism in a Head and Neck Squamous Cell Carcinoma Model. Biomolecules 2019; 9:biom9080351. [PMID: 31398842 PMCID: PMC6722992 DOI: 10.3390/biom9080351] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/05/2019] [Accepted: 08/06/2019] [Indexed: 02/07/2023] Open
Abstract
Head and neck squamous cell carcinoma (HNSCC) cells that are positive for human papillomavirus (HPV+) favor mitochondrial metabolism rather than glucose metabolism. However, the involvement of mitochondrial metabolism in HNSCC HPV+ cells is still unknown. The aim of this work was to evaluate the role of E6 oncoproteins from HPV16 and HPV18 in the mitochondrial metabolism in an HNSCC model. We found that E6 from both viral types abates the phosphorylation of protein kinase B-serine 473 (pAkt), which is associated with a shift in mitochondrial metabolism. E6 oncoproteins increased the levels of protein subunits of mitochondrial complexes (I to IV), as well as the ATP synthase and the protein levels of the voltage dependent anion channel (VDAC). Although E6 proteins increased the basal and leak respiration, the ATP-linked respiration was not affected, which resulted in mitochondrial decoupling. This increase in leak respiration was associated to the induction of oxidative stress (OS) in cells expressing E6, as it was observed by the fall in the glutathione/glutathione disulfide (GSH/GSSG) rate and the increase in reactive oxygen species (ROS), carbonylated proteins, and DNA damage. Taken together, our results suggest that E6 oncoproteins from HPV16 and HPV18 are inducers of mitochondrial metabolism.
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107
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Rajendran J, Purhonen J, Tegelberg S, Smolander OP, Mörgelin M, Rozman J, Gailus-Durner V, Fuchs H, Hrabe de Angelis M, Auvinen P, Mervaala E, Jacobs HT, Szibor M, Fellman V, Kallijärvi J. Alternative oxidase-mediated respiration prevents lethal mitochondrial cardiomyopathy. EMBO Mol Med 2019; 11:emmm.201809456. [PMID: 30530468 PMCID: PMC6328925 DOI: 10.15252/emmm.201809456] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Alternative oxidase (AOX) is a non‐mammalian enzyme that can bypass blockade of the complex III‐IV segment of the respiratory chain (RC). We crossed a Ciona intestinalis AOX transgene into RC complex III (cIII)‐deficient Bcs1lp.S78G knock‐in mice, displaying multiple visceral manifestations and premature death. The homozygotes expressing AOX were viable, and their median survival was extended from 210 to 590 days due to permanent prevention of lethal cardiomyopathy. AOX also prevented renal tubular atrophy and cerebral astrogliosis, but not liver disease, growth restriction, or lipodystrophy, suggesting distinct tissue‐specific pathogenetic mechanisms. Assessment of reactive oxygen species (ROS) production and damage suggested that ROS were not instrumental in the rescue. Cardiac mitochondrial ultrastructure, mitochondrial respiration, and pathological transcriptome and metabolome alterations were essentially normalized by AOX, showing that the restored electron flow upstream of cIII was sufficient to prevent cardiac energetic crisis and detrimental decompensation. These findings demonstrate the value of AOX, both as a mechanistic tool and a potential therapeutic strategy, for cIII deficiencies.
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Affiliation(s)
- Jayasimman Rajendran
- Folkhälsan Research Center, Helsinki, Finland.,Clinicum, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Janne Purhonen
- Folkhälsan Research Center, Helsinki, Finland.,Clinicum, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Saara Tegelberg
- Folkhälsan Research Center, Helsinki, Finland.,Department of Clinical Sciences, Lund, Pediatrics, Lund University, Lund, Sweden.,Molecular Neurology Research Program and Neuroscience Center, University of Helsinki, Helsinki, Finland
| | | | - Matthias Mörgelin
- Division of Infection Medicine, Clinical Sciences, Lund University, Lund, Sweden
| | - Jan Rozman
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Valerie Gailus-Durner
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Helmut Fuchs
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Martin Hrabe de Angelis
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany.,Chair of Experimental Genetics, Center of Life and Food Sciences Weihenstephan, TU Munich, Freising-Weihenstephan, Germany
| | - Petri Auvinen
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Eero Mervaala
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Howard T Jacobs
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland.,Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
| | - Marten Szibor
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland.,Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland
| | - Vineta Fellman
- Folkhälsan Research Center, Helsinki, Finland.,Department of Clinical Sciences, Lund, Pediatrics, Lund University, Lund, Sweden.,Children's Hospital, Helsinki University Hospital, University of Helsinki, Helsinki, Finland
| | - Jukka Kallijärvi
- Folkhälsan Research Center, Helsinki, Finland .,Clinicum, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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108
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Ibrahim M, Mendis N, Roma A, Jayanth P, Minden MD, Spagnuolo PA. Anti-leukemia effect of vitamin K3 is mediated through mitochondrial complexes I and II. Leuk Lymphoma 2019; 60:3071-3074. [PMID: 31164029 DOI: 10.1080/10428194.2019.1620940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Medhat Ibrahim
- Department of Food Science, University of Guelph, Guelph, Canada
| | - Nilmini Mendis
- Department of Food Science, University of Guelph, Guelph, Canada
| | - Alessia Roma
- Department of Food Science, University of Guelph, Guelph, Canada
| | - Preethi Jayanth
- Department of Food Science, University of Guelph, Guelph, Canada
| | - Mark D Minden
- Princess Margaret Cancer Center, Ontario Cancer Institute, Toronto, Canada
| | - Paul A Spagnuolo
- Department of Food Science, University of Guelph, Guelph, Canada
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109
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Koning G, Leverin AL, Nair S, Schwendimann L, Ek J, Carlsson Y, Gressens P, Thornton C, Wang X, Mallard C, Hagberg H. Magnesium induces preconditioning of the neonatal brain via profound mitochondrial protection. J Cereb Blood Flow Metab 2019; 39:1038-1055. [PMID: 29206066 PMCID: PMC6547197 DOI: 10.1177/0271678x17746132] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 10/12/2017] [Accepted: 11/06/2017] [Indexed: 12/11/2022]
Abstract
Magnesium sulphate (MgSO4) given to women in preterm labor reduces cerebral palsy in their offspring but the mechanism behind this protection is unclear, limiting its effective, safe clinical implementation. Previous studies suggest that MgSO4 is not neuroprotective if administered during or after the insult, so we hypothesised that MgSO4 induces preconditioning in the immature brain. Therefore, we administered MgSO4 at various time-points before/after unilateral hypoxia-ischemia (HI) in seven-day-old rats. We found that MgSO4 treatment administered as a bolus between 6 days and 12 h prior to HI markedly reduced the brain injury, with maximal protection achieved by 1.1 mg/g MgSO4 administered 24 h before HI. As serum magnesium levels returned to baseline before the induction of HI, we ascribed this reduction in brain injury to preconditioning. Cerebral blood flow was unaffected, but mRNAs/miRNAs involved in mitochondrial function and metabolism were modulated by MgSO4. Metabolomic analysis (H+-NMR) disclosed that MgSO4 attenuated HI-induced increases in succinate and prevented depletion of high-energy phosphates. MgSO4 pretreatment preserved mitochondrial respiration, reducing ROS production and inflammation after HI. Therefore, we propose that MgSO4 evokes preconditioning via induction of mitochondrial resistance and attenuation of inflammation.
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Affiliation(s)
- Gabriella Koning
- Perinatal Center, Institute of
Neuroscience and Physiology, Sahlgrenska Academy, Gothenburg University, Gothenburg,
Sweden
| | - Anna-Lena Leverin
- Perinatal Center, Institute of
Neuroscience and Physiology, Sahlgrenska Academy, Gothenburg University, Gothenburg,
Sweden
| | - Syam Nair
- Perinatal Center, Institute of
Neuroscience and Physiology, Sahlgrenska Academy, Gothenburg University, Gothenburg,
Sweden
| | - Leslie Schwendimann
- PROTECT, INSERM, Université Paris
Diderot, Sorbonne Paris Cité, Paris, France
| | - Joakim Ek
- Perinatal Center, Institute of
Neuroscience and Physiology, Sahlgrenska Academy, Gothenburg University, Gothenburg,
Sweden
| | - Ylva Carlsson
- Perinatal Center, Department of Clinical
Sciences, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden
| | - Pierre Gressens
- PROTECT, INSERM, Université Paris
Diderot, Sorbonne Paris Cité, Paris, France
- Centre for the Developing Brain,
Department of Perinatal Imaging and Health, King's College London, London, UK
| | - Claire Thornton
- Centre for the Developing Brain,
Department of Perinatal Imaging and Health, King's College London, London, UK
| | - Xiaoyang Wang
- Perinatal Center, Institute of
Neuroscience and Physiology, Sahlgrenska Academy, Gothenburg University, Gothenburg,
Sweden
| | - Carina Mallard
- Perinatal Center, Institute of
Neuroscience and Physiology, Sahlgrenska Academy, Gothenburg University, Gothenburg,
Sweden
| | - Henrik Hagberg
- Perinatal Center, Institute of
Neuroscience and Physiology, Sahlgrenska Academy, Gothenburg University, Gothenburg,
Sweden
- Perinatal Center, Department of Clinical
Sciences, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden
- Centre for the Developing Brain,
Department of Perinatal Imaging and Health, King's College London, London, UK
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110
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Warburg-like effect is a hallmark of complex I assembly defects. Biochim Biophys Acta Mol Basis Dis 2019; 1865:2475-2489. [PMID: 31121247 DOI: 10.1016/j.bbadis.2019.05.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 05/13/2019] [Accepted: 05/15/2019] [Indexed: 01/17/2023]
Abstract
Due to its pivotal role in NADH oxidation and ATP synthesis, mitochondrial complex I (CI) emerged as a crucial regulator of cellular metabolism. A functional CI relies on the sequential assembly of nuclear- and mtDNA-encoded subunits; however, whether CI assembly status is involved in the metabolic adaptations in CI deficiency still remains largely unknown. Here, we investigated the relationship between CI functions, its structure and the cellular metabolism in 29 patient fibroblasts representative of most CI mitochondrial diseases. Our results show that, contrary to the generally accepted view, a complex I deficiency does not necessarily lead to a glycolytic switch, i.e. the so-called Warburg effect, but that this particular metabolic adaptation is a feature of CI assembly defect. By contrast, a CI functional defect without disassembly induces a higher catabolism to sustain the oxidative metabolism. Mechanistically, we demonstrate that reactive oxygen species overproduction by CI assembly intermediates and subsequent AMPK-dependent Pyruvate Dehydrogenase inactivation are key players of this metabolic reprogramming. Thus, this study provides a two-way-model of metabolic responses to CI deficiencies that are central not only in defining therapeutic strategies for mitochondrial diseases, but also in all pathophysiological conditions involving a CI deficiency.
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111
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Experimental evidence that maleic acid markedly compromises glutamate oxidation through inhibition of glutamate dehydrogenase and α-ketoglutarate dehydrogenase activities in kidney of developing rats. Mol Cell Biochem 2019; 458:99-112. [DOI: 10.1007/s11010-019-03534-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 04/10/2019] [Indexed: 12/12/2022]
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112
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Iannetti EF, Prigione A, Smeitink JAM, Koopman WJH, Beyrath J, Renkema H. Live-Imaging Readouts and Cell Models for Phenotypic Profiling of Mitochondrial Function. Front Genet 2019; 10:131. [PMID: 30881379 PMCID: PMC6405630 DOI: 10.3389/fgene.2019.00131] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 02/06/2019] [Indexed: 12/16/2022] Open
Abstract
Mitochondria are best known as the powerhouses of the cells but their cellular role goes far beyond energy production; among others, they have a pivotal function in cellular calcium and redox homeostasis. Mitochondrial dysfunction is often associated with severe and relatively rare disorders with an unmet therapeutic need. Given their central integrating role in multiple cellular pathways, mitochondrial dysfunction is also relevant in the pathogenesis of various other, more common, human pathologies. Here we discuss how live-cell high content microscopy can be used for image-based phenotypic profiling to assess mitochondrial (dys) function. From this perspective, we discuss a selection of live-cell fluorescent reporters and imaging strategies and discuss the pros/cons of human cell models in mitochondrial research. We also present an overview of live-cell high content microscopy applications used to detect disease-associated cellular phenotypes and perform cell-based drug screening.
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Affiliation(s)
- Eligio F. Iannetti
- Khondrion BV, Nijmegen, Netherlands
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Jan A. M. Smeitink
- Khondrion BV, Nijmegen, Netherlands
- Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, Netherlands
| | - Werner J. H. Koopman
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
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113
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High-resolution respirometry in human endomyocardial biopsies shows reduced ventricular oxidative capacity related to heart failure. Exp Mol Med 2019; 51:1-10. [PMID: 30765687 PMCID: PMC6376010 DOI: 10.1038/s12276-019-0214-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 08/17/2018] [Accepted: 10/01/2018] [Indexed: 02/07/2023] Open
Abstract
The lifetime risk of developing heart failure is approximately 20%, and survival rates remain poor. Myocardial mitochondrial function has been suggested to play a pivotal role in heart failure pathophysiology. Human studies on ex vivo mitochondrial function have mostly been limited to atrial tissue obtained during open heart surgery and have provided contradictory results. This study aimed at measuring myocardial mitochondrial function in transcatheter ventricular endomyocardial biopsies and assessing the relationship between oxidative capacity and heart function. We enrolled 40 heart failure patients undergoing ventricular assist device surgery or heart transplantation (34 males, age 57 ± 11 years, body mass index 26.6 ± 4.8 kg/m2) and 29 heart transplant recipients of comparable age and body mass index with normal left ventricular function undergoing surveillance biopsies (23 males, 57 ± 12 years, body mass index 26.2 ± 4.1 kg/m2). High-resolution respirometry was established in the myocardium to measure oxidative capacity ex vivo. The mitochondrial oxidative capacity was 90% higher in ventricular compared to atrial tissues (n = 11, p < 0.01) of explanted hearts. Respiration rates were comparable in ventricular samples of heart failure patients obtained during open heart surgery by standard tissue preparation or ex vivo endomyocardial biopsy (r = 0.9988, p < 0.0001, n = 8), and the mitochondrial oxidative capacity in samples from these patients remained stable for 8 h when stored in either of two common preservation buffers. The oxidative capacity was 44% lower in heart failure than in transplant recipients (67 ± 3 vs. 97 ± 5 pmol/[s mg], p < 0.0001) and correlated positively with heart function (r = 0.49, p < 0.01). High-resolution respirometry of ventricular tissue is feasible in transcatheter biopsies, facilitating clinical studies on myocardial mitochondrial function in patients not undergoing heart surgery. The capacity of mitochondria in heart muscle cells to use oxygen to produce energy correlates with cardiac function. Julia Szendroedi at Heinrich-Heine University, Düsseldorf, Germany, and colleagues have established a technique to reliably evaluate mitochondrial energy metabolism in patients with or recovering from heart failure. They showed that the mitochondrial oxidative capacity of cells in the lower heart chambers (ventricles) was significantly higher than in the upper heart chambers (atria). Moreover, they found that mitochondrial oxidative capacity was reduced by 44% in heart muscle biopsies from patients with heart failure compared with biopsies from heart transplant recipients with normal ventricular function. Stimulating the respiration rate of mitochondria in ventricular heart cells could be a promising strategy for improving cardiac function.
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114
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Olean-Oliveira A, Olean-Oliveira T, Moreno ACR, Seraphim PM, Teixeira MFS. A Chemiresistor Sensor Based on Azo-Polymer and Graphene for Real-Time Monitoring of Mitochondrial Oxygen Consumption. ACS Sens 2019; 4:118-125. [PMID: 30474369 DOI: 10.1021/acssensors.8b01013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In the present study, a chemiresistor sensor based on a poly(Bismarck Brown Y)-reduced graphene oxide nanocomposite was developed to analyze the respiratory capacity of the constituent complexes of the electron transport chain. The sensorial platform was characterized using electrochemical impedance spectroscopy, and oxygen detection was accomplished by measuring the resistive properties of the sensor at fixed AC frequency. The impedance decreased significantly in response to small variations of the O2 concentrations tested up to saturation of the electrolyte solution with molecular oxygen. The resistive response of the sensor at 0.1 Hz was linear over the oxygen concentration range from 1.17 × 10-5 mol L-1 to 1.02 × 10-3 mol L-1, with a detection limit of 3.60 × 10-7 mol L-1. Using the new O2 sensing platform, we monitored gradients in static cultures of adherent cells exposed to graded oxygen both at rest and upon metabolic stimulation. Under high dissolved oxygen conditions, the respiration of resting cells dictated that local O2 was moderately reduced, while cell metabolic stimulation triggered a major redistribution of O2. The usefulness of the developed sensor was demonstrated by continuous monitoring of mitochondrial oxygen consumption in various biologic applications.
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115
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Musi N, Valentine JM, Sickora KR, Baeuerle E, Thompson CS, Shen Q, Orr ME. Tau protein aggregation is associated with cellular senescence in the brain. Aging Cell 2018; 17:e12840. [PMID: 30126037 PMCID: PMC6260915 DOI: 10.1111/acel.12840] [Citation(s) in RCA: 342] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 08/12/2018] [Accepted: 08/15/2018] [Indexed: 12/11/2022] Open
Abstract
Tau protein accumulation is the most common pathology among degenerative brain diseases, including Alzheimer's disease (AD), progressive supranuclear palsy (PSP), traumatic brain injury (TBI), and over twenty others. Tau-containing neurofibrillary tangle (NFT) accumulation is the closest correlate with cognitive decline and cell loss (Arriagada, Growdon, Hedley-Whyte, & Hyman, ), yet mechanisms mediating tau toxicity are poorly understood. NFT formation does not induce apoptosis (de Calignon, Spires-Jones, Pitstick, Carlson, & Hyman, 2009), which suggests that secondary mechanisms are driving toxicity. Transcriptomic analyses of NFT-containing neurons microdissected from postmortem AD brain revealed an expression profile consistent with cellular senescence. This complex stress response induces aberrant cell cycle activity, adaptations to maintain survival, cellular remodeling, and metabolic dysfunction. Using four AD transgenic mouse models, we found that NFTs, but not Aβ plaques, display a senescence-like phenotype. Cdkn2a transcript level, a hallmark measure of senescence, directly correlated with brain atrophy and NFT burden in mice. This relationship extended to postmortem brain tissue from humans with PSP to indicate a phenomenon common to tau toxicity. Tau transgenic mice with late-stage pathology were treated with senolytics to remove senescent cells. Despite the advanced age and disease progression, MRI brain imaging and histopathological analyses indicated a reduction in total NFT density, neuron loss, and ventricular enlargement. Collectively, these findings indicate a strong association between the presence of NFTs and cellular senescence in the brain, which contributes to neurodegeneration. Given the prevalence of tau protein deposition among neurodegenerative diseases, these findings have broad implications for understanding, and potentially treating, dozens of brain diseases.
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Affiliation(s)
- Nicolas Musi
- Barshop Institute for Longevity and Aging StudiesUniversity of Texas Health Science Center at San AntonioSan AntonioTexas
- San Antonio Geriatric ResearchEducation and Clinical CenterSouth Texas Veterans Health Care SystemSan AntonioTexas
- Glenn Biggs Institute for Alzheimer’s & Neurodegenerative DiseasesSan AntonioTexas
| | - Joseph M. Valentine
- Barshop Institute for Longevity and Aging StudiesUniversity of Texas Health Science Center at San AntonioSan AntonioTexas
| | - Kathryn R. Sickora
- Barshop Institute for Longevity and Aging StudiesUniversity of Texas Health Science Center at San AntonioSan AntonioTexas
| | - Eric Baeuerle
- Barshop Institute for Longevity and Aging StudiesUniversity of Texas Health Science Center at San AntonioSan AntonioTexas
| | - Cody S. Thompson
- Barshop Institute for Longevity and Aging StudiesUniversity of Texas Health Science Center at San AntonioSan AntonioTexas
| | - Qiang Shen
- Research Imaging InstituteUniversity of Texas Health Science Center San AntonioSan AntonioTexas
| | - Miranda E. Orr
- Barshop Institute for Longevity and Aging StudiesUniversity of Texas Health Science Center at San AntonioSan AntonioTexas
- San Antonio Geriatric ResearchEducation and Clinical CenterSouth Texas Veterans Health Care SystemSan AntonioTexas
- Glenn Biggs Institute for Alzheimer’s & Neurodegenerative DiseasesSan AntonioTexas
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116
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Vázquez-Cervantesa GI, Villaseñor-Aguayoa K, Hernández-Damiána J, Aparicio-Trejoa OE, Medina-Camposa ON, López-Marureb R, Pedraza-Chaverria J. Antitumor Effects of Nordihydroguaiaretic Acid (NDGA) in Bladder T24 Cancer Cells are Related to Increase in ROS Production and Mitochondrial Leak Respiration. Nat Prod Commun 2018. [DOI: 10.1177/1934578x1801301128] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The aim of this study was to evaluate the effect of nordihydroguaiaretic acid (NDGA) on tumor bladder T24 cells. Bladder cancer T24 cells were cultured on Dulbecco's Modified Eagle Medium in presence of NDGA. Cell viability and apoptosis were evaluated after 24, 48 and 72 h by using fluorescein diacetate (FDA) and Alexa fluor 488 annexin-V/propidium iodide solution, respectively. To determine the mitochondrial effects of NDGA (0-24 h), reactive oxygen species (ROS) levels by dihydroethidium fluorescence, mitochondrial membrane potential (ΔΨm) by 5,5’,6,6'-tetrachloro-1,1’,3,3'-tetraethyl-imidacarbocyanine iodide (JC-1) dual fluorescence and cellular respiration states by high resolution respirometry were evaluated. It was found that NDGA reduced T24 cell viability after 72 h of incubation in a concentration-dependent manner and apoptosis increased at 48 h. Furthermore, 20 μM NDGA increased ROS levels, decreased ΔΨm and promoted leak of respiration from mitochondrial respiratory chain in T24 cells which was associated to the death of tumor cells. Taken together these results suggested that antitumor effects of NDGA in T24 cells are related to its ability to induce mitochondrial alteration.
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Affiliation(s)
- Gustavo Ignacio Vázquez-Cervantesa
- Department of Biology, Faculty of Chemistry, National Autonomous University of Mexico (UNAM), Mexico City, 04510, Mexico
- Physiology Department (Cell Biology), National Institute of Cardiology “Ignacio Chávez”, Mexico City 14080, Mexico
| | - Karla Villaseñor-Aguayoa
- Department of Biology, Faculty of Chemistry, National Autonomous University of Mexico (UNAM), Mexico City, 04510, Mexico
- Physiology Department (Cell Biology), National Institute of Cardiology “Ignacio Chávez”, Mexico City 14080, Mexico
| | - Jacqueline Hernández-Damiána
- Department of Biology, Faculty of Chemistry, National Autonomous University of Mexico (UNAM), Mexico City, 04510, Mexico
- Physiology Department (Cell Biology), National Institute of Cardiology “Ignacio Chávez”, Mexico City 14080, Mexico
| | - Omar Emiliano Aparicio-Trejoa
- Department of Biology, Faculty of Chemistry, National Autonomous University of Mexico (UNAM), Mexico City, 04510, Mexico
- Physiology Department (Cell Biology), National Institute of Cardiology “Ignacio Chávez”, Mexico City 14080, Mexico
| | - Omar Noel Medina-Camposa
- Department of Biology, Faculty of Chemistry, National Autonomous University of Mexico (UNAM), Mexico City, 04510, Mexico
- Physiology Department (Cell Biology), National Institute of Cardiology “Ignacio Chávez”, Mexico City 14080, Mexico
| | - Rebeca López-Marureb
- Department of Biology, Faculty of Chemistry, National Autonomous University of Mexico (UNAM), Mexico City, 04510, Mexico
- Physiology Department (Cell Biology), National Institute of Cardiology “Ignacio Chávez”, Mexico City 14080, Mexico
| | - José Pedraza-Chaverria
- Department of Biology, Faculty of Chemistry, National Autonomous University of Mexico (UNAM), Mexico City, 04510, Mexico
- Physiology Department (Cell Biology), National Institute of Cardiology “Ignacio Chávez”, Mexico City 14080, Mexico
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Gonçalves DF, Courtes AA, Hartmann DD, da Rosa PC, Oliveira DM, Soares FAA, Dalla Corte CL. 6-Hydroxydopamine induces different mitochondrial bioenergetics response in brain regions of rat. Neurotoxicology 2018; 70:1-11. [PMID: 30359634 DOI: 10.1016/j.neuro.2018.10.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 10/07/2018] [Accepted: 10/10/2018] [Indexed: 11/30/2022]
Abstract
Mitochondrial dysfunction has been demonstrated to have a central role in Parkinson Disease (PD) pathophysiology. Some studies have indicated that PD causes an impairment in mitochondrial bioenergetics; however, the effects of PD on brain-region specific bioenergetics was never investigated before. This study aimed to evaluate mitochondrial bioenergetics in different rat brain structures in an in vitro model of PD using 6-OHDA. Rat brain slices of hippocampus, striatum, and cortex were exposed to 6-OHDA (100 μM) for 1 h and mitochondrial bioenergetic parameters, peroxide production, lactate dehydrogenase (LDH) and citrate synthase (CS) activities were analyzed. Hippocampus slices exposed to 6-OHDA presented increased peroxide production but, no mitochondrial adaptive response against 6-OHDA damage. Cortex slices exposed to 6-OHDA presented increased oxygen flux related to oxidative phosphorylation and energetic pathways exchange demonstrated by the increase in LDH activity, suggesting a mitochondrial compensatory response. Striatum slices exposed to 6-OHDA presented a decrease of oxidative phosphorylation and decrease of oxygen flux related to ATP-synthase indicating an impairment in the respiratory chain. The co-incubation of 6-OHDA with n-acetylcysteine (NAC) abolished the effects of 6-OHDA on mitochondrial function in all brain regions tested, indicating that the increased reactive oxygen species (ROS) production is responsible for the alterations observed in mitochondrial bioenergetics. The present results indicate a brain-region specific response against 6-OHDA, providing new insights into brain mitochondrial bioenergetic function in PD. These findings may contribute to the development of future therapies with a target on energy metabolism.
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Affiliation(s)
- Débora F Gonçalves
- Universidade Federal de Santa Maria, Centro de Ciências Naturais e Exatas, Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Camobi, 97105-900, Santa Maria, RS, Brazil
| | - Aline A Courtes
- Universidade Federal de Santa Maria, Centro de Ciências Naturais e Exatas, Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Camobi, 97105-900, Santa Maria, RS, Brazil
| | - Diane D Hartmann
- Universidade Federal de Santa Maria, Centro de Ciências Naturais e Exatas, Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Camobi, 97105-900, Santa Maria, RS, Brazil
| | - Pamela C da Rosa
- Universidade Federal de Santa Maria, Centro de Ciências Naturais e Exatas, Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Camobi, 97105-900, Santa Maria, RS, Brazil
| | - Débora M Oliveira
- Universidade Federal de Santa Maria, Centro de Ciências Naturais e Exatas, Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Camobi, 97105-900, Santa Maria, RS, Brazil
| | - Félix A A Soares
- Universidade Federal de Santa Maria, Centro de Ciências Naturais e Exatas, Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Camobi, 97105-900, Santa Maria, RS, Brazil
| | - Cristiane L Dalla Corte
- Universidade Federal de Santa Maria, Centro de Ciências Naturais e Exatas, Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Camobi, 97105-900, Santa Maria, RS, Brazil; Universidade Federal do Pampa - Campus Caçapava do Sul, 96570-000, Caçapava do Sul, RS, Brazil.
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118
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Audi SH, Friedly N, Dash RK, Beyer AM, Clough AV, Jacobs ER. Detection of hydrogen peroxide production in the isolated rat lung using Amplex red. Free Radic Res 2018; 52:1052-1062. [PMID: 30175632 DOI: 10.1080/10715762.2018.1511051] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The objectives of this study were to develop a robust protocol to measure the rate of hydrogen peroxide (H2O2) production in isolated perfused rat lungs, as an index of oxidative stress, and to determine the cellular sources of the measured H2O2 using the extracellular probe Amplex red (AR). AR was added to the recirculating perfusate in an isolated perfused rat lung. AR's highly fluorescent oxidation product resorufin was measured in the perfusate. Experiments were carried out without and with rotenone (complex I inhibitor), thenoyltrifluoroacetone (complex II inhibitor), antimycin A (complex III inhibitor), potassium cyanide (complex IV inhibitor), or diohenylene iodonium (inhibitor of flavin-containing enzymes, e.g. NAD(P)H oxidase or NOX) added to the perfusate. We also evaluated the effect of acute changes in oxygen (O2) concentration of ventilation gas on lung rate of H2O2 release into the perfusate. Baseline lung rate of H2O2 release was 8.45 ± 0.31 (SEM) nmol/min/g dry wt. Inhibiting mitochondrial complex II reduced this rate by 76%, and inhibiting flavin-containing enzymes reduced it by another 23%. Inhibiting complex I had a small (13%) effect on the rate, whereas inhibiting complex III had no effect. Inhibiting complex IV increased this rate by 310%. Increasing %O2 in the ventilation gas mixture from 15 to 95% had a small (27%) effect on this rate, and this O2-dependent increase was mostly nonmitochondrial. Results suggest complex II as a potentially important source and/or regulator of mitochondrial H2O2, and that most of acute hyperoxia-enhanced lung rate of H2O2 release is from nonmitochondrial rather than mitochondrial sources.
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Affiliation(s)
- Said H Audi
- a Medical College of Wisconsin Department of Biomedical Engineering , Marquette University , Milwaukee , WI , USA.,c Division of Pulmonary and Critical Care Medicine , Medical College of Wisconsin , Milwaukee, WI , USA
| | - Nina Friedly
- a Medical College of Wisconsin Department of Biomedical Engineering , Marquette University , Milwaukee , WI , USA
| | - Ranjan K Dash
- a Medical College of Wisconsin Department of Biomedical Engineering , Marquette University , Milwaukee , WI , USA
| | - Andreas M Beyer
- d Department of Medicine , Medical College of Wisconsin , Milwaukee, WI , USA
| | - Anne V Clough
- e Department of Mathematics, Statistics, and Computer Science , Marquette University , Milwaukee , WI , USA
| | - Elizabeth R Jacobs
- b Zablocki VA Medical Center , Milwaukee, WI , USA.,c Division of Pulmonary and Critical Care Medicine , Medical College of Wisconsin , Milwaukee, WI , USA
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119
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Ost M, Doerrier C, Gama-Perez P, Moreno-Gomez S. Analysis of mitochondrial respiratory function in tissue biopsies and blood cells. Curr Opin Clin Nutr Metab Care 2018; 21:336-342. [PMID: 29939971 DOI: 10.1097/mco.0000000000000486] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW The review provides an overview on latest methodological strategies to assess mitochondrial respiratory function in tissue biopsies or blood cells. In addition, it summarizes the recent literature related to this topic. RECENT FINDINGS Today, the study of mitochondrial function in key metabolic active tissues has been become more relevant, with increasing focus in clinical applications. In addition, assessment of mitochondrial function in blood cells by respirometry might be a sensitive biomarker of disease progression. High-Resolution Respirometry provides a modern tool to study mitochondrial respiratory physiology which allows direct measurement of cellular metabolic function during health and disease. Moreover, standard operating procedures are required regarding instrumental settings, sample collection and preparation, protocol design and respirometric data analysis of mitochondrial respiratory function in tissue biopsies (such as skeletal muscle, liver and adipose tissue), as well as isolated blood cells. SUMMARY Mitochondrial function is a key factor in many metabolic diseases. Although various analytical approaches are available, certain well-established protocols for isolated mitochondria are limited for the analysis of mitochondrial function in tissue biopsies or blood cells. Thus, cautious considerations in selecting appropriate protocols and analytical endpoints are crucial for the interpretation of the gained data and to draw robust conclusions.
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Affiliation(s)
- Mario Ost
- Department of Physiology of Energy Metabolism, German Institute of Human Nutrition Potsdam-Rehbrücke, Nuthetal, Germany
| | | | - Pau Gama-Perez
- Department of Physiological Sciences, University of Barcelona, Barcelona, Spain
| | - Sonia Moreno-Gomez
- Department of Physiological Sciences, University of Barcelona, Barcelona, Spain
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120
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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] [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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121
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Cooper MA, McCoin C, Pei D, Thyfault JP, Koestler D, Wright DE. Reduced mitochondrial reactive oxygen species production in peripheral nerves of mice fed a ketogenic diet. Exp Physiol 2018; 103:1206-1212. [PMID: 30088302 DOI: 10.1113/ep087083] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 07/20/2018] [Indexed: 12/13/2022]
Abstract
NEW FINDINGS What is the central question of this study? Do peripheral sensory neurons metabolize fat-based fuel sources, and does a ketogenic diet modify these processes? What is the main finding and its importance We show that peripheral axons from mice fed a ketogenic diet respond to fat-based fuel sources with reduced respiration and H2 O2 emission compared with mice fed a control diet. These results add to our understanding of the responses of sensory neurons to neuropathy associated with poor diet, obesity and metabolic syndrome. These findings should be incorporated into current ideas of axonal protection and might identify how dietary interventions may change mitochondrial function in settings of sensory dysfunction. ABSTRACT Metabolic syndrome and obesity are increasing epidemics that significantly impact the peripheral nervous system and lead to negative changes in sensation and peripheral nerve function. Research to understand the consequences of diet, obesity and fuel usage in sensory neurons has commonly focused on glucose metabolism. Here, we tested whether mouse sensory neurons and nerves have the capacity to metabolize fat-based fuels (palmitoyl-CoA) and whether these effects are altered by feeding of a ketogenic (90% kcal fat) diet compared with a control diet (14% kcal fat). Male C57Bl/6 mice were placed on the diets for 10 weeks, and after the mice were killed, the dorsal root ganglion (DRG) and sciatic nerve (SN) were placed in an Oroboros oxygraph-2K to examine diet-induced alterations in metabolism (respiration) of palmitoyl-CoA and H2 O2 emission (fluorescence). In addition, RNAseq was performed on the DRG of mice fed a control or a ketogenic diet for 12 weeks, and genes associated with mitochondrial respiratory function were analysed. Our results suggest that the sciatic nerves from mice fed a ketogenic diet display reduced O2 respiration and H2 O2 emission when metabolizing palmitoyl-CoA compared with mice fed a control diet. Assessments of changes in mRNA gene expression reveal alterations in genes encoding the NADH dehydrogenase complex and complex IV, which could alter production of reactive oxygen species. These new findings highlight the ability of sensory neurons and axons to oxidize fat-based fuel sources and show that these mechanisms are adaptable to dietary changes.
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Affiliation(s)
- Michael A Cooper
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Colin McCoin
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Dong Pei
- Department of Biostatistics, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - John P Thyfault
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Devin Koestler
- Department of Biostatistics, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Douglas E Wright
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
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Zhang L, Hao J, Zheng Y, Su R, Liao Y, Gong X, Liu L, Wang X. Fucoidan Protects Dopaminergic Neurons by Enhancing the Mitochondrial Function in a Rotenone-induced Rat Model of Parkinson's Disease. Aging Dis 2018; 9:590-604. [PMID: 30090649 PMCID: PMC6065300 DOI: 10.14336/ad.2017.0831] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 08/31/2017] [Indexed: 12/21/2022] Open
Abstract
The mitochondrion is susceptible to neurodegenerative disorders such as Parkinson’s disease (PD). Mitochondrial dysfunction has been considered to play an important role in the dopaminergic degeneration in PD. However, there are no effective drugs to protect mitochondria from dysfunction during the disease development. In the present study, fucoidan, a sulfated polysaccharide derived from Laminaria japonica, was investigated and characterized for its protective effect on the dopamine system and mitochondrial function of dopaminergic neurons in a rotenone-induced rat model of PD. We found that chronic treatment with fucoidan significantly reversed the loss of nigral dopaminergic neurons and striatal dopaminergic fibers and the reduction of striatal dopamine levels in PD rats. Fucoidan also alleviated rotenone-induced behavioral deficits. Moreover, the mitochondrial respiratory function as detected by the mitochondrial oxygen consumption and the expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and nuclear transcription factor 2 (NRF2) were reduced in the substantia nigra of PD rats, which were markedly reversed by fucoidan. Oxidative products induced by rotenone were significantly reduced by fucoidan. Taken together, these results demonstrate that fucoidan possesses the ability to protect the dopamine system in PD rats. The neuroprotective effect of fucoidan may be mediated via reserving mitochondrial function involving the PGC-1α/NRF2 pathway. This study provides new evidence that fucoidan can be explored in PD therapy.
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Affiliation(s)
- Li Zhang
- 1Department of Neurobiology.,3Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Junwei Hao
- 1Department of Neurobiology.,3Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Yan Zheng
- 2Department of Physiology.,3Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Ruijun Su
- 1Department of Neurobiology.,3Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Yajin Liao
- 4The Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing 100039, China
| | - Xiaoli Gong
- 2Department of Physiology.,3Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Limin Liu
- 2Department of Physiology.,3Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Capital Medical University, Beijing 100069, China
| | - Xiaomin Wang
- 1Department of Neurobiology.,3Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Capital Medical University, Beijing 100069, China.,5 Beijing Institute for Brain Disorders, Beijing 100069, China
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Adverse Outcome Prediction of Iron Deficiency in Patients with Acute Coronary Syndrome. Biomolecules 2018; 8:biom8030060. [PMID: 30037035 PMCID: PMC6163749 DOI: 10.3390/biom8030060] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/09/2018] [Accepted: 07/16/2018] [Indexed: 02/08/2023] Open
Abstract
Acute myocardial infarction remains a leading cause of morbidity and mortality. While iron deficient heart failure patients are at increased risk of future cardiovascular events and see improvement with intravenous supplementation, the clinical relevance of iron deficiency in acute coronary syndrome remains unclear. We aimed to evaluate the prognostic value of iron deficiency in the acute coronary syndrome (ACS). Levels of ferritin, iron, and transferrin were measured at baseline in 836 patients with ACS. A total of 29.1% was categorized as iron deficient. The prevalence of iron deficiency was clearly higher in women (42.8%), and in patients with anemia (42.5%). During a median follow-up of 4.0 years, 111 subjects (13.3%) experienced non-fatal myocardial infarction (MI) and cardiovascular mortality as combined endpoint. Iron deficiency strongly predicted non-fatal MI and cardiovascular mortality with a hazard ratio (HR) of 1.52 (95% confidence interval (CI) 1.03-2.26; p = 0.037) adjusted for age, sex, hypertension, smoking status, diabetes, hyperlipidemia, body-mass-index (BMI) This association remained significant (HR 1.73 (95% CI 1.07⁻2.81; p = 0.026)) after an additional adjustment for surrogates of cardiac function and heart failure severity (N-terminal pro B-type natriuretic peptide, NT-proBNP), for the size of myocardial necrosis (troponin), and for anemia (hemoglobin). Survival analyses for cardiovascular mortality and MI provided further evidence for the prognostic relevance of iron deficiency (HR 1.50 (95% CI 1.02⁻2.20)). Our data showed that iron deficiency is strongly associated with adverse outcome in acute coronary syndrome.
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Mitochondrial bioenergetics, redox state, dynamics and turnover alterations in renal mass reduction models of chronic kidney diseases and their possible implications in the progression of this illness. Pharmacol Res 2018; 135:1-11. [PMID: 30030169 DOI: 10.1016/j.phrs.2018.07.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/10/2018] [Accepted: 07/16/2018] [Indexed: 01/13/2023]
Abstract
Nowadays, chronic kidney disease (CKD) is considered a worldwide public health problem. CKD is a term used to describe a set of pathologies that structurally and functionally affect the kidney, it is mostly characterized by the progressive loss of kidney function. Current therapeutic approaches are insufficient to avoid the development of this disease, which highlights the necessity of developing new strategies to reverse or at least delay CKD progression. Kidney is highly dependent on mitochondrial homeostasis and function, consequently, the idea that mitochondrial pathologies could play a pivotal role in the genesis and development of kidney diseases has risen. Although many research groups have recently published studies of mitochondrial function in acute kidney disease models, the existing information about CKD is still limited, especially in renal mass reduction (RMR) models. This paper focuses on reviewing current experimental information about the bioenergetics, dynamics (fission and fusion processes), turnover (mitophagy and biogenesis) and redox mitochondrial alterations in RMR, to discuss and integrate the mitochondrial changes triggered by nephron loss, as well as its relationship with loss of kidney function in CKD, in these models. Understanding these mechanisms would allow us to design new therapies that target these mitochondrial alterations.
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125
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Souders CL, Liang X, Wang X, Ector N, Zhao YH, Martyniuk CJ. High-throughput assessment of oxidative respiration in fish embryos: Advancing adverse outcome pathways for mitochondrial dysfunction. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 199:162-173. [PMID: 29631217 DOI: 10.1016/j.aquatox.2018.03.031] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 03/21/2018] [Accepted: 03/26/2018] [Indexed: 06/08/2023]
Abstract
Mitochondrial dysfunction is a prevalent molecular event that can result in multiple adverse outcomes. Recently, a novel high throughput method to assess metabolic capacity in fish embryos following exposure to chemicals has been adapted for environmental toxicology. Assessments of oxygen consumption rates using the Seahorse XF(e) 24/96 Extracellular Flux Analyzer (Agilent Technologies) can be used to garner insight into toxicant effects at early stages of development. Here we synthesize the current state of the science using high throughput metabolic profiling in zebrafish embryos, and present considerations for those wishing to adopt high throughput methods for mitochondrial bioenergetics into their research. Chemicals that have been investigated in zebrafish using this metabolic platform include herbicides (e.g. paraquat, diquat), industrial compounds (e.g. benzo-[a]-pyrene, tributyltin), natural products (e.g. quercetin), and anti-bacterial chemicals (i.e. triclosan). Some of these chemicals inhibit mitochondrial endpoints in the μM-mM range, and reduce basal respiration, maximum respiration, and spare capacity. We present a theoretical framework for how one can use mitochondrial performance data in zebrafish to categorize chemicals of concern and prioritize mitochondrial toxicants. Noteworthy is that our studies demonstrate that there can be considerable variation in basal respiration of untreated zebrafish embryos due to clutch-specific effects as well as individual variability, and basal oxygen consumption rates (OCR) can vary on average between 100 and 300 pmol/min/embryo. We also compare OCR between chorionated and dechorionated embryos, as both models are employed to test chemicals. After 24 h, dechorionated embryos remain responsive to mitochondrial toxicants, although they show a blunted response to the uncoupling agent carbonylcyanide-4-trifluoromethoxyphenylhydrazone (FCCP); dechorionated embryos are therefore a viable option for investigations into mitochondrial bioenergetics. We present an adverse outcome pathway framework that incorporates endpoints related to mitochondrial bioenergetics. High throughput bioenergetics assays conducted using whole embryos are expected to support adverse outcome pathways for mitochondrial dysfunction.
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Affiliation(s)
- Christopher L Souders
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida Genetics Institute, Interdisciplinary Program in Biomedical Sciences Neuroscience, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Xuefang Liang
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida Genetics Institute, Interdisciplinary Program in Biomedical Sciences Neuroscience, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA; School of Ecology and Environment, Inner Mongolia University, Hohhot, 010021, China
| | - Xiaohong Wang
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida Genetics Institute, Interdisciplinary Program in Biomedical Sciences Neuroscience, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA; State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, Jilin, 130117, China
| | - Naomi Ector
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida Genetics Institute, Interdisciplinary Program in Biomedical Sciences Neuroscience, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Yuan H Zhao
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, Jilin, 130117, China
| | - Christopher J Martyniuk
- Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida Genetics Institute, Interdisciplinary Program in Biomedical Sciences Neuroscience, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA.
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126
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Kong D, Tian X, Li Y, Zhang S, Cheng Y, Huo L, Ma H, Yang Z, Ren L, Zhang M, Zhang W. Revealing the Inhibitory Effect of Ginseng on Mitochondrial Respiration through Synaptosomal Proteomics. Proteomics 2018; 18:e1700354. [PMID: 29687596 DOI: 10.1002/pmic.201700354] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 01/19/2018] [Indexed: 12/25/2022]
Abstract
Ginseng, the active ingredients of which are ginsenosides, is the most popular herbal medicine and has potential merit in the treatment of cerebral disorders. To better understand the function of Ginseng in the cerebral system, we examined changes in the protein expression profiles of synaptosomes extracted from the cerebral cortical and hippocampal tissues of rats administered a high or low dose of Ginseng for 2 weeks. More than 5000 proteins belonging to synaptosomes were simultaneously identified and quantitated by an approach combining tandem mass tags with 2D liquid chromatography-mass spectrometry (LC-MS). Regarding differentially expressed proteins, downregulated proteins were much more highly induced than upregulators in the cerebral cortical and hippocampal synaptosomes, regardless of the dose of Ginseng. Bioinformatic analysis indicated the majority of the altered proteins to be located in the mitochondria, directly or indirectly affecting mitochondrial oxidative respiration. Further functional experiments using the substrate-uncoupler inhibitor titration approach confirmed that three representative ginsenosides were able to inhibit oxidative phosphorylation in mitochondria. Our results demonstrate that Ginseng can regulate the function of mitochondria and alter the energy metabolism of cells, which may be useful for the treatment of central nervous disorders.
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Affiliation(s)
- Dezhi Kong
- Institute of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, 050017, P. R. China
| | - Xiaolin Tian
- Institute of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, 050017, P. R. China
| | - Yunshan Li
- Institute of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, 050017, P. R. China
| | - Saihang Zhang
- Institute of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, 050017, P. R. China
| | - Yiru Cheng
- Institute of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, 050017, P. R. China
| | - Lifang Huo
- Institute of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, 050017, P. R. China
| | - Huanhuan Ma
- Institute of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, 050017, P. R. China
| | - Zuxiao Yang
- Institute of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, 050017, P. R. China
| | - Leiming Ren
- Institute of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, 050017, P. R. China
| | - Mingquan Zhang
- Department of Basic Theory of Chinese Medicine, Hebei University of Chinese Medicine, Shijiazhuang, 050017, P. R. China
| | - Wei Zhang
- Institute of Chinese Integrative Medicine, Hebei Medical University, Shijiazhuang, 050017, P. R. China
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127
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Goedecke JH, Mendham AE, Clamp L, Nono Nankam PA, Fortuin-de Smidt MC, Phiri L, Micklesfield LK, Keswell D, Woudberg NJ, Lecour S, Alhamud A, Kaba M, Lutomia FM, van Jaarsveld PJ, de Villiers A, Kahn SE, Chorell E, Hauksson J, Olsson T. An Exercise Intervention to Unravel the Mechanisms Underlying Insulin Resistance in a Cohort of Black South African Women: Protocol for a Randomized Controlled Trial and Baseline Characteristics of Participants. JMIR Res Protoc 2018; 7:e75. [PMID: 29669711 PMCID: PMC5932332 DOI: 10.2196/resprot.9098] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 11/20/2017] [Accepted: 11/20/2017] [Indexed: 11/13/2022] Open
Abstract
Background The pathogenesis of type 2 diabetes (T2D) in black African women is complex and differs from that in their white counterparts. However, earlier studies have been cross-sectional and provide little insight into the causal pathways. Exercise training is consistently used as a model to examine the mechanisms underlying insulin resistance and risk for T2D. Objective The objective of the study was to examine the mechanisms underlying the changes in insulin sensitivity and secretion in response to a 12-week exercise intervention in obese black South African (SA) women. Methods A total of 45 obese (body mass index, BMI: 30-40 kg/m2) black SA women were randomized into a control (n=22) or experimental (exercise; n=23) group. The exercise group completed 12 weeks of supervised combined aerobic and resistance training (40-60 min, 4 days/week), while the control group maintained their typical physical activity patterns, and both groups were requested not to change their dietary patterns. Before and following the 12-week intervention period, insulin sensitivity and secretion (frequently sampled intravenous glucose tolerance test) and its primary and secondary determinants were measured. Dietary intake, sleep quality and quantity, physical activity, and sedentary behaviors were measured every 4 weeks. Results The final sample included 20 exercise and 15 control participants. Baseline sociodemographics, cardiorespiratory fitness, anthropometry, cardiometabolic risk factors, physical activity, and diet did not differ between the groups (P>.05). Conclusions The study describes a research protocol for an exercise intervention to understand the mechanisms underlying insulin sensitivity and secretion in obese black SA women and aims to identify causal pathways underlying the high prevalence of insulin resistance and risk for T2D in black SA women, targeting specific areas for therapeutic intervention. Trial Registration Pan African Clinical Trial Registry PACTR201711002789113; http://www.pactr.org/ATMWeb/ appmanager/atm/atmregistry?_nfpb=true&_pageLabel=portals_app_atmregistry_portal_page_13 (Archived by WebCite at http://www.webcitation.org/6xLEFqKr0)
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Affiliation(s)
- Julia H Goedecke
- Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa.,Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Amy E Mendham
- Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa.,Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Louise Clamp
- Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Pamela A Nono Nankam
- Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Melony C Fortuin-de Smidt
- Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Lindokuhle Phiri
- Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Lisa K Micklesfield
- Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa.,South African Medical Research Council / University of the Witwatersrand Developmental Pathways for Health Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Gauteng, South Africa
| | - Dheshnie Keswell
- Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Nicholas J Woudberg
- Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Sandrine Lecour
- Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Ali Alhamud
- Division of Biomedical Engineering, Department of Human Biology, University of Cape Town, Cape Town, South Africa
| | - Mamadou Kaba
- Division of Medical Microbiology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Faith M Lutomia
- Division of Medical Microbiology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Paul J van Jaarsveld
- Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa.,Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Anniza de Villiers
- Non-Communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa
| | - Steven E Kahn
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, Veterans Affairs Puget Sound Health Care System and University of Washington, Seattle, WA, United States
| | - Elin Chorell
- Department of Public Health and Clinical Medicine, Umeå University, Umea, Sweden
| | - Jon Hauksson
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | - Tommy Olsson
- Department of Public Health and Clinical Medicine, Umeå University, Umea, Sweden
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128
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Rajasekaran R, Felser A, Nuoffer JM, Dufour JF, St-Pierre MV. The histidine triad nucleotide-binding protein 2 (HINT-2) positively regulates hepatocellular energy metabolism. FASEB J 2018; 32:5143-5161. [PMID: 29913563 DOI: 10.1096/fj.201701429r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The histidine triad nucleotide-binding protein 2 (HINT-2) is a mitochondrial adenosine phosphoramidase expressed in hepatocytes. The phenotype of Hint2 knockout ( Hint2-/-) mice includes progressive hepatic steatosis and lysine hyperacetylation of mitochondrial proteins, which are features of respiratory chain malfunctions. We postulated that the absence of HINT-2 induces a defect in mitochondria bioenergetics. Isolated Hint2-/- hepatocytes produced less ATP and generated a lower mitochondrial membrane potential than did Hint2+/+ hepatocytes. In extracellular flux analyses with glucose, the basal, ATP-linked, and maximum oxygen consumption rates (OCRs) were decreased in Hint2-/- hepatocytes and in HepG2 cells lacking HINT-2. Conversely, in HINT-2 overexpressing SNU-449 and HepG2 cells, the basal, ATP-linked, and maximum OCRs were increased. Similarly, with palmitate, basal and maximum OCRs were decreased in Hint2-/- hepatocytes, but they were increased in HINT-2 overexpressing HepG2 cells. When assayed with radiolabeled substrate, palmitate oxidation was reduced by 25% in Hint2-/- mitochondria. In respirometry assays, complex I- and II-driven, coupled and uncoupled respirations and complex IV KCN-sensitive respiration were reduced in Hint2-/- mitochondria. Furthermore, HINT-2 associated with cardiolipin and glucose-regulated protein 75 kDa. Our study shows decreased electron transfer and oxidative phosphorylation capacity in the absence of HINT-2. The bioenergetics deficit accumulated over time in hepatocytes lacking HINT-2 likely leads to the secondary outcome of steatosis.-Rajasekaran, R., Felser, A., Nuoffer, J.-M., Dufour, J.-F., St-Pierre, M. V. The histidine triad nucleotide-binding protein 2 (HINT-2) positively regulates hepatocellular energy metabolism.
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Affiliation(s)
| | - Andrea Felser
- University Institute of Clinical Chemistry, University of Bern, Bern, Switzerland; and
| | - Jean-Marc Nuoffer
- University Institute of Clinical Chemistry, University of Bern, Bern, Switzerland; and
| | - Jean-François Dufour
- Department of Biomedical Research, University of Bern, Bern, Switzerland.,University Clinic of Visceral Surgery and Medicine, University Hospital Bern, Bern, Switzerland
| | - Marie V St-Pierre
- Department of Biomedical Research, University of Bern, Bern, Switzerland
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129
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Ahn B, Pharaoh G, Premkumar P, Huseman K, Ranjit R, Kinter M, Szweda L, Kiss T, Fulop G, Tarantini S, Csiszar A, Ungvari Z, Van Remmen H. Nrf2 deficiency exacerbates age-related contractile dysfunction and loss of skeletal muscle mass. Redox Biol 2018; 17:47-58. [PMID: 29673700 PMCID: PMC6006677 DOI: 10.1016/j.redox.2018.04.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 04/01/2018] [Accepted: 04/03/2018] [Indexed: 12/21/2022] Open
Affiliation(s)
- Bumsoo Ahn
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Gavin Pharaoh
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA; Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Pavithra Premkumar
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Kendra Huseman
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Rojina Ranjit
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Michael Kinter
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA; Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Luke Szweda
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Tamas Kiss
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Gabor Fulop
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Stefano Tarantini
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Anna Csiszar
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Zoltan Ungvari
- Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Holly Van Remmen
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA; Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Oklahoma City VA Medical Center, Oklahoma City, OK, USA.
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130
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Scheiber D, Zweck E, Jelenik T, Horn P, Albermann S, Masyuk M, Boeken U, Saeed D, Kelm M, Roden M, Szendroedi J, Westenfeld R. Reduced Myocardial Mitochondrial ROS Production in Mechanically Unloaded Hearts. J Cardiovasc Transl Res 2018; 12:107-115. [DOI: 10.1007/s12265-018-9803-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 03/16/2018] [Indexed: 12/20/2022]
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131
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Cecatto C, Amaral AU, da Silva JC, Wajner A, Schimit MDOV, da Silva LHR, Wajner SM, Zanatta Â, Castilho RF, Wajner M. Metabolite accumulation in VLCAD deficiency markedly disrupts mitochondrial bioenergetics and Ca 2+ homeostasis in the heart. FEBS J 2018; 285:1437-1455. [PMID: 29476646 DOI: 10.1111/febs.14419] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 01/19/2018] [Accepted: 02/20/2018] [Indexed: 12/11/2022]
Abstract
We studied the effects of the major long-chain fatty acids accumulating in very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency, namely cis-5-tetradecenoic acid (Cis-5) and myristic acid (Myr), on important mitochondrial functions in isolated mitochondria from cardiac fibers and cardiomyocytes of juvenile rats. Cis-5 and Myr at pathological concentrations markedly reduced mitochondrial membrane potential (ΔΨm ), matrix NAD(P)H pool, Ca2+ retention capacity, ADP- (state 3) and carbonyl cyanide 3-chlorophenyl hydrazine-stimulated (uncoupled) respiration, and ATP generation. By contrast, these fatty acids increased resting (state 4) respiration (uncoupling effect) with the involvement of the adenine nucleotide translocator because carboxyatractyloside significantly attenuated the increased state 4 respiration provoked by Cis-5 and Myr. Furthermore, the classical inhibitors of mitochondrial permeability transition (MPT) pore cyclosporin A plus ADP, as well as the Ca2+ uptake blocker ruthenium red, fully prevented the Cis-5- and Myr-induced decrease in ΔΨm in Ca2+ -loaded mitochondria, suggesting, respectively, the induction of MPT pore opening and the contribution of Ca2+ toward these effects. The findings of the present study indicate that the major long-chain fatty acids that accumulate in VLCAD deficiency disrupt mitochondrial bioenergetics and Ca2+ homeostasis, acting as uncouplers and metabolic inhibitors of oxidative phosphorylation, as well as inducers of MPT pore opening, in the heart at pathological relevant concentrations. It is therefore presumed that a disturbance of bioenergetics and Ca2+ homeostasis may contribute to the cardiac manifestations observed in VLCAD deficiency.
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Affiliation(s)
- Cristiane Cecatto
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Alexandre Umpierrez Amaral
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Departamento de Ciências Biológicas, Universidade Regional Integrada do Alto Uruguai e das Missões, Erechim, Brazil
| | - Janaína Camacho da Silva
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Alessandro Wajner
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Mariana de Oliveira Vargas Schimit
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Lucas Henrique Rodrigues da Silva
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Simone Magagnin Wajner
- Departamento de Medicina Interna, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Ângela Zanatta
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Roger Frigério Castilho
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Brazil
| | - Moacir Wajner
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.,Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Brazil
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Sulforaphane prevents maleic acid-induced nephropathy by modulating renal hemodynamics, mitochondrial bioenergetics and oxidative stress. Food Chem Toxicol 2018; 115:185-197. [PMID: 29548851 DOI: 10.1016/j.fct.2018.03.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/14/2018] [Accepted: 03/12/2018] [Indexed: 12/14/2022]
Abstract
Maleic acid (MA)-induced nephropathy that is characterized by proteinuria, glycosuria, phosphaturia and a deficient urinary acidification and concentration. Sulforaphane (SF) is an indirect antioxidant that shows nephroprotective effects. The aim of the present work was to test the pre-treatment with SF against the MA-induced nephropathy. Wistar rats (230-260 g) were separated in the following groups: control, MA (which received 400 mg/kg of MA), SF + MA (which received MA and 1 mg/kg of SF each day for four days) and SF (which only received SF). MA induced proteinuria, an increase in urinary excretion of N-acetyl-β-d-glucosaminidase, and a decrease in plasma glutathione peroxidase activity, renal blood flow, and oxygenation and perfusion of renal cortex. All these impairments correlated with higher levels of oxidative damage markers and exacerbated superoxide anion production on renal cortex. Moreover, MA impaired mitochondrial bioenergetics associated to complex I, mitochondrial membrane potential and respiratory control index and increased the mitochondrial production of hydrogen peroxide. Further it disrupted mitochondrial morphology. SF prevented all the above-described alterations. In conclusion, the protective effect of SF against MA-induced nephropathy is associated with preservation of mitochondrial bioenergetics, amelioration of oxidative stress and improvement of renal hemodynamics and renal cortex oxygenation.
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133
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High-Resolution FluoRespirometry and OXPHOS Protocols for Human Cells, Permeabilized Fibers from Small Biopsies of Muscle, and Isolated Mitochondria. Methods Mol Biol 2018; 1782:31-70. [PMID: 29850993 DOI: 10.1007/978-1-4939-7831-1_3] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Protocols for High-Resolution FluoRespirometry of intact cells, permeabilized cells, permeabilized muscle fibers, isolated mitochondria, and tissue homogenates offer sensitive diagnostic tests of integrated mitochondrial function using standard cell culture techniques, small needle biopsies of muscle, and mitochondrial preparation methods. Multiple substrate-uncoupler-inhibitor titration (SUIT) protocols for analysis of oxidative phosphorylation (OXPHOS) improve our understanding of mitochondrial respiratory control and the pathophysiology of mitochondrial diseases. Respiratory states are defined in functional terms to account for the network of metabolic interactions in complex SUIT protocols with stepwise modulation of coupling control and electron transfer pathway states. A regulated degree of intrinsic uncoupling is a hallmark of oxidative phosphorylation, whereas pathological and toxicological dyscoupling is evaluated as a mitochondrial defect. The noncoupled state of maximum respiration is experimentally induced by titration of established uncouplers (CCCP, FCCP, DNP) to collapse the protonmotive force across the mitochondrial inner membrane and measure the electron transfer (ET) capacity (open-circuit operation of respiration). Intrinsic uncoupling and dyscoupling are evaluated as the flux control ratio between non-phosphorylating LEAK respiration (electron flow coupled to proton pumping to compensate for proton leaks) and ET capacity. If OXPHOS capacity (maximally ADP-stimulated O2 flux) is less than ET capacity, the phosphorylation pathway contributes to flux control. Physiological substrate combinations supporting the NADH and succinate pathway are required to reconstitute tricarboxylic acid cycle function. This supports maximum ET and OXPHOS capacities, due to the additive effect of multiple electron supply pathways converging at the Q-junction. ET pathways with electron entry separately through NADH (pyruvate and malate or glutamate and malate) or succinate (succinate and rotenone) restrict ET capacity and artificially enhance flux control upstream of the Q-cycle, providing diagnostic information on specific ET-pathway branches. O2 concentration is maintained above air saturation in protocols with permeabilized muscle fibers to avoid experimental O2 limitation of respiration. Standardized two-point calibration of the polarographic oxygen sensor (static sensor calibration), calibration of the sensor response time (dynamic sensor calibration), and evaluation of instrumental background O2 flux (systemic flux compensation) provide the unique experimental basis for high accuracy of quantitative results and quality control in High-Resolution FluoRespirometry.
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Kras KA, Hoffman N, Roust LR, Patel SH, Carroll CC, Katsanos CS. Plasma Amino Acids Stimulate Uncoupled Respiration of Muscle Subsarcolemmal Mitochondria in Lean but Not Obese Humans. J Clin Endocrinol Metab 2017; 102:4515-4525. [PMID: 29029131 PMCID: PMC5718694 DOI: 10.1210/jc.2017-01201] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 09/19/2017] [Indexed: 11/19/2022]
Abstract
CONTEXT Obesity is associated with mitochondrial dysfunction in skeletal muscle. Increasing the plasma amino acid (AA) concentrations stimulates mitochondrial adenosine triphosphate (ATP) production in lean individuals. OBJECTIVE To determine whether acute elevation in plasma AAs enhances muscle mitochondrial respiration and ATP production in subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria in obese adults. DESIGN Assessment of SS and IMF mitochondrial function during saline (i.e., control) and AA infusions. PARTICIPANTS Eligible participants were healthy lean (body mass index, <25 kg/m2; age, 37 ± 3 years; n = 10) and obese (body mass index >30 kg/m2; age 35 ± 3 years; n = 11) subjects. INTERVENTION Single trial of saline infusion followed by AA infusion. SS and IMF mitochondria were isolated from muscle biopsies collected at the end of the saline and AA infusions. MAIN OUTCOMES Mitochondrial respiration and ATP production. RESULTS AA infusion increased adenosine 5'-diphosphate (ADP)-stimulated respiration and ATP production rates of SS mitochondria in the lean (P < 0.05), but not obese, subjects. Furthermore, AA infusion increased the uncoupled (i.e., non-ADP-stimulated) respiration of SS mitochondria in the lean subjects only (P < 0.05). AA infusion had no effect on any of these parameters in IMF mitochondria in either lean or obese subjects (P > 0.05). CONCLUSIONS Increasing the plasma AA concentrations enhances the capacity for respiration and ATP production of muscle SS, but not IMF, mitochondria in lean individuals, in parallel with increases in uncoupled respiration. However, neither of these parameters increases in muscle SS or IMF mitochondria in obese individuals.
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Affiliation(s)
- Katon A. Kras
- Center for Metabolic and Vascular Biology, Arizona State University/Mayo Clinic in Arizona, Scottsdale, Arizona 85259
| | - Nyssa Hoffman
- Center for Metabolic and Vascular Biology, Arizona State University/Mayo Clinic in Arizona, Scottsdale, Arizona 85259
| | - Lori R. Roust
- College of Medicine, Mayo Clinic in Arizona, Scottsdale, Arizona 85259
| | - Shivam H. Patel
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana 47907
| | - Chad C. Carroll
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana 47907
| | - Christos S. Katsanos
- Center for Metabolic and Vascular Biology, Arizona State University/Mayo Clinic in Arizona, Scottsdale, Arizona 85259
- College of Medicine, Mayo Clinic in Arizona, Scottsdale, Arizona 85259
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Trewin AJ, Levinger I, Parker L, Shaw CS, Serpiello FR, Anderson MJ, McConell GK, Hare DL, Stepto NK. Acute exercise alters skeletal muscle mitochondrial respiration and H2O2 emission in response to hyperinsulinemic-euglycemic clamp in middle-aged obese men. PLoS One 2017; 12:e0188421. [PMID: 29161316 PMCID: PMC5697830 DOI: 10.1371/journal.pone.0188421] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Accepted: 11/07/2017] [Indexed: 12/16/2022] Open
Abstract
Obesity, sedentary lifestyle and aging are associated with mitochondrial dysfunction and impaired insulin sensitivity. Acute exercise increases insulin sensitivity in skeletal muscle; however, whether mitochondria are involved in these processes remains unclear. The aim of this study was to investigate the effects of insulin stimulation at rest and after acute exercise on skeletal muscle mitochondrial respiratory function (JO2) and hydrogen peroxide emission (JH2O2), and the associations with insulin sensitivity in obese, sedentary men. Nine men (means ± SD: 57 ± 6 years; BMI 33 ± 5 kg.m2) underwent hyperinsulinemic-euglycemic clamps in two separate trials 1–3 weeks apart: one under resting conditions, and another 1 hour after high-intensity exercise (4x4 min cycling at 95% HRpeak). Muscle biopsies were obtained at baseline, and pre/post clamp to measure JO2 with high-resolution respirometry and JH2O2 via Amplex UltraRed from permeabilized fibers. Post-exercise, both JO2 and JH2O2 during ADP stimulated state-3/OXPHOS respiration were lower compared to baseline (P<0.05), but not after subsequent insulin stimulation. JH2O2 was lower post-exercise and after subsequent insulin stimulation compared to insulin stimulation in the rest trial during succinate supported state-4/leak respiration (P<0.05). In contrast, JH2O2 increased during complex-I supported leak respiration with insulin after exercise compared with resting conditions (P<0.05). Resting insulin sensitivity and JH2O2 during complex-I leak respiration were positively correlated (r = 0.77, P<0.05). We conclude that in obese, older and sedentary men, acute exercise modifies skeletal muscle mitochondrial respiration and H2O2 emission responses to hyperinsulinemia in a respiratory state-specific manner, which may have implications for metabolic diseases involving insulin resistance.
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Affiliation(s)
- Adam J. Trewin
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
| | - Itamar Levinger
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
- Australian Institute for Musculoskeletal Science (AIMSS), Victoria University, St. Albans, Australia
| | - Lewan Parker
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Christopher S. Shaw
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Fabio R. Serpiello
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
| | - Mitchell J. Anderson
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
| | - Glenn K. McConell
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
| | - David L. Hare
- University of Melbourne, and Department of Cardiology, Austin Health, Melbourne, Australia
| | - Nigel K. Stepto
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Australia
- Australian Institute for Musculoskeletal Science (AIMSS), Victoria University, St. Albans, Australia
- Monash Centre for Health Research and Implementation (MCHRI), Monash University and Monash Health, Clayton, Australia
- * E-mail:
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Tueller DJ, Harley JS, Hancock CR. Effects of curcumin and ursolic acid on the mitochondrial coupling efficiency and hydrogen peroxide emission of intact skeletal myoblasts. Biochem Biophys Res Commun 2017; 492:368-372. [PMID: 28847726 DOI: 10.1016/j.bbrc.2017.08.101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 08/25/2017] [Indexed: 11/17/2022]
Abstract
Curcumin may improve blood glucose management, but the mechanism is not fully established. We demonstrated that curcumin (40 μM) reduced the mitochondrial coupling efficiency (percentage of oxygen consumption coupled to ATP synthesis) of intact skeletal muscle cells. A 30-minute pretreatment with curcumin reduced mitochondrial coupling efficiency by 17.0 ± 0.4% relative to vehicle (p < 0.008). Curcumin pretreatment also decreased the rate of hydrogen peroxide emission by 43 ± 13% compared to vehicle (p < 0.05). Analysis of cell respiration in the presence of curcumin revealed a 40 ± 4% increase in the rate of oxygen consumption upon curcumin administration (p < 0.05 compared to vehicle). No difference in mitochondrial coupling efficiency was observed between vehicle- and curcumin-pretreated cells after permeabilization of cell membranes (p > 0.7). The interaction between curcumin and ursolic acid, another natural compound that may improve blood glucose management, was also examined. Pretreatment with ursolic acid (0.12 μM) increased the mitochondrial coupling efficiency of intact cells by 4.1 ± 1.1% relative to vehicle (p < 0.008) and attenuated the effect of curcumin when the two compounds were used in combination. The observed changes to mitochondrial coupling efficiency and hydrogen peroxide emission were consistent with the established effects of curcumin on blood glucose control. Our findings also show that changes to mitochondrial coupling efficiency after curcumin pretreatment may go undetected unless cells are assessed in the intact condition.
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Affiliation(s)
- Daniel J Tueller
- Department of Nutrition, Dietetics, and Food Science, Brigham Young University, Provo, UT 84602, USA
| | - Jackson S Harley
- Department of Nutrition, Dietetics, and Food Science, Brigham Young University, Provo, UT 84602, USA
| | - Chad R Hancock
- Department of Nutrition, Dietetics, and Food Science, Brigham Young University, Provo, UT 84602, USA.
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Electron leak from NDUFA13 within mitochondrial complex I attenuates ischemia-reperfusion injury via dimerized STAT3. Proc Natl Acad Sci U S A 2017; 114:11908-11913. [PMID: 29078279 PMCID: PMC5692532 DOI: 10.1073/pnas.1704723114] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Reactive oxygen species (ROS) generation due to electron leak from the mitochondria may be involved in physiological or pathological processes. NDUFA13 is an accessory subunit of mitochondria complex I with a unique molecular structure and is located close to FeS clusters with low electrochemical potentials. Here, we generated cardiac-specific conditional NDUFA13 heterozygous knockout mice. At the basal state, a moderate down-regulation of NDUFA13 created a leak within complex I, resulting in a mild increase in cytoplasm localized H2O2, but not superoxide. The resultant ROS served as a second messenger and was responsible for the STAT3 dimerization and, hence, the activation of antiapoptotic signaling, which eventually significantly suppressed the superoxide burst and decreased the infarct size during the ischemia-reperfusion process. The causative relationship between specific mitochondrial molecular structure and reactive oxygen species (ROS) generation has attracted much attention. NDUFA13 is a newly identified accessory subunit of mitochondria complex I with a unique molecular structure and a location that is very close to the subunits of complex I of low electrochemical potentials. It has been reported that down-regulated NDUFA13 rendered tumor cells more resistant to apoptosis. Thus, this molecule might provide an ideal opportunity for us to investigate the profile of ROS generation and its role in cell protection against apoptosis. In the present study, we generated cardiac-specific tamoxifen-inducible NDUFA13 knockout mice and demonstrated that cardiac-specific heterozygous knockout (cHet) mice exhibited normal cardiac morphology and function in the basal state but were more resistant to apoptosis when exposed to ischemia-reperfusion (I/R) injury. cHet mice showed a preserved capacity of oxygen consumption rate by complex I and II, which can match the oxygen consumption driven by electron donors of N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD)+ascorbate. Interestingly, at basal state, cHet mice exhibited a higher H2O2 level in the cytosol, but not in the mitochondria. Importantly, increased H2O2 served as a second messenger and led to the STAT3 dimerization and, hence, activation of antiapoptotic signaling, which eventually significantly suppressed the superoxide burst and decreased the infarct size during the I/R process in cHet mice.
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Mitochondrial transition ROS spike (mTRS) results from coordinated activities of complex I and nicotinamide nucleotide transhydrogenase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:955-965. [PMID: 28866380 DOI: 10.1016/j.bbabio.2017.08.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 08/20/2017] [Accepted: 08/28/2017] [Indexed: 02/06/2023]
Abstract
Mitochondria exhibit suppressed ATP production, membrane potential (∆Ψmt) polarization and reactive oxygen species (ROS) bursts during some cellular metabolic transitions. Although mitochondrial ROS release is influenced by ∆Ψmt and respiratory state, the relationship between these properties remains controversial primarily because they have not been measured simultaneously. We developed a multiparametric method for probing mitochondrial function that allowed precise characterization of the temporal relationship between ROS, ∆Ψmt and respiration. We uncovered a previously unknown spontaneous ROS spike - termed mitochondrial transition ROS spike (mTRS) - associated with re-polarization of ∆Ψmt that occurs at the transition between mitochondrial energy states. Pharmacological inhibition of complex CI (CI), nicotinamide nucleotide transhydrogenase (NNT) and antioxidant system significantly decreased the ability of mitochondria to exhibit mTRS. NADH levels followed a similar trend to that of ROS during the mTRS, providing a link between CI and NNT in mTRS regulation. We show that (i) mTRS is enhanced by simultaneous activation of CI and complex II (CII); (ii) CI is the principal origin of mTRS; (iii) NNT regulates mTRS via NADH- and ∆Ψmt-dependent mechanisms; (iv) mTRS is not a pH spike; and (v), mTRS changes in amplitude under stress conditions and its occurrence can be a signature of mitochondrial health. Collectively, we uncovered and characterized the biophysical properties and mechanisms of mTRS, and propose it as a potential diagnostic tool for CI-related dysfunctions, and as a biomarker of mitochondrial functional integrity.
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Ortega-Domínguez B, Aparicio-Trejo OE, García-Arroyo FE, León-Contreras JC, Tapia E, Molina-Jijón E, Hernández-Pando R, Sánchez-Lozada LG, Barrera-Oviedo D, Pedraza-Chaverri J. Curcumin prevents cisplatin-induced renal alterations in mitochondrial bioenergetics and dynamic. Food Chem Toxicol 2017; 107:373-385. [DOI: 10.1016/j.fct.2017.07.018] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 07/06/2017] [Accepted: 07/07/2017] [Indexed: 01/03/2023]
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Nan J, Hu H, Sun Y, Zhu L, Wang Y, Zhong Z, Zhao J, Zhang N, Wang Y, Wang Y, Ye J, Zhang L, Hu X, Zhu W, Wang J. TNFR2 Stimulation Promotes Mitochondrial Fusion via Stat3- and NF-kB-Dependent Activation of OPA1 Expression. Circ Res 2017. [PMID: 28637784 PMCID: PMC5542782 DOI: 10.1161/circresaha.117.311143] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Supplemental Digital Content is available in the text. Rationale: Mitochondria are important cellular organelles and play essential roles in maintaining cell structure and function. Emerging evidence indicates that in addition to having proinflammatory and proapoptotic effects, TNFα (tumor necrosis factor α) can, under certain circumstances, promote improvements in mitochondrial integrity and function, phenomena that can be ascribed to the existence of TNFR2 (TNFα receptor 2). Objective: The present study aimed to investigate whether and how TNFR2 activation mediates the effects of TNFα on mitochondria. Methods and Results: Freshly isolated neonatal mouse cardiac myocytes treated with shRNA targeting TNFR1 were used to study the effects of TNFR2 activation on mitochondrial function. Neonatal mouse cardiac myocytes exhibited increases in mitochondrial fusion, a change that was associated with increases in mitochondrial membrane potential, intracellular ATP levels, and oxygen consumption capacity. Importantly, TNFR2 activation–induced increases in OPA1 (optic atrophy 1) protein expression were responsible for the above enhancements, and these changes could be attenuated using siRNA targeting OPA1. Moreover, both Stat3 and RelA bound to the promoter region of OPA1 and their interactions synergistically upregulated OPA1 expression at the transcriptional level. Stat3 acetylation at lysine 370 or lysine 383 played a key role in the ability of Stat3 to form a supercomplex with RelA. Meanwhile, p300 modulated Stat3 acetylation in HEK293T (human embryonic kidney 293T) cells, and p300-mediated Stat3/RelA interactions played an indispensable role in OPA1 upregulation. Finally, TNFR2 activation exerted beneficial effects on OPA1 expression in an in vivo transverse aortic constriction model, whereby TNFR1-knockout mice exhibited better outcomes than in mice with both TNFR1 and TNFR2 knocked out. Conclusions: TNFR2 activation protects cardiac myocytes against stress by upregulating OPA1 expression. This process was facilitated by p300-mediated Stat3 acetylation and Stat3/RelA interactions, leading to improvements in mitochondrial morphology and function.
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Affiliation(s)
- Jinliang Nan
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hengxun Hu
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yong Sun
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Lianlian Zhu
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yingchao Wang
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhiwei Zhong
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jing Zhao
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Na Zhang
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Ya Wang
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yaping Wang
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jian Ye
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Ling Zhang
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xinyang Hu
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Wei Zhu
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jian'an Wang
- From the Cardiovascular Key Laboratory of Zhejiang Province, Department of Cardiology (J.N., H.H., Y.S., L.Z., Y.W., Z.Z., J.Z., N.Z., Y.W., Y.W., J.Y., L.Z., X.H., W.Z., J.W.) and Clinical Research Center (L.Z., Y.W., Z.Z., J.Z.), The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
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de Moura Alvorcem L, da Rosa MS, Glänzel NM, Parmeggiani B, Grings M, Schmitz F, Wyse ATS, Wajner M, Leipnitz G. Disruption of Energy Transfer and Redox Status by Sulfite in Hippocampus, Striatum, and Cerebellum of Developing Rats. Neurotox Res 2017; 32:264-275. [PMID: 28417315 DOI: 10.1007/s12640-017-9732-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 02/19/2017] [Accepted: 04/04/2017] [Indexed: 01/11/2023]
Abstract
Patients with sulfite oxidase (SO) deficiency present severe brain abnormalities, whose pathophysiology is not yet elucidated. We evaluated the effects of sulfite and thiosulfate, metabolites accumulated in SO deficiency, on creatine kinase (CK) activity, mitochondrial respiration and redox status in hippocampus, striatum and cerebellum of developing rats. Our in vitro results showed that sulfite and thiosulfate decreased CK activity, whereas sulfite also increased malondialdehyde (MDA) levels in all brain structures evaluated. Sulfite further diminished mitochondrial respiration and increased DCFH oxidation and hydrogen peroxide production in hippocampus. Sulfite-induced CK activity decrease was prevented by melatonin (MEL), resveratrol (RSV), and dithiothreitol while increase of MDA levels was prevented by MEL and RSV. Regarding the antioxidant system, sulfite increased glutathione concentrations in hippocampus and striatum. In addition, sulfite decreased the activities of glutathione peroxidase in all brain structures, of glutathione S-transferase in hippocampus and cerebellum, and of glutathione reductase in cerebellum. In vivo experiments performed with intrahippocampal administration of sulfite demonstrated that this metabolite increased superoxide dismutase activity without altering other biochemical parameters in rat hippocampus. Our data suggest that impairment of energy metabolism and redox status may be important pathomechanisms involved in brain damage observed in individuals with SO deficiency.
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Affiliation(s)
- Leonardo de Moura Alvorcem
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos N° 2600 - Attached, Porto Alegre, RS, CEP: 90035-003, Brazil
| | - Mateus Struecker da Rosa
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos N° 2600 - Attached, Porto Alegre, RS, CEP: 90035-003, Brazil
| | - Nícolas Manzke Glänzel
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos N° 2600 - Attached, Porto Alegre, RS, CEP: 90035-003, Brazil
| | - Belisa Parmeggiani
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos N° 2600 - Attached, Porto Alegre, RS, CEP: 90035-003, Brazil
| | - Mateus Grings
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos N° 2600 - Attached, Porto Alegre, RS, CEP: 90035-003, Brazil
| | - Felipe Schmitz
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos N° 2600 - Attached, Porto Alegre, RS, CEP: 90035-003, Brazil
| | - Angela T S Wyse
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos N° 2600 - Attached, Porto Alegre, RS, CEP: 90035-003, Brazil
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal de Rio Grande do Sul, Rua Ramiro Barcelos N° 2600 - Attached, Porto Alegre, RS, CEP 90035-003, Brazil
| | - Moacir Wajner
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos N° 2600 - Attached, Porto Alegre, RS, CEP: 90035-003, Brazil
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal de Rio Grande do Sul, Rua Ramiro Barcelos N° 2600 - Attached, Porto Alegre, RS, CEP 90035-003, Brazil
- Serviço de Genética Médica, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos, 2350, Porto Alegre, RS, CEP 90035-903, Brazil
| | - Guilhian Leipnitz
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos N° 2600 - Attached, Porto Alegre, RS, CEP: 90035-003, Brazil.
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal de Rio Grande do Sul, Rua Ramiro Barcelos N° 2600 - Attached, Porto Alegre, RS, CEP 90035-003, Brazil.
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Timpani CA, Trewin AJ, Stojanovska V, Robinson A, Goodman CA, Nurgali K, Betik AC, Stepto N, Hayes A, McConell GK, Rybalka E. Attempting to Compensate for Reduced Neuronal Nitric Oxide Synthase Protein with Nitrate Supplementation Cannot Overcome Metabolic Dysfunction but Rather Has Detrimental Effects in Dystrophin-Deficient mdx Muscle. Neurotherapeutics 2017; 14:429-446. [PMID: 27921261 PMCID: PMC5398978 DOI: 10.1007/s13311-016-0494-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Duchenne muscular dystrophy arises from the loss of dystrophin and is characterized by calcium dysregulation, muscular atrophy, and metabolic dysfunction. The secondary reduction of neuronal nitric oxide synthase (nNOS) from the sarcolemma reduces NO production and bioavailability. As NO modulates glucose uptake, metabolism, and mitochondrial bioenergetics, we investigated whether an 8-week nitrate supplementation regimen could overcome metabolic dysfunction in the mdx mouse. Dystrophin-positive control (C57BL/10) and dystrophin-deficient mdx mice were supplemented with sodium nitrate (85 mg/l) in drinking water. Following the supplementation period, extensor digitorum longus and soleus were excised and radioactive glucose uptake was measured at rest (basal) and during contraction. Gastrocnemius was excised and mitochondrial respiration was measured using the Oroboros Oxygraph. Tibialis anterior was analyzed immunohistochemically for the presence of dystrophin, nNOS, nitrotyrosine, IgG and CD45+ cells, and histologically to assess areas of damage and regeneration. Glucose uptake in the basal and contracting states was normal in unsupplemented mdx muscles but was reduced following nitrate supplementation in mdx muscles only. The mitochondrial utilization of substrates was also impaired in mdx gastrocnemius during phosphorylating and maximal uncoupled respiration, and nitrate could not improve respiration in mdx muscle. Although nitrate supplementation reduced mitochondrial hydrogen peroxide emission, it induced mitochondrial uncoupling in red gastrocnemius, increased muscle fiber peroxynitrite (nitrotyrosine), and promoted skeletal muscle damage. Our novel data suggest that despite lower nNOS protein expression and likely lower NO production in mdx muscle, enhancing NO production with nitrate supplementation in these mice has detrimental effects on skeletal muscle. This may have important relevance for those with DMD.
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Affiliation(s)
- Cara A Timpani
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia
| | - Adam J Trewin
- Institute of Sport, Exercise & Active Living (ISEAL), Victoria University, Melbourne, Victoria, 8001, Australia
| | - Vanesa Stojanovska
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia
| | - Ainsley Robinson
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia
| | - Craig A Goodman
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia
- Institute of Sport, Exercise & Active Living (ISEAL), Victoria University, Melbourne, Victoria, 8001, Australia
- Australian Institute of Musculoskeletal Science (AIMSS), Western Health, Melbourne, Victoria, 3021, Australia
| | - Kulmira Nurgali
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia
| | - Andrew C Betik
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia
- Institute of Sport, Exercise & Active Living (ISEAL), Victoria University, Melbourne, Victoria, 8001, Australia
| | - Nigel Stepto
- Institute of Sport, Exercise & Active Living (ISEAL), Victoria University, Melbourne, Victoria, 8001, Australia
| | - Alan Hayes
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia
- Institute of Sport, Exercise & Active Living (ISEAL), Victoria University, Melbourne, Victoria, 8001, Australia
- Australian Institute of Musculoskeletal Science (AIMSS), Western Health, Melbourne, Victoria, 3021, Australia
| | - Glenn K McConell
- Institute of Sport, Exercise & Active Living (ISEAL), Victoria University, Melbourne, Victoria, 8001, Australia
- Australian Institute of Musculoskeletal Science (AIMSS), Western Health, Melbourne, Victoria, 3021, Australia
| | - Emma Rybalka
- Centre for Chronic Disease, College of Health & Biomedicine, Victoria University, Melbourne, Victoria, 8001, Australia.
- Institute of Sport, Exercise & Active Living (ISEAL), Victoria University, Melbourne, Victoria, 8001, Australia.
- Australian Institute of Musculoskeletal Science (AIMSS), Western Health, Melbourne, Victoria, 3021, Australia.
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143
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Greggio C, Jha P, Kulkarni SS, Lagarrigue S, Broskey NT, Boutant M, Wang X, Conde Alonso S, Ofori E, Auwerx J, Cantó C, Amati F. Enhanced Respiratory Chain Supercomplex Formation in Response to Exercise in Human Skeletal Muscle. Cell Metab 2017; 25:301-311. [PMID: 27916530 DOI: 10.1016/j.cmet.2016.11.004] [Citation(s) in RCA: 181] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 09/08/2016] [Accepted: 11/05/2016] [Indexed: 12/19/2022]
Abstract
Mitochondrial dysfunction is a hallmark of multiple metabolic complications. Physical activity is known to increase mitochondrial content in skeletal muscle, counteracting age-related decline in muscle function and protecting against metabolic and cardiovascular complications. Here, we investigated the effect of 4 months of exercise training on skeletal muscle mitochondria electron transport chain complexes and supercomplexes in 26 healthy, sedentary older adults. Exercise differentially modulated respiratory complexes. Complex I was the most upregulated complex and not stoichiometrically associated to the other complexes. In contrast to the other complexes, complex I was almost exclusively found assembled in supercomplexes in muscle mitochondria. Overall, supercomplex content was increased after exercise. In particular, complexes I, III, and IV were redistributed to supercomplexes in the form of I+III2+IV. Taken together, our results provide the first evidence that exercise affects the stoichiometry of supercomplex formation in humans and thus reveal a novel adaptive mechanism for increased energy demand.
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Affiliation(s)
- Chiara Greggio
- Aging and Muscle Metabolism Laboratory, Department of Physiology, University of Lausanne, Lausanne 1005, Switzerland
| | - Pooja Jha
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | | | - Sylviane Lagarrigue
- Aging and Muscle Metabolism Laboratory, Department of Physiology, University of Lausanne, Lausanne 1005, Switzerland
| | - Nicholas T Broskey
- Aging and Muscle Metabolism Laboratory, Department of Physiology, University of Lausanne, Lausanne 1005, Switzerland
| | - Marie Boutant
- Nestlé Institute of Health Sciences, Lausanne 1015, Switzerland
| | - Xu Wang
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland
| | - Sonia Conde Alonso
- Aging and Muscle Metabolism Laboratory, Department of Physiology, University of Lausanne, Lausanne 1005, Switzerland; Institute of Sports Sciences, University of Lausanne, Lausanne 1005, Switzerland
| | - Emmanuel Ofori
- Aging and Muscle Metabolism Laboratory, Department of Physiology, University of Lausanne, Lausanne 1005, Switzerland
| | - Johan Auwerx
- Laboratory of Integrative and Systems Physiology, École Polytechnique Fédérale de Lausanne, Lausanne 1015, Switzerland.
| | - Carles Cantó
- Nestlé Institute of Health Sciences, Lausanne 1015, Switzerland.
| | - Francesca Amati
- Aging and Muscle Metabolism Laboratory, Department of Physiology, University of Lausanne, Lausanne 1005, Switzerland; Institute of Sports Sciences, University of Lausanne, Lausanne 1005, Switzerland; Service of Endocrinology, Diabetology, and Metabolism, Department of Medicine, Lausanne University Hospital, Lausanne 1011, Switzerland.
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144
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Makrecka-Kuka M, Volska K, Antone U, Vilskersts R, Grinberga S, Bandere D, Liepinsh E, Dambrova M. Trimethylamine N-oxide impairs pyruvate and fatty acid oxidation in cardiac mitochondria. Toxicol Lett 2017; 267:32-38. [DOI: 10.1016/j.toxlet.2016.12.017] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 12/16/2016] [Accepted: 12/29/2016] [Indexed: 02/08/2023]
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145
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Salin K, Villasevil EM, Auer SK, Anderson GJ, Selman C, Metcalfe NB, Chinopoulos C. Simultaneous measurement of mitochondrial respiration and ATP production in tissue homogenates and calculation of effective P/O ratios. Physiol Rep 2016; 4:e13007. [PMID: 27798358 PMCID: PMC5099967 DOI: 10.14814/phy2.13007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 09/23/2016] [Indexed: 01/30/2023] Open
Abstract
The use of tissue homogenate has greatly aided the study of the functioning of mitochondria. However, the amount of ATP produced per oxygen molecule consumed, that is, the effective P/O ratio, has never been measured directly in tissue homogenate. Here we combine and refine existing methods previously used in permeabilized cells and isolated mitochondria to simultaneously measure mitochondrial ATP production (JATP) and oxygen consumption (JO2) in tissue homogenate. A major improvement over existing methods is in the control of ATPases that otherwise interfere with the ATP assay: our modified technique facilitates simultaneous measurement of the rates of "uncorrected" ATP synthesis and of ATP hydrolysis, thus minimizing the amount of tissue and time needed. Finally, we develop a novel method of calculating effective P/O ratios which corrects measurements of JATP and JO2 for rates of nonmitochondrial ATP hydrolysis and respiration, respectively. Measurements of JATP and JO2 in liver homogenates from brown trout (Salmo trutta) were highly reproducible, although activity declined once homogenates were 2 h old. We compared mitochondrial properties from fed and food-deprived animals to demonstrate that the method can detect mitochondrial flexibility in P/O ratios in response to nutritional state. This method simplifies studies examining the mitochondrial bioenergetics of tissue homogenates, obviating the need for differential centrifugation or chemical permeabilization and avoiding the use of nonmitochondrial ATPase inhibitors. We conclude that our approach for characterizing effective P/O ratio opens up new possibilities in the study of mitochondrial function in very small samples, where the use of other methods is limited.
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Affiliation(s)
- Karine Salin
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Eugenia M Villasevil
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Sonya K Auer
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Graeme J Anderson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Colin Selman
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Neil B Metcalfe
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Christos Chinopoulos
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
- MTA-SE Lendület Neurobiochemistry Research Group, Budapest, Hungary
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146
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Vajrala VS, Suraniti E, Rigoulet M, Devin A, Sojic N, Arbault S. PDMS microwells for multi-parametric monitoring of single mitochondria on a large scale: a study of their individual membrane potential and endogenous NADH. Integr Biol (Camb) 2016; 8:836-43. [PMID: 27384613 DOI: 10.1039/c6ib00064a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Microwell arrays have been developed to monitor simultaneously, and on a large scale, multiple metabolic responses of single mitochondria. Wells of 50 to 1000 μm-diameter were prepared based on easy structuration of thin polydimethylsiloxane layers (PDMS; 100 μm thickness). Their surface treatment with oxygen plasma allowed the immobilization in situ and observation with time of populations of single isolated mitochondria. Their metabolic activities could be monitored individually by fluorescence microscopy under several activation/inhibition conditions. We measured the concomitant variations of two main metabolic parameters - the endogenous NADH level and the internal membrane potential difference Δψ owing to a cationic fluorescent probe (TMRM) - at energized, uncoupled and inhibited stages of the mitochondrial respiratory chain. Microwell arrays allowed analyses on large populations, and consequently statistical studies with a single organelle resolution. Thus, we observed rapid individual polarizations and depolarizations of mitochondria following their supply with the energetic substrate, while an averaged global polarization (increase of TMRM fluorescence within mitochondria) and NADH increase were detected for the whole population. In addition, statistical correlation studies show that the NADH content of all mitochondria tends toward a metabolic limit and that their polarization-depolarization ability is ubiquitous. These results demonstrate that PDMS microwell platforms provide an innovative approach to better characterize the individual metabolic status of isolated mitochondria, possibly as a function of their cell or organ origin or in different physio-pathological situations.
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147
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Age-dependent changes in the glutamate-nitric oxide pathway in the hippocampus of the triple transgenic model of Alzheimer's disease: implications for neurometabolic regulation. Neurobiol Aging 2016; 46:84-95. [PMID: 27460153 DOI: 10.1016/j.neurobiolaging.2016.06.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 06/16/2016] [Accepted: 06/21/2016] [Indexed: 12/26/2022]
Abstract
Age-dependent changes in nitric oxide ((•)NO) concentration dynamics may play a significant role in both decaying synaptic and metabolic functions in Alzheimer's disease (AD). This neuromodulator acts presynaptically to increase vesicle release and glutamatergic transmission and also regulates mitochondrial function. Under conditions of altered intracellular redox environment, (•)NO may react and produce reactive species such as peroxynitrite. Using the triple transgenic mouse model of AD (3xTgAD), we investigated age-dependent changes in the glutamate-(•)NO axis in the hippocampus. Direct measurement of (•)NO concentration dynamics revealed a significant increase in N-methyl-D-aspartate type receptor-evoked peak (•)NO in the 3xTgAD model at an early age. Aging produced a decrease in peak (•)NO accompanied by significant decrease in production and decay rates in the transgenic model. Evaluation of energy metabolism revealed age-dependent decrease in basal oxygen consumption rate, a general decrease in mitochondrial oxidative phosphorylation parameters, and loss in mitochondrial sparing capacity in both genotypes. Finally, we observed age-dependent increase in 3-nitrotyrosine residues in the hippocampus, consistent with a putative shift in (•)NO bioactivity toward oxidative chemistry associated with neurotoxicity.
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148
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Long-chain acylcarnitines determine ischaemia/reperfusion-induced damage in heart mitochondria. Biochem J 2016; 473:1191-202. [PMID: 26936967 DOI: 10.1042/bcj20160164] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 03/02/2016] [Indexed: 11/17/2022]
Abstract
The accumulation of long-chain fatty acids (FAs) and their CoA and carnitine esters is observed in the ischaemic myocardium after acute ischaemia/reperfusion. The aim of the present study was to identify harmful FA intermediates and their detrimental mechanisms of action in mitochondria and the ischaemic myocardium. In the present study, we found that the long-chain acyl-CoA and acylcarnitine content is increased in mitochondria isolated from an ischaemic area of the myocardium. In analysing the FA derivative content, we discovered that long-chain acylcarnitines, but not acyl-CoAs, accumulate at concentrations that are harmful to mitochondria. Acylcarnitine accumulation in the mitochondrial intermembrane space is a result of increased carnitine palmitoyltransferase 1 (CPT1) and decreased carnitine palmitoyltransferase 2 (CPT2) activity in ischaemic myocardium and it leads to inhibition of oxidative phosphorylation, which in turn induces mitochondrial membrane hyperpolarization and stimulates the production of reactive oxygen species (ROS) in cardiac mitochondria. Thanks to protection mediated by acyl-CoA-binding protein (ACBP), the heart is much better guarded against the damaging effects of acyl-CoAs than against acylcarnitines. Supplementation of perfusion buffer with palmitoylcarnitine (PC) before occlusion resulted in a 2-fold increase in the acylcarnitine content of the heart and increased the infarct size (IS) by 33%. A pharmacologically induced decrease in the mitochondrial acylcarnitine content reduced the IS by 44%. Long-chain acylcarnitines are harmful FA intermediates, accumulating in ischaemic heart mitochondria and inducing inhibition of oxidative phosphorylation. Therefore, decreasing the acylcarnitine content via cardioprotective drugs may represent a novel treatment strategy.
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149
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Jang DH, Shofer FS, Weiss SL, Becker LB. Impairment of mitochondrial respiration following ex vivo cyanide exposure in peripheral blood mononuclear cells. Clin Toxicol (Phila) 2016; 54:303-7. [PMID: 26846815 DOI: 10.3109/15563650.2016.1139712] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
OBJECTIVES The objective of this study is to measure mitochondrial respiration using intact cells from whole blood exposed to cyanide as a new biomarker for mitochondrial inhibition. METHODS A single nontourniqueted venous blood sample was collected from 10 healthy volunteers after informed consent. Venous lactate was measured immediately following blood collection. Half of the remaining blood sample was then incubated with 100 mM of potassium cyanide (KCN) for 5 min, and half of the sample remained unexposed. Repeat lactate measurements were performed from blood exposed and not exposed to KCN. Measurement of mitochondrial respiration: intact PBMCs were placed in a 2-mL chamber at a final concentration of 2-3 × 10(6) cells/mL. Measurements of oxygen consumption were performed at 37°C in a high-resolution oxygraph (Oxygraph-2k Oroboros Instruments, Innsbruck, Austria). Oxygen flux (in pmol O2/s/10(6) cells), which is directly proportional to oxygen consumption, was recorded continuously using DatLab software 6 (Oroboros Instruments). RESULTS There were significance differences in the relevant key parameters of mitochondrial respiration: Of the parameters measuring mitochondrial respiration, four of the six demonstrated a statistically significant mean difference between control and cyanide: for routine respiration (mean difference [control-cyanide]: 8.9 pmol O2/s/10(6) cells; 95% CI: 5.6-12.2, p < 0.0001); Proton Leak (mean difference: 0.73 pmol O2/s/10(6) cells; 95% CI: -0.33-1.79, p = 0.157); Maximal respiration (mean difference: 21.7 pmol O2/s/10(6) cells; 95% CI: 16.0-27.6, p < 0.0001); Residual oxygen consumption (mean difference 0.25 pmol O2/s/10(6) cells; 95% CI: -0.68-1.18, p = 0.557). There was a significant difference in spare respiratory capacity (SRC) and adenosine triphosphate (ATP)-linked respiration with the control samples demonstrating a higher SRC and ATP-linked respiration. Finally, there is a statistically significant difference in lactate (mean difference -0.32, 95% CI: -0.41 to -0.23, p < 0.0001), though clinically similar level, with a higher lactate concentration in the cyanide samples. CONCLUSIONS In this ex vivo model, the measurements of key parameters in mitochondrial respiration may be a more sensitive measure of cellular function when compared to lactate.
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Affiliation(s)
- David H Jang
- a Department of Emergency Medicine , Center for Mitochondrial Bioenergetics in Emergency Medicine and Critical Care (MitoEM), University of Pennsylvania Perelman School of Medicine , Philadelphia , PA , USA
| | - Frances S Shofer
- a Department of Emergency Medicine , Center for Mitochondrial Bioenergetics in Emergency Medicine and Critical Care (MitoEM), University of Pennsylvania Perelman School of Medicine , Philadelphia , PA , USA
| | - Scott L Weiss
- b Department of Anesthesia and Critical Care, Division of Critical Care Medicine , The Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine , Philadelphia , PA , USA
| | - Lance B Becker
- a Department of Emergency Medicine , Center for Mitochondrial Bioenergetics in Emergency Medicine and Critical Care (MitoEM), University of Pennsylvania Perelman School of Medicine , Philadelphia , PA , USA
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