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Olszewska AM, Zmijewski MA. Genomic and non-genomic action of vitamin D on ion channels - Targeting mitochondria. Mitochondrion 2024; 77:101891. [PMID: 38692383 DOI: 10.1016/j.mito.2024.101891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 04/26/2024] [Accepted: 04/28/2024] [Indexed: 05/03/2024]
Abstract
Recent studies revealed that mitochondria are not only a place of vitamin D3 metabolism but also direct or indirect targets of its activities. This review summarizes current knowledge on the regulation of ion channels from plasma and mitochondrial membranes by the active form of vitamin D3 (1,25(OH)2D3). 1,25(OH)2D3, is a naturally occurring hormone with pleiotropic activities; implicated in the modulation of cell differentiation, and proliferation and in the prevention of various diseases, including cancer. Many experimental data indicate that 1,25(OH)2D3 deficiency induces ionic remodeling and 1,25(OH)2D3 regulates the activity of multiple ion channels. There are two main theories on how 1,25(OH)2D3 can modify the function of ion channels. First, describes the involvement of genomic pathways of response to 1,25(OH)2D3 in the regulation of the expression of the genes encoding channels, their auxiliary subunits, or additional regulators. Interestingly, intracellular ion channels, like mitochondrial, are encoded by the same genes as plasma membrane channels. Therefore, the comprehensive genomic regulation of the channels from these two different cellular compartments we analyzed using a bioinformatic approach. The second theory explores non-genomic pathways of vitamin D3 activities. It was shown, that 1,25(OH)2D3 indirectly regulates enzymes that impact ion channels, change membrane physical properties, or directly bind to channel proteins. In this article, the involvement of genomic and non-genomic pathways regulated by 1,25(OH)2D3 in the modulation of the levels and activity of plasma membrane and mitochondrial ion channels was investigated by an extensive review of the literature and analysis of the transcriptomic data using bioinformatics.
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Affiliation(s)
- A M Olszewska
- Department of Histology, Medical University of Gdansk, 1a Debinki, 80-211 Gdansk, Poland
| | - M A Zmijewski
- Department of Histology, Medical University of Gdansk, 1a Debinki, 80-211 Gdansk, Poland.
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Palácio PB, de Freitas Soares GC, Lima GMB, Cunha PLO, Varela ALN, Facundo HT. Competitive interaction between ATP and GTP regulates mitochondrial ATP-sensitive potassium channels. Chem Biol Interact 2023:110560. [PMID: 37244398 DOI: 10.1016/j.cbi.2023.110560] [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: 01/24/2023] [Revised: 03/28/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
Mitochondrial ATP-sensitive K+ channels (mitoKATP) have been recently characterized structurally, and possess a protein through which K+ enters mitochondria (MitoKIR), and a regulatory subunit (mitoSUR). The mitoSUR regulatory subunit is an ATP-binding cassette (ABC) protein isoform 8 (ABCB8). Opening these channels is known to be cardioprotective, but the molecular and physiological mechanisms that activate them are not fully known. Here, to better understand the molecular and physiological mechanisms of activators (GTP) and inhibitors (ATP) on the activity of mitoKATP, we exposed isolated mitochondria to both nucleotides. We also used molecular docking directed to the nucleotide-binding domain of human ABCB8/mitoSUR to test a comparative model of ATP and GTP effects. As expected, we find that ATP dose-dependently inhibits mitoKATP activity (IC50 = 21.24 ± 1.4 mM). However, simultaneous exposure of mitochondria to GTP dose-dependently (EC50 = 13.19 ± 1.33 mM) reversed ATP inhibition. Pharmacological and computational studies suggest that GTP reverses ATP activity competitively. Docking directed to the site of crystallized ADP reveals that both nucleotides bind to mitoSUR with high affinity, with their phosphates directed to the Mg2+ ion and the walker A motif of the protein (SGGGKTT). These effects, when combined, result in GTP binding, ATP displacement, mitochondrial ATP-sensitive K+ transport, and lower formation of reactive oxygen species. Overall, our findings demonstrate the basis for ATP and GTP binding in mitoSUR using a combination of biochemical, pharmacological, and computational experiments. Future studies may reveal the extent to which the balance between ATP and GTP actions contributes toward cardioprotection against ischemic events.
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Kampa RP, Sęk A, Bednarczyk P, Szewczyk A, Calderone V, Testai L. Flavonoids as new regulators of mitochondrial potassium channels: contribution to cardioprotection. J Pharm Pharmacol 2022; 75:466-481. [PMID: 36508341 DOI: 10.1093/jpp/rgac093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 11/18/2022] [Indexed: 12/14/2022]
Abstract
Abstract
Objectives
Acute myocardial ischemia is one of the major causes of illness in western society. Reduced coronary blood supply leads to cell death and loss of cardiomyocyte population, resulting in serious and often irreversible consequences on myocardial function. Mitochondrial potassium (mitoK) channels have been identified as fine regulators of mitochondrial function and, consequently, in the metabolism of the whole cell, and in the mechanisms underlying the cardioprotection. Interestingly, mitoK channels represent a novel putative target for treating cardiovascular diseases, particularly myocardial infarction, and their modulators represent an interesting tool for pharmacological intervention. In this review, we took up the challenge of selecting flavonoids that show cardioprotective properties through the activation of mitoK channels.
Key findings
A brief overview of the main information on mitoK channels and their participation in the induction of cytoprotective processes was provided. Then, naringenin, quercetin, morin, theaflavin, baicalein, epigallocatechin gallate, genistein, puerarin, luteolin and proanthocyanidins demonstrated to be effective modulators of mitoK channels activity, mediating many beneficial effects.
Summary
The pathophysiological role of mitoK channels has been investigated as well as the impact of flavonoids on this target with particular attention to their potential role in the prevention of cardiovascular disorders.
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Affiliation(s)
- Rafał P Kampa
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology PAS , Warsaw , Poland
- Department of Pharmacy, University of Pisa , Italy
| | - Aleksandra Sęk
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology PAS , Warsaw , Poland
- Faculty of Chemistry, University of Warsaw , Warsaw , Poland
| | - Piotr Bednarczyk
- Department of Physics and Biophysics, Institute of Biology, Warsaw University of Life Sciences, SGGW , Warsaw , Poland
| | - Adam Szewczyk
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology PAS , Warsaw , Poland
| | | | - Lara Testai
- Department of Pharmacy, University of Pisa , Italy
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Alberici LC, Oliveira HCF. Mitochondrial Adaptive Responses to Hypertriglyceridemia and Bioactive Lipids. Antioxid Redox Signal 2022; 36:953-968. [PMID: 34409856 DOI: 10.1089/ars.2021.0180] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Significance: Altered plasma triglyceride metabolism and changes in dietary fatty acid types and levels are major contributors to the development of metabolic and cardiovascular diseases such as fatty liver disease, obesity, diabetes, and atherosclerosis. Lipid accumulation in visceral adipose tissue and ectopically in other organs, as well as lipid-induced redox imbalance, is connected to mitochondrial dysfunction in a range of oxidative stress-associated metabolic and degenerative disorders. Recent Advances: Successful mitochondrial adaptive responses in the context of hypertriglyceridemia and dietary bioactive polyunsaturated fatty acids contribute to increase body energy expenditure and reduce oxidative stress, thus allowing several cell types to cope with metabolic challenges and stresses. These responses include mitochondrial redox signaling, mild uncoupling, and changes in network dynamic behavior. Critical Issues: Mitochondrial bioenergetics and redox changes in a lipid overload context are relatively well characterized. However, the turning point between adaptive and maladaptive mitochondrial responses remains a critical issue to be elucidated. In addition, the relationship between changes in fusion/fission machinery and mitochondrial function is less well understood. Future Directions: The effective mitochondrial responses described here support the research for new drug design and diet or nutraceutical formulations targeting mitochondrial mild uncoupling and effective quality control as putative strategies for cardiometabolic diseases. Antioxid. Redox Signal. 36, 953-968.
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Affiliation(s)
- Luciane C Alberici
- Departamento de Ciências BioMoleculares, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Helena C F Oliveira
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
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Olszewska AM, Sieradzan AK, Bednarczyk P, Szewczyk A, Żmijewski MA. Mitochondrial potassium channels: A novel calcitriol target. Cell Mol Biol Lett 2022; 27:3. [PMID: 34979905 PMCID: PMC8903690 DOI: 10.1186/s11658-021-00299-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 12/20/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Calcitriol (an active metabolite of vitamin D) modulates the expression of hundreds of human genes by activation of the vitamin D nuclear receptor (VDR). However, VDR-mediated transcriptional modulation does not fully explain various phenotypic effects of calcitriol. Recently a fast non-genomic response to vitamin D has been described, and it seems that mitochondria are one of the targets of calcitriol. These non-classical calcitriol targets open up a new area of research with potential clinical applications. The goal of our study was to ascertain whether calcitriol can modulate mitochondrial function through regulation of the potassium channels present in the inner mitochondrial membrane. METHODS The effects of calcitriol on the potassium ion current were measured using the patch-clamp method modified for the inner mitochondrial membrane. Molecular docking experiments were conducted in the Autodock4 program. Additionally, changes in gene expression were investigated by qPCR, and transcription factor binding sites were analyzed in the CiiiDER program. RESULTS For the first time, our results indicate that calcitriol directly affects the activity of the mitochondrial large-conductance Ca2+-regulated potassium channel (mitoBKCa) from the human astrocytoma (U-87 MG) cell line but not the mitochondrial calcium-independent two-pore domain potassium channel (mitoTASK-3) from human keratinocytes (HaCaT). The open probability of the mitoBKCa channel in high calcium conditions decreased after calcitriol treatment and the opposite effect was observed in low calcium conditions. Moreover, using the AutoDock4 program we predicted the binding poses of calcitriol to the calcium-bound BKCa channel and identified amino acids interacting with the calcitriol molecule. Additionally, we found that calcitriol influences the expression of genes encoding potassium channels. Such a dual, genomic and non-genomic action explains the pleiotropic activity of calcitriol. CONCLUSIONS Calcitriol can regulate the mitochondrial large-conductance calcium-regulated potassium channel. Our data open a new chapter in the study of non-genomic responses to vitamin D with potential implications for mitochondrial bioenergetics and cytoprotective mechanisms.
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Affiliation(s)
- Anna M Olszewska
- Department of Histology, Medical University of Gdańsk, 1a Dębinki, 80-211, Gdańsk, Poland
| | - Adam K Sieradzan
- Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308, Gdańsk, Poland
| | - Piotr Bednarczyk
- Department of Physics and Biophysics, Warsaw University of Life Sciences-SGGW, Nowoursynowska 159, 02-776, Warsaw, Poland
| | - Adam Szewczyk
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093, Warsaw, Poland
| | - Michał A Żmijewski
- Department of Histology, Medical University of Gdańsk, 1a Dębinki, 80-211, Gdańsk, Poland.
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Bezerra Palácio P, Brito Lucas AM, Varlla de Lacerda Alexandre J, Oliveira Cunha PL, Ponte Viana YI, Albuquerque AC, Nunes Varela AL, Facundo HT. Pharmacological and molecular docking studies reveal that glibenclamide competitively inhibits diazoxide-induced mitochondrial ATP-sensitive potassium channel activation and pharmacological preconditioning. Eur J Pharmacol 2021; 908:174379. [PMID: 34324857 DOI: 10.1016/j.ejphar.2021.174379] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 07/19/2021] [Accepted: 07/21/2021] [Indexed: 11/15/2022]
Abstract
Mitochondrial ATP-sensitive potassium channels (mitoKATP) locate in the inner mitochondrial membrane and possess protective cellular properties. mitoKATP opening-induced cardioprotection (using the pharmacological agent diazoxide) is preventable by antagonists, such as glibenclamide. However, the mechanisms of action of these drugs and how mitoKATP respond to them are poorly understood. Here, we show data that reinforce the existence of a mitochondrial sulfonylurea receptor (mitoSUR) as part of the mitoKATP. We also show how diazoxide and glibenclamide compete for the same binding site in mitoSUR. A glibenclamide analog that lacks its cyclohexylurea portion (IMP-A) loses its ability to inhibit diazoxide-induced swelling. These results suggest that the cyclohexylureia portion of glibenclamide is indispensable for mitoKATP inhibition. Moreover, IMP-A did not suppress diazoxide-induced preconditioning (EC50 10.66 μM) in a rat model of a cardiac ischemia/reperfusion. Importantly, glibenclamide inhibited both diazoxide-induced cardioprotection (IC50 86 nM). We suggest that IMP-A must be used with caution since we found this drug possesses significant inhibitory effects on mitochondrial respiration. We characterized the binding of glibenclamide and diazoxide using a molecular simulation (docking) approach. Using the molecular structure of the ATP binding protein ABCB8 (pointed by others as the mitoSUR) we demonstrate that glibenclamide competitively inhibits diazoxide actions. This was reinforced (pharmacologically) in a competitive antagonism test. Taken together, these results bring valuable and novel insights into the pharmacological/biochemical aspects of mitokATP activation and cardioprotection. This study may lead to the discovery of novel therapeutic strategies that may impact ischemia-reperfusion injury.
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Gunata M, Parlakpinar H. A review of myocardial ischaemia/reperfusion injury: Pathophysiology, experimental models, biomarkers, genetics and pharmacological treatment. Cell Biochem Funct 2020; 39:190-217. [PMID: 32892450 DOI: 10.1002/cbf.3587] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 08/03/2020] [Accepted: 08/14/2020] [Indexed: 12/14/2022]
Abstract
Cardiovascular diseases are known to be the most fatal diseases worldwide. Ischaemia/reperfusion (I/R) injury is at the centre of the pathology of the most common cardiovascular diseases. According to the World Health Organization estimates, ischaemic heart disease is the leading global cause of death, causing more than 9 million deaths in 2016. After cardiovascular events, thrombolysis, percutaneous transluminal coronary angioplasty or coronary bypass surgery are applied as treatment. However, after restoring coronary blood flow, myocardial I/R injury may occur. It is known that this damage occurs due to many pathophysiological mechanisms, especially increasing reactive oxygen types. Besides causing cardiomyocyte death through multiple mechanisms, it may be an important reason for affecting other cell types such as platelets, fibroblasts, endothelial and smooth muscle cells and immune cells. Also, polymorphonuclear leukocytes are associated with myocardial I/R damage during reperfusion. This damage may be insufficient in patients with co-morbidity, as it is demonstrated that it can be prevented by various endogenous antioxidant systems. In this context, the resulting data suggest that optimal cardioprotection may require a combination of additional or synergistic multi-target treatments. In this review, we discussed the pathophysiology, experimental models, biomarkers, treatment and its relationship with genetics in myocardial I/R injury. SIGNIFICANCE OF THE STUDY: This review summarized current information on myocardial ischaemia/reperfusion injury (pathophysiology, experimental models, biomarkers, genetics and pharmacological therapy) for researchers and reveals guiding data for researchers, especially in the field of cardiovascular system and pharmacology.
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Affiliation(s)
- Mehmet Gunata
- Department of Medical Pharmacology, Faculty of Medicine, Inonu University, Malatya, Turkey
| | - Hakan Parlakpinar
- Department of Medical Pharmacology, Faculty of Medicine, Inonu University, Malatya, Turkey
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Signaling pathways targeting mitochondrial potassium channels. Int J Biochem Cell Biol 2020; 125:105792. [PMID: 32574707 DOI: 10.1016/j.biocel.2020.105792] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/08/2020] [Accepted: 06/11/2020] [Indexed: 12/11/2022]
Abstract
In this review, we describe key signaling pathways regulating potassium channels present in the inner mitochondrial membrane. The signaling cascades covered here include phosphorylation, redox reactions, modulation by calcium ions and nucleotides. The following types of potassium channels have been identified in the inner mitochondrial membrane of various tissues: ATP-sensitive, Ca2+-activated, voltage-gated and two-pore domain potassium channels. The direct roles of these channels involve regulation of mitochondrial respiration, membrane potential and synthesis of reactive oxygen species (ROS). Changes in channel activity lead to diverse pro-life and pro-death responses in different cell types. Hence, characterizing the signaling pathways regulating mitochondrial potassium channels will facilitate understanding the physiological role of these proteins. Additionally, we describe in this paper certain regulatory mechanisms, which are unique to mitochondrial potassium channels.
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Akopova O, Kolchinskaya L, Nosar V, Mankovska I, Sagach V. Diazoxide affects mitochondrial bioenergetics by the opening of mKATP channel on submicromolar scale. BMC Mol Cell Biol 2020; 21:31. [PMID: 32306897 PMCID: PMC7168813 DOI: 10.1186/s12860-020-00275-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 04/07/2020] [Indexed: 12/21/2022] Open
Abstract
Background Cytoprotection afforded by mitochondrial ATP-sensitive K+-channel (mKATP-channel) opener diazoxide (DZ) largely depends on the activation of potassium cycle with eventual modulation of mitochondrial functions and ROS production. However, generally these effects were studied in the presence of Mg∙ATP known to block K+ transport. Thus, the purpose of our work was the estimation of DZ effects on K+ transport, K+ cycle and ROS production in rat liver mitochondria in the absence of Mg∙ATP. Results Without Mg·ATP, full activation of native mKATP-channel, accompanied by the increase in ATP-insensitive K+ uptake, activation of K+-cycle and respiratory uncoupling, was reached at ≤0.5 μM of DZ,. Higher diazoxide concentrations augmented ATP-insensitive K+ uptake, but not mKATP-channel activity. mKATP-channel was blocked by Mg·ATP, reactivated by DZ, and repeatedly blocked by mKATP-channel blockers glibenclamide and 5-hydroxydecanoate, whereas ATP-insensitive potassium transport was blocked by Mg2+ and was not restored by DZ. High sensitivity of potassium transport to DZ in native mitochondria resulted in suppression of mitochondrial ROS production caused by the activation of K+-cycle on sub-micromolar scale. Based on the oxygen consumption study, the share of mKATP-channel in respiratory uncoupling by DZ was found. Conclusions The study of mKATP-channel activation by diazoxide in the absence of MgATP discloses novel, not described earlier, aspects of mKATP-channel interaction with this drug. High sensitivity of mKATP-channel to DZ results in the modulation of mitochondrial functions and ROS production by DZ on sub-micromolar concentration scale. Our experiments led us to the hypothesis that under the conditions marked by ATP deficiency affinity of mKATP-channel to DZ can increase, which might contribute to the high effectiveness of this drug in cardio- and neuroprotection.
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Affiliation(s)
- Olga Akopova
- Circulation department, Bogomoletz Institute of Physiology, NAS of Ukraine, Bogomoletz str. 4, Kiev, 01601, Ukraine.
| | - Liudmila Kolchinskaya
- Circulation department, Bogomoletz Institute of Physiology, NAS of Ukraine, Bogomoletz str. 4, Kiev, 01601, Ukraine
| | - Valentina Nosar
- Hypoxic States Research Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Kiev, Ukraine
| | - Iryna Mankovska
- Hypoxic States Research Department, Bogomoletz Institute of Physiology, NAS of Ukraine, Kiev, Ukraine
| | - Vadim Sagach
- Circulation department, Bogomoletz Institute of Physiology, NAS of Ukraine, Bogomoletz str. 4, Kiev, 01601, Ukraine
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Oliveira MS, Tanaka LY, Antonio EL, Brandizzi LI, Serra AJ, Dos Santos L, Krieger JE, Laurindo FRM, Tucci PJF. Hyperbaric oxygenation improves redox control and reduces mortality in the acute phase of myocardial infarction in a rat model. Mol Med Rep 2020; 21:1431-1438. [PMID: 32016473 PMCID: PMC7003025 DOI: 10.3892/mmr.2020.10968] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Accepted: 07/18/2019] [Indexed: 01/02/2023] Open
Abstract
Among the mechanisms of action of hyperbaric oxygenation (HBO), the chance of reducing injury by interfering with the mechanisms of redox homeostasis in the heart leads to the possibility of extending the period of viability of the myocardium at risk. This would benefit late interventions for reperfusion to the ischemic area. The objective of the present study was to investigate the changes in the redox system associated with HBO therapy maintained during the first hour after coronary occlusion in an acute myocardial infarction (MI) rat model. Surviving male rats (n=105) were randomly assigned to one of three groups: Sham (SH=26), myocardial infarction (MI=45) and infarction+hyperbaric therapy (HBO=34, 1 h at 2.5 atm). After 90 min of coronary occlusion, a sample of the heart was collected for western blot analysis of total protein levels of superoxide dismutase, catalase, peroxiredoxin and 3‑nitrotyrosine. Glutathione was measured by enzyme‑linked immunosorbent assay (ELISA). The detection of the superoxide radical anion was carried out by oxidation of dihydroethidium analyzed with confocal microscopy. The mortality rate of the MI group was significantly higher than that of the HBO group. No difference was noted in the myocardial infarction size. The oxidized/reduced glutathione ratio and peroxiredoxin were significantly higher in the SH and MI when compared to the HBO group. Superoxide dismutase enzymes and catalase were significantly higher in the HBO group compared to the MI and SH groups. 3‑Nitrotyrosine and the superoxide radical were significantly lower in the HBO group compared to these in the MI and SH groups. These data demonstrated that hyperbaric oxygenation therapy decreased mortality by improving redox control in the hearts of rats in the acute phase of myocardial infarction.
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Affiliation(s)
- Mario S Oliveira
- Division of Cardiology, Federal University of São Paulo (UNIFESP), São Paulo 04039‑032, Brazil
| | - Leonardo Y Tanaka
- Vascular Biology Laboratory, Heart Institute, University of São Paulo (USP), São Paulo 05403‑900, Brazil
| | - Ednei L Antonio
- Division of Cardiology, Federal University of São Paulo (UNIFESP), São Paulo 04039‑032, Brazil
| | - Laura I Brandizzi
- Vascular Biology Laboratory, Heart Institute, University of São Paulo (USP), São Paulo 05403‑900, Brazil
| | - Andrey J Serra
- Division of Cardiology, Federal University of São Paulo (UNIFESP), São Paulo 04039‑032, Brazil
| | - Leonardo Dos Santos
- Department of Physiological Sciences, Federal University of Espírito Santo (UFES), Vitória, Espírito Santo 29043‑215, Brazil
| | - José E Krieger
- Laboratory of Genetics and Molecular Cardiology, Heart Institute, University of São Paulo (USP), São Paulo 05403‑900, Brazil
| | - Francisco R M Laurindo
- Vascular Biology Laboratory, Heart Institute, University of São Paulo (USP), São Paulo 05403‑900, Brazil
| | - Paulo J F Tucci
- Division of Cardiology, Federal University of São Paulo (UNIFESP), São Paulo 04039‑032, Brazil
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Yang M, Mao G, Ouyang L, Shi C, Hu P, Huang S. Crocetin alleviates myocardial ischemia/reperfusion injury by regulating inflammation and the unfolded protein response. Mol Med Rep 2019; 21:641-648. [PMID: 31974615 PMCID: PMC6947891 DOI: 10.3892/mmr.2019.10891] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 10/25/2019] [Indexed: 12/12/2022] Open
Abstract
Crocetin, a natural compound, has been demonstrated to exhibit beneficial effects in cardiovascular diseases. Previous studies demonstrated that crocetin reduced ischemia/reperfusion (I/R) injury by attenuating cytotoxicity and cellular apoptosis. However, the previous mechanistic studies did not fully elucidate its pharmacological effects on cardiac damage, especially I/R injury. The present study verified its cardioprotective effects in a Langendorff perfusion system, an ex vivo model of I/R. It was demonstrated that crocetin significantly attenuated the activities of pro-inflammatory cytokines and nuclear factor erythroid-2 related factor 2 (Nrf2)/heme oxygenase-1 signaling. The present study provided novel insight that crocetin regulated the unfolded protein response (UPR) and decreased associated protein levels to protect the heart. Furthermore, it was identified that Nrf2 played a key role in the cardioprotective effect of crocetin by attenuating inflammation and the UPR.
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Affiliation(s)
- Ming Yang
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Genxiang Mao
- Department of Geriatrics, Zhejiang Provincial Key Laboratory of Geriatrics and Geriatrics Institute of Zhejiang Province, Zhejiang Hospital, Hangzhou, Zhejiang 310013, P.R. China
| | - Lili Ouyang
- The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310005, P.R. China
| | - Chenhui Shi
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Pengfei Hu
- Department of Cardiology, The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310005, P.R. China
| | - Shuwei Huang
- Department of Cardiology, The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310005, P.R. China
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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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Laursen MR, Hansen J, Elkjær C, Stavnager N, Nielsen CB, Pryds K, Johnsen J, Nielsen JM, Bøtker HE, Johannsen M. Untargeted metabolomics reveals a mild impact of remote ischemic conditioning on the plasma metabolome and α-hydroxybutyrate as a possible cardioprotective factor and biomarker of tissue ischemia. Metabolomics 2017; 13:67. [PMID: 28473744 PMCID: PMC5392534 DOI: 10.1007/s11306-017-1202-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 03/27/2017] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Remote ischemic conditioning (RIC) is a maneuver by which short non-lethal ischemic events are applied on distant organs or limbs to reduce ischemia and reperfusion injuries caused by e.g. myocardial infarct. Although intensively investigated, the specific mechanism of this protective phenomenon remains incompletely understood and in particular, knowledge on the role of small metabolites is scarce. OBJECTIVES In this study, we aimed to study perturbations in the plasma metabolome following RIC and gain insight into metabolic changes by the intervention as well as to identify potential novel cardio-protective metabolites. METHODS Blood plasma samples from ten healthy males were collected prior to and after RIC and tested for bioactivity in a HL-1 based cellular model of ischemia-reperfusion damage. Following this, the plasma was analyzed using untargeted LC-qTOF-MS and regulated metabolites were identified using univariate and multivariate statistical analysis. Results were finally verified in a second plasma study from the same group of volunteers and by testing a metabolite ester in the HL-1 cell model. RESULTS The analysis revealed a moderate impact on the plasma metabolome following RIC. One metabolite, α-hydroxybutyrate (AHB) however, stood out as highly significantly upregulated after RIC. AHB might be a novel and more sensitive plasma-biomarker of transient tissue ischemia than lactate. Importantly, it was also found that a cell permeable AHB precursor protects cardiomyocytes from ischemia-reperfusion damage. CONCLUSION Untargeted metabolomics analysis of plasma following RIC has led to insight into metabolism during RIC and revealed a possible novel metabolite of relevance to ischemic-reperfusion damage.
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Affiliation(s)
- Mia Roest Laursen
- 0000 0001 1956 2722grid.7048.bDepartment of Forensic Medicine, Section for Forensic Chemistry, Aarhus University, Aarhus N, Denmark
| | - Jakob Hansen
- 0000 0001 1956 2722grid.7048.bDepartment of Forensic Medicine, Section for Forensic Chemistry, Aarhus University, Aarhus N, Denmark
| | - Casper Elkjær
- 0000 0004 0512 597Xgrid.154185.cDepartment of Cardiology, Aarhus University Hospital, Aarhus N, Denmark
| | - Ninna Stavnager
- 0000 0001 1956 2722grid.7048.bDepartment of Forensic Medicine, Section for Forensic Chemistry, Aarhus University, Aarhus N, Denmark
| | - Camilla Bak Nielsen
- 0000 0001 1956 2722grid.7048.bDepartment of Forensic Medicine, Section for Forensic Chemistry, Aarhus University, Aarhus N, Denmark
| | - Kasper Pryds
- 0000 0004 0512 597Xgrid.154185.cDepartment of Cardiology, Aarhus University Hospital, Aarhus N, Denmark
| | - Jacob Johnsen
- 0000 0004 0512 597Xgrid.154185.cDepartment of Cardiology, Aarhus University Hospital, Aarhus N, Denmark
| | - Jan Møller Nielsen
- 0000 0004 0512 597Xgrid.154185.cDepartment of Cardiology, Aarhus University Hospital, Aarhus N, Denmark
| | - Hans Erik Bøtker
- 0000 0004 0512 597Xgrid.154185.cDepartment of Cardiology, Aarhus University Hospital, Aarhus N, Denmark
| | - Mogens Johannsen
- 0000 0001 1956 2722grid.7048.bDepartment of Forensic Medicine, Section for Forensic Chemistry, Aarhus University, Aarhus N, Denmark
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Mitochondria and Cardiac Hypertrophy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 982:203-226. [DOI: 10.1007/978-3-319-55330-6_11] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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15
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Queliconi BB, Kowaltowski AJ, Gottlieb RA. Bicarbonate Increases Ischemia-Reperfusion Damage by Inhibiting Mitophagy. PLoS One 2016; 11:e0167678. [PMID: 27973540 PMCID: PMC5156406 DOI: 10.1371/journal.pone.0167678] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 11/20/2016] [Indexed: 12/31/2022] Open
Abstract
During an ischemic event, bicarbonate and CO2 concentration increase as a consequence of O2 consumption and lack of blood flow. This event is important as bicarbonate/CO2 is determinant for several redox and enzymatic reactions, in addition to pH regulation. Until now, most work done on the role of bicarbonate in ischemia-reperfusion injury focused on pH changes; although reperfusion solutions have a fixed pH, cardiac resuscitation protocols commonly employ bicarbonate to correct the profound acidosis associated with respiratory arrest. However, we previously showed that bicarbonate can increase tissue damage and protein oxidative damage independent of pH. Here we show the molecular basis of bicarbonate-induced reperfusion damage: the presence of bicarbonate selectively impairs mitophagy, with no detectable effect on autophagy, proteasome activity, reactive oxygen species production or protein oxidation. We also show that inhibition of autophagy reproduces the effects of bicarbonate in reperfusion injury, providing additional evidence in support of this mechanism. This phenomenon is especially important because bicarbonate is widely used in resuscitation protocols after cardiac arrest, and while effective as a buffer, may also contribute to myocardial injury.
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Affiliation(s)
- Bruno B. Queliconi
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo, Brazil
- Cedars-Sinai Heart Institute, Los Angeles, California, United States of America
| | - Alicia J. Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, São Paulo, Brazil
| | - Roberta A. Gottlieb
- Cedars-Sinai Heart Institute, Los Angeles, California, United States of America
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16
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Mitochondrial ATP-sensitive potassium channel opening inhibits isoproterenol-induced cardiac hypertrophy by preventing oxidative damage. J Cardiovasc Pharmacol 2016; 65:393-7. [PMID: 25850726 DOI: 10.1097/fjc.0000000000000210] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cardiac hypertrophy is a chronic complex disease that occurs in response to hemodynamic load and is accompanied by oxidative stress and mitochondrial dysfunction. Mitochondrial ATP-sensitive K channels (mitoKATPs) have previously been shown to prevent oxidative cardiac damage under conditions of ischemia/reperfusion. However, the effect of these channels on cardiac hypertrophy has not been tested to date. In this study, we show that treatment of Swiss mice with isoproterenol (30 mg·kg·d) induces cardiac hypertrophy while significantly decreasing the levels of reduced protein thiols, glutathione, catalase, and superoxide dismutase activity, indicative of a condition of oxidative imbalance. Treatment with diazoxide (a mitoKATP opener, 5 mg·kg·d) normalized the levels of protein thiols and reduced glutathione, rescued superoxide dismutase activity, and significantly prevented cardiac hypertrophy. The protective effects of diazoxide were mitigated by the mitoKATP blockers 5-hydroxydecanoate (5 mg·kg·d) and glibenclamide (3 mg·kg·d), demonstrating that they were related to activation of the channel. Taken together, our results establish that mitoKATP activation promotes very robust prevention of cardiac hypertrophy and associated oxidative imbalance and suggest that these channels can be important drug targets for the pharmacological control of cardiac hypertrophy.
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17
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Nogueira MA, Coelho AMM, Sampietre SN, Patzina RA, Pinheiro da Silva F, D'Albuquerque LAC, Machado MCC. Beneficial effects of adenosine triphosphate-sensitive K + channel opener on liver ischemia/reperfusion injury. World J Gastroenterol 2014; 20:15319-15326. [PMID: 25386080 PMCID: PMC4223265 DOI: 10.3748/wjg.v20.i41.15319] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 05/28/2014] [Accepted: 07/11/2014] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effect of diazoxide administration on liver ischemia/reperfusion injury.
METHODS: Wistar male rats underwent partial liver ischemia performed by clamping the pedicle from the medium and left anterior lateral segments for 1 h under mechanical ventilation. They were divided into 3 groups: Control Group, rats submitted to liver manipulation, Saline Group, rats received saline, and Diazoxide Group, rats received intravenous injection diazoxide (3.5 mg/kg) 15 min before liver reperfusion. 4 h and 24 h after reperfusion, blood was collected for determination of aspartate transaminase (AST), alanine transaminase (ALT), tumor necrosis factor (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), nitrite/nitrate, creatinine and tumor growth factor-β1 (TGF-β1). Liver tissues were assembled for mitochondrial oxidation and phosphorylation, malondialdehyde (MDA) content, and histologic analysis. Pulmonary vascular permeability and myeloperoxidase (MPO) were also determined.
RESULTS: Four hours after reperfusion the diazoxide group presented with significant reduction of AST (2009 ± 257 U/L vs 3523 ± 424 U/L, P = 0.005); ALT (1794 ± 295 U/L vs 3316 ± 413 U/L, P = 0.005); TNF-α (17 ± 9 pg/mL vs 152 ± 43 pg/mL, P = 0.013; IL-6 (62 ± 18 pg/mL vs 281 ± 92 pg/mL); IL-10 (40 ± 9 pg/mL vs 78 ± 10 pg/mL P = 0.03), and nitrite/nitrate (3.8 ± 0.9 μmol/L vs 10.2 ± 2.4 μmol/L, P = 0.025) when compared to the saline group. A significant reduction in liver mitochondrial dysfunction was observed in the diazoxide group compared to the saline group (P < 0.05). No differences in liver MDA content, serum creatinine, pulmonary vascular permeability and MPO activity were observed between groups. Twenty four hours after reperfusion the diazoxide group showed a reduction of AST (495 ± 78 U/L vs 978 ± 192 U/L, P = 0.032); ALT (335 ± 59 U/L vs 742 ± 182 U/L, P = 0.048), and TGF-β1 (11 ± 1 ng/mL vs 17 ± 0.5 ng/mL, P = 0.004) serum levels when compared to the saline group. The control group did not present alterations when compared to the diazoxide and saline groups.
CONCLUSION: Diazoxide maintains liver mitochondrial function, increases liver tolerance to ischemia/reperfusion injury, and reduces the systemic inflammatory response. These effects require further evaluation for using in a clinical setting.
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18
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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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19
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Wang ZH, Liu JL, Wu L, Yu Z, Yang HT. Concentration-dependent wrestling between detrimental and protective effects of H2O2 during myocardial ischemia/reperfusion. Cell Death Dis 2014; 5:e1297. [PMID: 24946090 PMCID: PMC4611739 DOI: 10.1038/cddis.2014.267] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 05/04/2014] [Accepted: 05/19/2014] [Indexed: 12/17/2022]
Abstract
Reactive oxygen species (ROS) and endoplasmic reticulum (ER) stress are paradoxically implicated in myocardial ischemia/reperfusion (I/R) injury and cardioprotection. However, the precise interpretation for the dual roles of ROS and its relationship with the ER stress during I/R remain elusive. Here we investigated the concentration-dependent effects of hydrogen peroxide (H2O2) preconditioning (PC) and postconditioning (PoC) on the ER stress and prosurvival reperfusion injury salvage kinase (RISK) activation using an ex vivo rat myocardial I/R model. The effects of H2O2 PC and PoC showed three phases. At a low level (1 μM), H2O2 exacerbated I/R-induced left ventricular (LV) contractile dysfunction and ER stress, as indicated by enhanced phosphorylation of protein kinase-like ER kinase and expressions of glucose-regulated protein 78, X-box-binding protein 1 splicing variant, TNF receptor-associated factor 2, activating transcription factor-6 cleaved 50 kDa fragment, and caspase-12 cleavage, but the I/R-induced RISK activation including protein kinase B (PKB/Akt) and protein kinase Cɛ (PKCɛ) remained unchanged. Consistently, the postischemic LV performance in 1 μM H2O2 PC and PoC groups was improved by inhibiting ER stress with 4-phenyl butyric acid but not affected by the ER stress inducer, tunicamycin. At a moderate level (10-100 μM), H2O2 significantly improved postischemic LV performance and enhanced RISK activation, but it did no further alter the ER stress. The cardioprotection but not ER stress was abrogated with Akt or PKCɛ inhibitor wortmannin or ɛV1-2. At a high level (1 mM), H2O2 markedly aggravated the reperfusion injury and the oxidative stress but did not further enhance the RISK activation. In addition, 1 or 20 μM of H2O2 PC did not alter cardioprotective effects of ischemic PC in postischemic contractile performance and protein oxidation. Our data suggest that the differential effects of H2O2 are derived from a concentration-dependent wrestling between its detrimental stress and protective signaling.
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Affiliation(s)
- Z-H Wang
- 1] Key Laboratory of Stem Cell Biology and Laboratory of Molecular Cardiology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences (SIBS), Chinese Academy of Sciences (CAS) and Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai, China [2] Division of Molecular Medicine, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - J-L Liu
- Key Laboratory of Stem Cell Biology and Laboratory of Molecular Cardiology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences (SIBS), Chinese Academy of Sciences (CAS) and Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai, China
| | - L Wu
- Key Laboratory of Stem Cell Biology and Laboratory of Molecular Cardiology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences (SIBS), Chinese Academy of Sciences (CAS) and Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai, China
| | - Z Yu
- Key Laboratory of Stem Cell Biology and Laboratory of Molecular Cardiology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences (SIBS), Chinese Academy of Sciences (CAS) and Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai, China
| | - H-T Yang
- Key Laboratory of Stem Cell Biology and Laboratory of Molecular Cardiology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences (SIBS), Chinese Academy of Sciences (CAS) and Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai, China
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20
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Abstract
The field of mitochondrial ion channels has recently seen substantial progress, including the molecular identification of some of the channels. An integrative approach using genetics, electrophysiology, pharmacology, and cell biology to clarify the roles of these channels has thus become possible. It is by now clear that many of these channels are important for energy supply by the mitochondria and have a major impact on the fate of the entire cell as well. The purpose of this review is to provide an up-to-date overview of the electrophysiological properties, molecular identity, and pathophysiological functions of the mitochondrial ion channels studied so far and to highlight possible therapeutic perspectives based on current information.
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21
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Yan LJ. Positive oxidative stress in aging and aging-related disease tolerance. Redox Biol 2014; 2:165-9. [PMID: 25460727 PMCID: PMC4297947 DOI: 10.1016/j.redox.2014.01.002] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 12/30/2013] [Accepted: 01/01/2014] [Indexed: 12/14/2022] Open
Abstract
It is now well established that reactive oxygen species (ROS), reactive nitrogen species (RNS), and a basal level of oxidative stress are essential for cell survival. It is also well known that while severe oxidative stress often leads to widespread oxidative damage and cell death, a moderate level of oxidative stress, induced by a variety of stressors, can yield great beneficial effects on adaptive cellular responses to pathological challenges in aging and aging-associated disease tolerance such as ischemia tolerance. Here in this review, I term this moderate level of oxidative stress as positive oxidative stress, which usually involves imprinting molecular signatures on lipids and proteins via formation of lipid peroxidation by-products and protein oxidation adducts. As ROS/RNS are short-lived molecules, these molecular signatures can thus execute the ultimate function of ROS/RNS. Representative examples of lipid peroxidation products and protein oxidation adducts are presented to illustrate the role of positive oxidative stress in a variety of pathological settings, demonstrating that positive oxidative stress could be a valuable prophylactic and/or therapeutic approach targeting aging and aging-associated diseases.
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Affiliation(s)
- Liang-Jun Yan
- Department of Pharmacology and Neuroscience, and Institute for Aging and Alzheimer's Disease, University of North Texas Health Science Center, Fort Worth, TX 76107, United States.
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22
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Schönfeld P, Reiser G. Why does brain metabolism not favor burning of fatty acids to provide energy? Reflections on disadvantages of the use of free fatty acids as fuel for brain. J Cereb Blood Flow Metab 2013; 33:1493-9. [PMID: 23921897 PMCID: PMC3790936 DOI: 10.1038/jcbfm.2013.128] [Citation(s) in RCA: 285] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 06/11/2013] [Accepted: 07/05/2013] [Indexed: 02/08/2023]
Abstract
It is puzzling that hydrogen-rich fatty acids are used only poorly as fuel in the brain. The long-standing belief that a slow passage of fatty acids across the blood-brain barrier might be the reason. However, this has been corrected by experimental results. Otherwise, accumulated nonesterified fatty acids or their activated derivatives could exert detrimental activities on mitochondria, which might trigger the mitochondrial route of apoptosis. Here, we draw attention to three particular problems: (1) ATP generation linked to β-oxidation of fatty acids demands more oxygen than glucose, thereby enhancing the risk for neurons to become hypoxic; (2) β-oxidation of fatty acids generates superoxide, which, taken together with the poor anti-oxidative defense in neurons, causes severe oxidative stress; (3) the rate of ATP generation based on adipose tissue-derived fatty acids is slower than that using blood glucose as fuel. Thus, in periods of extended continuous and rapid neuronal firing, fatty acid oxidation cannot guarantee rapid ATP generation in neurons. We conjecture that the disadvantages connected with using fatty acids as fuel have created evolutionary pressure on lowering the expression of the β-oxidation enzyme equipment in brain mitochondria to avoid extensive fatty acid oxidation and to favor glucose oxidation in brain.
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Affiliation(s)
- Peter Schönfeld
- Institute of Biochemistry and Cell Biology, Medical Faculty of Otto-von-Guericke-University, Magdeburg, Germany
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23
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Dröse S. Differential effects of complex II on mitochondrial ROS production and their relation to cardioprotective pre- and postconditioning. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1827:578-87. [DOI: 10.1016/j.bbabio.2013.01.004] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 01/04/2013] [Accepted: 01/09/2013] [Indexed: 11/30/2022]
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Queliconi BB, Marazzi TBM, Vaz SM, Brookes PS, Nehrke K, Augusto O, Kowaltowski AJ. Bicarbonate modulates oxidative and functional damage in ischemia-reperfusion. Free Radic Biol Med 2013; 55:46-53. [PMID: 23195687 PMCID: PMC3995138 DOI: 10.1016/j.freeradbiomed.2012.11.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 11/01/2012] [Accepted: 11/13/2012] [Indexed: 11/25/2022]
Abstract
The carbon dioxide/bicarbonate (CO(2)/HCO(3)(-)) pair is the main biological pH buffer. However, its influence on biological processes, and in particular redox processes, is still poorly explored. Here we study the effect of CO(2)/HCO(3)(-) on ischemic injury in three distinct models (cardiac HL-1 cells, perfused rat heart, and Caenorhabditis elegans). We found that, although various concentrations of CO(2)/HCO(3)(-) do not affect function under basal conditions, ischemia-reperfusion or similar insults in the presence of higher CO(2)/HCO(3)(-) resulted in greater functional loss associated with higher oxidative damage in all models. Because the effect of CO(2)/HCO(3)(-) was observed in all models tested, we believe this buffer is an important determinant of oxidative damage after ischemia-reperfusion.
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Affiliation(s)
- Bruno B. Queliconi
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Thire B. M. Marazzi
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Sandra M. Vaz
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | | | - Keith Nehrke
- University of Rochester Medical Center, Rochester, NY, USA
| | - Ohara Augusto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Alicia J. Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
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25
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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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26
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Zhang H, Wang ZQ, Zhao DY, Zheng DM, Feng J, Song LC, Luo Y. AIF-mediated mitochondrial pathway is critical for the protective effect of diazoxide against SH-SY5Y cell apoptosis. Brain Res 2011; 1370:89-98. [DOI: 10.1016/j.brainres.2010.11.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 11/02/2010] [Accepted: 11/05/2010] [Indexed: 02/01/2023]
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27
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Wu YN, Yu H, Zhu XH, Yuan HJ, Kang Y, Jiao JJ, Gao WZ, Liu YX, Lou JS. Noninvasive delayed limb ischemic preconditioning attenuates myocardial ischemia-reperfusion injury in rats by a mitochondrial K(ATP) channel-dependent mechanism. Physiol Res 2010; 60:271-9. [PMID: 21114361 DOI: 10.33549/physiolres.931944] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
We previously demonstrated in rats that noninvasive delayed limb ischemic preconditioning (LIPC) induced by three cycles of 5-min occlusion and 5-min reperfusion of the left hind limb per day for three days confers the same cardioprotective effect as local ischemic preconditioning of the heart, but the mechanism has not been studied in depth. The aim of this project was to test the hypothesis that delayed LIPC enhances myocardial antioxidative ability during ischemia-reperfusion by a mitochondrial K(ATP) channel (mito K(ATP))-dependent mechanism. Rats were randomized to five groups: ischemia-reperfusion (IR)-control group, myocardial ischemic preconditioning (MIPC) group, LIPC group, IR-5HD group and LIPC-5HD group. The MIPC group underwent local ischemic preconditioning induced by three cycles of 5-min occlusion and 5-min reperfusion of the left anterior descending coronary arteries. The LIPC and LIPC-5HD groups underwent LIPC induced by three cycles of 5-min occlusion and 5-min reperfusion of the left hind limb using a modified blood pressure aerocyst per day for three days. All rats were subjected to myocardial ischemia-reperfusion injury. The IR-5HD and LIPC-5HD groups received the mito K(ATP) channel blocker 5-hydroxydecanoate Na (5-HD) before and during the myocardial ischemia-reperfusion injury. Compared with the IR-control group, both the LIPC and MIPC groups showed an amelioration of ventricular arrhythmia, reduced myocardial infarct size, increased activities of total superoxide dismutase, manganese-superoxide dismutase (Mn-SOD) and glutathione peroxidase, increased expression of Mn-SOD mRNA and decreased xanthine oxidase activity and malondialdehyde concentration. These beneficial effects of LIPC were prevented by 5-HD. In conclusion, delayed LIPC offers similar cardioprotection as local IPC. These results support the hypothesis that the activation of mito K(ATP) channels enhances myocardial antioxidative ability during ischemia-reperfusion, thereby contributing, at least in part, to the anti-arrhythmic and anti-infarct effects of delayed LIPC.
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Affiliation(s)
- Y-N Wu
- Department of Pharmacology, Tianjin Medical University, Tianjin, China
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28
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Queliconi BB, Wojtovich AP, Nadtochiy SM, Kowaltowski AJ, Brookes PS. Redox regulation of the mitochondrial K(ATP) channel in cardioprotection. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1813:1309-15. [PMID: 21094666 DOI: 10.1016/j.bbamcr.2010.11.005] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 10/05/2010] [Accepted: 11/11/2010] [Indexed: 12/12/2022]
Abstract
The mitochondrial ATP-sensitive potassium channel (mK(ATP)) is important in the protective mechanism of ischemic preconditioning (IPC). The channel is reportedly sensitive to reactive oxygen and nitrogen species, and the aim of this study was to compare such species in parallel, to build a more comprehensive picture of mK(ATP) regulation. mK(ATP) activity was measured by both osmotic swelling and Tl(+) flux assays, in isolated rat heart mitochondria. An isolated adult rat cardiomyocyte model of ischemia-reperfusion (IR) injury was also used to determine the role of mK(ATP) in cardioprotection by nitroxyl. Key findings were as follows: (i) mK(ATP) was activated by O(2)(-) and H(2)O(2) but not other peroxides. (ii) mK(ATP) was inhibited by NADPH. (iii) mK(ATP) was activated by S-nitrosothiols, nitroxyl, and nitrolinoleate. The latter two species also inhibited mitochondrial complex II. (iv) Nitroxyl protected cardiomyocytes against IR injury in an mK(ATP)-dependent manner. Overall, these results suggest that the mK(ATP) channel is activated by specific reactive oxygen and nitrogen species, and inhibited by NADPH. The redox modulation of mK(ATP) may be an underlying mechanism for its regulation in the context of IPC. This article is part of a Special Issue entitled: Mitochondria and Cardioprotection.
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Affiliation(s)
- Bruno B Queliconi
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
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29
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Milder JB, Liang LP, Patel M. Acute oxidative stress and systemic Nrf2 activation by the ketogenic diet. Neurobiol Dis 2010; 40:238-44. [PMID: 20594978 DOI: 10.1016/j.nbd.2010.05.030] [Citation(s) in RCA: 133] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Revised: 05/05/2010] [Accepted: 05/25/2010] [Indexed: 10/19/2022] Open
Abstract
The mechanisms underlying the efficacy of the ketogenic diet (KD) remain unknown. Recently, we showed that the KD increased glutathione (GSH) biosynthesis. Since the NF E2-related factor 2 (Nrf2) transcription factor is a primary responder to cellular stress and can upregulate GSH biosynthesis, we asked whether the KD activates the Nrf2 pathway. Here we report that rats consuming a KD show acute production of H(2)O(2) from hippocampal mitochondria, which decreases below control levels by 3 weeks, suggestive of an adaptive response. 4-Hydroxy-2-nonenal (4-HNE), an electrophilic lipid peroxidation end product known to activate the Nrf2 detoxification pathway, was also acutely increased by the KD. Nrf2 nuclear accumulation was evident in both the hippocampus and liver, and the Nrf2 target, NAD(P)H:quinone oxidoreductase (NQO1), exhibited increased activity in both the hippocampus and liver after 3 weeks. We also found chronic depletion of liver tissue GSH, while liver mitochondrial antioxidant capacity was preserved. These data suggest that the KD initially produces mild oxidative and electrophilic stress, which may systemically activate the Nrf2 pathway via redox signaling, leading to chronic cellular adaptation, induction of protective proteins, and improvement of the mitochondrial redox state.
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Affiliation(s)
- Julie B Milder
- Graduate Program in Neuroscience, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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Cavalheiro RA, Marin RM, Rocco SA, Cerqueira FM, Caldeira da Silva CC, Rittner R, Kowaltowski AJ, Vercesi AE, Franchini KG, Castilho RF. Potent cardioprotective effect of the 4-anilinoquinazoline derivative PD153035: involvement of mitochondrial K(ATP) channel activation. PLoS One 2010; 5:e10666. [PMID: 20498724 PMCID: PMC2871796 DOI: 10.1371/journal.pone.0010666] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2009] [Accepted: 04/27/2010] [Indexed: 11/21/2022] Open
Abstract
Background The aim of the present study was to evaluate the protective effects of the 4-anilinoquinazoline derivative PD153035 on cardiac ischemia/reperfusion and mitochondrial function. Methodology/Principal Findings Perfused rat hearts and cardiac HL-1 cells were used to determine cardioprotective effects of PD153035. Isolated rat heart mitochondria were studied to uncover mechanisms of cardioprotection. Nanomolar doses of PD153035 strongly protect against heart and cardiomyocyte damage induced by ischemia/reperfusion and cyanide/aglycemia. PD153035 did not alter oxidative phosphorylation, nor directly prevent Ca2+ induced mitochondrial membrane permeability transition. The protective effect of PD153035 on HL-1 cells was also independent of AKT phosphorylation state. Interestingly, PD153035 activated K+ transport in isolated mitochondria, in a manner prevented by ATP and 5-hydroxydecanoate, inhibitors of mitochondrial ATP-sensitive K+ channels (mitoKATP). 5-Hydroxydecanoate also inhibited the cardioprotective effect of PD153035 in cardiac HL-1 cells, demonstrating that this protection is dependent on mitoKATP activation. Conclusions/Significance We conclude that PD153035 is a potent cardioprotective compound and acts in a mechanism involving mitoKATP activation.
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Affiliation(s)
- Renata A. Cavalheiro
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, Brazil
| | - Rodrigo M. Marin
- Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, Brazil
| | - Silvana A. Rocco
- Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, Brazil
| | - Fernanda M. Cerqueira
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | | | - Roberto Rittner
- Departamento de Química Orgânica, Instituto de Química, Universidade Estadual de Campinas, Campinas, Brazil
| | - Alicia J. Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Anibal E. Vercesi
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, Brazil
| | - Kleber G. Franchini
- Departamento de Clínica Médica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, Brazil
- * E-mail: (RFC); (KGF)
| | - Roger F. Castilho
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, Brazil
- * E-mail: (RFC); (KGF)
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Blokhina O, Fagerstedt KV. Reactive oxygen species and nitric oxide in plant mitochondria: origin and redundant regulatory systems. PHYSIOLOGIA PLANTARUM 2010; 138:447-62. [PMID: 20059731 DOI: 10.1111/j.1399-3054.2009.01340.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Plant mitochondria differ from their mammalian counterparts in many respects, which are due to the unique and variable surroundings of plant mitochondria. In green leaves, plant mitochondria are surrounded by ample respiratory substrates and abundant molecular oxygen, both resulting from active photosynthesis, while in roots and bulky rhizomes and fruit carbohydrates may be plenty, whereas oxygen levels are falling. Several enzymatic complexes in mitochondrial electron transport chain (ETC) are capable of reactive oxygen species (ROS) formation under physiological and pathological conditions. Inherently connected parameters such as the redox state of electron carriers in the ETC, ATP synthase activity and inner mitochondrial membrane potential, when affected by external stimuli, can give rise to ROS formation via complexes I and III, and by reverse electron transport (RET) from complex II. Superoxide radicals produced are quickly scavenged by superoxide dismutase (MnSOD), and the resulting H(2)O(2) is detoxified by peroxiredoxin-thioredoxin system or by the enzymes of ascorbate-glutathione cycle, found in the mitochondrial matrix. Arginine-dependent nitric oxide (NO)-releasing activity of enzymatic origin has been detected in plant mitochondria. The molecular identity of the enzyme is not clear but the involvement of mitochondria-localized enzymes responsible for arginine catabolism, arginase and ornithine aminotransferase has been shown in the regulation of NO efflux. Besides direct control by antioxidants, mitochondrial ROS production is tightly controlled by multiple redundant systems affecting inner membrane potential: NAD(P)H-dependent dehydrogenases, alternative oxidase (AOX), uncoupling proteins, ATP-sensitive K(+) channel and a number of matrix and intermembrane enzymes capable of direct electron donation to ETC. NO removal, on the other hand, takes place either by reactions with molecular oxygen or superoxide resulting in peroxynitrite, nitrite or nitrate ions or through interaction with non-symbiotic hemoglobins or glutathione. Mitochondrial ROS and NO production is tightly controlled by multiple redundant systems providing the regulatory mechanism for redox homeostasis and specific ROS/NO signaling.
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Affiliation(s)
- Olga Blokhina
- Department of Biological and Environmental Sciences, University of Helsinki, P.O. Box 65, FI-00014 Helsinki, Finland.
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32
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Mitochondrial ion transport pathways: role in metabolic diseases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:832-8. [PMID: 20044972 DOI: 10.1016/j.bbabio.2009.12.017] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2009] [Revised: 12/16/2009] [Accepted: 12/21/2009] [Indexed: 12/22/2022]
Abstract
Mitochondria are the central coordinators of energy metabolism and alterations in their function and number have long been associated with metabolic disorders such as obesity, diabetes and hyperlipidemias. Since oxidative phosphorylation requires an electrochemical gradient across the inner mitochondrial membrane, ion channels in this membrane certainly must play an important role in the regulation of energy metabolism. However, in many experimental settings, the relationship between the activity of mitochondrial ion transport and metabolic disorders is still poorly understood. This review briefly summarizes some aspects of mitochondrial H+ transport (promoted by uncoupling proteins, UCPs), Ca2+ and K+ uniporters which may be determinant in metabolic disorders.
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Ha SJ, Kim W. Mechanism of Ischemia and Reperfusion Injury to the Heart: From the Viewpoint of Nitric Oxide and Mitochondria. Chonnam Med J 2010. [DOI: 10.4068/cmj.2010.46.3.129] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Sang-Jin Ha
- Cardiology Division, Department of Internal Medicine, Kyung Hee University Hospital, Seoul, Korea
| | - Weon Kim
- Cardiology Division, Department of Internal Medicine, Kyung Hee University Hospital, Seoul, Korea
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Kowaltowski AJ, de Souza-Pinto NC, Castilho RF, Vercesi AE. Mitochondria and reactive oxygen species. Free Radic Biol Med 2009; 47:333-43. [PMID: 19427899 DOI: 10.1016/j.freeradbiomed.2009.05.004] [Citation(s) in RCA: 789] [Impact Index Per Article: 52.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Revised: 04/29/2009] [Accepted: 05/06/2009] [Indexed: 01/02/2023]
Abstract
Mitochondria are a quantitatively relevant source of reactive oxygen species (ROS) in the majority of cell types. Here we review the sources and metabolism of ROS in this organelle, including the conditions that regulate the production of these species, such as mild uncoupling, oxygen tension, respiratory inhibition, Ca2+ and K+ transport, and mitochondrial content and morphology. We discuss substrate-, tissue-, and organism-specific characteristics of mitochondrial oxidant generation. Several aspects of the physiological and pathological roles of mitochondrial ROS production are also addressed.
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Affiliation(s)
- Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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35
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Ambivalent effects of diazoxide on mitochondrial ROS production at respiratory chain complexes I and III. Biochim Biophys Acta Gen Subj 2009; 1790:558-65. [DOI: 10.1016/j.bbagen.2009.01.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 01/27/2009] [Accepted: 01/30/2009] [Indexed: 12/31/2022]
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36
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Stowe DF, Camara AKS. Mitochondrial reactive oxygen species production in excitable cells: modulators of mitochondrial and cell function. Antioxid Redox Signal 2009; 11:1373-414. [PMID: 19187004 PMCID: PMC2842133 DOI: 10.1089/ars.2008.2331] [Citation(s) in RCA: 341] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Revised: 01/12/2009] [Accepted: 01/13/2009] [Indexed: 12/14/2022]
Abstract
The mitochondrion is a major source of reactive oxygen species (ROS). Superoxide (O(2)(*-)) is generated under specific bioenergetic conditions at several sites within the electron-transport system; most is converted to H(2)O(2) inside and outside the mitochondrial matrix by superoxide dismutases. H(2)O(2) is a major chemical messenger that, in low amounts and with its products, physiologically modulates cell function. The redox state and ROS scavengers largely control the emission (generation scavenging) of O(2)(*-). Cell ischemia, hypoxia, or toxins can result in excess O(2)(*-) production when the redox state is altered and the ROS scavenger systems are overwhelmed. Too much H(2)O(2) can combine with Fe(2+) complexes to form reactive ferryl species (e.g., Fe(IV) = O(*)). In the presence of nitric oxide (NO(*)), O(2)(*-) forms the reactant peroxynitrite (ONOO(-)), and ONOOH-induced nitrosylation of proteins, DNA, and lipids can modify their structure and function. An initial increase in ROS can cause an even greater increase in ROS and allow excess mitochondrial Ca(2+) entry, both of which are factors that induce cell apoptosis and necrosis. Approaches to reduce excess O(2)(*-) emission include selectively boosting the antioxidant capacity, uncoupling of oxidative phosphorylation to reduce generation of O(2)(*-) by inducing proton leak, and reversibly inhibiting electron transport. Mitochondrial cation channels and exchangers function to maintain matrix homeostasis and likely play a role in modulating mitochondrial function, in part by regulating O(2)(*-) generation. Cell-signaling pathways induced physiologically by ROS include effects on thiol groups and disulfide linkages to modify posttranslationally protein structure to activate/inactivate specific kinase/phosphatase pathways. Hypoxia-inducible factors that stimulate a cascade of gene transcription may be mediated physiologically by ROS. Our knowledge of the role played by ROS and their scavenging systems in modulation of cell function and cell death has grown exponentially over the past few years, but we are still limited in how to apply this knowledge to develop its full therapeutic potential.
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Affiliation(s)
- David F Stowe
- Anesthesiology Research Laboratories, Department of Anesthesiology, The Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
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37
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Tahara EB, Navarete FDT, Kowaltowski AJ. Tissue-, substrate-, and site-specific characteristics of mitochondrial reactive oxygen species generation. Free Radic Biol Med 2009; 46:1283-97. [PMID: 19245829 DOI: 10.1016/j.freeradbiomed.2009.02.008] [Citation(s) in RCA: 313] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2008] [Revised: 01/29/2009] [Accepted: 02/05/2009] [Indexed: 12/16/2022]
Abstract
Reactive oxygen species are a by-product of mitochondrial oxidative phosphorylation, derived from a small quantity of superoxide radicals generated during electron transport. We conducted a comprehensive and quantitative study of oxygen consumption, inner membrane potentials, and H(2)O(2) release in mitochondria isolated from rat brain, heart, kidney, liver, and skeletal muscle, using various respiratory substrates (alpha-ketoglutarate, glutamate, succinate, glycerol phosphate, and palmitoyl carnitine). The locations and properties of reactive oxygen species formation were determined using oxidative phosphorylation and the respiratory chain modulators oligomycin, rotenone, myxothiazol, and antimycin A and the uncoupler CCCP. We found that in mitochondria isolated from most tissues incubated under physiologically relevant conditions, reactive oxygen release accounts for 0.1-0.2% of O(2) consumed. Our findings support an important participation of flavoenzymes and complex III and a substantial role for reverse electron transport to complex I as reactive oxygen species sources. Our results also indicate that succinate is an important substrate for isolated mitochondrial reactive oxygen production in brain, heart, kidney, and skeletal muscle, whereas fatty acids generate significant quantities of oxidants in kidney and liver. Finally, we found that increasing respiratory rates is an effective way to prevent mitochondrial oxidant release under many, but not all, conditions. Altogether, our data uncover and quantify many tissue-, substrate-, and site-specific characteristics of mitochondrial ROS release.
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Affiliation(s)
- Erich B Tahara
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
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38
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Rodriguez-Pallares J, Parga JA, Joglar B, Guerra MJ, Labandeira-Garcia JL. The Mitochondrial ATP-Sensitive Potassium Channel Blocker 5-Hydroxydecanoate Inhibits Toxicity of 6-Hydroxydopamine on Dopaminergic Neurons. Neurotox Res 2009; 15:82-95. [DOI: 10.1007/s12640-009-9010-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Revised: 12/12/2008] [Accepted: 12/17/2008] [Indexed: 12/21/2022]
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Nadtochiy SM, Baker PRS, Freeman BA, Brookes PS. Mitochondrial nitroalkene formation and mild uncoupling in ischaemic preconditioning: implications for cardioprotection. Cardiovasc Res 2008; 82:333-40. [PMID: 19050010 DOI: 10.1093/cvr/cvn323] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
AIMS Both mitochondria and nitric oxide (NO*) contribute to cardioprotection by ischaemic preconditioning (IPC). IPC causes mild uncoupling of mitochondria via uncoupling proteins (UCPs) and the adenine nucleotide translocase (ANT), and mild uncoupling per se is cardioprotective. Although electrophilic lipids are known to activate mitochondrial uncoupling, the role of such species in IPC-induced uncoupling and cardioprotection is unclear. We hypothesized that endogenous formation of NO*-derived electrophilic lipids (nitroalkenes such as nitro-linoleate, LNO2) during IPC may stimulate mitochondrial uncoupling via post-translational modification of UCPs and ANT, thus affording cardioprotection. METHODS Hearts from male Sprague-Dawley rats were Langendorff-perfused and subjected to IPC. Nitroalkene formation was measured by HPLC-ESI-MS/MS. The effects of exogenous LNO2 and biotin-tagged LNO2 on isolated heart mitochondria and cardiomyocytes were also investigated. RESULTS Nitroalkenes including LNO2 were endogenously generated in mitochondria of IPC hearts. Synthetic LNO2 (<1 microM) activated mild uncoupling, an effect blocked by UCP and ANT inhibitors. LNO2 (<1 microM) also protected cardiomyocytes against simulated ischaemia-reperfusion injury. Biotinylated LNO2 covalently modified ANT thiols and possibly UCP-2. No effects of LNO2 were attributable to NO* release, cGMP signalling, mitochondrial KATP channels, or protective kinase signalling. CONCLUSION Components of a novel signalling pathway are inferred, wherein nitroalkenes formed by IPC-stimulated nitration reactions may induce mild mitochondrial uncoupling via post-translational modification of ANT and UCP-2, subsequently conferring resistance to ischaemia-reperfusion injury.
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Affiliation(s)
- Sergiy M Nadtochiy
- Department of Anesthesiology, Box 604, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA
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Simerabet M, Robin E, Aristi I, Adamczyk S, Tavernier B, Vallet B, Bordet R, Lebuffe G. Preconditioning by an in situ administration of hydrogen peroxide: involvement of reactive oxygen species and mitochondrial ATP-dependent potassium channel in a cerebral ischemia-reperfusion model. Brain Res 2008; 1240:177-84. [PMID: 18793617 DOI: 10.1016/j.brainres.2008.08.070] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 08/24/2008] [Accepted: 08/25/2008] [Indexed: 02/03/2023]
Abstract
Reactive oxygen species (ROS) and the mitochondrial ATP-dependent potassium channel (mitoK(+)(-)(ATP)) play a major role in myocardial preconditioning. The same pathways seem to be involved in cerebral preconditioning. The aim of this study was to evaluate ROS involvement during the initial phase of delayed preconditioning and its relationship with mitoK(+)(-ATP) opening in a rat model of cerebral ischemia-reperfusion. Ischemia was induced by a 1-h occlusion of middle cerebral artery followed by a 24-h reperfusion period. A delayed preconditioning was induced by a 3-min ischemia (IPC), an in situ infusion of hydrogen peroxide (H(2)O(2)), or an administration of mitoK(+)(-ATP) agonist diazoxide, 72 h before the ischemia-reperfusion (I/R). IPC was performed in the presence or not of N-acetyl-cysteine (NAC) or 5-hydroxydecanoate (5-HD). A neuroprotection was induced by IPC and administration of H(2)O(2) or diazoxide. The decrease in infarct size was respectively 24.5%, 45.7% and 24.6%. IPC was abolished by 5-HD and NAC, indicating that mitoK(+)(-ATP) and ROS are involved. The protection induced by H(2)O(2) was blocked by 5-HD and diazoxide triggering was abolished by NAC. This strong relationship between ROS and mitoK(+)(-ATP) needs to be clarified as ROS might be involved both upstream and downstream of mitoK(+)(-ATP) opening.
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Affiliation(s)
- Malika Simerabet
- Department of Pharmacology, Faculty of Medicine, University of Lille2, France
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41
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Shahid M, Tauseef M, Sharma KK, Fahim M. Brief femoral artery ischaemia provides protection against myocardial ischaemia-reperfusion injury in rats: the possible mechanisms. Exp Physiol 2008; 93:954-68. [DOI: 10.1113/expphysiol.2007.041442] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Fornazari M, de Paula JG, Castilho RF, Kowaltowski AJ. Redox properties of the adenoside triphosphate-sensitive K+ channel in brain mitochondria. J Neurosci Res 2008; 86:1548-56. [PMID: 18189325 DOI: 10.1002/jnr.21614] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Brain mitochondrial ATP-sensitive K+ channel (mitoK(ATP)) opening by diazoxide protects against ischemic damage and excitotoxic cell death. Here we studied the redox properties of brain mitoK(ATP) . MitoK(ATP) activation during excitotoxicity in cultured cerebellar granule neurons prevented the accumulation of reactive oxygen species (ROS) and cell death. Furthermore, mitoK(ATP) activation in isolated brain mitochondria significantly prevented H2O2 release by these organelles but did not change Ca2+ accumulation capacity. Interestingly, the activity of mitoK(ATP) was highly dependent on redox state. The thiol reductant mercaptopropionylglycine prevented mitoK(ATP) activity, whereas exogenous ROS activated the channel. In addition, the use of mitochondrial substrates that led to higher levels of endogenous mitochondrial ROS release closely correlated with enhanced K+ transport activity through mitoK(ATP). Altogether, our results indicate that brain mitoK(ATP) is a redox-sensitive channel that controls mitochondrial ROS release.
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Affiliation(s)
- Maynara Fornazari
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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Sardão VA, Pereira SL, Oliveira PJ. Drug-induced mitochondrial dysfunction in cardiac and skeletal muscle injury. Expert Opin Drug Saf 2008; 7:129-46. [PMID: 18324876 DOI: 10.1517/14740338.7.2.129] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND The list of clinically relevant molecules that affect skeletal and cardiac muscle mitochondria is gradually increasing, which strongly suggest that mitochondrial toxicity should be an important end point during the design and testing of novel pharmaceuticals. OBJECTIVE The present review intends to describe mechanisms by which clinically relevant drugs are known to alter mitochondrial function in cardiac and skeletal muscle, which is suggested to be involved in the toxicity associated with those drugs. METHODS Literature databases were searched in order to identify clinically relevant drugs with associated mitochondrial muscle toxicity. CONCLUSION Mitochondrial function is important in the context of muscle survival, hence, the requirement to identify novel mitochondrial targets and develop new therapies to counteract chemical-induced degeneration of mitochondrial function and muscle performance.
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Affiliation(s)
- Vilma A Sardão
- University of Coimbra, Center for Neurosciences and Cell Biology, Department of Zoology, 3004-517 Coimbra, Portugal
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44
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ROS-independent preconditioning in neurons via activation of mitoK(ATP) channels by BMS-191095. J Cereb Blood Flow Metab 2008; 28:1090-103. [PMID: 18212794 DOI: 10.1038/sj.jcbfm.9600611] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Previously, we have shown that the selective mitochondrial ATP-sensitive potassium (mitoK(ATP)) channel opener BMS-191095 (BMS) induces neuronal preconditioning (PC); however, the exact mechanism of BMS-induced neuroprotection remains unclear. In this study, we have identified key components of the cascade resulting in delayed neuronal PC with BMS using isolated rat brain mitochondria and primary cultures of rat cortical neurons. BMS depolarized isolated mitochondria without an increase in reactive oxygen species (ROS) generation and induced rapid phosphorylation of Akt and glycogen synthase kinase-3beta. Long-term (3 days) treatment of neurons with BMS resulted in sustained mitochondrial depolarization, decreased basal ROS generation, and elevated ATP levels. This treatment also elicited almost complete protection against glutamate excitotoxicity, which could be abolished using the phosphoinositide 3-kinase (PI3K) inhibitor wortmannin, but not with the superoxide dismutase (SOD) mimetic M40401. Long-term BMS treatment induced a PI3K-dependent increase in the expression and activity of catalase without affecting manganese SOD and copper/zinc-dependent SOD. Finally, the catalase inhibitor 3-aminotriazole dose-dependently antagonized the neuroprotective effect of BMS-induced PC. In summary, BMS depolarizes mitochondria without ROS generation, activates the PI3K-Akt pathway, improves ATP content, and increases catalase expression. These mechanisms appear to play important roles in the neuroprotective effect of BMS.
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Dost T, Cohen MV, Downey JM. Redox signaling triggers protection during the reperfusion rather than the ischemic phase of preconditioning. Basic Res Cardiol 2008; 103:378-84. [PMID: 18347834 DOI: 10.1007/s00395-008-0718-z] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2007] [Accepted: 01/11/2008] [Indexed: 10/22/2022]
Abstract
In ischemic preconditioning (IPC) brief ischemia/reperfusion renders the heart resistant to infarction from any subsequent ischemic insult. Protection results from binding of surface receptors by ligands released during the preconditioning ischemia. The downstream pathway involves redox signaling as IPC will not protect in the presence of a free radical scavenger. To determine when in the IPC protocol the redox signaling occurs, seven groups of isolated rabbit hearts were studied. All hearts underwent 30 min of coronary branch occlusion and 2 h of reperfusion. IPC groups were subjected to 5 min of regional ischemia followed by 10 min of reperfusion prior to the 30-min coronary occlusion. The Control group had only the 30-min occlusion and 2-h reperfusion. In the second group IPC preceded the index coronary occlusion. The third group was also preconditioned, but the free radical scavenger N-2-mercaptopropionyl glycine (MPG 300 microM) was infused during the 10-min reperfusion and therefore was present in the myocardium in the distribution of the snared coronary artery during the entire reperfusion phase and also during the subsequent 30-min ischemia. In another preconditioned group MPG was added to the perfusate before the preconditioning ischemia and therefore was present in the tissue only during the preconditioning ischemia and then was washed out during reperfusion. In the fifth group MPG was added to the perfusate for only the last 5 min of the preconditioning reperfusion and therefore was present in the tissue during the last minutes of the reperfusion phase and the 30 min of ischemia. In an additional group of IPC hearts MPG was infused for only the initial 5 min of the preconditioning reperfusion and then allowed to wash out so that the scavenger was present for only the first half of the reperfusion phase. Infarct and risk zone sizes were measured by triphenyltetrazolium staining and fluorescent microspheres, resp. IPC reduced infarct size from 31.3 +/- 2.7% of the ischemic zone in control hearts to only 8.4 +/- 1.9%. MPG completely blocked IPC's protection in the third (39.4 +/- 2.8%) and sixth (36.1 +/- 7.7%) groups but did not affect its protection in groups 4 (8.1 +/- 1.5%) or 5 (7.8 +/- 1.1%). When deoxygenated buffer was used during IPC's reperfusion phase in the seventh group of hearts, protection was lost and infarct size was increased over that seen in control hearts (74.5 +/- 9.0%). Hence redox signaling occurs during the reperfusion phase of IPC, and the critical component in that reperfusion phase appears to be molecular oxygen.
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Affiliation(s)
- Turhan Dost
- Dept. of Physiology, MSB 3074, University of South Alabama, College of Medicine, Mobile, AL, 36688, USA
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Burwell LS, Brookes PS. Mitochondria as a target for the cardioprotective effects of nitric oxide in ischemia-reperfusion injury. Antioxid Redox Signal 2008; 10:579-99. [PMID: 18052718 DOI: 10.1089/ars.2007.1845] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
During cardiac ischemia-reperfusion (IR) injury, excessive generation of reactive oxygen species (ROS) and overload of Ca(2+) at the mitochondrial level both lead to opening of the mitochondrial permeability transition (PT) pore on reperfusion. This can result in the depletion of ATP, irreversible oxidation of proteins, lipids, and DNA within the cardiomyocyte, and can trigger cell-death pathways. In contrast, mitochondria are also implicated in the cardioprotective signaling processes of ischemic preconditioning (IPC), to prevent IR-related pathology. Nitric oxide (NO*) has emerged as a potent effector molecule for a variety of cardioprotective strategies, including IPC. Whereas NO* is most noted for its activation of the "classic" soluble guanylate cyclase (sGC) signaling pathway, emerging evidence indicates that NO can directly act on mitochondria, independent of the sGC pathway, affording acute cardioprotection against IR injury. These direct effects of NO* on mitochondria are the focus of this review.
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Affiliation(s)
- Lindsay S Burwell
- Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York 14642, USA
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Carreira RS, Miyamoto S, Di Mascio P, Gonçalves LM, Monteiro P, Providência LA, Kowaltowski AJ. Ischemic preconditioning enhances fatty acid-dependent mitochondrial uncoupling. J Bioenerg Biomembr 2007; 39:313-20. [PMID: 17917798 DOI: 10.1007/s10863-007-9093-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Accepted: 05/29/2007] [Indexed: 01/23/2023]
Abstract
This study tests the hypothesis that ischemic preconditioning (IP) changes fatty acid (FA)-dependent uncoupling between mitochondrial respiration and oxidative phosphorylation. We found that IP does not alter mitochondrial membrane integrity or FA levels, but enhances membrane potential decreases when FA are present, in an ATP-sensitive manner. FA hydroperoxides had equal effects in control and preconditioned mitochondria, and GTP did not abrogate the IP effect, suggesting uncoupling proteins were not involved. Conversely, thiol reductants and atractyloside, which inhibits the adenine nucleotide translocator, eliminated the differences in responses to FA. Together, our results suggest that IP leads to thiol oxidation and activation of the adenine nucleotide translocator, resulting in enhanced FA transport and mild mitochondrial uncoupling.
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Affiliation(s)
- Raquel S Carreira
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, Cidade Universitária, 05508-900 São Paulo, São Paulo, Brazil
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Halestrap AP, Clarke SJ, Khaliulin I. The role of mitochondria in protection of the heart by preconditioning. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:1007-31. [PMID: 17631856 PMCID: PMC2212780 DOI: 10.1016/j.bbabio.2007.05.008] [Citation(s) in RCA: 299] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Revised: 05/18/2007] [Accepted: 05/23/2007] [Indexed: 12/16/2022]
Abstract
A prolonged period of ischaemia followed by reperfusion irreversibly damages the heart. Such reperfusion injury (RI) involves opening of the mitochondrial permeability transition pore (MPTP) under the conditions of calcium overload and oxidative stress that accompany reperfusion. Protection from MPTP opening and hence RI can be mediated by ischaemic preconditioning (IP) where the prolonged ischaemic period is preceded by one or more brief (2–5 min) cycles of ischaemia and reperfusion. Following a brief overview of the molecular characterisation and regulation of the MPTP, the proposed mechanisms by which IP reduces pore opening are reviewed including the potential roles for reactive oxygen species (ROS), protein kinase cascades, and mitochondrial potassium channels. It is proposed that IP-mediated inhibition of MPTP opening at reperfusion does not involve direct phosphorylation of mitochondrial proteins, but rather reflects diminished oxidative stress during prolonged ischaemia and reperfusion. This causes less oxidation of critical thiol groups on the MPTP that are known to sensitise pore opening to calcium. The mechanisms by which ROS levels are decreased in the IP hearts during prolonged ischaemia and reperfusion are not known, but appear to require activation of protein kinase Cε, either by receptor-mediated events or through transient increases in ROS during the IP protocol. Other signalling pathways may show cross-talk with this primary mechanism, but we suggest that a role for mitochondrial potassium channels is unlikely. The evidence for their activity in isolated mitochondria and cardiac myocytes is reviewed and the lack of specificity of the pharmacological agents used to implicate them in IP is noted. Some K+ channel openers uncouple mitochondria and others inhibit respiratory chain complexes, and their ability to produce ROS and precondition hearts is mimicked by bona fide uncouplers and respiratory chain inhibitors. IP may also provide continuing protection during reperfusion by preventing a cascade of MPTP-induced ROS production followed by further MPTP opening. This phase of protection may involve survival kinase pathways such as Akt and glycogen synthase kinase 3 (GSK3) either increasing ROS removal or reducing mitochondrial ROS production.
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Affiliation(s)
- Andrew P Halestrap
- Department of Biochemistry and Bristol Heart Institute, University of Bristol, School of Medical Sciences, University Walk, Bristol BS8 1TD, UK.
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Abstract
The redox environment of the cell is currently thought to be extremely important to control cell growth, differentiation, and apoptosis as many redox-sensitive proteins characterize these networks. A recent, widely accepted theory is that free radicals are not only dangerous species but, at low concentration, they have been designed by evolution to participate in the maintenance of cellular redox (reduction/oxidation) homeostasis. This notion derives from the evidence that cells constantly generate free radicals both as waste products of aerobic metabolism and in response to a large variety of stimuli. Free radicals, once produced, provoked cellular responses (redox regulation) against oxidative stress transducing the signals to maintain the cellular redox balance. Growing evidence suggests that in many instances the production of radical species is tightly regulated and their downstream targets are very specific, indicating that reactive oxygen species and reactive nitrogen species actively participate in several cell-signalling pathways as physiological "second messengers." In this review, we provide a general overview and novel insights into the redox-dependent pathways involved in programmed cell death.
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Brookes PS, Freeman RS, Barone MC. A shortcut to mitochondrial signaling and pathology: a commentary on "Nonenzymatic formation of succinate in mitochondria under oxidative stress". Free Radic Biol Med 2006; 41:41-5. [PMID: 16781451 DOI: 10.1016/j.freeradbiomed.2006.03.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Accepted: 03/22/2006] [Indexed: 01/06/2023]
Affiliation(s)
- Paul S Brookes
- Department of Anesthesiology, University of Rochester Medical Center, Box 604, 601 Elmwood Avenue, Rochester, NY 14642, USA.
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