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Chen PH, Lee TW, Liu SH, Huynh TV, Chung CC, Yeh YH, Kao YH, Chen YJ. Lithium downregulates phosphorylated acetyl‑CoA carboxylase 2 and attenuates mitochondrial fatty acid utilization and oxidative stress in cardiomyocytes. Exp Ther Med 2024; 27:126. [PMID: 38414784 PMCID: PMC10895620 DOI: 10.3892/etm.2024.12413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 01/11/2024] [Indexed: 02/29/2024] Open
Abstract
Acetyl-CoA carboxylase 2 plays a crucial role in regulating mitochondrial fatty acid oxidation in cardiomyocytes. Lithium, a monovalent cation known for its cardioprotective potential, has been investigated for its influence on mitochondrial bioenergetics. The present study explored whether lithium modulated acetyl-CoA carboxylase 2 and mitochondrial fatty acid metabolism in cardiomyocytes and the potential therapeutic applications of lithium in alleviating metabolic stress. Mitochondrial bioenergetic function, fatty acid oxidation, reactive oxygen species production, membrane potential and the expression of proteins involved in fatty acid metabolism in H9c2 cardiomyocytes treated with LiCl for 48 h was measured by using a Seahorse extracellular flux analyzer, fluorescence microscopy and western blotting. Small interfering RNA against glucose transporter type 4 was transfected into H9c2 cardiomyocytes for 48 h to induce metabolic stress mimicking insulin resistance. The results revealed that LiCl at a concentration of 0.3 mM (but not at a concentration of 0.1 or 1.0 mM) upregulated the expression of phosphorylated (p-)glycogen synthase kinase-3 beta and downregulated the expression of p-acetyl-CoA carboxylase 2 but did not affect the expression of adenosine monophosphate-activated protein kinase or calcineurin. Cotreatment with TWS119 (8 µM) and LiCl (0.3 mM) downregulated p-acetyl-CoA carboxylase 2 expression to a similar extent as did treatment with TWS119 (8 µM) alone. Moreover, LiCl (0.3 mM) inhibited mitochondrial fatty acid oxidation, improved coupling efficiency and the cellular respiratory control ratio, hindered reactive oxygen species production and proton leakage and restored mitochondrial membrane potential in glucose transporter type 4 knockdown-H9c2 cardiomyocytes. These findings suggested that low therapeutic levels of lithium can downregulate p-acetyl-CoA carboxylase 2, thus reducing mitochondrial fatty acid oxidation and oxidative stress in cardiomyocytes.
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Affiliation(s)
- Pao-Huan Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan, R.O.C
- Department of Psychiatry, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan, R.O.C
- Department of Psychiatry, Taipei Medical University Hospital, Taipei 11031, Taiwan, R.O.C
| | - Ting-Wei Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan, R.O.C
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan, R.O.C
| | - Shuen-Hsin Liu
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan, R.O.C
- Division of Cardiology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City 23561, Taiwan, R.O.C
| | - Tin Van Huynh
- International PhD Program in Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan, R.O.C
- Department of Interventional Cardiology, Thong Nhat Hospital, Ho Chi Minh City 700000, Vietnam
| | - Cheng-Chih Chung
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan, R.O.C
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan, R.O.C
| | - Yung-Hsin Yeh
- Division of Cardiology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan, R.O.C
- Department of Medicine, College of Medicine, Chang Gung University, Taoyuan 33305, Taiwan, R.O.C
| | - Yu-Hsun Kao
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan, R.O.C
- Department of Medical Education and Research, Wan Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan, R.O.C
| | - Yi-Jen Chen
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan, R.O.C
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan, R.O.C
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei 11696, Taiwan, R.O.C
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da Rocha GL, Guimarães DSPSF, da Cruz MV, Mizobuti DS, da Silva HNM, Pereira ECL, Silveira LR, Minatel E. Antioxidant effects of LEDT in dystrophic muscle cells: involvement of PGC-1α and UCP-3 pathways. Photochem Photobiol Sci 2024; 23:107-118. [PMID: 38057632 DOI: 10.1007/s43630-023-00506-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 11/07/2023] [Indexed: 12/08/2023]
Abstract
PURPOSE Reactive oxygen species and mitochondrial dysfunction play a crucial role in the pathophysiology of Duchenne muscular dystrophy (DMD). The light-emitting diode therapy (LEDT) showed beneficial effects on the dystrophic muscles. However, the mechanisms of this therapy influence the molecular pathways in the dystrophic muscles, particularly related to antioxidant effects, which still needs to be elucidated. The current study provides muscle cell-specific insights into the effect of LEDT, 48 h post-irradiation, on oxidative stress and mitochondrial parameters in the dystrophic primary muscle cells in culture. METHODS Dystrophic primary muscle cells were submitted to LEDT, at multiple wavelengths (420 nm, 470 nm, 660 nm and 850 nm), 0.5 J dose, and evaluated after 48 h based on oxidative stress markers, antioxidant enzymatic system and biogenesis, and functional mitochondrial parameters. RESULTS The mdx muscle cells treated with LEDT showed a significant reduction of H2O2 production and 4-HNE, catalase, SOD-2, and GR levels. Upregulation of UCP3 was observed with all wavelengths while upregulation of PGC-1α and a slight upregulation of electron transport chain complexes III and V was only observed following 850 nm LEDT. In addition, the mitochondrial membrane potential and mitochondrial mass mostly tended to be increased following LEDT, while parameters like O2·- production tended to be decreased. CONCLUSION The data shown here highlight the potential of LEDT as a therapeutic agent for DMD through its antioxidant action by modulating PGC-1α and UCP3 levels.
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Affiliation(s)
- Guilherme Luiz da Rocha
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, 13083-970862, Brazil
| | - Dimitrius Santiago Passos Simões Fróes Guimarães
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, 13083-970862, Brazil
- Obesity and Comorbidities Research Center (OCRC), Campinas, Brazil
| | - Marcos Vinicius da Cruz
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, 13083-970862, Brazil
- Obesity and Comorbidities Research Center (OCRC), Campinas, Brazil
| | - Daniela Sayuri Mizobuti
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, 13083-970862, Brazil
| | - Heloina Nathalliê Mariano da Silva
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, 13083-970862, Brazil
| | - Elaine Cristina Leite Pereira
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, 13083-970862, Brazil
- Faculty of Ceilândia, University of Brasília (UnB), Brasília, Brazil
| | - Leonardo Reis Silveira
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, 13083-970862, Brazil
- Obesity and Comorbidities Research Center (OCRC), Campinas, Brazil
| | - Elaine Minatel
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, 13083-970862, Brazil.
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Qi X, Rusch NJ, Fan J, Mora CJ, Xie L, Mu S, Rabinovitch PS, Zhang H. Mitochondrial proton leak in cardiac aging. GeroScience 2023; 45:2135-2143. [PMID: 36856945 PMCID: PMC10651624 DOI: 10.1007/s11357-023-00757-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 02/16/2023] [Indexed: 03/02/2023] Open
Abstract
Age-associated diseases are becoming progressively more prevalent, reflecting the increased lifespan of the world's population. However, the fundamental mechanisms of physiologic aging are poorly understood, and in particular, the molecular pathways that mediate cardiac aging and its associated dysfunction are unclear. Here, we focus on certain ion flux abnormalities of the mitochondria that may contribute to cardiac aging and age-related heart failure. Using oxidative phosphorylation, mitochondria pump protons from the matrix to the intermembrane space to generate a proton gradient across the inner membrane. The protons are returned to the matrix by the ATPase complex within the membrane to generate ATP. However, a portion of protons leak back to the matrix and do not drive ATP production, and this event is called proton leak or uncoupling. Accumulating evidence suggests that mitochondrial proton leak is increased in the cardiac myocytes of aged hearts. In this mini-review, we discuss the measurement methods and major sites of mitochondrial proton leak with an emphasis on the adenine nucleotide transporter 1 (ANT1), and explore the possibility of inhibiting augmented mitochondrial proton leak as a therapeutic intervention to mitigate cardiac aging.
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Affiliation(s)
- Xingyun Qi
- Department of Biology, Rutgers University, Camden, USA
| | - Nancy J Rusch
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Jiaojiao Fan
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Christoph J Mora
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Lixin Xie
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Shengyu Mu
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Peter S Rabinovitch
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, USA.
| | - Huiliang Zhang
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, USA.
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Turner JA, Fredrickson MA, D'Antonio M, Katsnelson E, MacBeth M, Van Gulick R, Chimed TS, McCarter M, D'Alessandro A, Robinson WA, Couts KL, Pelanda R, Klarquist J, Tobin RP, Torres RM. Lysophosphatidic acid modulates CD8 T cell immunosurveillance and metabolism to impair anti-tumor immunity. Nat Commun 2023; 14:3214. [PMID: 37270644 PMCID: PMC10239450 DOI: 10.1038/s41467-023-38933-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 05/19/2023] [Indexed: 06/05/2023] Open
Abstract
Lysophosphatidic acid (LPA) is a bioactive lipid which increases in concentration locally and systemically across different cancer types. Yet, the exact mechanism(s) of how LPA affects CD8 T cell immunosurveillance during tumor progression remain unknown. We show LPA receptor (LPAR) signaling by CD8 T cells promotes tolerogenic states via metabolic reprogramming and potentiating exhaustive-like differentiation to modulate anti-tumor immunity. We found LPA levels predict response to immunotherapy and Lpar5 signaling promotes cellular states associated with exhausted phenotypes on CD8 T cells. Importantly, we show that Lpar5 regulates CD8 T cell respiration, proton leak, and reactive oxygen species. Together, our findings reveal that LPA serves as a lipid-regulated immune checkpoint by modulating metabolic efficiency through LPAR5 signaling on CD8 T cells. Our study offers key insights into the mechanisms governing adaptive anti-tumor immunity and demonstrates LPA could be exploited as a T cell directed therapy to improve dysfunctional anti-tumor immunity.
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Affiliation(s)
- Jacqueline A Turner
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
- Medical Scientist Training Program, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - Malia A Fredrickson
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - Marc D'Antonio
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - Elizabeth Katsnelson
- Division of Surgical Oncology, Department of Surgery, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - Morgan MacBeth
- Division of Medical Oncology, Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - Robert Van Gulick
- Division of Medical Oncology, Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - Tugs-Saikhan Chimed
- Division of Medical Oncology, Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - Martin McCarter
- Division of Surgical Oncology, Department of Surgery, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - Angelo D'Alessandro
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - William A Robinson
- Division of Medical Oncology, Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - Kasey L Couts
- Division of Medical Oncology, Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - Roberta Pelanda
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - Jared Klarquist
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - Richard P Tobin
- Division of Surgical Oncology, Department of Surgery, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA
| | - Raul M Torres
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, USA.
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Targeting mitochondrial impairment for the treatment of cardiovascular diseases: From hypertension to ischemia-reperfusion injury, searching for new pharmacological targets. Biochem Pharmacol 2023; 208:115405. [PMID: 36603686 DOI: 10.1016/j.bcp.2022.115405] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/26/2022] [Accepted: 12/28/2022] [Indexed: 01/03/2023]
Abstract
Mitochondria and mitochondrial proteins represent a group of promising pharmacological target candidates in the search of new molecular targets and drugs to counteract the onset of hypertension and more in general cardiovascular diseases (CVDs). Indeed, several mitochondrial pathways result impaired in CVDs, showing ATP depletion and ROS production as common traits of cardiac tissue degeneration. Thus, targeting mitochondrial dysfunction in cardiomyocytes can represent a successful strategy to prevent heart failure. In this context, the identification of new pharmacological targets among mitochondrial proteins paves the way for the design of new selective drugs. Thanks to the advances in omics approaches, to a greater availability of mitochondrial crystallized protein structures and to the development of new computational approaches for protein 3D-modelling and drug design, it is now possible to investigate in detail impaired mitochondrial pathways in CVDs. Furthermore, it is possible to design new powerful drugs able to hit the selected pharmacological targets in a highly selective way to rescue mitochondrial dysfunction and prevent cardiac tissue degeneration. The role of mitochondrial dysfunction in the onset of CVDs appears increasingly evident, as reflected by the impairment of proteins involved in lipid peroxidation, mitochondrial dynamics, respiratory chain complexes, and membrane polarization maintenance in CVD patients. Conversely, little is known about proteins responsible for the cross-talk between mitochondria and cytoplasm in cardiomyocytes. Mitochondrial transporters of the SLC25A family, in particular, are responsible for the translocation of nucleotides (e.g., ATP), amino acids (e.g., aspartate, glutamate, ornithine), organic acids (e.g. malate and 2-oxoglutarate), and other cofactors (e.g., inorganic phosphate, NAD+, FAD, carnitine, CoA derivatives) between the mitochondrial and cytosolic compartments. Thus, mitochondrial transporters play a key role in the mitochondria-cytosol cross-talk by leading metabolic pathways such as the malate/aspartate shuttle, the carnitine shuttle, the ATP export from mitochondria, and the regulation of permeability transition pore opening. Since all these pathways are crucial for maintaining healthy cardiomyocytes, mitochondrial carriers emerge as an interesting class of new possible pharmacological targets for CVD treatments.
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Zhang J, Riquelme MA, Hua R, Acosta FM, Gu S, Jiang JX. Connexin 43 hemichannels regulate mitochondrial ATP generation, mobilization, and mitochondrial homeostasis against oxidative stress. eLife 2022; 11:82206. [DOI: 10.7554/elife.82206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 10/25/2022] [Indexed: 11/09/2022] Open
Abstract
Oxidative stress is a major risk factor that causes osteocyte cell death and bone loss. Prior studies primarily focus on the function of cell surface expressed Cx43 channels. Here, we reported a new role of mitochondrial Cx43 (mtCx43) and hemichannels (HCs) in modulating mitochondria homeostasis and function in bone osteocytes under oxidative stress. In murine long bone osteocyte-Y4 cells, the translocation of Cx43 to mitochondria was increased under H2O2-induced oxidative stress. H2O2 increased the mtCx43 level accompanied by elevated mtCx43 HC activity, determined by dye uptake assay. Cx43 knockdown (KD) by the CRISPR-Cas9 lentivirus system resulted in impairment of mitochondrial function, primarily manifested as decreased ATP production. Cx43 KD had reduced intracellular reactive oxidative species levels and mitochondrial membrane potential. Additionally, live-cell imaging results demonstrated that the proton flux was dependent on mtCx43 HCs because its activity was specifically inhibited by an antibody targeting Cx43 C-terminus. The co-localization and interaction of mtCx43 and ATP synthase subunit F (ATP5J2) were confirmed by Förster resonance energy transfer and a protein pull-down assay. Together, our study suggests that mtCx43 HCs regulate mitochondrial ATP generation by mediating K+, H+, and ATP transfer across the mitochondrial inner membrane and the interaction with mitochondrial ATP synthase, contributing to the maintenance of mitochondrial redox levels in response to oxidative stress.
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Affiliation(s)
- Jingruo Zhang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center
| | - Manuel A Riquelme
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center
| | - Rui Hua
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center
| | - Francisca M Acosta
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center
| | - Sumin Gu
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center
| | - Jean X Jiang
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center
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Peden DL, Mitchell EA, Bailey SJ, Ferguson RA. Ischaemic preconditioning blunts exercise-induced mitochondrial dysfunction, speeds oxygen uptake kinetics but does not alter severe-intensity exercise capacity. Exp Physiol 2022; 107:1241-1254. [PMID: 36030522 PMCID: PMC9826326 DOI: 10.1113/ep090264] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 08/12/2022] [Indexed: 01/11/2023]
Abstract
NEW FINDINGS What is the central question of this study? Ischaemic preconditioning is a novel pre-exercise priming strategy. We asked whether ischaemic preconditioning would alter mitochondrial respiratory function and pulmonary oxygen uptake kinetics and improve severe-intensity exercise performance. What is the main finding and its importance? Ischaemic preconditioning expedited overall pulmonary oxygen uptake kinetics and appeared to prevent an increase in leak respiration, proportional to maximal electron transfer system and ADP-stimulated respiration, that was evoked by severe-intensity exercise in sham-control conditions. However, severe-intensity exercise performance was not improved. The results do not support ischaemic preconditioning as a pre-exercise strategy to improve exercise performance in recreationally active participants. ABSTRACT We examined the effect of ischaemic preconditioning (IPC) on severe-intensity exercise performance, pulmonary oxygen uptake ( V ̇ O 2 ${\dot V_{{{\rm{O}}_{\rm{2}}}}}$ ) kinetics, skeletal muscle oxygenation (muscle tissue O2 saturation index) and mitochondrial respiration. Eight men underwent contralateral IPC (4 × 5 min at 220 mmHg) or sham-control (SHAM; 20 mmHg) before performing a cycling time-to-exhaustion test (92% maximum aerobic power). Muscle (vastus lateralis) biopsies were obtained before IPC or SHAM and ∼1.5 min postexercise. The time to exhaustion did not differ between SHAM and IPC (249 ± 37 vs. 240 ± 32 s; P = 0.62). Pre- and postexercise ADP-stimulated (P) and maximal (E) mitochondrial respiration through protein complexes (C) I, II and IV did not differ (P > 0.05). Complex I leak respiration was greater postexercise compared with baseline in SHAM, but not in IPC, when normalized to wet mass (P = 0.01 vs. P = 0.19), mitochondrial content (citrate synthase activity, P = 0.003 vs. P = 0.16; CI+IIP, P = 0.03 vs. P = 0.23) and expressed relative to P (P = 0.006 vs. P = 0.30) and E (P = 0.004 vs. P = 0.26). The V ̇ O 2 ${\dot V_{{{\rm{O}}_{\rm{2}}}}}$ mean response time was faster (51.3 ± 15.5 vs. 63.7 ± 14.5 s; P = 0.003), with a smaller slow component (270 ± 105 vs. 377 ± 188 ml min-1 ; P = 0.03), in IPC compared with SHAM. The muscle tissue O2 saturation index did not differ between trials (P > 0.05). Ischaemic preconditioning expedited V ̇ O 2 ${\dot V_{{{\rm{O}}_{\rm{2}}}}}$ kinetics and appeared to prevent an increase in leak respiration through CI, when expressed proportional to E and P evoked by severe-intensity exercise, but did not improve exercise performance.
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Affiliation(s)
- Donald L. Peden
- School of SportExercise and Health SciencesLoughborough UniversityLoughboroughUK
| | - Emma A. Mitchell
- School of SportExercise and Health SciencesLoughborough UniversityLoughboroughUK
| | - Stephen J. Bailey
- School of SportExercise and Health SciencesLoughborough UniversityLoughboroughUK
| | - Richard A. Ferguson
- School of SportExercise and Health SciencesLoughborough UniversityLoughboroughUK
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DHA Supplementation Attenuates MI-Induced LV Matrix Remodeling and Dysfunction in Mice. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:7606938. [PMID: 32832005 PMCID: PMC7424392 DOI: 10.1155/2020/7606938] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 03/24/2020] [Accepted: 04/07/2020] [Indexed: 01/12/2023]
Abstract
Objective Myocardial ischemia and reperfusion (I/R) injury is associated with oxidative stress and inflammation, leading to scar development and malfunction. The marine omega-3 fatty acids (ω-3 FA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are mediating cardioprotection and improving clinical outcomes in patients with heart disease. Therefore, we tested the hypothesis that docosahexaenoic acid (DHA) supplementation prior to LAD occlusion-induced myocardial injury (MI) confers cardioprotection in mice. Methods C57BL/6N mice were placed on DHA or control diets (CD) beginning 7 d prior to 60 min LAD occlusion-induced MI or sham surgery. The expression of inflammatory mediators was measured via RT-qPCR. Besides FACS analysis for macrophage quantification and subtype evaluation, macrophage accumulation as well as collagen deposition was quantified in histological sections. Cardiac function was assessed using a pressure-volume catheter for up to 14 d. Results DHA supplementation significantly attenuated the induction of peroxisome proliferator-activated receptor-α (PPAR-α) (2.3 ± 0.4 CD vs. 1.4 ± 0.3 DHA) after LAD occlusion. Furthermore, TNF-α (4.0 ± 0.6 CD vs. 1.5 ± 0.2 DHA), IL-1β (60.7 ± 7.0 CD vs. 11.6 ± 1.9 DHA), and IL-10 (223.8 ± 62.1 CD vs. 135.5 ± 38.5 DHA) mRNA expression increase was diminished in DHA-supplemented mice after 72 h reperfusion. These changes were accompanied by a less prominent switch in α/β myosin heavy chain isoforms. Chemokine mRNA expression was stronger initiated (CCL2 6 h: 32.8 ± 11.5 CD vs. 78.8 ± 13.6 DHA) but terminated earlier (CCL2 72 h: 39.5 ± 7.8 CD vs. 8.2 ± 1.9 DHA; CCL3 72 h: 794.3 ± 270.9 CD vs. 258.2 ± 57.8 DHA) in DHA supplementation compared to CD mice after LAD occlusion. Correspondingly, DHA supplementation was associated with a stronger increase of predominantly alternatively activated Ly6C-positive macrophage phenotype, being associated with less collagen deposition and better LV function (EF 14 d: 17.6 ± 2.6 CD vs. 31.4 ± 1.5 DHA). Conclusion Our data indicate that DHA supplementation mediates cardioprotection from MI via modulation of the inflammatory response with timely and attenuated remodeling. DHA seems to attenuate MI-induced cardiomyocyte injury partly by transient PPAR-α downregulation, diminishing the need for antioxidant mechanisms including mitochondrial function, or α- to β-MHC isoform switch.
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Liu Y, Ren Y, Wang X, Liu X, Xu Y, He Y. Down regulation of UCP2 expression in retinal pigment epithelium cells under oxidative stress: an in vitro study. Int J Ophthalmol 2019; 12:1089-1094. [PMID: 31341797 DOI: 10.18240/ijo.2019.07.06] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 05/06/2019] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the expression of uncoupling protein 2 (UCP2) in a retinal pigment epithelium cell line (ARPE-19), under oxidative stress (OS). METHODS ARPE-19 cells were divided into groups treated with various concentrations of hydrogen peroxide (H2O2; 0, 150, 300, 500, 700, and 900 µmol/L) for 24h, to induce oxidative damage and cell viability was assessed by MTT assay. UCP2 mRNA expression in cells treated with H2O2 was investigated by reverse transcription-polymerase chain reaction (RT-PCR). UCP2 protein expression was assessed by Western blotting and ROS levels analyzed by flow cytometry (FCM). Further, UCP2-siRNA treated cultures were exposed to H2O2 (0, 75, 150, and 300 µmol/L) for 2h and cell viability determined by MTT assay. RESULTS Cells treated with higher concentrations of H2O2 appeared shrunken; their adhesion to adjacent cells was disrupted, and the number of dead cells increased. The results of cell viability assays demonstrated that the numbers of cells were decreased in a dose-dependent manner following treatment with H2O2. Compared with untreated controls, cell viability was significantly reduced after treatment with >300 µmol/L H2O2 (P<0.05). Cell metabolic activity was decreased with increased concentrations of H2O2 as detected by MTT assay. Levels of OS were further decreased in cells treated with UCP2-siRNA compared with those treated with H2O2 alone (P<0.05). The results of RT-PCR and Western blotting demonstrated that UCP2 expression was reduced in H2O2-treated groups compared with controls (P<0.05). FCM analysis showed that cell reactive oxygen species (ROS) levels were increased in H2O2-treated groups and further upregulated by UCP2-siRNA treatment (P<0.05). CONCLUSION Expression levels of UCP2 are decreased in ARPE-19 cells treated with H2O2. ROS levels are further increased in cells treated with UCP2-siRNA relative to those treated with H2O2 alone. UCP2 may have a protective role in ARPE-19 cells during oxidative injury.
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Affiliation(s)
- Ying Liu
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Medical University; Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an 710038, Shaanxi Province, China
| | - Yuan Ren
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Medical University; Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an 710038, Shaanxi Province, China
| | - Xia Wang
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Medical University; Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an 710038, Shaanxi Province, China
| | - Xu Liu
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Medical University; Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an 710038, Shaanxi Province, China
| | - Yun Xu
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Medical University; Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an 710038, Shaanxi Province, China
| | - Yuan He
- Department of Ophthalmology, the Second Affiliated Hospital of Xi'an Medical University; Ocular Immunology and Inflammation Institute, Shaanxi Provincial Clinical Research Center for Ophthalmology, Xi'an 710038, Shaanxi Province, China
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Rutkai I, Merdzo I, Wunnava SV, Curtin GT, Katakam PVG, Busija DW. Cerebrovascular function and mitochondrial bioenergetics after ischemia-reperfusion in male rats. J Cereb Blood Flow Metab 2019; 39:1056-1068. [PMID: 29215305 PMCID: PMC6547195 DOI: 10.1177/0271678x17745028] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 11/06/2017] [Indexed: 12/16/2022]
Abstract
The underlying factors promoting increased mitochondrial proteins, mtDNA, and dilation to mitochondrial-specific agents in male rats following tMCAO are not fully elucidated. Our goal was to determine the morphological and functional effects of ischemia/reperfusion (I/R) on mitochondria using electron microscopy, Western blot, mitochondrial oxygen consumption rate (OCR), and Ca2+ sparks activity measurements in middle cerebral arteries (MCAs) from male Sprague Dawley rats (Naïve, tMCAO, Sham). We found a greatly increased OCR in ipsilateral MCAs (IPSI) compared with contralateral (CONTRA), Sham, and Naïve MCAs. Consistent with our earlier findings, the expression of Mitofusin-2 and OPA-1 was significantly decreased in IPSI arteries compared with Sham and Naïve. Mitochondrial morphology was disrupted in vascular smooth muscle, but morphology with normal and perhaps greater numbers of mitochondria were observed in IPSI compared with CONTRA MCAs. Consistently, there were significantly fewer baseline Ca2+ events in IPSI MCAs compared with CONTRA, Sham, and Naïve. Mitochondrial depolarization significantly increased Ca2+ sparks activity in the IPSI, Sham, Naïve, but not in the CONTRA group. Our data indicate that altered mitochondrial structure and function occur in MCAs exposed to I/R and that these changes impact not only OCR but Ca2+ sparks activity in both IPSI and CONTRA MCAs.
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Affiliation(s)
- Ibolya Rutkai
- Department of Pharmacology,
Tulane
University School of Medicine, New Orleans,
LA, USA
| | - Ivan Merdzo
- Department of Pharmacology,
Tulane
University School of Medicine, New Orleans,
LA, USA
- Department of Pharmacology, University
of Mostar School of Medicine, Mostar, Bosnia and Herzegovina
| | - Sanjay V Wunnava
- Department of Pharmacology,
Tulane
University School of Medicine, New Orleans,
LA, USA
| | - Genevieve T Curtin
- Department of Pharmacology,
Tulane
University School of Medicine, New Orleans,
LA, USA
| | - Prasad VG Katakam
- Department of Pharmacology,
Tulane
University School of Medicine, New Orleans,
LA, USA
| | - David W Busija
- Department of Pharmacology,
Tulane
University School of Medicine, New Orleans,
LA, USA
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11
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Jarmuszkiewicz W, Szewczyk A. Energy-dissipating hub in muscle mitochondria: Potassium channels and uncoupling proteins. Arch Biochem Biophys 2019; 664:102-109. [DOI: 10.1016/j.abb.2019.01.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 01/30/2019] [Accepted: 01/31/2019] [Indexed: 01/15/2023]
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12
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Nanayakkara GK, Wang H, Yang X. Proton leak regulates mitochondrial reactive oxygen species generation in endothelial cell activation and inflammation - A novel concept. Arch Biochem Biophys 2018; 662:68-74. [PMID: 30521782 DOI: 10.1016/j.abb.2018.12.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 11/27/2018] [Accepted: 12/02/2018] [Indexed: 12/18/2022]
Abstract
Mitochondria are capable of detecting cellular insults and orchestrating inflammatory responses. Mitochondrial reactive oxygen species (mtROS) are intermediates that trigger inflammatory signaling cascades in response to our newly proposed conditional damage associated molecular patterns (DAMP). We recently reported that increased proton leak regulates mtROS generation and thereby exert physiological and pathological activation of endothelial cells. Herein, we report the recent progress in determining the roles of proton leak in regulating mtROS, and highlight several important findings: 1) The majority of mtROS are generated in the complexes I and III of electron transport chain (ETC); 2) Inducible proton leak and mtROS production are mutually regulated; 3) ATP synthase-uncoupled ETC activity and mtROS regulate both physiological and pathological endothelial cell activation and inflammation initiation; 4) Mitochondrial Ca2+ uniporter and exchanger proteins have an impact on proton leak and mtROS generation; 5) MtROS connect signaling pathways between conditional DAMP-regulated immunometabolism and histone post-translational modifications (PTM) and gene expression. Continuous improvement of our understanding in this aspect of mitochondrial function would provide novel insights and generate novel therapeutic targets for the treatment of sterile inflammatory disorders such as metabolic diseases, cardiovascular diseases and cancers.
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Affiliation(s)
- Gayani K Nanayakkara
- Centers for Metabolic Disease Research, Cardiovascular Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, 19140, USA
| | - Hong Wang
- Centers for Metabolic Disease Research, Cardiovascular Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, 19140, USA
| | - Xiaofeng Yang
- Centers for Metabolic Disease Research, Cardiovascular Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, 19140, USA.
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13
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Salazar C, Ruiz-Hincapie P, Ruiz LM. The Interplay among PINK1/PARKIN/Dj-1 Network during Mitochondrial Quality Control in Cancer Biology: Protein Interaction Analysis. Cells 2018; 7:cells7100154. [PMID: 30274236 PMCID: PMC6210981 DOI: 10.3390/cells7100154] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 09/14/2018] [Accepted: 09/25/2018] [Indexed: 12/18/2022] Open
Abstract
PARKIN (E3 ubiquitin ligase PARK2), PINK1 (PTEN induced kinase 1) and DJ-1 (PARK7) are proteins involved in autosomal recessive parkinsonism, and carcinogenic processes. In damaged mitochondria, PINK1’s importing into the inner mitochondrial membrane is prevented, PARKIN presents a partial mitochondrial localization at the outer mitochondrial membrane and DJ-1 relocates to mitochondria when oxidative stress increases. Depletion of these proteins result in abnormal mitochondrial morphology. PINK1, PARKIN, and DJ-1 participate in mitochondrial remodeling and actively regulate mitochondrial quality control. In this review, we highlight that PARKIN, PINK1, and DJ-1 should be regarded as having an important role in Cancer Biology. The STRING database and Gene Ontology (GO) enrichment analysis were performed to consolidate knowledge of well-known protein interactions for PINK1, PARKIN, and DJ-1 and envisage new ones. The enrichment analysis of KEGG pathways showed that the PINK1/PARKIN/DJ-1 network resulted in Parkinson disease as the main feature, while the protein DJ-1 showed enrichment in prostate cancer and p53 signaling pathway. Some predicted transcription factors regulating PINK1, PARK2 (PARKIN) and PARK7 (DJ-1) gene expression are related to cell cycle control. We can therefore suggest that the interplay among PINK1/PARKIN/DJ-1 network during mitochondrial quality control in cancer biology may occur at the transcriptional level. Further analysis, like a systems biology approach, will be helpful in the understanding of PINK1/PARKIN/DJ-1 network.
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Affiliation(s)
- Celia Salazar
- Instituto de Investigaciones Biomédicas, Universidad Autónoma de Chile, Santiago 8910060, Chile.
| | - Paula Ruiz-Hincapie
- School of Engineering and Technology, University of Hertfordshire, Hatfield AL 10 9AB, UK.
| | - Lina María Ruiz
- Instituto de Investigaciones Biomédicas, Universidad Autónoma de Chile, Santiago 8910060, Chile.
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14
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Cadenas S. Mitochondrial uncoupling, ROS generation and cardioprotection. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:940-950. [DOI: 10.1016/j.bbabio.2018.05.019] [Citation(s) in RCA: 238] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 05/11/2018] [Accepted: 05/29/2018] [Indexed: 12/31/2022]
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15
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Hassanpour SH, Dehghani MA, Karami SZ. Study of respiratory chain dysfunction in heart disease. J Cardiovasc Thorac Res 2018; 10:1-13. [PMID: 29707171 PMCID: PMC5913686 DOI: 10.15171/jcvtr.2018.01] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 12/25/2017] [Indexed: 02/06/2023] Open
Abstract
The relentlessly beating heart has the greatest oxygen consumption of any organ in the body at rest reflecting its huge metabolic turnover and energetic demands. The vast majority of its energy is produced and cycled in form of ATP which stems mainly from oxidative phosphorylation occurring at the respiratory chain in the mitochondria. A part from energy production, the respiratory chain is also the main source of reactive oxygen species and plays a pivotal role in the regulation of oxidative stress. Dysfunction of the respiratory chain is therefore found in most common heart conditions. The pathophysiology of mitochondrial respiratory chain dysfunction in hereditary cardiac mitochondrial disease, the aging heart, in LV hypertrophy and heart failure, and in ischaemia-reperfusion injury is reviewed. We introduce the practicing clinician to the complex physiology of the respiratory chain, highlight its impact on common cardiac disorders and review translational pharmacological and non-pharmacological treatment strategies.
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Affiliation(s)
| | - Mohammad Amin Dehghani
- Department of Toxicology, School of Pharmacy, Ahvaz Jundishapour University of Medical Sciences, Ahvaz, Iran
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16
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Xu F, Qiao S, Li H, Deng Y, Wang C, An J. The Effect of Mitochondrial Complex I-Linked Respiration by Isoflurane Is Independent of Mitochondrial Nitric Oxide Production. Cardiorenal Med 2018; 8:113-122. [PMID: 29617003 DOI: 10.1159/000485936] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 10/30/2017] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Anesthetic preconditioning (APC) of the myocardium is mediated in part by reversible alteration of mitochondrial function. Nitric oxide (NO) inhibits mitochondrial respiration and may mediate APC-induced cardioprotection. In this study, the effects of isoflurane on different states of mitochondrial respiration during the oxidation of complex I-linked substrates and the role of NO were investigated. METHODS Mitochondria were isolated from Sprague-Dawley rat hearts. Respiration rates were measured polarographically at 28ºC with a computer-controlled Clark-type O2 electrode in the mitochondria (0.5 mg/mL) with complex I substrates glutamate/malate (5 mM). Isoflurane (0.25 mM) was administered before or after adenosine diphosphate (ADP)-initiated state 3 respiration. The NO synthase (NOS) inhibitor L-N5-(1-iminoethyl)-ornithine (L-NIO, 10 μM) and the NO donor S-nitroso-N-acetylpenicillamine (SNAP, 1 μM) were added before or after the addition of ADP. RESULTS Isoflurane administered in state 2 increased state 2 respiration and decreased state 3 respiration. This attenuation of state 3 respiration by isoflurane was similar when it was given during state 3. L-NIO did not alter mitochondrial respiration or the effect of isoflurane. SNAP only, added in state 3, decreased state 3 respiration and enhanced the isoflurane-induced attenuation of state 3 respiration. CONCLUSION Isoflurane has clearly distinguishable effects on different states of mitochondrial respiration during the oxidation of complex I substrates. The uncoupling effect during state 2 respiration and the attenuation of state 3 respiration may contribute to the mechanism of APC-induced cardioprotection. These effects of isoflurane do not depend on endogenous mitochondrial NO, as the NOS inhibitor L-NIO did not alter the effects of isoflurane on mitochondrial respiration.
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Affiliation(s)
- Fuqi Xu
- Department of Anesthesiology and Perioperative Medicine, Suzhou, China
| | - Shigang Qiao
- Department of Anesthesiology and Perioperative Medicine, Suzhou, China.,Institute of Clinical Medicine Research, Suzhou Hospital (West District) Affiliated to Nanjing Medical University, Suzhou Science and Technology Town Hospital, Suzhou, China
| | - Hua Li
- Department of Anesthesiology and Perioperative Medicine, Suzhou, China
| | - Yanjun Deng
- Department of Anesthesiology and Perioperative Medicine, Suzhou, China
| | - Chen Wang
- Department of Anesthesiology and Perioperative Medicine, Suzhou, China.,Institute of Clinical Medicine Research, Suzhou Hospital (West District) Affiliated to Nanjing Medical University, Suzhou Science and Technology Town Hospital, Suzhou, China
| | - Jianzhong An
- Institute of Clinical Medicine Research, Suzhou Hospital (West District) Affiliated to Nanjing Medical University, Suzhou Science and Technology Town Hospital, Suzhou, China
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17
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Cheng J, Nanayakkara G, Shao Y, Cueto R, Wang L, Yang WY, Tian Y, Wang H, Yang X. Mitochondrial Proton Leak Plays a Critical Role in Pathogenesis of Cardiovascular Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 982:359-370. [PMID: 28551798 DOI: 10.1007/978-3-319-55330-6_20] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mitochondrial proton leak is the principal mechanism that incompletely couples substrate oxygen to ATP generation. This chapter briefly addresses the recent progress made in understanding the role of proton leak in the pathogenesis of cardiovascular diseases. Majority of the proton conductance is mediated by uncoupling proteins (UCPs) located in the mitochondrial inner membrane. It is evident that the proton leak and reactive oxygen species (ROS) generated from electron transport chain (ETC) in mitochondria are linked to each other. Increased ROS production has been shown to induce proton conductance, and in return, increased proton conductance suppresses ROS production, suggesting the existence of a positive feedback loop that protects the biological systems from detrimental effects of augmented oxidative stress. There is mounting evidence attributing to proton leak and uncoupling proteins a crucial role in the pathogenesis of cardiovascular disease. We can surmise the role of "uncoupling" in cardiovascular disorders as follows; First, the magnitude of the proton leak and the mechanism involved in mediating the proton leak determine whether there is a protective effect against ischemia-reperfusion (IR) injury. Second, uncoupling by UCP2 preserves vascular function in diet-induced obese mice as well as in diabetes. Third, etiology determines whether the proton conductance is altered or not during hypertension. And fourth, proton leak regulates ATP synthesis-uncoupled mitochondrial ROS generation, which determines pathological activation of endothelial cells for recruitment of inflammatory cells. Continue effort in improving our understanding in the role of proton leak in the pathogenesis of cardiovascular and metabolic diseases would lead to identification of novel therapeutic targets for treatment.
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Affiliation(s)
- Jiali Cheng
- Department of Cardiovascular Medicine, The First Affiliate Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China
- Centers for Metabolic Disease Research, Cardiovascular Research, & Thrombosis Research, Department of Pharmacology, Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, MERB-1059, Philadelphia, PA, 19140, USA
| | - Gayani Nanayakkara
- Centers for Metabolic Disease Research, Cardiovascular Research, & Thrombosis Research, Department of Pharmacology, Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, MERB-1059, Philadelphia, PA, 19140, USA
| | - Ying Shao
- Centers for Metabolic Disease Research, Cardiovascular Research, & Thrombosis Research, Department of Pharmacology, Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, MERB-1059, Philadelphia, PA, 19140, USA
| | - Ramon Cueto
- Centers for Metabolic Disease Research, Cardiovascular Research, & Thrombosis Research, Department of Pharmacology, Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, MERB-1059, Philadelphia, PA, 19140, USA
| | - Luqiao Wang
- Centers for Metabolic Disease Research, Cardiovascular Research, & Thrombosis Research, Department of Pharmacology, Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, MERB-1059, Philadelphia, PA, 19140, USA
| | - William Y Yang
- Department of Cardiovascular Medicine, The First Affiliate Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Ye Tian
- Department of Cardiovascular Medicine, The First Affiliate Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Hong Wang
- Centers for Metabolic Disease Research, Cardiovascular Research, & Thrombosis Research, Department of Pharmacology, Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, MERB-1059, Philadelphia, PA, 19140, USA
| | - Xiaofeng Yang
- Centers for Metabolic Disease Research, Cardiovascular Research, & Thrombosis Research, Department of Pharmacology, Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, MERB-1059, Philadelphia, PA, 19140, USA.
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18
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Schwarz K, Singh S, Parasuraman SK, Rudd A, Shepstone L, Feelisch M, Minnion M, Ahmad S, Madhani M, Horowitz J, Dawson DK, Frenneaux MP. Inorganic Nitrate in Angina Study: A Randomized Double-Blind Placebo-Controlled Trial. J Am Heart Assoc 2017; 6:JAHA.117.006478. [PMID: 28887315 PMCID: PMC5634294 DOI: 10.1161/jaha.117.006478] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Background In this double‐blind randomized placebo‐controlled crossover trial, we investigated whether oral sodium nitrate, when added to existing background medication, reduces exertional ischemia in patients with angina. Methods and Results Seventy patients with stable angina, positive electrocardiogram treadmill test, and either angiographic or functional test evidence of significant ischemic heart disease were randomized to receive oral treatment with either placebo or sodium nitrate (600 mg; 7 mmol) for 7 to 10 days, followed by a 2‐week washout period before crossing over to the other treatment (n=34 placebo‐nitrate, n=36 nitrate‐placebo). At baseline and at the end of each treatment, patients underwent modified Bruce electrocardiogram treadmill test, modified Seattle Questionnaire, and subgroups were investigated with dobutamine stress, echocardiogram, and blood tests. The primary outcome was time to 1 mm ST depression on electrocardiogram treadmill test. Compared with placebo, inorganic nitrate treatment tended to increase the primary outcome exercise time to 1 mm ST segment depression (645.6 [603.1, 688.0] seconds versus 661.2 [6183, 704.0] seconds, P=0.10) and significantly increased total exercise time (744.4 [702.4, 786.4] seconds versus 760.9 [719.5, 802.2] seconds, P=0.04; mean [95% confidence interval]). Nitrate treatment robustly increased plasma nitrate (18.3 [15.2, 21.5] versus 297.6 [218.4, 376.8] μmol/L, P<0.0001) and almost doubled circulating nitrite concentrations (346 [285, 405] versus 552 [398, 706] nmol/L, P=0.003; placebo versus nitrate treatment). Other secondary outcomes were not significantly altered by the intervention. Patients on antacid medication appeared to benefit less from nitrate supplementation. Conclusions Sodium nitrate treatment may confer a modest exercise capacity benefit in patients with chronic angina who are taking other background medication. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02078921. EudraCT number: 2012‐000196‐17.
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Affiliation(s)
- Konstantin Schwarz
- School of Medicine & Dentistry, University of Aberdeen, Aberdeen, UK.,Royal Wolverhampton Hospital, Wolverhampton, UK
| | - Satnam Singh
- School of Medicine & Dentistry, University of Aberdeen, Aberdeen, UK
| | - Satish K Parasuraman
- School of Medicine & Dentistry, University of Aberdeen, Aberdeen, UK.,Norwich Medical School, University of East Anglia, Norwich, UK
| | - Amelia Rudd
- School of Medicine & Dentistry, University of Aberdeen, Aberdeen, UK
| | - Lee Shepstone
- Norwich Medical School, University of East Anglia, Norwich, UK
| | | | | | - Shakil Ahmad
- Aston Medical Research Institute, Aston University, Birmingham, UK
| | - Melanie Madhani
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - John Horowitz
- Basil Hetzel Institute, University of Adelaide, Adelaide, Australia
| | - Dana K Dawson
- School of Medicine & Dentistry, University of Aberdeen, Aberdeen, UK
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19
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Vishwakarma VK, Upadhyay PK, Gupta JK, Yadav HN. Pathophysiologic role of ischemia reperfusion injury: A review. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.jicc.2017.06.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
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20
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The Slo(w) path to identifying the mitochondrial channels responsible for ischemic protection. Biochem J 2017; 474:2067-2094. [PMID: 28600454 DOI: 10.1042/bcj20160623] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 02/10/2017] [Accepted: 02/13/2017] [Indexed: 12/19/2022]
Abstract
Mitochondria play an important role in tissue ischemia and reperfusion (IR) injury, with energetic failure and the opening of the mitochondrial permeability transition pore being the major causes of IR-induced cell death. Thus, mitochondria are an appropriate focus for strategies to protect against IR injury. Two widely studied paradigms of IR protection, particularly in the field of cardiac IR, are ischemic preconditioning (IPC) and volatile anesthetic preconditioning (APC). While the molecular mechanisms recruited by these protective paradigms are not fully elucidated, a commonality is the involvement of mitochondrial K+ channel opening. In the case of IPC, research has focused on a mitochondrial ATP-sensitive K+ channel (mitoKATP), but, despite recent progress, the molecular identity of this channel remains a subject of contention. In the case of APC, early research suggested the existence of a mitochondrial large-conductance K+ (BK, big conductance of potassium) channel encoded by the Kcnma1 gene, although more recent work has shown that the channel that underlies APC is in fact encoded by Kcnt2 In this review, we discuss both the pharmacologic and genetic evidence for the existence and identity of mitochondrial K+ channels, and the role of these channels both in IR protection and in regulating normal mitochondrial function.
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21
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Rines AK, Chang HC, Wu R, Sato T, Khechaduri A, Kouzu H, Shapiro J, Shang M, Burke MA, Abdelwahid E, Jiang X, Chen C, Rawlings TA, Lopaschuk GD, Schumacker PT, Abel ED, Ardehali H. Snf1-related kinase improves cardiac mitochondrial efficiency and decreases mitochondrial uncoupling. Nat Commun 2017; 8:14095. [PMID: 28117339 PMCID: PMC5286102 DOI: 10.1038/ncomms14095] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 11/28/2016] [Indexed: 12/26/2022] Open
Abstract
Ischaemic heart disease limits oxygen and metabolic substrate availability to the heart, resulting in tissue death. Here, we demonstrate that the AMP-activated protein kinase (AMPK)-related protein Snf1-related kinase (SNRK) decreases cardiac metabolic substrate usage and mitochondrial uncoupling, and protects against ischaemia/reperfusion. Hearts from transgenic mice overexpressing SNRK have decreased glucose and palmitate metabolism and oxygen consumption, but maintained power and function. They also exhibit decreased uncoupling protein 3 (UCP3) and mitochondrial uncoupling. Conversely, Snrk knockout mouse hearts have increased glucose and palmitate oxidation and UCP3. SNRK knockdown in cardiac cells decreases mitochondrial efficiency, which is abolished with UCP3 knockdown. We show that Tribbles homologue 3 (Trib3) binds to SNRK, and downregulates UCP3 through PPARα. Finally, SNRK is increased in cardiomyopathy patients, and SNRK reduces infarct size after ischaemia/reperfusion. SNRK also decreases cardiac cell death in a UCP3-dependent manner. Our results suggest that SNRK improves cardiac mitochondrial efficiency and ischaemic protection. The Snf1-related kinase (SNRK) is widely expressed and yet its function is poorly understood. Here the authors show that SNRK regulates mitochondrial coupling via the Trib3-PPARα-UCP3 pathway and that cardiac overexpression of SNRK decreases metabolic substrate usage and oxygen consumption but maintains cardiac function and energy in mice.
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Affiliation(s)
- Amy K Rines
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Hsiang-Chun Chang
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Rongxue Wu
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Tatsuya Sato
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Arineh Khechaduri
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Hidemichi Kouzu
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Jason Shapiro
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Meng Shang
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Michael A Burke
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Eltyeb Abdelwahid
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Xinghang Jiang
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Chunlei Chen
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Tenley A Rawlings
- Division of Endocrinology, Metabolism, and Diabetes and Program in Molecular Medicine, University of Utah, School of Medicine, Salt Lake City, Utah 84132, USA
| | - Gary D Lopaschuk
- Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada T6G 2B7
| | - Paul T Schumacker
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - E Dale Abel
- Division of Endocrinology, Metabolism, and Diabetes and Program in Molecular Medicine, University of Utah, School of Medicine, Salt Lake City, Utah 84132, USA
| | - Hossein Ardehali
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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22
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Zhou Y, Zhang MJ, Li BH, Chen L, Pi Y, Yin YW, Long CY, Wang X, Sun MJ, Chen X, Gao CY, Li JC, Zhang LL. PPARγ Inhibits VSMC Proliferation and Migration via Attenuating Oxidative Stress through Upregulating UCP2. PLoS One 2016; 11:e0154720. [PMID: 27144886 PMCID: PMC4856345 DOI: 10.1371/journal.pone.0154720] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 04/18/2016] [Indexed: 01/20/2023] Open
Abstract
Increasing evidence showed that abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) are common event in the pathophysiology of many vascular diseases, including atherosclerosis and restenosis after angioplasty. Among the underlying mechanisms, oxidative stress is one of the principal contributors to the proliferation and migration of VSMCs. Oxidative stress occurs as a result of persistent production of reactive oxygen species (ROS). Recently, the protective effects of peroxisome proliferator-activated receptor γ (PPARγ) against oxidative stress/ROS in other cell types provide new insights to inhibit the suggests that PPARγ may regulate VSMCs function. However, it remains unclear whether activation of PPARγ can attenuate oxidative stress and further inhibit VSMC proliferation and migration. In this study, we therefore investigated the effect of PPARγ on inhibiting VSMC oxidative stress and the capability of proliferation and migration, and the potential role of mitochondrial uncoupling protein 2 (UCP2) in oxidative stress. It was found that platelet derived growth factor-BB (PDGF-BB) induced VSMC proliferation and migration as well as ROS production; PPARγ inhibited PDGF-BB-induced VSMC proliferation, migration and oxidative stress; PPARγ activation upregulated UCP2 expression in VSMCs; PPARγ inhibited PDGF-BB-induced ROS in VSMCs by upregulating UCP2 expression; PPARγ ameliorated injury-induced oxidative stress and intimal hyperplasia (IH) in UCP2-dependent manner. In conclusion, our study provides evidence that activation of PPARγ can attenuate ROS and VSMC proliferation and migration by upregulating UCP2 expression, and thus inhibit IH following carotid injury. These findings suggest PPARγ may represent a prospective target for the prevention and treatment of IH-associated vascular diseases.
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Affiliation(s)
- Yi Zhou
- Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, PR China
| | - Ming-Jie Zhang
- Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, PR China
| | - Bing-Hu Li
- Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, PR China
| | - Lei Chen
- Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, PR China
| | - Yan Pi
- Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, PR China
| | - Yan-Wei Yin
- Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, PR China
| | - Chun-Yan Long
- Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, PR China
| | - Xu Wang
- Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, PR China
| | - Meng-Jiao Sun
- Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, PR China
| | - Xue Chen
- Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, PR China
| | - Chang-Yue Gao
- Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, PR China
| | - Jing-Cheng Li
- Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, PR China
- * E-mail: (L-LZ); (J-CL)
| | - Li-Li Zhang
- Department of Neurology, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 10 Changjiang Branch Road, Yuzhong District, Chongqing, 400042, PR China
- * E-mail: (L-LZ); (J-CL)
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23
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The Role of Mitochondrial Functional Proteins in ROS Production in Ischemic Heart Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:5470457. [PMID: 27119006 PMCID: PMC4826939 DOI: 10.1155/2016/5470457] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 01/27/2016] [Accepted: 01/28/2016] [Indexed: 02/06/2023]
Abstract
Ischemic heart diseases (IHD) have become the leading cause of death around the world, killing more than 7 million people annually. In IHD, the blockage of coronary vessels will cause irreversible cell injury and even death. As the “powerhouse” and “apoptosis center” in cardiomyocytes, mitochondria play critical roles in IHD. Ischemia insult can reduce myocardial ATP content, resulting in energy stress and overproduction of reactive oxygen species (ROS). Thus, mitochondrial abnormality has been identified as a hallmark of multiple cardiovascular disorders. To date, many studies have suggested that these mitochondrial proteins, such as electron transport chain (ETC) complexes, uncoupling proteins (UCPs), mitochondrial dynamic proteins, translocases of outer membrane (Tom) complex, and mitochondrial permeability transition pore (MPTP), can directly or indirectly influence mitochondria-originated ROS production, consequently determining the degree of mitochondrial dysfunction and myocardial impairment. Here, the focus of this review is to summarize the present understanding of the relationship between some mitochondrial functional proteins and ROS production in IHD.
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Nadtochiy SM, Urciuoli W, Zhang J, Schafer X, Munger J, Brookes PS. Metabolomic profiling of the heart during acute ischemic preconditioning reveals a role for SIRT1 in rapid cardioprotective metabolic adaptation. J Mol Cell Cardiol 2015; 88:64-72. [PMID: 26388263 DOI: 10.1016/j.yjmcc.2015.09.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 09/14/2015] [Accepted: 09/16/2015] [Indexed: 12/13/2022]
Abstract
Ischemic preconditioning (IPC) protects tissues such as the heart from prolonged ischemia-reperfusion (IR) injury. We previously showed that the lysine deacetylase SIRT1 is required for acute IPC, and has numerous metabolic targets. While it is known that metabolism is altered during IPC, the underlying metabolic regulatory mechanisms are unknown, including the relative importance of SIRT1. Thus, we sought to test the hypothesis that some of the metabolic adaptations that occur in IPC may require SIRT1 as a regulatory mediator. Using both ex-vivo-perfused and in-vivo mouse hearts, LC-MS/MS based metabolomics and (13)C-labeled substrate tracing, we found that acute IPC altered several metabolic pathways including: (i) stimulation of glycolysis, (ii) increased synthesis of glycogen and several amino acids, (iii) increased reduced glutathione levels, (iv) elevation in the oncometabolite 2-hydroxyglutarate, and (v) inhibition of fatty-acid dependent respiration. The majority (83%) of metabolic alterations induced by IPC were ablated when SIRT1 was acutely inhibited with splitomicin, and a principal component analysis revealed that metabolic changes in response to IPC were fundamentally different in nature when SIRT1 was inhibited. Furthermore, the protective benefit of IPC was abrogated by eliminating glucose from perfusion media while sustaining normal cardiac function by burning fat, thus indicating that glucose dependency is required for acute IPC. Together, these data suggest that SIRT1 signaling is required for rapid cardioprotective metabolic adaptation in acute IPC.
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Affiliation(s)
- Sergiy M Nadtochiy
- Department of Anesthesiology, University of Rochester Medical Center, Rochester, NY, USA
| | - William Urciuoli
- Department of Anesthesiology, University of Rochester Medical Center, Rochester, NY, USA
| | - Jimmy Zhang
- Department of Pharmacology & Physiology, University of Rochester Medical Center, Rochester, NY, USA
| | - Xenia Schafer
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, NY, USA
| | - Joshua Munger
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, NY, USA
| | - Paul S Brookes
- Department of Anesthesiology, University of Rochester Medical Center, Rochester, NY, USA.
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25
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Hoshovs'ka IV. [The role of uncoupling proteins in mechanisms of protection from oxidative stress]. ACTA ACUST UNITED AC 2015; 61:91-101. [PMID: 26040041 DOI: 10.15407/fz61.01.091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Uncoupling proteins, UCPs, are located in the inner mitochondrial membrane and catalize proton leak across the inner mitochondrial membrane. While UCP1 from brown adipose tissue (BAT) dissipates energy of proton gradient as heat mediating process of thermogenesis, the function of cardiac isoforms of UCPs is still debated. Since the content of UCPs in heart tissue is much lesser then in BAT mild uncoupling of respiratory chain by UCPs might regulate membrane potential of cardiac mitochondria, preventing excessive production of reactive oxygen species. The review is focused on own and literature evidences suggesting the protective role of UCPs activation from oxidative stress under ischemia-reperfusion conditions and aging. Participation of UCPs in endogenous mechanisms of cardioprotection induced by ischemic preconditioning is discussed.
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26
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Agarwal B, Stowe DF, Dash RK, Bosnjak ZJ, Camara AKS. Mitochondrial targets for volatile anesthetics against cardiac ischemia-reperfusion injury. Front Physiol 2014; 5:341. [PMID: 25278902 PMCID: PMC4165278 DOI: 10.3389/fphys.2014.00341] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 08/20/2014] [Indexed: 12/15/2022] Open
Abstract
Mitochondria are critical modulators of cell function and are increasingly recognized as proximal sensors and effectors that ultimately determine the balance between cell survival and cell death. Volatile anesthetics (VA) are long known for their cardioprotective effects, as demonstrated by improved mitochondrial and cellular functions, and by reduced necrotic and apoptotic cell death during cardiac ischemia and reperfusion (IR) injury. The molecular mechanisms by which VA impart cardioprotection are still poorly understood. Because of the emerging role of mitochondria as therapeutic targets in diseases, including ischemic heart disease, it is important to know if VA-induced cytoprotective mechanisms are mediated at the mitochondrial level. In recent years, considerable evidence points to direct effects of VA on mitochondrial channel/transporter protein functions and electron transport chain (ETC) complexes as potential targets in mediating cardioprotection. This review furnishes an integrated overview of targets that VA impart on mitochondrial channels/transporters and ETC proteins that could provide a basis for cation regulation and homeostasis, mitochondrial bioenergetics, and reactive oxygen species (ROS) emission in redox signaling for cardiac cell protection during IR injury.
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Affiliation(s)
- Bhawana Agarwal
- Department of Anesthesiology, Medical College of WisconsinMilwaukee, WI, USA
| | - David F. Stowe
- Department of Anesthesiology, Medical College of WisconsinMilwaukee, WI, USA
- Department of Physiology, Medical College of WisconsinMilwaukee, WI, USA
- Cardiovascular Research Center, Medical College of WisconsinMilwaukee, WI, USA
- Zablocki VA Medical CenterMilwaukee, WI, USA
- Department of Biomedical Engineering, Marquette UniversityMilwaukee, WI, USA
| | - Ranjan K. Dash
- Department of Physiology, Medical College of WisconsinMilwaukee, WI, USA
- Department of Biomedical Engineering, Marquette UniversityMilwaukee, WI, USA
- Biotechnology and Bioengineering Center, Medical College of WisconsinMilwaukee, WI, USA
| | - Zeljko J. Bosnjak
- Department of Anesthesiology, Medical College of WisconsinMilwaukee, WI, USA
- Department of Physiology, Medical College of WisconsinMilwaukee, WI, USA
- Cardiovascular Research Center, Medical College of WisconsinMilwaukee, WI, USA
| | - Amadou K. S. Camara
- Department of Anesthesiology, Medical College of WisconsinMilwaukee, WI, USA
- Cardiovascular Research Center, Medical College of WisconsinMilwaukee, WI, USA
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27
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Quarrie R, Lee DS, Reyes L, Erdahl W, Pfeiffer DR, Zweier JL, Crestanello JA. Mitochondrial uncoupling does not decrease reactive oxygen species production after ischemia-reperfusion. Am J Physiol Heart Circ Physiol 2014; 307:H996-H1004. [PMID: 25085966 DOI: 10.1152/ajpheart.00189.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Cardiac ischemia-reperfusion (IR) leads to myocardial dysfunction by increasing production of reactive oxygen species (ROS). Mitochondrial H(+) leak decreases ROS formation; it has been postulated that increasing H(+) leak may be a mechanism of decreasing ROS production after IR. Ischemic preconditioning (IPC) decreases ROS formation after IR, but the mechanism is unknown. We hypothesize that pharmacologically increasing mitochondrial H(+) leak would decrease ROS production after IR. We further hypothesize that IPC would be associated with an increase in the rate of H(+) leak. Isolated male Sprague-Dawley rat hearts were subjected to either control or IPC. Mitochondria were isolated at end equilibration, end ischemia, and end reperfusion. Mitochondrial membrane potential (mΔΨ) was measured using a tetraphenylphosphonium electrode. Mitochondrial uncoupling was achieved by adding increasing concentrations of FCCP. Mitochondrial ROS production was measured by fluorometry using Amplex-Red. Pyridine dinucleotide levels were measured using HPLC. Before IR, increasing H(+) leak decreased mitochondrial ROS production. After IR, ROS production was not affected by increasing H(+) leak. H(+) leak increased at end ischemia in control mitochondria. IPC mitochondria showed no change in the rate of H(+) leak throughout IR. NADPH levels decreased after IR in both IPC and control mitochondria while NADH increased. Pharmacologically, increasing H(+) leak is not a method of decreasing ROS production after IR. Replenishing the NADPH pool may be a means of scavenging the excess ROS thereby attenuating oxidative damage after IR.
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Affiliation(s)
- Ricardo Quarrie
- Division of Cardiac Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Daniel S Lee
- Division of Cardiac Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Levy Reyes
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio; and
| | - Warren Erdahl
- Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio
| | - Douglas R Pfeiffer
- Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio
| | - Jay L Zweier
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio; and Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio
| | - Juan A Crestanello
- Division of Cardiac Surgery, The Ohio State University Wexner Medical Center, Columbus, Ohio; The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio; and
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28
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Plotnikov EY, Silachev DN, Jankauskas SS, Rokitskaya TI, Chupyrkina AA, Pevzner IB, Zorova LD, Isaev NK, Antonenko YN, Skulachev VP, Zorov DB. Mild uncoupling of respiration and phosphorylation as a mechanism providing nephro- and neuroprotective effects of penetrating cations of the SkQ family. BIOCHEMISTRY (MOSCOW) 2014; 77:1029-37. [PMID: 23157263 DOI: 10.1134/s0006297912090106] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
It is generally accepted that mitochondrial production of reactive oxygen species is nonlinearly related to the value of the mitochondrial membrane potential with significant increment at values exceeding 150 mV. Due to this, high values of the membrane potential are highly dangerous, specifically under pathological conditions associated with oxidative stress. Mild uncoupling of oxidative phosphorylation is an approach to preventing hyperpolarization of the mitochondrial membrane. We confirmed data obtained earlier in our group that dodecylrhodamine 19 (C(12)R1) (a penetrating cation from SkQ family not possessing a plastoquinone group) has uncoupling properties, this fact making it highly potent for use in prevention of pathologies associated with oxidative stress induced by mitochondrial hyperpolarization. Further experiments showed that C(12)R1 provided nephroprotection under ischemia/reperfusion of the kidney as well as under rhabdomyolysis through diminishing of renal dysfunction manifested by elevated level of blood creatinine and urea. Similar nephroprotective properties were observed for low doses (275 nmol/kg) of the conventional uncoupler 2,4-dinitrophenol. Another penetrating cation that did not demonstrate protonophorous activity (SkQR4) had no effect on renal dysfunction. In experiments with induced ischemic stroke, C(12)R1 did not have any effect on the area of ischemic damage, but it significantly lowered neurological deficit. We conclude that beneficial effects of penetrating cation derivatives of rhodamine 19 in renal pathologies and brain ischemia may be at least partially explained by uncoupling of oxidation and phosphorylation.
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Affiliation(s)
- E Y Plotnikov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119991 Moscow, Russia.
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Jara JA, Castro-Castillo V, Saavedra-Olavarría J, Peredo L, Pavanni M, Jaña F, Letelier ME, Parra E, Becker MI, Morello A, Kemmerling U, Maya JD, Ferreira J. Antiproliferative and uncoupling effects of delocalized, lipophilic, cationic gallic acid derivatives on cancer cell lines. Validation in vivo in singenic mice. J Med Chem 2014; 57:2440-54. [PMID: 24568614 DOI: 10.1021/jm500174v] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Tumor cells principally exhibit increased mitochondrial transmembrane potential (ΔΨ(m)) and altered metabolic pathways. The therapeutic targeting and delivery of anticancer drugs to the mitochondria might improve treatment efficacy. Gallic acid exhibits a variety of biological activities, and its ester derivatives can induce mitochondrial dysfunction. Four alkyl gallate triphenylphosphonium lipophilic cations were synthesized, each differing in the size of the linker chain at the cationic moiety. These derivatives were selectively cytotoxic toward tumor cells. The better compound (TPP(+)C10) contained 10 carbon atoms within the linker chain and exhibited an IC50 value of approximately 0.4-1.6 μM for tumor cells and a selectivity index of approximately 17-fold for tumor compared with normal cells. Consequently, its antiproliferative effect was also assessed in vivo. The oxygen consumption rate and NAD(P)H oxidation levels increased in the tumor cell lines (uncoupling effect), resulting in a ΔΨ(m) decrease and a consequent decrease in intracellular ATP levels. Moreover, TPP(+)C10 significantly inhibited the growth of TA3/Ha tumors in mice. According to these results, the antineoplastic activity and safety of TPP(+)C10 warrant further comprehensive evaluation.
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Affiliation(s)
- José A Jara
- Clinical and Molecular Pharmacology Program, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, University of Chile , Independencia 1027, Santiago 8380453, Chile
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30
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Galli GLJ, Lau GY, Richards JG. Beating oxygen: chronic anoxia exposure reduces mitochondrial F1FO-ATPase activity in turtle (Trachemys scripta) heart. ACTA ACUST UNITED AC 2014; 216:3283-93. [PMID: 23926310 DOI: 10.1242/jeb.087155] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The freshwater turtle Trachemys scripta can survive in the complete absence of O2 (anoxia) for periods lasting several months. In mammals, anoxia leads to mitochondrial dysfunction, which culminates in cellular necrosis and apoptosis. Despite the obvious clinical benefits of understanding anoxia tolerance, little is known about the effects of chronic oxygen deprivation on the function of turtle mitochondria. In this study, we compared mitochondrial function in hearts of T. scripta exposed to either normoxia or 2 weeks of complete anoxia at 5°C and during simulated acute anoxia/reoxygenation. Mitochondrial respiration, electron transport chain activities, enzyme activities, proton conductance and membrane potential were measured in permeabilised cardiac fibres and isolated mitochondria. Two weeks of anoxia exposure at 5°C resulted in an increase in lactate, and decreases in ATP, glycogen, pH and phosphocreatine in the heart. Mitochondrial proton conductance and membrane potential were similar between experimental groups, while aerobic capacity was dramatically reduced. The reduced aerobic capacity was the result of a severe downregulation of the F1FO-ATPase (Complex V), which we assessed as a decrease in enzyme activity. Furthermore, in stark contrast to mammalian paradigms, isolated turtle heart mitochondria endured 20 min of anoxia followed by reoxygenation without any impact on subsequent ADP-stimulated O2 consumption (State III respiration) or State IV respiration. Results from this study demonstrate that turtle mitochondria remodel in response to chronic anoxia exposure and a reduction in Complex V activity is a fundamental component of mitochondrial and cellular anoxia survival.
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Affiliation(s)
- Gina L J Galli
- Department of Zoology, The University of British Columbia, Vancouver, BC, Canada.
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31
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Galli GLJ, Richards JG. Mitochondria from anoxia-tolerant animals reveal common strategies to survive without oxygen. J Comp Physiol B 2014; 184:285-302. [DOI: 10.1007/s00360-014-0806-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Revised: 01/09/2014] [Accepted: 01/17/2014] [Indexed: 12/15/2022]
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32
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Ischemic preconditioning protects cardiomyocyte mitochondria through mechanisms independent of cytosol. J Mol Cell Cardiol 2014; 68:79-88. [PMID: 24434643 DOI: 10.1016/j.yjmcc.2014.01.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 01/03/2014] [Indexed: 12/22/2022]
Abstract
Mitochondria play a central role in the protection conferred by ischemic preconditioning (IP) by not fully elucidated mechanisms. We investigated whether IP protects mitochondria against ischemia-reperfusion (IR) injury through mechanisms independent of cytosolic signaling. In isolated rat hearts, sublethal IR increased superoxide production and reduced complex-I- and II-mediated respiration in subsarcolemmal (SS), but not interfibrillar (IF) mitochondria. This effect of IR on mitochondrial respiration was significantly attenuated by IP. Similar results were obtained in isolated cardiac mitochondria subjected to in vitro IR. The reduction in SS mitochondrial respiration in the heart and in vitro model was paralleled by an increase in oxidized cysteine residues, which was also prevented by IP. IP was also protective in mitochondria submitted to lethal IR. The protective effect of IP against respiratory failure was unaffected by inhibition of mitochondrial KATP channels or mitochondrial permeability transition. However, IP protection was lost in mitochondria from genetically-modified animals in which connexin-43, a protein present in SS but not IF mitochondria, was replaced by connexin-32. Our results demonstrate the existence of a protective mitochondrial mechanism or "mitochondrial preconditioning" independent of cytosol that confers protection against IR-induced respiratory failure and oxidative damage, and requires connexin-43.
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33
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Schwarz K, Siddiqi N, Singh S, Neil CJ, Dawson DK, Frenneaux MP. The breathing heart - mitochondrial respiratory chain dysfunction in cardiac disease. Int J Cardiol 2013; 171:134-43. [PMID: 24377708 DOI: 10.1016/j.ijcard.2013.12.014] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 11/04/2013] [Accepted: 12/11/2013] [Indexed: 01/20/2023]
Abstract
The relentlessly beating heart has the greatest oxygen consumption of any organ in the body at rest reflecting its huge metabolic turnover and energetic demands. The vast majority of its energy is produced and cycled in form of ATP which stems mainly from oxidative phosphorylation occurring at the respiratory chain in the mitochondria. Apart from energy production, the respiratory chain is also the main source of reactive oxygen species and plays a pivotal role in the regulation of oxidative stress. Dysfunction of the respiratory chain is therefore found in most common heart conditions. The pathophysiology of mitochondrial respiratory chain dysfunction in hereditary cardiac mitochondrial disease, the ageing heart, in LV hypertrophy and heart failure, and in ischaemia-reperfusion injury is reviewed. We introduce the practising clinician to the complex physiology of the respiratory chain, highlight its impact on common cardiac disorders and review translational pharmacological and non-pharmacological treatment strategies.
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Affiliation(s)
| | | | | | - Christopher J Neil
- University of Aberdeen, United Kingdom; Western Health, Victoria, Australia
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34
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Agarwal B, Dash RK, Stowe DF, Bosnjak ZJ, Camara AKS. Isoflurane modulates cardiac mitochondrial bioenergetics by selectively attenuating respiratory complexes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1837:354-65. [PMID: 24355434 DOI: 10.1016/j.bbabio.2013.11.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 10/28/2013] [Accepted: 11/13/2013] [Indexed: 12/12/2022]
Abstract
Mitochondrial dysfunction contributes to cardiac ischemia-reperfusion (IR) injury but volatile anesthetics (VA) may alter mitochondrial function to trigger cardioprotection. We hypothesized that the VA isoflurane (ISO) mediates cardioprotection in part by altering the function of several respiratory and transport proteins involved in oxidative phosphorylation (OxPhos). To test this we used fluorescence spectrophotometry to measure the effects of ISO (0, 0.5, 1, 2mM) on the time-course of interlinked mitochondrial bioenergetic variables during states 2, 3 and 4 respiration in the presence of either complex I substrate K(+)-pyruvate/malate (PM) or complex II substrate K(+)-succinate (SUC) at physiological levels of extra-matrix free Ca(2+) (~200nM) and Na(+) (10mM). To mimic ISO effects on mitochondrial functions and to clearly delineate the possible ISO targets, the observed actions of ISO were interpreted by comparing effects of ISO to those elicited by low concentrations of inhibitors that act at each respiratory complex, e.g. rotenone (ROT) at complex I or antimycin A (AA) at complex III. Our conclusions are based primarily on the similar responses of ISO and titrated concentrations of ETC. inhibitors during state 3. We found that with the substrate PM, ISO and ROT similarly decreased the magnitude of state 3 NADH oxidation and increased the duration of state 3 NADH oxidation, ΔΨm depolarization, and respiration in a concentration-dependent manner, whereas with substrate SUC, ISO and ROT decreased the duration of state 3 NADH oxidation, ΔΨm depolarization and respiration. Unlike AA, ISO reduced the magnitude of state 3 NADH oxidation with PM or SUC as substrate. With substrate SUC, after complete block of complex I with ROT, ISO and AA similarly increased the duration of state 3 ΔΨm depolarization and respiration. This study provides a mechanistic understanding in how ISO alters mitochondrial function in a way that may lead to cardioprotection.
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Affiliation(s)
- Bhawana Agarwal
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Ranjan K Dash
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA; Biotechnology and Bioengineering Center, Medical College of Wisconsin, Milwaukee, WI, USA; Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - David F Stowe
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA; Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI, USA; Research Service, Zablocki VA Medical Center, Milwaukee, WI, USA; Department of Biomedical Engineering, Marquette University, Milwaukee, WI, USA
| | - Zeljko J Bosnjak
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA; Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Amadou K S Camara
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, USA; Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI, USA
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35
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ADP protects cardiac mitochondria under severe oxidative stress. PLoS One 2013; 8:e83214. [PMID: 24349464 PMCID: PMC3862761 DOI: 10.1371/journal.pone.0083214] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 10/31/2013] [Indexed: 12/31/2022] Open
Abstract
ADP is not only a key substrate for ATP generation, but also a potent inhibitor of mitochondrial permeability transition pore (mPTP). In this study, we assessed how oxidative stress affects the potency of ADP as an mPTP inhibitor and whether its reduction of reactive oxygen species (ROS) production might be involved. We determined quantitatively the effects of ADP on mitochondrial Ca(2+) retention capacity (CRC) until the induction of mPTP in normal and stressed isolated cardiac mitochondria. We used two models of chronic oxidative stress (old and diabetic mice) and two models of acute oxidative stress (ischemia reperfusion (IR) and tert-butyl hydroperoxide (t-BH)). In control mitochondria, the CRC was 344 ± 32 nmol/mg protein. 500 μmol/L ADP increased CRC to 774 ± 65 nmol/mg protein. This effect of ADP seemed to relate to its concentration as 50 μmol/L had a significantly smaller effect. Also, oligomycin, which inhibits the conversion of ADP to ATP by F0F1ATPase, significantly increased the effect of 50 μmol/L ADP. Chronic oxidative stress did not affect CRC or the effect of 500 μmol/L ADP. After IR or t-BH exposure, CRC was drastically reduced to 1 ± 0.2 and 32 ± 4 nmol/mg protein, respectively. Surprisingly, ADP increased the CRC to 447 ± 105 and 514 ± 103 nmol/mg protein in IR and t-BH, respectively. Thus, it increased CRC by the same amount as in control. In control mitochondria, ADP decreased both substrate and Ca(2+)-induced increase of ROS. However, in t-BH mitochondria the effect of ADP on ROS was relatively small. We conclude that ADP potently restores CRC capacity in severely stressed mitochondria. This effect is most likely not related to a reduction in ROS production. As the effect of ADP relates to its concentration, increased ADP as occurs in the pathophysiological situation may protect mitochondrial integrity and function.
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36
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Ceusters JD, Mouithys-Mickalad AA, Franck TJ, Deby-Dupont GP, Derochette S, Serteyn DA. Effect of different kinds of anoxia/reoxygenation on the mitochondrial function and the free radicals production of cultured primary equine skeletal myoblasts. Res Vet Sci 2013; 95:870-8. [PMID: 24099743 DOI: 10.1016/j.rvsc.2013.09.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 08/22/2013] [Accepted: 09/07/2013] [Indexed: 10/26/2022]
Abstract
Horses are outstanding athletes, performing in many different disciplines involving different kinds of efforts and metabolic responses. Depending on exercise intensity, their skeletal muscle oxygenation decreases, and the reperfusion at cessation of the exercise can cause excessive production of free radicals. This study on cultured primary equine myoblasts investigated the effect of different kinds of anoxia/reoxygenation (A/R) on routine respiration, mitochondrial complex I specific activity and free radicals production. Our data revealed that short cycles of A/R caused a decrease of all the parameters, opposite to what a single long period of anoxia did. A preconditioning-like effect could explain our first pattern of results whereas mild uncoupling could be more appropriate for the second one. Anyway, it seems that mitochondrial complex I could play a major role in the regulation of the balance between metabolic and antioxidant protection of the muscular function of athletic horses.
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Affiliation(s)
- Justine D Ceusters
- Center for Oxygen Research and Development, Institute of Chemistry B6a, University of Liège, Sart Tilman, 4000 Liège, Belgium.
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Yoshioka J, Lee RT. Thioredoxin-interacting protein and myocardial mitochondrial function in ischemia-reperfusion injury. Trends Cardiovasc Med 2013; 24:75-80. [PMID: 23891554 DOI: 10.1016/j.tcm.2013.06.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 06/12/2013] [Accepted: 06/13/2013] [Indexed: 01/15/2023]
Abstract
Cellular metabolism and reactive oxygen species (ROS) formation are interrelated processes in mitochondria and are implicated in a variety of human diseases including ischemic heart disease. During ischemia, mitochondrial respiration rates fall. Though seemingly paradoxical, reduced respiration has been observed to be cardioprotective due in part to reduced generation of ROS. Enhanced myocardial glucose uptake is considered beneficial for the myocardium under stress, as glucose is the primary substrate to support anaerobic metabolism. Thus, inhibition of mitochondrial respiration and uncoupling oxidative phosphorylation can protect the myocardium from irreversible ischemic damage. Growing evidence now positions the TXNIP/thioredoxin system at a nodal point linking pathways of antioxidant defense, cell survival, and energy metabolism. This emerging picture reveals TXNIP's function as a regulator of glucose homeostasis and may prove central to regulation of mitochondrial function during ischemia. In this review, we summarize how TXNIP and its binding partner thioredoxin act as regulators of mitochondrial metabolism. While the precise mechanism remains incompletely defined, the TXNIP-thioredoxin interaction has the potential to affect signaling that regulates mitochondrial bioenergetics and respiratory function with potential cardioprotection against ischemic injury.
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Affiliation(s)
- Jun Yoshioka
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA; Brigham Regenerative Medicine Center, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Richard T Lee
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA; Brigham Regenerative Medicine Center, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA; Harvard Stem Cell Institute, Cambridge, Massachusetts, USA.
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Perrino C, Schiattarella GG, Sannino A, Pironti G, Petretta MP, Cannavo A, Gargiulo G, Ilardi F, Magliulo F, Franzone A, Carotenuto G, Serino F, Altobelli GG, Cimini V, Cuocolo A, Lombardi A, Goglia F, Indolfi C, Trimarco B, Esposito G. Genetic deletion of uncoupling protein 3 exaggerates apoptotic cell death in the ischemic heart leading to heart failure. J Am Heart Assoc 2013; 2:e000086. [PMID: 23688674 PMCID: PMC3698767 DOI: 10.1161/jaha.113.000086] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND Uncoupling protein 3 (ucp3) is a member of the mitochondrial anion carrier superfamily of proteins uncoupling mitochondrial respiration. In this study, we investigated the effects of ucp3 genetic deletion on mitochondrial function and cell survival under low oxygen conditions in vitro and in vivo. METHODS AND RESULTS To test the effects of ucp3 deletion in vitro, murine embryonic fibroblasts and adult cardiomyocytes were isolated from wild-type (WT, n=67) and ucp3 knockout mice (ucp3(-/-), n=70). To test the effects of ucp3 genetic deletion in vivo, myocardial infarction (MI) was induced by permanent coronary artery ligation in WT and ucp3(-/-) mice. Compared with WT, ucp3(-/-) murine embryonic fibroblasts and cardiomyocytes exhibited mitochondrial dysfunction and increased mitochondrial reactive oxygen species generation and apoptotic cell death under hypoxic conditions in vitro (terminal deoxynucleotidyl transferase-dUTP nick end labeling-positive nuclei: WT hypoxia, 70.3 ± 1.2%; ucp3(-/-) hypoxia, 85.3 ± 0.9%; P<0.05). After MI, despite similar areas at risk in the 2 groups, ucp3(-/-) hearts demonstrated a significantly larger infarct size compared with WT (infarct area/area at risk: WT, 48.2 ± 3.7%; ucp3(-/-), 65.0 ± 2.9%; P<0.05). Eight weeks after MI, cardiac function was significantly decreased in ucp3(-/-) mice compared with WT (fractional shortening: WT MI, 42.7 ± 3.1%; ucp3(-/-) MI, 24.4 ± 2.9; P<0.05), and this was associated with heightened apoptotic cell death (terminal deoxynucleotidyl transferase-dUTP nick end labeling-positive nuclei: WT MI, 0.7 ± 0.04%; ucp3(-/-) MI, 1.1 ± 0.09%, P<0.05). CONCLUSIONS Our data indicate that ucp3 levels regulate reactive oxygen species levels and cell survival during hypoxia, modulating infarct size in the ischemic heart.
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Affiliation(s)
- Cinzia Perrino
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Gabriele G. Schiattarella
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Anna Sannino
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Gianluigi Pironti
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Maria Piera Petretta
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Alessandro Cannavo
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Giuseppe Gargiulo
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Federica Ilardi
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Fabio Magliulo
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Anna Franzone
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Giuseppe Carotenuto
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Federica Serino
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Giovanna G. Altobelli
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Vincenzo Cimini
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Alberto Cuocolo
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Assunta Lombardi
- Department of Biology, Federico II University, Naples, Italy (A.L.)
| | - Fernando Goglia
- Department of Biology Sciences, Geology and Environment, Sannio University, Benevento, Italy (F.G.)
| | - Ciro Indolfi
- Department of Cardiology, Magna Graecia University, Catanzaro, Italy (C.I.)
| | - Bruno Trimarco
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
| | - Giovanni Esposito
- Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (C.P., G.G.S., A.S., G.P., M.P.P., A.C., G.G., F.I., F.M., A.F., G.C., F.S., G.G.A., V.C., A.C., B.T., G.E.)
- Correspondence to: Giovanni Esposito, MD, PhD, or Cinzia Perrino, MD, PhD, Division of Cardiology, Federico II University, Via Pansini 5, 80131 Naples, Italy. E‐mail: ,
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Ozcan C, Palmeri M, Horvath TL, Russell KS, Russell RR. Role of uncoupling protein 3 in ischemia-reperfusion injury, arrhythmias, and preconditioning. Am J Physiol Heart Circ Physiol 2013; 304:H1192-200. [PMID: 23457013 DOI: 10.1152/ajpheart.00592.2012] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Overexpression of mitochondrial uncoupling proteins (UCPs) attenuates ischemia-reperfusion (I/R) injury in cultured cardiomyocytes. However, it is not known whether UCPs play an essential role in cardioprotection in the intact heart. This study evaluated the cardioprotective efficacy of UCPs against I/R injury and characterized the mechanism of UCP-mediated protection in addition to the role of UCPs in ischemic preconditioning (IPC). Cardiac UCP3 knockout (UCP3(-/-)) and wild-type (WT) mice hearts were subjected to ex vivo and in vivo models of I/R injury and IPC. Isolated UCP3(-/-) mouse hearts were retrogradely perfused and found to have poorer recovery of left ventricular function compared with WT hearts under I/R conditions. In vivo occlusion of the left coronary artery resulted in twofold larger infarcts in UCP3(-/-) mice compared with WT mice. Moreover, the incidence of in vivo I/R arrhythmias was higher in UCP3(-/-) mice. Myocardial energetics were significantly impaired with I/R, as reflected by a decreased ATP content and an increase in the AMP-to-ATP ratio. UCP3(-/-) hearts generated more reactive oxygen species (ROS) than WT hearts during I/R. Pretreatment of UCP3(-/-) hearts with the pharmacological uncoupling agent carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone improved postischemic functional recovery. Also the protective efficacy of IPC was abolished in UCP3(-/-) mice. We conclude that UCP3 plays a critical role in cardioprotection against I/R injury and the IPC phenomenon. There is increased myocardial vulnerability to I/R injury in hearts lacking UCP3. The mechanisms of UCP3-mediated cardioprotection include regulation of myocardial energetics and ROS generation by UCP3 during I/R.
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Affiliation(s)
- Cevher Ozcan
- Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
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Walters AM, Porter GA, Brookes PS. Mitochondria as a drug target in ischemic heart disease and cardiomyopathy. Circ Res 2013; 111:1222-36. [PMID: 23065345 DOI: 10.1161/circresaha.112.265660] [Citation(s) in RCA: 204] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Ischemic heart disease is a significant cause of morbidity and mortality in Western society. Although interventions, such as thrombolysis and percutaneous coronary intervention, have proven efficacious in ischemia and reperfusion injury, the underlying pathological process of ischemic heart disease, laboratory studies suggest further protection is possible, and an expansive research effort is aimed at bringing new therapeutic options to the clinic. Mitochondrial dysfunction plays a key role in the pathogenesis of ischemia and reperfusion injury and cardiomyopathy. However, despite promising mitochondria-targeted drugs emerging from the laboratory, very few have successfully completed clinical trials. As such, the mitochondrion is a potential untapped target for new ischemic heart disease and cardiomyopathy therapies. Notably, there are a number of overlapping therapies for both these diseases, and as such novel therapeutic options for one condition may find use in the other. This review summarizes efforts to date in targeting mitochondria for ischemic heart disease and cardiomyopathy therapy and outlines emerging drug targets in this field.
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Affiliation(s)
- Andrew M Walters
- School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA
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41
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Shymans'ka TV, Hoshovs'ka I, Semenikhina OM, Sahach VF. Effect of hydrogen sulfide on isolated rat heart reaction under volume load and ischemia-reperfusion. ACTA ACUST UNITED AC 2012. [DOI: 10.15407/fz58.06.057] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Percival JM, Siegel MP, Knowels G, Marcinek DJ. Defects in mitochondrial localization and ATP synthesis in the mdx mouse model of Duchenne muscular dystrophy are not alleviated by PDE5 inhibition. Hum Mol Genet 2012; 22:153-67. [PMID: 23049075 DOI: 10.1093/hmg/dds415] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Given the crucial roles for mitochondria in ATP energy supply, Ca(2+) handling and cell death, mitochondrial dysfunction has long been suspected to be an important pathogenic feature in Duchenne muscular dystrophy (DMD). Despite this foresight, mitochondrial function in dystrophin-deficient muscles has remained poorly defined and unknown in vivo. Here, we used the mdx mouse model of DMD and non-invasive spectroscopy to determine the impact of dystrophin-deficiency on skeletal muscle mitochondrial localization and oxidative phosphorylation function in vivo. Mdx mitochondria exhibited significant uncoupling of oxidative phosphorylation (reduced P/O) and a reduction in maximal ATP synthesis capacity that together decreased intramuscular ATP levels. Uncoupling was not driven by increased UCP3 or ANT1 expression. Dystrophin was required to maintain subsarcolemmal mitochondria (SSM) pool density, implicating it in the spatial control of mitochondrial localization. Given that nitric oxide-cGMP pathways regulate mitochondria and that sildenafil-mediated phosphodiesterase 5 inhibition ameliorates dystrophic pathology, we tested whether sildenafil's benefits result from decreased mitochondrial dysfunction in mdx mice. Unexpectedly, sildenafil treatment did not affect mitochondrial content or oxidative phosphorylation defects in mdx mice. Rather, PDE5 inhibition decreased resting levels of ATP, phosphocreatine and myoglobin, suggesting that sildenafil improves dystrophic pathology through other mechanisms. Overall, these data indicate that dystrophin-deficiency disrupts SSM localization, promotes mitochondrial inefficiency and restricts maximal mitochondrial ATP-generating capacity. Together these defects decrease intramuscular ATP and the ability of mdx muscle mitochondria to meet ATP demand. These findings further understanding of how mitochondrial bioenergetic dysfunction contributes to disease pathogenesis in dystrophin-deficient skeletal muscle in vivo.
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Affiliation(s)
- Justin M Percival
- Department of Physiology and Biophysics, University of Washington Medical School, Seattle, WA, USA.
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Rau TF, Lu Q, Sharma S, Sun X, Leary G, Beckman ML, Hou Y, Wainwright MS, Kavanaugh M, Poulsen DJ, Black SM. Oxygen glucose deprivation in rat hippocampal slice cultures results in alterations in carnitine homeostasis and mitochondrial dysfunction. PLoS One 2012; 7:e40881. [PMID: 22984394 PMCID: PMC3439445 DOI: 10.1371/journal.pone.0040881] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 06/18/2012] [Indexed: 12/02/2022] Open
Abstract
Mitochondrial dysfunction characterized by depolarization of mitochondrial membranes and the initiation of mitochondrial-mediated apoptosis are pathological responses to hypoxia-ischemia (HI) in the neonatal brain. Carnitine metabolism directly supports mitochondrial metabolism by shuttling long chain fatty acids across the inner mitochondrial membrane for beta-oxidation. Our previous studies have shown that HI disrupts carnitine homeostasis in neonatal rats and that L-carnitine can be neuroprotective. Thus, this study was undertaken to elucidate the molecular mechanisms by which HI alters carnitine metabolism and to begin to elucidate the mechanism underlying the neuroprotective effect of L-carnitine (LCAR) supplementation. Utilizing neonatal rat hippocampal slice cultures we found that oxygen glucose deprivation (OGD) decreased the levels of free carnitines (FC) and increased the acylcarnitine (AC): FC ratio. These changes in carnitine homeostasis correlated with decreases in the protein levels of carnitine palmitoyl transferase (CPT) 1 and 2. LCAR supplementation prevented the decrease in CPT1 and CPT2, enhanced both FC and the AC∶FC ratio and increased slice culture metabolic viability, the mitochondrial membrane potential prior to OGD and prevented the subsequent loss of neurons during later stages of reperfusion through a reduction in apoptotic cell death. Finally, we found that LCAR supplementation preserved the structural integrity and synaptic transmission within the hippocampus after OGD. Thus, we conclude that LCAR supplementation preserves the key enzymes responsible for maintaining carnitine homeostasis and preserves both cell viability and synaptic transmission after OGD.
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Affiliation(s)
- Thomas F. Rau
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana, United States of America
| | - Qing Lu
- Vascular Biology Center, Medical College of Georgia, Augusta, Georgia, United States of America
| | - Shruti Sharma
- Vascular Biology Center, Medical College of Georgia, Augusta, Georgia, United States of America
| | - Xutong Sun
- Vascular Biology Center, Medical College of Georgia, Augusta, Georgia, United States of America
| | - Gregory Leary
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana, United States of America
| | - Matthew L. Beckman
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana, United States of America
| | - Yali Hou
- Vascular Biology Center, Medical College of Georgia, Augusta, Georgia, United States of America
| | - Mark S. Wainwright
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, Children's Memorial Hospital, 2300 Children's Plaza, Chicago, Illinois, United States of America
| | - Michael Kavanaugh
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana, United States of America
| | - David J. Poulsen
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana, United States of America
- * E-mail: (SMB); (DJP)
| | - Stephen M. Black
- Vascular Biology Center, Medical College of Georgia, Augusta, Georgia, United States of America
- * E-mail: (SMB); (DJP)
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Complex I and ATP synthase mediate membrane depolarization and matrix acidification by isoflurane in mitochondria. Eur J Pharmacol 2012; 690:149-57. [PMID: 22796646 DOI: 10.1016/j.ejphar.2012.07.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 06/21/2012] [Accepted: 07/02/2012] [Indexed: 11/22/2022]
Abstract
Short application of the volatile anesthetic isoflurane at reperfusion after ischemia exerts strong protection of the heart against injury. Mild depolarization and acidification of the mitochondrial matrix are involved in the protective mechanisms of isoflurane, but the molecular basis for these changes is not clear. In this study, mitochondrial respiration, membrane potential, matrix pH, matrix swelling, ATP synthesis and -hydrolysis, and H(2)O(2) release were assessed in isolated mitochondria. We hypothesized that isoflurane induces mitochondrial depolarization and matrix acidification through direct action on both complex I and ATP synthase. With complex I-linked substrates, isoflurane (0.5mM) inhibited mitochondrial respiration by 28 ± 10%, and slightly, but significantly depolarized membrane potential and decreased matrix pH. With complex II- and complex IV-linked substrates, respiration was not changed, but isoflurane still decreased matrix pH and depolarized mitochondrial membrane potential. Depolarization and matrix acidification were attenuated by inhibition of ATP synthase with oligomycin, but not by inhibition of mitochondrial ATP- and Ca(2+)-sensitive K(+) channels or uncoupling proteins. Isoflurane did not induce matrix swelling and did not affect ATP synthesis and hydrolysis, but decreased H(2)O(2) release in the presence of succinate in an oligomycin- and matrix pH-sensitive manner. Isoflurane modulated H(+) flux through ATP synthase in an oligomycin-sensitive manner. Our results indicate that isoflurane-induced mitochondrial depolarization and acidification occur due to inhibition of the electron transport chain at the site of complex I and increased proton flux through ATP synthase. K(+) channels and uncoupling proteins appear not to be involved in the direct effects of isoflurane on mitochondria.
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Handy DE, Loscalzo J. Redox regulation of mitochondrial function. Antioxid Redox Signal 2012; 16:1323-67. [PMID: 22146081 PMCID: PMC3324814 DOI: 10.1089/ars.2011.4123] [Citation(s) in RCA: 372] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 12/06/2011] [Accepted: 12/06/2011] [Indexed: 02/06/2023]
Abstract
Redox-dependent processes influence most cellular functions, such as differentiation, proliferation, and apoptosis. Mitochondria are at the center of these processes, as mitochondria both generate reactive oxygen species (ROS) that drive redox-sensitive events and respond to ROS-mediated changes in the cellular redox state. In this review, we examine the regulation of cellular ROS, their modes of production and removal, and the redox-sensitive targets that are modified by their flux. In particular, we focus on the actions of redox-sensitive targets that alter mitochondrial function and the role of these redox modifications on metabolism, mitochondrial biogenesis, receptor-mediated signaling, and apoptotic pathways. We also consider the role of mitochondria in modulating these pathways, and discuss how redox-dependent events may contribute to pathobiology by altering mitochondrial function.
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Affiliation(s)
- Diane E Handy
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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Cabrera JA, Ziemba EA, Colbert R, Kelly RF, Kuskowski M, Arriaga EA, Sluiter W, Duncker DJ, Ward HB, McFalls EO. Uncoupling protein-2 expression and effects on mitochondrial membrane potential and oxidant stress in heart tissue. Transl Res 2012; 159:383-90. [PMID: 22500511 PMCID: PMC3328031 DOI: 10.1016/j.trsl.2011.11.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 11/01/2011] [Accepted: 11/03/2011] [Indexed: 10/14/2022]
Abstract
Myocardial uncoupling protein (UCP)-2 is increased with chronic peroxisome proliferator-activated receptor γ (PPARγ) stimulation, but the effect on membrane potential and superoxide is unclear. Wild-type (WT) and UCP-2 knockout (KO) mice were given a 3-week diet of control (C) or the PPARγ agonist pioglitazone (PIO; 50 μg/g-chow per day). In isolated mitochondria, UCP-2 content by Western blots, membrane potential (ΔΨm) by tetraphenylphosphonium (TPP), and relative superoxide levels by dihydroethidium (DHE) were measured. Oxygen respiration was determined at baseline and after 10 min anoxia-reoxygenation. PIO induced a 2-fold increase in UCP-2 and nuclear-bound PGC1α in WT mice with no UCP-2 expression in KO mice. Mitochondrial ΔΨm from WT mice on C and PIO diets was -166±4 mV and -147±6 mV, respectively (P<0.05). These values were lower than in UCP-2 KO mice on C and PIO (-180±4 mV and -180±4 mV, respectively; P<0.05). Maximal complex III inhibitable superoxide from WT mice on C and PIO diets was 22.5±1.3 and 17.8±1.1 AU, respectively (P<0.05), and were lower than UCP-2 KO on C and PIO (32.9±2.3 and 29.2±1.9 AU, respectively; P<0.05). Postanoxia, the respiratory control index (RCI) in mitochondria from WT mice with and without PIO was 2.5±0.3 and 2.4±0.2, respectively, and exceeded that of UCP-2 KO mice on C and PIO (1.2±0.1 and 1.4±0.1, respectively; P<0.05). In summary, chronic PPARγ stimulation leads to depolarization of the inner membrane and reduced superoxide of isolated heart mitochondria, which was critically dependent on increased expression of UCP-2. Thus, UCP-2 expression affords resistance to brief anoxia-reoxygenation.
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Affiliation(s)
- Jesús A Cabrera
- Department of Cardiology & Cardiac Surgery Sections, VA Medical Center, University of Minnesota, Minneapolis, MN 55417, USA
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Blockade of electron transport at the onset of reperfusion decreases cardiac injury in aged hearts by protecting the inner mitochondrial membrane. J Aging Res 2012; 2012:753949. [PMID: 22619720 PMCID: PMC3347723 DOI: 10.1155/2012/753949] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 11/23/2011] [Accepted: 12/27/2011] [Indexed: 12/23/2022] Open
Abstract
Myocardial injury is increased in the aged heart following ischemia-reperfusion (ISC-REP) compared to adult hearts. Intervention at REP with ischemic postconditioning decreases injury in the adult heart by attenuating mitochondrial driven cell injury. Unfortunately, postconditioning is ineffective in aged hearts. Blockade of electron transport at the onset of REP with the reversible inhibitor amobarbital (AMO) decreases injury in adult hearts. We tested if AMO treatment at REP protects the aged heart via preservation of mitochondrial integrity. Buffer-perfused elderly Fischer 344 24 mo. rat hearts underwent 25 min global ISC and 30 min REP. AMO (2.5 mM) or vehicle was given for 3 min at the onset of REP. Subsarcolemmal (SSM) and interfibrillar (IFM) mitochondria were isolated after REP. Oxidative phosphorylation (OXPHOS) and mitochondrial inner membrane potential were measured. AMO treatment at REP decreased cardiac injury. Compared to untreated ISC-REP, AMO improved inner membrane potential in SSM and IFM during REP, indicating preserved inner membrane integrity. Thus, direct pharmacologic modulation of electron transport at REP protects mitochondria and decreases cardiac injury in the aged heart, even when signaling-induced pathways of postconditioning that are upstream of mitochondria are ineffective.
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Carreira RS, Lee P, Gottlieb RA. Mitochondrial therapeutics for cardioprotection. Curr Pharm Des 2012; 17:2017-35. [PMID: 21718247 DOI: 10.2174/138161211796904777] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 06/27/2011] [Indexed: 12/22/2022]
Abstract
Mitochondria represent approximately one-third of the mass of the heart and play a critical role in maintaining cellular function-however, they are also a potent source of free radicals and pro-apoptotic factors. As such, maintaining mitochondrial homeostasis is essential to cell survival. As the dominant source of ATP, continuous quality control is mandatory to ensure their ongoing optimal function. Mitochondrial quality control is accomplished by the dynamic interplay of fusion, fission, autophagy, and mitochondrial biogenesis. This review examines these processes in the heart and considers their role in the context of ischemia-reperfusion injury. Interventions that modulate mitochondrial turnover, including pharmacologic agents, exercise, and caloric restriction are discussed as a means to improve mitochondrial quality control, ameliorate cardiovascular dysfunction, and enhance longevity.
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Affiliation(s)
- Raquel S Carreira
- BioScience Center, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182-4650, USA
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Yoshioka J, Chutkow WA, Lee S, Kim JB, Yan J, Tian R, Lindsey ML, Feener EP, Seidman CE, Seidman JG, Lee RT. Deletion of thioredoxin-interacting protein in mice impairs mitochondrial function but protects the myocardium from ischemia-reperfusion injury. J Clin Invest 2011; 122:267-79. [PMID: 22201682 DOI: 10.1172/jci44927] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Accepted: 10/12/2011] [Indexed: 12/11/2022] Open
Abstract
Classic therapeutics for ischemic heart disease are less effective in individuals with the metabolic syndrome. As the prevalence of the metabolic syndrome is increasing, better understanding of cardiac metabolism is needed to identify potential new targets for therapeutic intervention. Thioredoxin-interacting protein (Txnip) is a regulator of metabolism and an inhibitor of the antioxidant thioredoxins, but little is known about its roles in the myocardium. We examined hearts from Txnip-KO mice by polony multiplex analysis of gene expression and an independent proteomic approach; both methods indicated suppression of genes and proteins participating in mitochondrial metabolism. Consistently, Txnip-KO mitochondria were functionally and structurally altered, showing reduced oxygen consumption and ultrastructural derangements. Given the central role that mitochondria play during hypoxia, we hypothesized that Txnip deletion would enhance ischemia-reperfusion damage. Surprisingly, Txnip-KO hearts had greater recovery of cardiac function after an ischemia-reperfusion insult. Similarly, cardiomyocyte-specific Txnip deletion reduced infarct size after reversible coronary ligation. Coordinated with reduced mitochondrial function, deletion of Txnip enhanced anaerobic glycolysis. Whereas mitochondrial ATP synthesis was minimally decreased by Txnip deletion, cellular ATP content and lactate formation were higher in Txnip-KO hearts after ischemia-reperfusion injury. Pharmacologic inhibition of glycolytic metabolism completely abolished the protection afforded the heart by Txnip deficiency under hypoxic conditions. Thus, although Txnip deletion suppresses mitochondrial function, protection from myocardial ischemia is enhanced as a result of a coordinated shift to enhanced anaerobic metabolism, which provides an energy source outside of mitochondria.
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Affiliation(s)
- Jun Yoshioka
- Cardiovascular Division, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA
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Nadtochiy SM, Zhu QM, Zhu Q, Urciuoli W, Rafikov R, Black SM, Brookes PS. Nitroalkenes confer acute cardioprotection via adenine nucleotide translocase 1. J Biol Chem 2011; 287:3573-80. [PMID: 22158628 DOI: 10.1074/jbc.m111.298406] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Electrophilic nitrated lipids (nitroalkenes) are emerging as an important class of protective cardiovascular signaling molecules. Although species such as nitro-linoleate (LNO(2)) and nitro-oleate can confer acute protection against cardiac ischemic injury, their mechanism of action is unclear. Mild uncoupling of mitochondria is known to be cardioprotective, and adenine nucleotide translocase 1 (ANT1) is a key mediator of mitochondrial uncoupling. ANT1 also contains redox-sensitive cysteines that may be targets for modification by nitroalkenes. Therefore, in this study we tested the hypothesis that nitroalkenes directly modify ANT1 and that nitroalkene-mediated cardioprotection requires ANT1. Using biotin-tagged LNO(2) infused into intact perfused hearts, we obtained mass spectrometric (MALDI-TOF-TOF) evidence for direct modification (nitroalkylation) of ANT1 on cysteine 57. Furthermore, in a cell model of ischemia-reperfusion injury, siRNA knockdown of ANT1 inhibited the cardioprotective effect of LNO(2). Although the molecular mechanism linking ANT1-Cys(57) nitroalkylation and uncoupling is not yet known, these data suggest that ANT1-mediated uncoupling may be a mechanism for nitroalkene-induced cardioprotection.
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Affiliation(s)
- Sergiy M Nadtochiy
- Department of Anesthesiology, University of Rochester Medical Center, Rochester, New York 14642, USA
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