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AlAhmad M, Isbea H, Shitaw E, Li F, Sivaprasadarao A. NOX2-TRPM2 coupling promotes Zn 2+ inhibition of complex III to exacerbate ROS production in a cellular model of Parkinson's disease. Sci Rep 2024; 14:18431. [PMID: 39117781 PMCID: PMC11310326 DOI: 10.1038/s41598-024-66630-9] [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: 03/10/2024] [Accepted: 07/03/2024] [Indexed: 08/10/2024] Open
Abstract
Reactive oxygen species (ROS) serve vital physiological functions, but aberrant ROS production contributes to numerous diseases. Unfortunately, therapeutic progress targeting pathogenic ROS has been hindered by the limited understanding of whether the mechanisms driving pathogenic ROS differ from those governing physiological ROS generation. To address this knowledge gap, we utilised a cellular model of Parkinson's disease (PD), as an exemplar of ROS-associated diseases. We exposed SH-SY5Y neuroblastoma cells to the PD-toxin, MPP+ (1-methyl-4-phenylpyridinium) and studied ROS upregulation leading to cell death, the primary cause of PD. We demonstrate: (1) MPP+ stimulates ROS production by raising cytoplasmic Ca2+ levels, rather than acting directly on mitochondria. (2) To raise the Ca2+, MPP+ co-stimulates NADPH oxidase-2 (NOX2) and the Transient Receptor Potential Melastatin2 (TRPM2) channel that form a positive feedback loop to support each other's function. (3) Ca2+ exacerbates mitochondrial ROS (mtROS) production not directly, but via Zn2+. (4) Zn2+ promotes electron escape from respiratory complexes, predominantly from complex III, to generate mtROS. These conclusions are drawn from data, wherein inhibition of TRPM2 and NOX2, chelation of Ca2+ and Zn2+, and prevention of electron escape from complexes -all abolished the ability of MPP+ to induce mtROS production and the associated cell death. Furthermore, calcium ionophore mimicked the effects of MPP+, while Zn2+ ionophore replicated the effects of both MPP+ and Ca2+. Thus, we unveil a previously unrecognized signalling circuit involving NOX2, TRPM2, Ca2+, Zn2+, and complex III that drives cytotoxic ROS production. This circuit lies dormant in healthy cells but is triggered by pathogenic insults and could therefore represent a safe therapeutic target for PD and other ROS-linked diseases.
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Affiliation(s)
- Maali AlAhmad
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, G6.44d, Garstang Building, Leeds, LS29JT, UK
- Department of Biological Sciences, College of Science, Kuwait University, Alshadadiya, PO Box 5969, 130602, Safat, Kuwait
| | - Hala Isbea
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, G6.44d, Garstang Building, Leeds, LS29JT, UK
| | - Esra Shitaw
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, G6.44d, Garstang Building, Leeds, LS29JT, UK
| | - Fangfang Li
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, G6.44d, Garstang Building, Leeds, LS29JT, UK
- Center for Rehabilitation Medicine, Rehabilitation and Sports Medicine Research Institute of Zhejiang Province, Department of Rehabilitation Medicine, Zhejiang Provincial People's Hospital, Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, China
| | - Asipu Sivaprasadarao
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, G6.44d, Garstang Building, Leeds, LS29JT, UK.
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2
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Tetteh PA, Kalvani Z, Stevens D, Sappal R, Kamunde C. Interactions of binary mixtures of metals on rainbow trout (Oncorhynchus mykiss) heart mitochondrial H 2O 2 homeodynamics. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2024; 273:106986. [PMID: 38851027 DOI: 10.1016/j.aquatox.2024.106986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 05/30/2024] [Accepted: 06/01/2024] [Indexed: 06/10/2024]
Abstract
For continuous pumping of blood, the heart needs a constant supply of energy (ATP) that is primarily met via oxidative phosphorylation in the mitochondria of cardiomyocytes. However, sustained high rates of electron transport for energy conversion redox reactions predisposes the heart to the production of reactive oxygen species (ROS) and oxidative stress. Mitochondrial ROS are fundamental drivers of responses to environmental stressors including metals but knowledge of how combinations of metals alter mitochondrial ROS homeodynamics remains sparse. We explored the effects and interactions of binary mixtures of copper (Cu), cadmium (Cd), and zinc (Zn), metals that are common contaminants of aquatic systems, on ROS (hydrogen peroxide, H2O2) homeodynamics in rainbow trout (Oncorhynchus mykiss) heart mitochondria. Isolated mitochondria were energized with glutamate-malate or succinate and exposed to a range of concentrations of the metals singly and in equimolar binary concentrations. Speciation analysis revealed that Cu was highly complexed by glutamate or Tris resulting in Cu2+ concentrations in the picomolar to nanomolar range. The concentration of Cd2+ was 7.2-7.5 % of the total while Zn2+ was 15 % and 21 % of the total during glutamate-malate and succinate oxidation, respectively. The concentration-effect relationships for Cu and Cd on mitochondrial H2O2 emission depended on the substrate while those for Zn were similar during glutamate-malate and succinate oxidation. Cu + Zn and Cu + Cd mixtures exhibited antagonistic interactions wherein Cu reduced the effects of both Cd and Zn, suggesting that Cu can mitigate oxidative distress caused by Cd or Zn. Binary combinations of the metals acted additively to reduce the rate constant and increase the half-life of H2O2 consumption while concomitantly suppressing thioredoxin reductase and stimulating glutathione peroxidase activities. Collectively, our study indicates that binary mixtures of Cu, Zn, and Cd act additively or antagonistically to modulate H2O2 homeodynamics in heart mitochondria.
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Affiliation(s)
- Pius Abraham Tetteh
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, PE, Canada
| | - Zahra Kalvani
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, PE, Canada
| | - Don Stevens
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, PE, Canada
| | - Ravinder Sappal
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, PE, Canada; Department of Veterinary Biomedical Sciences, College of Veterinary Medicine, Long Island University, New York, USA
| | - Collins Kamunde
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, PE, Canada.
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Isaev NK, Genrikhs EE, Stelmashook EV. Methylene blue and its potential in the treatment of traumatic brain injury, brain ischemia, and Alzheimer's disease. Rev Neurosci 2024; 35:585-595. [PMID: 38530227 DOI: 10.1515/revneuro-2024-0007] [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: 01/15/2024] [Accepted: 03/07/2024] [Indexed: 03/27/2024]
Abstract
Traumatic brain injury (TBI) and brain ischemia/reperfusion cause neurodegenerative processes that can continue after the acute stage with the development of severe brain atrophy with dementia. In this case, the long-term neurodegeneration of the brain is similar to the neurodegeneration characteristic of Alzheimer's disease (AD) and is associated with the accumulation of beta amyloid and tau protein. In the pathogenesis of AD as well as in the pathogenesis of cerebral ischemia and TBI oxidative stress, progressive inflammation, glial activation, blood-brain barrier dysfunction, and excessive activation of autophagy are involved, which implies the presence of many targets that can be affected by neuroprotectors. That is, multivariate cascades of nerve tissue damage represent many potential targets for therapeutic interventions. One of such substances that can be used in multi-purpose therapeutic strategies is methylene blue (MB). This drug can have an antiapoptotic and anti-inflammatory effect, activate autophagy, inhibit the aggregation of proteins with an irregular shape, inhibit NO synthase, and bypass impaired electron transfer in the respiratory chain of mitochondria. MB is a well-described treatment for methemoglobinemia, malaria, and encephalopathy caused by ifosfamide. In recent years, this drug has attracted great interest as a potential treatment for a number of neurodegenerative disorders, including the effects of TBI, ischemia, and AD.
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Affiliation(s)
- Nickolay K Isaev
- 64935 M.V. Lomonosov Moscow State University , 119991, Moscow, Russia
- Research Center of Neurology, 125367, Moscow, Russia
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4
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Yang Y, Fan H, Guo Z. Modulation of Metal Homeostasis for Cancer Therapy. Chempluschem 2024; 89:e202300624. [PMID: 38315756 DOI: 10.1002/cplu.202300624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/16/2023] [Accepted: 02/05/2024] [Indexed: 02/07/2024]
Abstract
Metal ions such as iron, zinc, copper, manganese, and calcium are essential for normal cellular processes, including DNA synthesis, enzyme activity, cellular signaling, and oxidative stress regulation. When the balance of metal homeostasis is disrupted, it can lead to various pathological conditions, including cancer. Thus, understanding the role of metal homeostasis in cancer has led to the development of anti-tumor strategies that specifically target the metal imbalance. Up to now, diverse small molecule-based chelators, ionophores, metal complexes, and metal-based nanomaterials have been developed to restore the normal balance of metals or exploit the dysregulation for therapeutic purposes. They hold great promise in inhibiting tumor growth, preventing metastasis, and enhancing the effectiveness of existing cancer therapies. In this review, we aim to provide a comprehensive summary of the strategies employed to modulate the homeostasis of iron, zinc, copper, manganese, and calcium for cancer therapy. Their modulation mechanisms for metal homeostasis are succinctly described, and their recent applications in the field of cancer therapy are discussed. At the end, the limitations of these approaches are addressed, and potential avenues for future developments are explored.
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Affiliation(s)
- Ying Yang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, 210023, Nanjing, Jiangsu, P. R. China
| | - Huanhuan Fan
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, 210023, Nanjing, Jiangsu, P. R. China
| | - Zijian Guo
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University, 210023, Nanjing, Jiangsu, P. R. China
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5
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Zhao X, Cheng H, Wang Q, Nie W, Yang Y, Yang X, Zhang K, Shi J, Liu J. Regulating Photosensitizer Metabolism with DNAzyme-Loaded Nanoparticles for Amplified Mitochondria-Targeting Photodynamic Immunotherapy. ACS NANO 2023; 17:13746-13759. [PMID: 37438324 DOI: 10.1021/acsnano.3c03308] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Mitochondria-specific photosensitizer accumulation is highly recommended for photodynamic therapy and mitochondrial DNA (mtDNA) oxidative damage-based innate immunotherapy but remains challenging. 5-Aminolevulinic acid (ALA), precursor of photosensitizer protoporphyrin IX (PpIX), can induce the exclusive biosynthesis of PpIX in mitochondria. Nevertheless, its photodynamic effect is limited by the intracellular biotransformation of ALA in tumors. Here, we report a photosensitizer metabolism-regulating strategy using ALA/DNAzyme-co-loaded nanoparticles (ALA&Dz@ZIF-PEG) for mitochondria-targeting photodynamic immunotherapy. The zeolitic imidazolate framework (ZIF-8) nanoparticles can be disassembled and release large amounts of zinc ions (Zn2+) within tumor cells. Notably, Zn2+ can relieve tumor hypoxia for promoting the conversion of ALA to PpIX. Moreover, Zn2+ acts as a cofactor of rationally designed DNAzyme for silencing excessive ferrochelatase (FECH; which catalyzes PpIX into photoinactive Heme), cooperatively promoting the exclusive accumulation of PpIX in mitochondria via the "open source and reduced expenditure" manner. Subsequently, the photodynamic effects derived from PpIX lead to the damage and release of mtDNA and activate the innate immune response. In addition, the released Zn2+ further enhances the mtDNA/cGAS-STING pathway mediated innate immunity. The ALA&Dz@ZIF-PEG system induced 3 times more PpIX accumulation than ALA-loaded liposome, significantly enhancing tumor regression in xenograft tumor models.
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Affiliation(s)
- Xiu Zhao
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, People's Republic of China
- Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases, Zhengzhou 450001, People's Republic of China
| | - Hui Cheng
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, People's Republic of China
- Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases, Zhengzhou 450001, People's Republic of China
| | - Qiongwei Wang
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, People's Republic of China
- Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases, Zhengzhou 450001, People's Republic of China
| | - Weimin Nie
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, People's Republic of China
- Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases, Zhengzhou 450001, People's Republic of China
| | - Yue Yang
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, People's Republic of China
- Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases, Zhengzhou 450001, People's Republic of China
| | - Xinyuan Yang
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, People's Republic of China
- Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases, Zhengzhou 450001, People's Republic of China
| | - Kaixiang Zhang
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, People's Republic of China
- Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases, Zhengzhou 450001, People's Republic of China
- Collaborative Innovation Center of New Drug Research and Safety Evaluation, Zhengzhou 450001, People's Republic of China
| | - Jinjin Shi
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, People's Republic of China
- Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases, Zhengzhou 450001, People's Republic of China
- Collaborative Innovation Center of New Drug Research and Safety Evaluation, Zhengzhou 450001, People's Republic of China
| | - Junjie Liu
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou 450001, People's Republic of China
- Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases, Zhengzhou 450001, People's Republic of China
- Collaborative Innovation Center of New Drug Research and Safety Evaluation, Zhengzhou 450001, People's Republic of China
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Shedenkova MO, Stelmashook EV, Golyshev SA, Genrikhs EE, Isaev NK. Extracellular Alkalosis Reduces the Neurotoxicity of Zinc Ions in Cultured Cerebellar Granule Neurons. Biol Trace Elem Res 2023; 201:856-864. [PMID: 35665882 DOI: 10.1007/s12011-022-03214-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 03/22/2022] [Indexed: 01/21/2023]
Abstract
Zn2+ is known to be important for the normal brain functions. Disruption of zinc homeostasis and zinc-induced neurotoxicity has been shown to play a role in the development of neurodegenerative diseases. In this work, we investigated the effect of extracellular alkalosis on the zinc ions neurotoxicity in the cultured rat cerebellar granule neurons. Zinc chloride (0.03-0.06 mM, 24 h) added to the culture medium of rat cerebellar granule neurons caused the dose-dependent death of these cells. According to ultrastructural morphological features, the process of cell death could be attributed to necrosis, since it was accompanied by swelling of intracellular organelles and disruption of cell membranes against the background of relatively intact nuclear membranes. Neuronal death was associated with an increase in the level of intracellular free zinc. The toxic effect of zinc ions was significantly decreased when ionotropic glutamate NMDA-receptors were blocked by MK-801 or when the extracellular pH was increased from 7.3 to 7.8, due to a decrease in the zinc overload of the cytoplasm of these cells. The presented results demonstrate that NMDA channels are one of the Zn ion entry pathways in the cultured cerebellar granule neurons. Extracellular alkalosis reduces the zinc overload of the cytoplasm and, consequently, promotes the survival of neurons. Probably, zinc's neurotoxicity is inextricably linked with changes in the intracellular concentration of protons.
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Affiliation(s)
- Margarita O Shedenkova
- M.V. Lomonosov Moscow State University, Leninskiye gory, 119234, Moscow, Russia
- Research Center of Neurology, Moscow, Russia
| | | | - Sergey A Golyshev
- M.V. Lomonosov Moscow State University, Leninskiye gory, 119234, Moscow, Russia
| | | | - Nickolay K Isaev
- M.V. Lomonosov Moscow State University, Leninskiye gory, 119234, Moscow, Russia.
- Research Center of Neurology, Moscow, Russia.
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7
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Hada B, Karmacharya MB, Park SR, Choi BH. Low-intensity ultrasound (LIUS) differentially modulates mitochondrial reactive oxygen species (mtROS) generation by three different chemicals in PC12 cells. Free Radic Res 2021; 55:1037-1047. [PMID: 34814783 DOI: 10.1080/10715762.2021.2010730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
We have previously shown that low-intensity ultrasound (LIUS) can modulate mitochondrial complex I activity and the generation of mitochondrial reactive oxygen species (mtROS) in PC12 cells. This study investigated the mechanism of LIUS by comparing its effect on mitochondrial dysfunction by three different pathways. LIUS was shown to reverse the effects of rotenone, a Q-site blocker, on the complex I inhibition, mtROS generation, and drop of mitochondrial membrane potential (Δψm). In contrast, common antioxidants, N-acetyl cysteine (NAC), and uric acid (UA) blocked rotenone-induced mtROS generation and Δψm drop without recovering the complex I activity, which suggested that Δψm drop is correlated with mtROS generation rather than complex I inhibition itself. Ionomycin, an ionophore for Ca2+, and L-buthionine-S,R-sulfoximine (BSO), an inhibitor of glutathione (GSH) biosynthesis, induced mtROS generation and Δψm drop without inhibiting complex I activity via different mechanisms. LIUS showed no effect on ionomycin-induced Δψm drop but showed partial inhibition on the other effects of ionomycin and BSO. These results suggest that LIUS might have redundant mechanisms but acted mainly on the complex I activity thereby modulating mtROS and Δψm levels. LIUS appeared to act on the Q-module of complex I because it showed no inhibitory effect on Zn2+, an inhibitor of the proton transporting P-module of complex I. Interestingly, pretreatment of LIUS for up to an hour in advance blocked the rotenone effect as efficiently as the co-treatment. Further studies are needed to reveal the exact mechanism of LIUS to inhibit complex I activity.
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Affiliation(s)
- Binika Hada
- Department of Biomedical Sciences, Inha University College of Medicine, Incheon, Korea
| | | | - So Ra Park
- Department of Physiology and Biophysics, Inha University College of Medicine, Incheon, Korea
| | - Byung Hyune Choi
- Department of Biomedical Sciences, Inha University College of Medicine, Incheon, Korea
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9
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Matyja K, Wasiela A, Dobicki W, Pokorny P, Trusek A. Dynamic modeling of the activated sludge microbial growth and activity under exposure to heavy metals. BIORESOURCE TECHNOLOGY 2021; 339:125623. [PMID: 34315088 DOI: 10.1016/j.biortech.2021.125623] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 07/14/2021] [Accepted: 07/16/2021] [Indexed: 06/13/2023]
Abstract
The presence of heavy metals in the environment can lead to ecological and health problems. The evolution of biological systems, such as activated sludge, exposed to heavy metals is still underexplored. Therefore, this study sought to develop a model of microorganism activity and growth in activated sludge and used it to investigate the toxicity of five metals: Cu, Cd, Ni, Zn, and Ag. Patterns in the evolution of the toxic effects caused by these metals were similar at the beginning of exposure. Differences in toxicity between metal ions were noted for longer exposure times. Changes in model parameters indicate the influence of metal ions on the mass and energy balance of living cells. Decreases in new enzyme units and biomass production yields in contaminated activated sludge indicate a shift from anabolic reactions to metal homeostasis and resistance.
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Affiliation(s)
- Konrad Matyja
- Wroclaw University of Science and Technology, Faculty of Chemistry, Department of Micro, Nano, and Bioprocess Engineering, Norwida 4/6, 50-373 Wrocław, Poland.
| | - Aleksandra Wasiela
- Wroclaw University of Science and Technology, Faculty of Chemistry, Department of Micro, Nano, and Bioprocess Engineering, Norwida 4/6, 50-373 Wrocław, Poland
| | - Wojciech Dobicki
- Wrocław University of Environmental and Life Sciences, Institute of Animal Breeding, Department of Limnology and Fishery, Chelmonskiego 38C, PL-51630 Wroclaw, Poland
| | - Przemysław Pokorny
- Wrocław University of Environmental and Life Sciences, Institute of Animal Breeding, Department of Limnology and Fishery, Chelmonskiego 38C, PL-51630 Wroclaw, Poland
| | - Anna Trusek
- Wroclaw University of Science and Technology, Faculty of Chemistry, Department of Micro, Nano, and Bioprocess Engineering, Norwida 4/6, 50-373 Wrocław, Poland
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10
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Isaev NK, Stelmashook EV, Genrikhs EE. Role of zinc and copper ions in the pathogenetic mechanisms of traumatic brain injury and Alzheimer's disease. Rev Neurosci 2021; 31:233-243. [PMID: 31747384 DOI: 10.1515/revneuro-2019-0052] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 08/24/2019] [Indexed: 12/24/2022]
Abstract
The disruption of homeostasis of zinc (Zn2+) and copper (Cu2+) ions in the central nervous system is involved in the pathogenesis of many neurodegenerative diseases, such as amyotrophic lateral sclerosis, Wilson's, Creutzfeldt-Jakob, Parkinson's, and Alzheimer's diseases (AD), and traumatic brain injury (TBI). The last two pathological conditions of the brain are the most common; moreover, it is possible that TBI is a risk factor for the development of AD. Disruptions of Zn2+ and Cu2+ homeostasis play an important role in the mechanisms of pathogenesis of both TBI and AD. This review attempts to summarize and systematize the currently available research data on this issue. The neurocytotoxicity of Cu2+ and Zn2+, the synergism of the toxic effect of calcium and Zn2+ ions on the mitochondria of neurons, and the interaction of Zn2+ and Cu2+ with β-amyloid (Abeta) and tau protein are considered.
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Affiliation(s)
- Nickolay K Isaev
- M.V. Lomonosov Moscow State University, N.A. Belozersky Institute of Physico-Chemical Biology, Biological Faculty, Moscow 119991, Russia.,Research Center of Neurology, Moscow 125367, Russia
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The Multifaceted Roles of Zinc in Neuronal Mitochondrial Dysfunction. Biomedicines 2021; 9:biomedicines9050489. [PMID: 33946782 PMCID: PMC8145363 DOI: 10.3390/biomedicines9050489] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 03/05/2021] [Accepted: 03/07/2021] [Indexed: 12/17/2022] Open
Abstract
Zinc is a highly abundant cation in the brain, essential for cellular functions, including transcription, enzymatic activity, and cell signaling. However, zinc can also trigger injurious cascades in neurons, contributing to the pathology of neurodegenerative diseases. Mitochondria, critical for meeting the high energy demands of the central nervous system (CNS), are a principal target of the deleterious actions of zinc. An increasing body of work suggests that intracellular zinc can, under certain circumstances, contribute to neuronal damage by inhibiting mitochondrial energy processes, including dissipation of the mitochondrial membrane potential (MMP), leading to ATP depletion. Additional consequences of zinc-mediated mitochondrial damage include reactive oxygen species (ROS) generation, mitochondrial permeability transition, and excitotoxic calcium deregulation. Zinc can also induce mitochondrial fission, resulting in mitochondrial fragmentation, as well as inhibition of mitochondrial motility. Here, we review the known mechanisms responsible for the deleterious actions of zinc on the organelle, within the context of neuronal injury associated with neurodegenerative processes. Elucidating the critical contributions of zinc-induced mitochondrial defects to neurotoxicity and neurodegeneration may provide insight into novel therapeutic targets in the clinical setting.
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12
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Green Etxabe A, Pini JM, Short S, Cunha L, Kille P, Watson GJ. Identifying conserved polychaete molecular markers of metal exposure: Comparative analyses using the Alitta virens (Annelida, Lophotrochozoa) transcriptome. Comp Biochem Physiol C Toxicol Pharmacol 2021; 240:108913. [PMID: 33164845 DOI: 10.1016/j.cbpc.2020.108913] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/07/2020] [Accepted: 10/12/2020] [Indexed: 12/13/2022]
Abstract
Polychaetes are vital for evaluating the effects of toxic metals in marine systems, and sensitive molecular biomarkers should be integral to monitoring efforts. However, the few polychaete markers that exist are inconsistent, even within the same species, failing to identify gene expression changes in metal-exposed animals incurring clear metabolic costs. Comparing previously characterised polychaete metal-responsive genes with those of another carefully selected species could identify biomarkers applicable across polychaetes. The ragworm Alitta virens (Sars, 1835) is particularly suited for such comparisons due to its dominance of fully saline coastal areas, widespread distribution, large biomass, and its phylogenetic position relative to other polychaete 'omic' resources. A transcriptome atlas for A. virens was generated and an RNASeq-qPCR screening approach was used to characterise the response to chronic exposures of environmentally relevant concentrations of copper and zinc in controlled mesocosms. Genes presenting dramatic expression changes in A. virens were compared with known metal-responsive genes in other polychaetes to identify new possible biomarkers and assess those currently used. This revealed some current markers should probably be abandoned (e.g. Atox1), while others, such as GST-Omega, should be used with caution, as different polychaete species appear to upregulate distinct GST-Omega orthologues. In addition, the comparisons give some indication of genes that are induced by metal exposure across phylogenetically divergent polychaetes, including a suite of haemoglobin subunits and linker chains that could play conserved roles in metal-stress response. Although such newly identified markers need further characterisation, they offer alternatives to current markers that are plainly insufficient.
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Affiliation(s)
- Amaia Green Etxabe
- UK Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Wallingford, Oxfordshire OX10 8BB, UK
| | - Jennifer M Pini
- CP-Texinfine (France), 60 Rue Duguesclin, 69006 Lyon, France
| | - Stephen Short
- Cardiff School of Biosciences, Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AT, UK.
| | - Luis Cunha
- University of Coimbra, Centre for Functional Ecology, Department of Life Sciences, Calçada Martim de Freitas, 3000-456 Coimbra, Portugal; School of Applied Sciences, University of South Wales, Pontypridd, Wales CF37 4BD, UK
| | - Peter Kille
- Cardiff School of Biosciences, Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AT, UK
| | - Gordon J Watson
- Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Ferry Road, Portsmouth PO4 9LY, UK
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13
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Siletsky SA, Gennis RB. Time-Resolved Electrometric Study of the F→O Transition in Cytochrome c Oxidase. The Effect of Zn2+ Ions on the Positive Side of the Membrane. BIOCHEMISTRY (MOSCOW) 2021; 86:105-122. [DOI: 10.1134/s0006297921010107] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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The role of labile Zn 2+ and Zn 2+-transporters in the pathophysiology of mitochondria dysfunction in cardiomyocytes. Mol Cell Biochem 2020; 476:971-989. [PMID: 33225416 DOI: 10.1007/s11010-020-03964-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 10/23/2020] [Indexed: 02/06/2023]
Abstract
An important energy supplier of cardiomyocytes is mitochondria, similar to other mammalian cells. Studies have demonstrated that any defect in the normal processes controlled by mitochondria can lead to abnormal ROS production, thereby high oxidative stress as well as lack of ATP. Taken into consideration, the relationship between mitochondrial dysfunction and overproduction of ROS as well as the relation between increased ROS and high-level release of intracellular labile Zn2+, those bring into consideration the importance of the events related with those stimuli in cardiomyocytes responsible from cellular Zn2+-homeostasis and responsible Zn2+-transporters associated with the Zn2+-homeostasis and Zn2+-signaling. Zn2+-signaling, controlled by cellular Zn2+-homeostatic mechanisms, is regulated with intracellular labile Zn2+ levels, which are controlled, especially, with the two Zn2+-transporter families; ZIPs and ZnTs. Our experimental studies in mammalian cardiomyocytes and human heart tissue showed that Zn2+-transporters localizes to mitochondria besides sarco(endo)plasmic reticulum and Golgi under physiological condition. The protein levels as well as functions of those transporters can re-distribute under pathological conditions, therefore, they can interplay among organelles in cardiomyocytes to adjust a proper intracellular labile Zn2+ level. In the present review, we aimed to summarize the already known Zn2+-transporters localize to mitochondria and function to stabilize not only the cellular Zn2+ level but also cellular oxidative stress status. In conclusion, one can propose that a detailed understanding of cellular Zn2+-homeostasis and Zn2+-signaling through mitochondria may emphasize the importance of new mitochondria-targeting agents for prevention and/or therapy of cardiovascular dysfunction in humans.
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15
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Melin F, Hellwig P. Redox Properties of the Membrane Proteins from the Respiratory Chain. Chem Rev 2020; 120:10244-10297. [DOI: 10.1021/acs.chemrev.0c00249] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Frederic Melin
- Chimie de la Matière Complexe UMR 7140, Laboratoire de Bioelectrochimie et Spectroscopie, CNRS-Université de Strasbourg, 1 rue Blaise Pascal, 67070 Strasbourg, France
| | - Petra Hellwig
- Chimie de la Matière Complexe UMR 7140, Laboratoire de Bioelectrochimie et Spectroscopie, CNRS-Université de Strasbourg, 1 rue Blaise Pascal, 67070 Strasbourg, France
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16
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Tsentsevitsky AN, Zakyrjanova GF, Petrov AM. Cadmium desynchronizes neurotransmitter release in the neuromuscular junction: Key role of ROS. Free Radic Biol Med 2020; 155:19-28. [PMID: 32445865 DOI: 10.1016/j.freeradbiomed.2020.05.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 05/18/2020] [Accepted: 05/18/2020] [Indexed: 12/11/2022]
Abstract
Cd2+ is one of the most widespread environmental pollutants and its accumulation in central and peripheral nervous systems leads to neurotoxicity as well as aggravation of common neurodegenerative diseases. Mechanism of the Cd2+ toxicity is far from being resolved. Here, using microelectrode recordings of postsynaptic responses and fluorescent redox indicators we studied the effect of Cd2+ in the submicromolar range on timing of neurotransmitter release and oxidative status in two functionally different compartments of the same frog motor nerve terminal. Cd2+ (0.1-1 μM) acting as typical voltage-gated Ca2+channel (VGCC) antagonist decreased neurotransmitter release in both distal and proximal parts of the nerve terminal, but in contrast to the VGCC blockers Cd2+(0.1-0.5 μM) desynchronized the release selectively in the distal region. The latter action of Cd2+ was completely prevented by inhibitor of NADPH-oxidase and antioxidants, including mitochondrial specific, as well as redox-sensitive TRPV1 channel blocker. Cd2+ markedly increased levels of mitochondrial reactive oxygen species (ROS) in both the distal and proximal compartments of the nerve terminal, which was associated with lipid peroxidation mainly in the distal region. Zn2+, whose transport systems translocate Cd2+, markedly enhanced the effects of Cd2+ on both the mitochondrial ROS levels and timing of neurotransmitter release. Furthermore, in the presence of Zn2+ ions, Cd2+ also desynchronized the neurotransmitter release in the proximal region. Thus, in synapses Cd2+ at very low concentrations can increase mitochondrial ROS, lipid peroxidation and disturb the timing of neurotransmitter release via a ROS/TRPV-dependent mechanism. Desynchronization of neurotransmitter release and synaptic oxidative stress could be early events in Cd2+ neurotoxicity.
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Affiliation(s)
- A N Tsentsevitsky
- Laboratory of Biophysics of Synaptic Processes, Kazan Institute of Biochemistry and Biophysics, Federal Research Center ''Kazan Scientific Center of RAS", 2/31 Lobachevsky Street, Box 30, Kazan, 420111, Russia
| | - G F Zakyrjanova
- Laboratory of Biophysics of Synaptic Processes, Kazan Institute of Biochemistry and Biophysics, Federal Research Center ''Kazan Scientific Center of RAS", 2/31 Lobachevsky Street, Box 30, Kazan, 420111, Russia; Institute of Neuroscience, Kazan State Medial University, 49 Butlerova Street, Kazan, 420012, Russia
| | - A M Petrov
- Laboratory of Biophysics of Synaptic Processes, Kazan Institute of Biochemistry and Biophysics, Federal Research Center ''Kazan Scientific Center of RAS", 2/31 Lobachevsky Street, Box 30, Kazan, 420111, Russia; Institute of Neuroscience, Kazan State Medial University, 49 Butlerova Street, Kazan, 420012, Russia.
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Babin A, Moreau J, Moret Y. Storage of Carotenoids in Crustaceans as an Adaptation to Modulate Immunopathology and Optimize Immunological and Life-History Strategies. Bioessays 2019; 41:e1800254. [PMID: 31566782 DOI: 10.1002/bies.201800254] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 08/11/2019] [Indexed: 12/14/2022]
Abstract
Why do some invertebrates store so much carotenoids in their tissues? Storage of carotenoids may not simply be passive and dependent on their environmental availability, as storage variation exists at various taxonomic scales, including among individuals within species. While the strong antioxidant and sometimes immune-stimulating properties of carotenoids may be beneficial enough to cause the evolution of features improving their assimilation and storage, they may also have fitness downsides explaining why massive carotenoid storage is not universal. Here, the functional and ecological implications of carotenoid storage for the evolution of invertebrate innate immune defenses are examined, especially in crustaceans, which massively store carotenoids for unclear reasons. Three testable hypotheses about the role of carotenoid storage in immunological (resistance and tolerance) and life-history strategies (with a focus on aging) are proposed, which may ultimately explain the storage of large amounts of these pigments in a context of host-pathogen interactions.
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Affiliation(s)
- Aurélie Babin
- Équipe Écologie Évolutive, UMR CNRS 6282 Biogéosciences, Université Bourgogne Franche-Comté, 6 Boulevard Gabriel, F-21000, Dijon, France
| | - Jérôme Moreau
- Équipe Écologie Évolutive, UMR CNRS 6282 Biogéosciences, Université Bourgogne Franche-Comté, 6 Boulevard Gabriel, F-21000, Dijon, France
| | - Yannick Moret
- Équipe Écologie Évolutive, UMR CNRS 6282 Biogéosciences, Université Bourgogne Franche-Comté, 6 Boulevard Gabriel, F-21000, Dijon, France
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18
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Neuroprotective Effects of Methylene Blue In Vivo and In Vitro. Bull Exp Biol Med 2019; 167:455-459. [DOI: 10.1007/s10517-019-04548-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Indexed: 10/26/2022]
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19
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Abstract
In this issue of Molecular Cell, Cho et al. (2019) identify a mechanism by which the mitochondrial division machinery provides selective pressure to identify dysfunctional organelles through the coordinated action of DRP1, Zip1, and Zn2+ transport into mitochondria.
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Zinc Toxicity and Iron-Sulfur Cluster Biogenesis in Escherichia coli. Appl Environ Microbiol 2019; 85:AEM.01967-18. [PMID: 30824435 PMCID: PMC6495748 DOI: 10.1128/aem.01967-18] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 02/01/2019] [Indexed: 12/20/2022] Open
Abstract
While zinc is an essential trace metal in biology, excess zinc is toxic to organisms. Previous studies have shown that zinc toxicity is associated with disruption of the [4Fe-4S] clusters in various dehydratases in Escherichia coli Here, we report that the intracellular zinc overload in E. coli cells inhibits iron-sulfur cluster biogenesis without affecting the preassembled iron-sulfur clusters in proteins. Among the housekeeping iron-sulfur cluster assembly proteins encoded by the gene cluster iscSUA-hscBA-fdx-iscX in E. coli cells, the scaffold IscU, the iron chaperone IscA, and ferredoxin have strong zinc binding activity in cells, suggesting that intracellular zinc overload inhibits iron-sulfur cluster biogenesis by binding to the iron-sulfur cluster assembly proteins. Mutations of the conserved cysteine residues to serine in IscA, IscU, or ferredoxin completely abolish the zinc binding activity of the proteins, indicating that zinc can compete with iron or iron-sulfur cluster binding in IscA, IscU, and ferredoxin and block iron-sulfur cluster biogenesis. Furthermore, intracellular zinc overload appears to emulate the slow-growth phenotype of the E. coli mutant cells with deletion of the iron-sulfur cluster assembly proteins IscU, IscA, and ferredoxin. Our results suggest that intracellular zinc overload inhibits iron-sulfur cluster biogenesis by targeting the iron-sulfur cluster assembly proteins IscU, IscA, and ferredoxin in E. coli cells.IMPORTANCE Zinc toxicity has been implicated in causing various human diseases. High concentrations of zinc can also inhibit bacterial cell growth. However, the underlying mechanism has not been fully understood. Here, we report that zinc overload in Escherichia coli cells inhibits iron-sulfur cluster biogenesis by targeting specific iron-sulfur cluster assembly proteins. Because iron-sulfur proteins are involved in diverse physiological processes, the zinc-mediated inhibition of iron-sulfur cluster biogenesis could be largely responsible for the zinc-mediated cytotoxicity. Our finding provides new insights on how intracellular zinc overload may inhibit cellular functions in bacteria.
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Abstract
Zinc(II) ions are redox-inert in biology. Yet, their interaction with sulfur of cysteine in cellular proteins can confer ligand-centered redox activity on zinc coordination sites, control protein functions, and generate signalling zinc ions as potent effectors of many cellular processes. The specificity and relative high affinity of binding sites for zinc allow regulation in redox biology, free radical biology, and the biology of reactive species. Understanding the role of zinc in these areas of biology requires an understanding of how cellular Zn2+ is homeostatically controlled and can serve as a regulatory ion in addition to Ca2+, albeit at much lower concentrations. A rather complex system of dozens of transporters and metallothioneins buffer the relatively high (hundreds of micromolar) total cellular zinc concentrations in such a way that the available zinc ion concentrations are only picomolar but can fluctuate in signalling. The proteins targeted by Zn2+ transients include enzymes controlling phosphorylation and redox signalling pathways. Networks of regulatory functions of zinc integrate gene expression and metabolic and signalling pathways at several hierarchical levels. They affect enzymatic catalysis, protein structure and protein-protein/biomolecular interactions and add to the already impressive number of catalytic and structural functions of zinc in an estimated three thousand human zinc proteins. The effects of zinc on redox biology have adduced evidence that zinc is an antioxidant. Without further qualifications, this notion is misleading and prevents a true understanding of the roles of zinc in biology. Its antioxidant-like effects are indirect and expressed only in certain conditions because a lack of zinc and too much zinc have pro-oxidant effects. Teasing apart these functions based on quantitative considerations of homeostatic control of cellular zinc is critical because opposite consequences are observed depending on the concentrations of zinc: pro- or anti-apoptotic, pro- or anti-inflammatory and cytoprotective or cytotoxic. The article provides a biochemical basis for the links between redox and zinc biology and discusses why zinc has pleiotropic functions. Perturbation of zinc metabolism is a consequence of conditions of redox stress. Zinc deficiency, either nutritional or conditioned, and cellular zinc overload cause oxidative stress. Thus, there is causation in the relationship between zinc metabolism and the many diseases associated with oxidative stress.
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Affiliation(s)
- Wolfgang Maret
- Metal Metabolism Group, Department of Nutritional Sciences, School of Life Course Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.
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Tuncay E, Bitirim CV, Olgar Y, Durak A, Rutter GA, Turan B. Zn2+-transporters ZIP7 and ZnT7 play important role in progression of cardiac dysfunction via affecting sarco(endo)plasmic reticulum-mitochondria coupling in hyperglycemic cardiomyocytes. Mitochondrion 2019; 44:41-52. [DOI: 10.1016/j.mito.2017.12.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 12/13/2017] [Accepted: 12/27/2017] [Indexed: 12/20/2022]
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Drp1-Zip1 Interaction Regulates Mitochondrial Quality Surveillance System. Mol Cell 2018; 73:364-376.e8. [PMID: 30581142 DOI: 10.1016/j.molcel.2018.11.009] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 09/11/2018] [Accepted: 11/07/2018] [Indexed: 01/09/2023]
Abstract
Mitophagy, a mitochondrial quality control process for eliminating dysfunctional mitochondria, can be induced by a response of dynamin-related protein 1 (Drp1) to a reduction in mitochondrial membrane potential (MMP) and mitochondrial division. However, the coordination between MMP and mitochondrial division for selecting the damaged portion of the mitochondrial network is less understood. Here, we found that MMP is reduced focally at a fission site by the Drp1 recruitment, which is initiated by the interaction of Drp1 with mitochondrial zinc transporter Zip1 and Zn2+ entry through the Zip1-MCU complex. After division, healthy mitochondria restore MMP levels and participate in the fusion-fission cycle again, but mitochondria that fail to restore MMP undergo mitophagy. Thus, interfering with the interaction between Drp1 and Zip1 blocks the reduction of MMP and the subsequent mitophagic selection of damaged mitochondria. These results suggest that Drp1-dependent fission provides selective pressure for eliminating "bad sectors" in the mitochondrial network, serving as a mitochondrial quality surveillance system.
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Degirmenci S, Olgar Y, Durak A, Tuncay E, Turan B. Cytosolic increased labile Zn 2+ contributes to arrhythmogenic action potentials in left ventricular cardiomyocytes through protein thiol oxidation and cellular ATP depletion. J Trace Elem Med Biol 2018; 48:202-212. [PMID: 29773183 DOI: 10.1016/j.jtemb.2018.04.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 04/12/2018] [Accepted: 04/12/2018] [Indexed: 02/06/2023]
Abstract
Intracellular labile (free) Zn2+-level ([Zn2+]i) is low and increases markedly under pathophysiological conditions in cardiomyocytes. High [Zn2+]i is associated with alterations in excitability and ionic-conductances while exact mechanisms are not clarified yet. Therefore, we examined the elevated-[Zn2+]i on some sarcolemmal ionic-mechanisms, which can mediate cardiomyocyte dysfunction. High-[Zn2+]i induced significant changes in action potential (AP) parameters, including depolarization in resting membrane-potential and prolongations in AP-repolarizing phases. We detected also the time-dependent effects such as induction of spontaneous APs at the time of ≥ 3 min following [Zn2+]i increases, a manner of cellular ATP dependent and reversible with disulfide-reducing agent dithiothreitol, DTT. High-[Zn2+]i induced inhibitions in voltage-dependent K+-channel currents, such as transient outward K+-currents, Ito, steady-state currents, Iss and inward-rectifier K+-currents, IK1, reversible with DTT seemed to be responsible from the prolongations in APs. We, for the first time, demonstrated that lowering cellular ATP level induced significant decreaeses in both Iss and IK1, while no effect on Ito. However, the increased-[Zn2+]i could induce marked activation in ATP-sensitive K+-channel currents, IKATP, depending on low cellular ATP and thiol-oxidation levels of these channels. The mRNA levels of Kv4.3, Kv1.4 and Kv2.1 were depressed markedly with increased-[Zn2+]i with no change in mRNA level of Kv4.2, while the mRNA level of IKATP subunit, SUR2A was increased significantly with increased-[Zn2+]i, being reversible with DTT. Overall we demonstrated that high-[Zn2+]i, even if nanomolar levels, alters cardiac function via prolonged APs of cardiomyocytes, at most, due to inhibitions in voltage-dependent K+-currents, although activation of IKATP is playing cardioprotective role, through some biochemical changes in cellular ATP- and thiol-oxidation levels. It seems, a well-controlled [Zn2+]i can be novel therapeutic target for cardiac complications under pathological conditions including oxidative stress.
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Affiliation(s)
- Sinan Degirmenci
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Yusuf Olgar
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Aysegul Durak
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Erkan Tuncay
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Belma Turan
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey.
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Critical Role of Zinc as Either an Antioxidant or a Prooxidant in Cellular Systems. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:9156285. [PMID: 29743987 PMCID: PMC5884210 DOI: 10.1155/2018/9156285] [Citation(s) in RCA: 183] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 01/09/2018] [Accepted: 01/16/2018] [Indexed: 01/11/2023]
Abstract
Zinc is recognized as an essential trace metal required for human health; its deficiency is strongly associated with neuronal and immune system defects. Although zinc is a redox-inert metal, it functions as an antioxidant through the catalytic action of copper/zinc-superoxide dismutase, stabilization of membrane structure, protection of the protein sulfhydryl groups, and upregulation of the expression of metallothionein, which possesses a metal-binding capacity and also exhibits antioxidant functions. In addition, zinc suppresses anti-inflammatory responses that would otherwise augment oxidative stress. The actions of zinc are not straightforward owing to its numerous roles in biological systems. It has been shown that zinc deficiency and zinc excess cause cellular oxidative stress. To gain insights into the dual action of zinc, as either an antioxidant or a prooxidant, and the conditions under which each role is performed, the oxidative stresses that occur in zinc deficiency and zinc overload in conjunction with the intracellular regulation of free zinc are summarized. Additionally, the regulatory role of zinc in mitochondrial homeostasis and its impact on oxidative stress are briefly addressed.
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26
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Nam E, Han J, Suh JM, Yi Y, Lim MH. Link of impaired metal ion homeostasis to mitochondrial dysfunction in neurons. Curr Opin Chem Biol 2017; 43:8-14. [PMID: 29100100 DOI: 10.1016/j.cbpa.2017.09.009] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/03/2017] [Accepted: 09/12/2017] [Indexed: 02/07/2023]
Abstract
Manganese, iron, copper, and zinc are observed to play essential roles in mitochondria. The overload and depletion of metal ions in mitochondria under pathological conditions, however, could disturb mitochondrial compartments and functions leading to cell death. In this review, we mainly summarize how impaired metal ion homeostasis affects mitochondrial systems, such as membrane potentials, the tricarboxylic acid cycle, oxidative phosphorylation, and glutathione metabolism. In addition, based on current findings, we briefly describe a recent understanding of the relationship among metal ion dysregulation, mitochondrial dysfunction, and the pathogeneses of neurodegenerative diseases.
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Affiliation(s)
- Eunju Nam
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Jiyeon Han
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Jong-Min Suh
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Yelim Yi
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Mi Hee Lim
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea.
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27
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Meyer M, Kovács AD, Pearce DA. Decreased sensitivity of palmitoyl protein thioesterase 1-deficient neurons to chemical anoxia. Metab Brain Dis 2017; 32:275-279. [PMID: 27722792 PMCID: PMC5335868 DOI: 10.1007/s11011-016-9919-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 10/03/2016] [Indexed: 01/12/2023]
Abstract
Infantile CLN1 disease, also known as infantile neuronal ceroid lipofuscinosis, is a fatal childhood neurodegenerative disorder caused by mutations in the CLN1 gene. CLN1 encodes a soluble lysosomal enzyme, palmitoyl protein thioesterase 1 (PPT1), and it is still unclear why neurons are selectively vulnerable to the loss of PPT1 enzyme activity in infantile CLN1 disease. To examine the effects of PPT1 deficiency on several well-defined neuronal signaling and cell death pathways, different toxic insults were applied in cerebellar granule neuron cultures prepared from wild type (WT) and palmitoyl protein thioesterase 1-deficient (Ppt1 -/- ) mice, a model of infantile CLN1 disease. Glutamate uptake inhibition by t-PDC (L-trans-pyrrolidine-2,4-dicarboxylic acid) or Zn2+-induced general mitochondrial dysfunction caused similar toxicity in WT and Ppt1 -/- cultures. Ppt1 -/- neurons, however, were more sensitive to mitochondrial complex I inhibition by MPP+ (1-methyl-4-phenylpyridinium), and had significantly decreased sensitivity to chemical anoxia induced by the mitochondrial complex IV inhibitor, sodium azide. Our results indicate that PPT1 deficiency causes alterations in the mitochondrial respiratory chain.
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Affiliation(s)
- Meredith Meyer
- Sanford Children's Health Research Center, Sanford Research, 2301 E. 60th Street, Sioux Falls, SD, 57104, USA
| | - Attila D Kovács
- Sanford Children's Health Research Center, Sanford Research, 2301 E. 60th Street, Sioux Falls, SD, 57104, USA
- Department of Pediatrics, Sanford School of Medicine, University of South Dakota Sioux Falls, Sioux Falls, SD, 57104, USA
| | - David A Pearce
- Sanford Children's Health Research Center, Sanford Research, 2301 E. 60th Street, Sioux Falls, SD, 57104, USA.
- Department of Pediatrics, Sanford School of Medicine, University of South Dakota Sioux Falls, Sioux Falls, SD, 57104, USA.
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Siebels I, Dröse S. Charge translocation by mitochondrial NADH:ubiquinone oxidoreductase (complex I) from Yarrowia lipolytica measured on solid-supported membranes. Biochem Biophys Res Commun 2016; 479:277-282. [PMID: 27639643 DOI: 10.1016/j.bbrc.2016.09.059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 09/12/2016] [Indexed: 11/17/2022]
Abstract
The charge translocation by purified reconstituted mitochondrial complex I from the obligate aerobic yeast Yarrowia lipolytica was investigated after adsorption of proteoliposomes to solid-supported membranes. In presence of n-decylubiquinone (DBQ), pulses of NADH provided by rapid solution exchange induced charge transfer reflecting steady-state pumping activity of the reconstituted enzyme. The signal amplitude increased with time, indicating 'deactive→active' transition of the Yarrowia complex I. Furthermore, an increase of the membrane-conductivity after addition of 5-(N-ethyl-N-isopropyl)amiloride (EIPA) was detected which questiones the use of EIPA as an inhibitor of the Na+/H+-antiporter-like subunits of complex I. This investigation shows that electrical measurements on solid-supported membranes are a suitable method to analyze transport events and 'active/deactive' transition of mitochondrial complex I.
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Affiliation(s)
- Ilka Siebels
- Molecular Bioenergetics Group, Medical School, Johann Wolfgang Goethe-University, 60590, Frankfurt am Main, Germany; Goethe University Frankfurt, Institute of Organic Chemistry and Chemical Biology, Buchmann Institute for Molecular Life Sciences, Protein Reaction Control Group, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany
| | - Stefan Dröse
- Molecular Bioenergetics Group, Medical School, Johann Wolfgang Goethe-University, 60590, Frankfurt am Main, Germany; Department of Anesthesiology, Intensive-Care Medicine and Pain Therapy, University Hospital Frankfurt, 60590, Frankfurt am Main, Germany.
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Francia F, Malferrari M, Lanciano P, Steimle S, Daldal F, Venturoli G. The cytochrome b Zn binding amino acid residue histidine 291 is essential for ubihydroquinone oxidation at the Q o site of bacterial cytochrome bc 1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1796-1806. [PMID: 27550309 DOI: 10.1016/j.bbabio.2016.08.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 06/27/2016] [Accepted: 08/17/2016] [Indexed: 11/18/2022]
Abstract
The ubiquinol:cytochrome (cyt) c oxidoreductase (or cyt bc1) is an important membrane protein complex in photosynthetic and respiratory energy transduction. In bacteria such as Rhodobacter capsulatus it is constituted of three subunits: the iron-sulfur protein, cyt b and cyt c1, which form two catalytic domains, the Qo (hydroquinone (QH2) oxidation) and Qi (quinone (Q) reduction) sites. At the Qo site, the pathways of bifurcated electron transfers emanating from QH2 oxidation are known, but the associated proton release routes are not well defined. In energy transducing complexes, Zn2+ binding amino acid residues often correlate with proton uptake or release pathways. Earlier, using combined EXAFS and structural studies, we identified Zn coordinating residues of mitochondrial and bacterial cyt bc1. In this work, using the genetically tractable bacterial cyt bc1, we substituted each of the proposed Zn binding residues with non-protonatable side chains. Among these mutants, only the His291Leu substitution destroyed almost completely the Qo site catalysis without perturbing significantly the redox properties of the cofactors or the assembly of the complex. In this mutant, which is unable to support photosynthetic growth, the bifurcated electron transfer reactions that result from QH2 oxidation at the Qo site, as well as the associated proton(s) release, were dramatically impaired. Based on these findings, on the putative role of His291 in liganding Zn, and on its solvent exposed and highly conserved position, we propose that His291 of cyt b is critical for proton release associated to QH2 oxidation at the Qo site of cyt bc1.
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Affiliation(s)
- Francesco Francia
- Laboratorio di Biochimica e Biofisica Molecolare, Dipartimento di Farmacia e Biotecnologie, FaBiT, Università di Bologna, 40126 Bologna, Italy
| | - Marco Malferrari
- Laboratorio di Biochimica e Biofisica Molecolare, Dipartimento di Farmacia e Biotecnologie, FaBiT, Università di Bologna, 40126 Bologna, Italy
| | - Pascal Lanciano
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Stefan Steimle
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Fevzi Daldal
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Giovanni Venturoli
- Laboratorio di Biochimica e Biofisica Molecolare, Dipartimento di Farmacia e Biotecnologie, FaBiT, Università di Bologna, 40126 Bologna, Italy; Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), Dipartimento di Fisica, Università di Bologna, 40127 Bologna, Italy
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Narayanan M, Sakyiama JA, Elguindy MM, Nakamaru-Ogiso E. Roles of subunit NuoL in the proton pumping coupling mechanism of NADH:ubiquinone oxidoreductase (complex I) from Escherichia coli. J Biochem 2016; 160:205-215. [PMID: 27118783 DOI: 10.1093/jb/mvw027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 03/09/2016] [Indexed: 01/13/2023] Open
Abstract
Respiratory complex I has an L-shaped structure formed by the hydrophilic arm responsible for electron transfer and the membrane arm that contains protons pumping machinery. Here, to gain mechanistic insights into the role of subunit NuoL, we investigated the effects of Mg2+, Zn2+ and the Na+/H+ antiporter inhibitor 5-(N-ethyl-N-isopropyl)-amiloride (EIPA) on proton pumping activities of various isolated NuoL mutant complex I after reconstitution into Escherichia coli double knockout (DKO) membrane vesicles lacking complex I and the NADH dehydrogenase type 2. We found that Mg2+ was critical for proton pumping activity of complex I. At 2 µM Zn2+, proton pumping of the wild-type was selectively inhibited without affecting electron transfer; no inhibition in proton pumping of D178N and D400A was observed, suggesting the involvement of these residues in Zn2+ binding. Fifteen micromolar of EIPA caused up to ∼40% decrease in the proton pumping activity of the wild-type, D303A and D400A/E, whereas no significant change was detected in D178N, indicating its possible involvement in the EIPA binding. Furthermore, when menaquinone-rich DKO membranes were used, the proton pumping efficiency in the wild-type was decreased significantly (∼50%) compared with NuoL mutants strongly suggesting that NuoL is involved in the high efficiency pumping mechanism in complex I.
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Affiliation(s)
- Madhavan Narayanan
- Johnson Research Foundation, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, 422 Curie Boulevard, Philadelphia, PA 19104, USA
| | - Joseph A Sakyiama
- Johnson Research Foundation, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, 422 Curie Boulevard, Philadelphia, PA 19104, USA
| | - Mahmoud M Elguindy
- Johnson Research Foundation, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, 422 Curie Boulevard, Philadelphia, PA 19104, USA
| | - Eiko Nakamaru-Ogiso
- Johnson Research Foundation, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, 422 Curie Boulevard, Philadelphia, PA 19104, USA
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Superoxide generation explains common features of optic neuropathies associated with cecocentral scotomas. J Neuroophthalmol 2016; 35:152-60. [PMID: 25985432 DOI: 10.1097/wno.0000000000000250] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
I have presented above a hypothesis that ties together several disparate optic neuropathies, all characterized by a similar clinical presentation. The hypothesis is predicated on the formation of intracellular superoxide within RGCs as a common pathological pathway for the type of cell death that occurs. The anatomical predisposition of the papillomacular bundle to have elevated superoxide levels is tied to the size of the fibers involved, a hypothesis that also implicates the crossing fibers of the chiasm. Much of this work is speculative and is an interpretation of several experimental studies that have been performed to date. Hopefully, this hypothesis will be developed further, and its validity tested in both experimental models and, ultimately, in humans.
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32
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Tuncay E, Turan B. Intracellular Zn(2+) Increase in Cardiomyocytes Induces both Electrical and Mechanical Dysfunction in Heart via Endogenous Generation of Reactive Nitrogen Species. Biol Trace Elem Res 2016; 169:294-302. [PMID: 26138011 DOI: 10.1007/s12011-015-0423-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 06/23/2015] [Indexed: 12/23/2022]
Abstract
Oxidants increase intracellular free Zn(2+) concentration ([Zn(2+)]i) in ventricular myocytes, which contributes to oxidant-induced alterations in excitation-contraction coupling (ECC). However, it is not clear whether increased [Zn(2+)]i in cardiomyocytes via increased reactive nitrogen species (RNS) has a role on heart function under pathological conditions, such as hyperglycemia. In this study, first we aimed to investigate the role of increased [Zn(2+)]i under in vitro condition in the development of both electrical and mechanical dysfunction of isolated papillary muscle strips from rat heart via exposed samples to a Zn(2+)-ionophore (Zn-pyrithione; 1 μM) for 20 min. Under simultaneous measurement of intracellular action potential and contractile activity in these preparations, Zn-pyrithione exposure caused marked prolongation in action potential repolarization phase and slowdown in both contraction and relaxation rates of twitch activity. Second, in order to demonstrate an association between increased [Zn(2+)]i and increased RNS, we monitored intracellular [Zn(2+)]i under an acute exposure of nitric oxide (NO) donor sodium nitroprusside, SNP, in freshly isolated quiescent cardiomyocytes loaded with FluoZin-3. Resting level of free Zn(2+) is significantly higher in cardiomyocytes under hyperglycemic condition compared to those of the controls, which seems to be associated with increased level of RNS production in hyperglycemic cardiomyocytes. Western blot analysis showed that Zn-pyrithione exposure induced a marked decrease in the activity of protein phosphatase 1 and 2A, member of macromolecular protein complex of cardiac ryanodine receptors, RyR2, besides significant increase in the phosphorylation level of extracellular signal-regulated kinase1/2 as a concentration-dependent manner. Overall, the present data demonstrated that there is a cross-relationship between increased RNS production and increased [Zn(2+)]i level in cardiomyocytes under pathological conditions such as hyperglycemia.
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Affiliation(s)
- Erkan Tuncay
- Department of Biophysics, Ankara University Faculty of Medicine, 06100, Ankara, Turkey
| | - Belma Turan
- Department of Biophysics, Ankara University Faculty of Medicine, 06100, Ankara, Turkey.
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33
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Hirst J, Roessler MM. Energy conversion, redox catalysis and generation of reactive oxygen species by respiratory complex I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:872-83. [PMID: 26721206 PMCID: PMC4893023 DOI: 10.1016/j.bbabio.2015.12.009] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 12/15/2015] [Accepted: 12/16/2015] [Indexed: 12/30/2022]
Abstract
Complex I (NADH:ubiquinone oxidoreductase) is critical for respiration in mammalian mitochondria. It oxidizes NADH produced by the Krebs' tricarboxylic acid cycle and β-oxidation of fatty acids, reduces ubiquinone, and transports protons to contribute to the proton-motive force across the inner membrane. Complex I is also a significant contributor to cellular oxidative stress. In complex I, NADH oxidation by a flavin mononucleotide, followed by intramolecular electron transfer along a chain of iron–sulfur clusters, delivers electrons and energy to bound ubiquinone. Either at cluster N2 (the terminal cluster in the chain) or upon the binding/reduction/dissociation of ubiquinone/ubiquinol, energy from the redox process is captured to initiate long-range energy transfer through the complex and drive proton translocation. This review focuses on current knowledge of how the redox reaction and proton transfer are coupled, with particular emphasis on the formation and role of semiquinone intermediates in both energy transduction and reactive oxygen species production. This article is part of a Special Issue entitled Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt. Current knowledge of the redox reactions catalyzed by complex I is reviewed. Possible quinone reduction pathways are presented. The presence and number of semiquinone intermediates are deliberated. The involvement of cluster N2/semiquinones in coupled proton transfer is discussed. Evidence for reactive oxygen species production by semiquinones is examined.
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Affiliation(s)
- Judy Hirst
- Medical Research Council Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, United Kingdom.
| | - Maxie M Roessler
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom.
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34
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Kriegel S, Srour B, Steimle S, Friedrich T, Hellwig P. Involvement of Acidic Amino Acid Residues in Zn2+Binding to Respiratory Complex I. Chembiochem 2015; 16:2080-5. [DOI: 10.1002/cbic.201500273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Indexed: 12/13/2022]
Affiliation(s)
- Sébastien Kriegel
- Laboratoire de Bioelectrochimie et Spectroscopie; UMR 7140; Chimie de la Matière Complexe; Université de Strasbourg; CNRS; 1 rue Blaise Pascal 67070 Strasbourg France
- Université Paris Diderot; Sorbonne Paris Cité; Laboratoire d'Electrochimie Moléculaire; Unité Mixte de Recherche Université-; CNRS No. 7591; Bâtiment Lavoisier 15 rue Jean de Baïf 75205 Paris Cedex 13 France
| | - Batoul Srour
- Laboratoire de Bioelectrochimie et Spectroscopie; UMR 7140; Chimie de la Matière Complexe; Université de Strasbourg; CNRS; 1 rue Blaise Pascal 67070 Strasbourg France
| | - Stefan Steimle
- Albert-Ludwigs-Universität Freiburg; Institut für Biochemie; Albertstrasse 21 79104 Freiburg Germany
| | - Thorsten Friedrich
- Albert-Ludwigs-Universität Freiburg; Institut für Biochemie; Albertstrasse 21 79104 Freiburg Germany
| | - Petra Hellwig
- Laboratoire de Bioelectrochimie et Spectroscopie; UMR 7140; Chimie de la Matière Complexe; Université de Strasbourg; CNRS; 1 rue Blaise Pascal 67070 Strasbourg France
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Sharaf MS, van den Heuvel MR, Stevens D, Kamunde C. Zinc and calcium modulate mitochondrial redox state and morphofunctional integrity. Free Radic Biol Med 2015; 84:142-153. [PMID: 25841782 DOI: 10.1016/j.freeradbiomed.2015.03.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Revised: 03/03/2015] [Accepted: 03/08/2015] [Indexed: 01/08/2023]
Abstract
Zinc and calcium have highly interwoven functions that are essential for cellular homeostasis. Here we first present a novel real-time flow cytometric technique to measure mitochondrial redox state and show it is modulated by zinc and calcium, individually and combined. We then assess the interactions of zinc and calcium on mitochondrial H2O2 production, membrane potential (ΔΨm), morphological status, oxidative phosphorylation (OXPHOS), complex I activity, and structural integrity. Whereas zinc at low doses and both cations at high doses individually and combined promoted H2O2 production, the two cations individually did not alter mitochondrial redox state. However, when combined at low and high doses the two cations synergistically suppressed and promoted, respectively, mitochondrial shift to a more oxidized state. Surprisingly, the antioxidants vitamin E and N-acetylcysteine showed pro-oxidant activity at low doses, whereas at high antioxidant doses NAC inhibited OXPHOS and dyscoupled mitochondria. Individually, zinc was more potent than calcium in inhibiting OXPHOS, whereas calcium more potently dissipated the ΔΨm and altered mitochondrial volume and ultrastructure. The two cations synergistically inhibited OXPHOS but antagonistically dissipated ΔΨm and altered mitochondrial volume and morphology. Overall, our study highlights the importance of zinc and calcium in mitochondrial redox regulation and functional integrity. Importantly, we uncovered previously unrecognized bidirectional interactions of zinc and calcium that reveal distinctive foci for modulating mitochondrial function in normal and disease states because they are potentially protective or damaging depending on conditions.
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Affiliation(s)
- Mahmoud S Sharaf
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada; Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt
| | - Michael R van den Heuvel
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada; Canadian Rivers Institute, Department of Biology, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada
| | - Don Stevens
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada
| | - Collins Kamunde
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada.
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Goswami S, Diengdoh OL, Syiem MB, Pakshirajan K, Kiran MG. Zn(II) and Cu(II) removal byNostoc muscorum: a cyanobacterium isolated from a coal mining pit in Chiehruphi, Meghalaya, India. Can J Microbiol 2015; 61:209-15. [DOI: 10.1139/cjm-2014-0599] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nostoc muscorum was isolated from a coal mining pit in Chiehruphi, Meghalaya, India, and its potential to remove Zn(II) and Cu(II) from media and the various biochemical alterations it undergoes during metal stress were studied. Metal uptake measured as a function of the ions removed by N. muscorum from media supplemented independently with 20 μmol/L ZnSO4and CuSO4established the ability of this cyanobacterium to remove 66% of Zn2+and 71% of Cu2+within 24 h of contact time. Metal binding on the cell surface was found to be the primary mode of uptake, followed by internalization. Within 7 days of contact, Zn2+and Cu2+mediated dissimilar effects on the organism. For instance, although chlorophyll a synthesis was increased by 12% in Zn2+-treated cells, it was reduced by 26% in Cu2+-treated cells. Total protein content remained unaltered in Zn2+-supplemented medium; however, a 15% reduction was noticed upon Cu2+exposure. Copper enhanced both photosynthesis and respiration by 15% and 19%, respectively; in contrast, photosynthesis was unchanged and respiration dropped by 11% upon Zn2+treatment. Inoculum age also influenced metal removal ability. Experiments in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (a photosynthetic inhibitor), carbonyl cyanide m-chlorophenyl hydrazone (an uncoupler), and exogenous ATP established that metal uptake was energy dependent, and photosynthesis contributed significantly towards the energy pool required to mediate metal removals.
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Affiliation(s)
- Smita Goswami
- Department of Biochemistry, North-Eastern Hill University, Shillong 793022, Meghalaya, India
| | - Omega L. Diengdoh
- Department of Biochemistry, North-Eastern Hill University, Shillong 793022, Meghalaya, India
| | - Mayashree B. Syiem
- Department of Biochemistry, North-Eastern Hill University, Shillong 793022, Meghalaya, India
| | - Kannan Pakshirajan
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Mothe Gopi Kiran
- Centre for the Environment, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
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37
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Electrochemistry suggests proton access from the exit site to the binuclear center in Paracoccus denitrificans cytochrome c oxidase pathway variants. FEBS Lett 2015; 589:565-8. [PMID: 25637325 DOI: 10.1016/j.febslet.2015.01.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 01/05/2015] [Accepted: 01/07/2015] [Indexed: 11/27/2022]
Abstract
Two different pathways through which protons access cytochrome c oxidase operate during oxygen reduction from the mitochondrial matrix, or the bacterial cytoplasm. Here, we use electrocatalytic current measurements to follow oxygen reduction coupled to proton uptake in cytochrome c oxidase isolated from Paracoccus denitrificans. Wild type enzyme and site-specific variants with defects in both proton uptake pathways (K354M, D124N and K354M/D124N) were immobilized on gold nanoparticles, and oxygen reduction was probed electrochemically in the presence of varying concentrations of Zn(2+) ions, which are known to inhibit both the entry and the exit proton pathways in the enzyme. Our data suggest that under these conditions substrate protons gain access to the oxygen reduction site via the exit pathway.
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38
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Schulte M, Mattay D, Kriegel S, Hellwig P, Friedrich T. Inhibition of Escherichia coli respiratory complex I by Zn(2+). Biochemistry 2014; 53:6332-9. [PMID: 25238255 DOI: 10.1021/bi5009276] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The energy-converting NADH:ubiquinone oxidoreductase, respiratory complex I, couples NADH oxidation and quinone reduction with the translocation of protons across the membrane. Complex I exhibits a unique L shape with a peripheral arm extending in the aqueous phase and a membrane arm embedded in the lipid bilayer. Both arms have a length of ∼180 Å. The electron transfer reaction is catalyzed by a series of cofactors in the peripheral arm, while the membrane arm catalyzes proton translocation. We used the inhibition of complex I by zinc to shed light on the coupling of the two processes, which is not yet understood. Enzyme kinetics revealed the presence of two high-affinity binding sites for Zn(2+) that are attributed to the proton translocation pathways in the membrane arm. Electrochemically induced Fourier transform infrared difference spectroscopy demonstrated that zinc binding involves at least two protonated acidic residues. Electron paramagnetic resonance spectroscopy showed that one of the cofactors is only partially reduced by NADH in the presence of Zn(2+). We conclude that blocking the proton channels in the membrane arm leads to a partial block of the electron transfer in the peripheral arm, indicating the long-range coupling between both processes.
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Affiliation(s)
- Marius Schulte
- Institut für Biochemie, Albert-Ludwigs-Universität , 79104 Freiburg, Germany
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39
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Migliore A, Polizzi NF, Therien M, Beratan DN. Biochemistry and theory of proton-coupled electron transfer. Chem Rev 2014; 114:3381-465. [PMID: 24684625 PMCID: PMC4317057 DOI: 10.1021/cr4006654] [Citation(s) in RCA: 354] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Indexed: 02/01/2023]
Affiliation(s)
- Agostino Migliore
- Department
of Chemistry, Department of Biochemistry, and Department of Physics, Duke University, Durham, North Carolina 27708, United States
| | - Nicholas F. Polizzi
- Department
of Chemistry, Department of Biochemistry, and Department of Physics, Duke University, Durham, North Carolina 27708, United States
| | - Michael
J. Therien
- Department
of Chemistry, Department of Biochemistry, and Department of Physics, Duke University, Durham, North Carolina 27708, United States
| | - David N. Beratan
- Department
of Chemistry, Department of Biochemistry, and Department of Physics, Duke University, Durham, North Carolina 27708, United States
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40
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Trevisan R, Flesch S, Mattos JJ, Milani MR, Bainy ACD, Dafre AL. Zinc causes acute impairment of glutathione metabolism followed by coordinated antioxidant defenses amplification in gills of brown mussels Perna perna. Comp Biochem Physiol C Toxicol Pharmacol 2014; 159:22-30. [PMID: 24095941 DOI: 10.1016/j.cbpc.2013.09.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 09/21/2013] [Accepted: 09/23/2013] [Indexed: 01/28/2023]
Abstract
Zinc demonstrates protective and antioxidant properties at physiological levels, although these characteristics are not attributed at moderate or high concentrations. Zinc toxicity has been related to a number of factors, including interference with antioxidant defenses. In particular, the inhibition of glutathione reductase (GR) has been suggested as a possible mechanism for acute zinc toxicity in bivalves. The present work investigates the biochemical effects of a non-lethal zinc concentration on antioxidant-related parameters in gills of brown mussels Perna perna exposed for 21 days to 2.6 μM zinc chloride. After 2 days of exposure, zinc caused impairment of the antioxidant system, decreasing GR activity and glutathione levels. An increase in antioxidant defenses became evident at 7 and 21 days of exposure, as an increase in superoxide dismutase and glutathione peroxidase activity along with restoration of glutathione levels and GR activity. After 7 and 21 days, an increase in cellular peroxides and lipid peroxidation end products were also detected, which are indicative of oxidative damage. Changes in GR activity contrasts with protein immunoblotting data, suggesting that zinc produces a long lasting inhibition of GR. Contrary to the general trend in antioxidants, levels of peroxiredoxin 6 decreased after 21 days of exposure. The data presented here support the hypothesis that zinc can impair thiol homeostasis, causes an increase in lipid peroxidation and inhibits GR, imposing a pro-oxidant status, which seems to trigger homeostatic mechanisms leading to a subsequent increase on antioxidant-related defenses.
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Affiliation(s)
- Rafael Trevisan
- Department of Biochemistry, Biological Sciences Centre, Federal University of Santa Catarina, 88040-900 Florianópolis, Santa Catarina, Brazil
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41
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Carter RE, Seidel JL, Lindquist BE, Sheline CT, Shuttleworth CW. Intracellular Zn2+ accumulation enhances suppression of synaptic activity following spreading depolarization. J Neurochem 2013; 125:673-84. [PMID: 23495967 PMCID: PMC3666321 DOI: 10.1111/jnc.12237] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2013] [Revised: 03/05/2013] [Accepted: 03/11/2013] [Indexed: 12/27/2022]
Abstract
Spreading depolarization (SD) is a feed-forward wave that propagates slowly throughout brain tissue and recovery from SD involves substantial metabolic demand. Presynaptic Zn(2+) release and intracellular accumulation occurs with SD, and elevated intracellular Zn(2+) ([Zn(2+) ]i ) can impair cellular metabolism through multiple pathways. We tested here whether increased [Zn(2+) ]i could exacerbate the metabolic challenge of SD, induced by KCl, and delay recovery in acute murine hippocampal slices. [Zn(2+) ]i loading prior to SD, by transient ZnCl2 application with the Zn(2+) ionophore pyrithione (Zn/Pyr), delayed recovery of field excitatory post-synaptic potentials (fEPSPs) in a concentration-dependent manner, prolonged DC shifts, and significantly increased extracellular adenosine accumulation. These effects could be due to metabolic inhibition, occurring downstream of pyruvate utilization. Prolonged [Zn(2+) ]i accumulation prior to SD was required for effects on fEPSP recovery and consistent with this, endogenous synaptic Zn(2+) release during SD propagation did not delay recovery from SD. The effects of exogenous [Zn(2+) ]i loading were also lost in slices preconditioned with repetitive SDs, implying a rapid adaptation. Together, these results suggest that [Zn(2+) ]i loading prior to SD can provide significant additional challenge to brain tissue, and could contribute to deleterious effects of [Zn(2+) ]i accumulation in a range of brain injury models.
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Affiliation(s)
- Russell E. Carter
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - Jessica L. Seidel
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - Britta E. Lindquist
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - Christian T. Sheline
- Department of Ophthalmology and the Neuroscience Center of Excellence LSU, Health Sciences Center, New Orleans, LA, USA
| | - C. William Shuttleworth
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, USA
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42
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Zhang Y, Xing F, Zheng H, Xi J, Cui X, Xu Z. Roles of mitochondrial Src tyrosine kinase and zinc in nitric oxide-induced cardioprotection against ischemia/reperfusion injury. Free Radic Res 2013; 47:517-25. [DOI: 10.3109/10715762.2013.796044] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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43
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Abstract
Complex I (NADH:ubiquinone oxidoreductase) is crucial for respiration in many aerobic organisms. In mitochondria, it oxidizes NADH from the tricarboxylic acid cycle and β-oxidation, reduces ubiquinone, and transports protons across the inner membrane, contributing to the proton-motive force. It is also a major contributor to cellular production of reactive oxygen species. The redox reaction of complex I is catalyzed in the hydrophilic domain; it comprises NADH oxidation by a flavin mononucleotide, intramolecular electron transfer along a chain of iron-sulfur clusters, and ubiquinone reduction. Redox-coupled proton translocation in the membrane domain requires long-range energy transfer through the protein complex, and the molecular mechanisms that couple the redox and proton-transfer half-reactions are currently unknown. This review evaluates extant data on the mechanisms of energy transduction and superoxide production by complex I, discusses contemporary mechanistic models, and explores how mechanistic studies may contribute to understanding the roles of complex I dysfunctions in human diseases.
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Affiliation(s)
- Judy Hirst
- Medical Research Council Mitochondrial Biology Unit, Cambridge, CB2 0XY, United Kingdom.
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44
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Tan G, Landry AP, Dai R, Wang L, Lu J, Ding H. Competition of zinc ion for the [2Fe-2S] cluster binding site in the diabetes drug target protein mitoNEET. Biometals 2012; 25:1177-84. [PMID: 22945239 DOI: 10.1007/s10534-012-9580-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 08/27/2012] [Indexed: 12/23/2022]
Abstract
Human mitochondrial protein mitoNEET is a novel target of type II diabetes drug pioglitazone, and contains a redox active [2Fe-2S] cluster that is hosted by a unique ligand arrangement of three cysteine and one histidine residues. Here we report that zinc ion can compete for the [2Fe-2S] cluster binding site in human mitoNEET and potentially modulate the physiological function of mitoNEET. When recombinant mitoNEET is expressed in Escherichia coli cells grown in M9 minimal media, purified mitoNEET contains very little or no iron-sulfur clusters. Addition of exogenous iron or zinc ion in the media produces mitoNEET bound with a [2Fe-2S] cluster or zinc, respectively. Mutations of the amino acid residues that hosting the [2Fe-2S] cluster in mitoNEET diminish the zinc binding activity, indicating that zinc ion and the [2Fe-2S] cluster may share the same binding site in mitoNEET. Finally, excess zinc ion effectively inhibits the [2Fe-2S] cluster assembly in mitoNEET in E. coli cells, suggesting that zinc ion may impede the function of mitoNEET by blocking the [2Fe-2S] cluster assembly in the protein.
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Affiliation(s)
- Guoqiang Tan
- Laboratory of Molecular Medicine, Wenzhou Medical College, Wenzhou, 325035, Zhejiang, People's Republic of China
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45
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Weiss SA, Bushby RJ, Evans SD, Jeuken LJC. A study of cytochrome bo3 in a tethered bilayer lipid membrane. BIOCHIMICA ET BIOPHYSICA ACTA 2010; 1797:1917-23. [PMID: 20096262 PMCID: PMC3827738 DOI: 10.1016/j.bbabio.2010.01.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 12/20/2009] [Accepted: 01/12/2010] [Indexed: 10/19/2022]
Abstract
An assay has been developed in which the activity of an ubiquinol oxidase from Escherichia coli, cytochrome bo(3) (cbo(3)), is determined as a function of the hydrophobic substrate ubiquinol-10 (UQ-10) in tethered bilayer lipid membranes (tBLMs). UQ-10 was added in situ, while the enzyme activity and the UQ-10 concentration in the membrane have been determined by cyclic voltammetry. Cbo(3) is inhibited by UQ-10 at concentrations above 5-10 pmol/cm(2), while product inhibition is absent. Cyclic voltammetry has also been used to characterise the effects of three inhibitors; cyanide, inhibiting oxygen reduction; 2-n-Heptyl-4-hydroxyquinoline N-oxide (HQNO), inhibiting the quinone oxidation and Zn(II), thought to block the proton channels required for oxygen reduction and proton pumping activity. The electrochemical behaviour of cbo(3) inhibited with HQNO and Zn(II) is almost identical, suggesting that Zn(II) ions inhibit the enzyme reduction by quinol, rather than oxygen reduction. This suggests that at Zn(II) concentration below 50µM the proton release of cbo(3) is inhibited, but not the proton uptake required to reduce oxygen to water.
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Affiliation(s)
- Sophie A. Weiss
- School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK
| | - Richard J. Bushby
- Centre for Self Organising Molecular Systems, University of Leeds, Leeds, LS2 9JT, UK
| | - Stephen D. Evans
- School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK
| | - Lars J. C. Jeuken
- Centre for Self Organising Molecular Systems, University of Leeds, Leeds, LS2 9JT, UK
- Institute of Membrane and Systems Biology, University of Leeds, Leeds, LS2 9JT, UK
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46
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Yip CY, Harbour ME, Jayawardena K, Fearnley IM, Sazanov LA. Evolution of respiratory complex I: "supernumerary" subunits are present in the alpha-proteobacterial enzyme. J Biol Chem 2010; 286:5023-33. [PMID: 21115482 DOI: 10.1074/jbc.m110.194993] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Modern α-proteobacteria are thought to be closely related to the ancient symbiont of eukaryotes, an ancestor of mitochondria. Respiratory complex I from α-proteobacteria and mitochondria is well conserved at the level of the 14 "core" subunits, consistent with that notion. Mitochondrial complex I contains the core subunits, present in all species, and up to 31 "supernumerary" subunits, generally thought to have originated only within eukaryotic lineages. However, the full protein composition of an α-proteobacterial complex I has not been established previously. Here, we report the first purification and characterization of complex I from the α-proteobacterium Paracoccus denitrificans. Single particle electron microscopy shows that the complex has a well defined L-shape. Unexpectedly, in addition to the 14 core subunits, the enzyme also contains homologues of three supernumerary mitochondrial subunits as follows: B17.2, AQDQ/18, and 13 kDa (bovine nomenclature). This finding suggests that evolution of complex I via addition of supernumerary or "accessory" subunits started before the original endosymbiotic event that led to the creation of the eukaryotic cell. It also provides further confirmation that α-proteobacteria are the closest extant relatives of mitochondria.
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Affiliation(s)
- Chui-ying Yip
- Medical Research Council Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, United Kingdom
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47
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Polyakov NE, Focsan AL, Bowman MK, Kispert LD. Free radical formation in novel carotenoid metal ion complexes of astaxanthin. J Phys Chem B 2010; 114:16968-77. [PMID: 21114306 DOI: 10.1021/jp109039v] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The carotenoid astaxanthin forms novel metal ion complexes with Ca(2+), Zn(2+), and Fe(2+). MS and NMR measurements indicate that the two oxygen atoms on the terminal cyclohexene ring of astaxanthin chelate the metal to form 1:1 complexes with Ca(2+) and Zn(2+) at low salt concentrations <0.2 mM. The stability constants of these complexes increased by a factor of 85 upon changing the solvent from acetonitrile to ethanol for Ca(2+) and by a factor of 7 for Zn(2+) as a consequence of acetonitrile being a part of the complex. Optical studies showed that at high concentrations (>0.2 mM) of salt, 2:1 metal/astaxanthin complexes were formed in ethanol. In the presence of Ca(2+) and Zn(2+), salts the lifetime of the radical cation and dication formed electrochemically decreased relative to those formed from the uncomplexed carotenoid. DFT calculations showed that the deprotonation of the radical cation at the carbon C3 position resulted in the lowest energy neutral radical, while proton loss at the C5, C9, or C13 methyl groups was less favorable. Pulsed EPR measurements were carried out on UV-produced radicals of astaxanthin supported on silica-alumina, MCM-41, or Ti-MCM-41. The pulsed EPR measurements detected the radical cation and neutral radicals formed by proton loss at 77 K from the C3, C5, C9, and C13 methyl groups and a radical anion formed by deprotonation of the neutral radical at C3. There was more than an order of magnitude increase in the concentration of radicals on Ti-MCM-41 relative to MCM-41, and the radical cation concentration exceeded that of the neutral radicals.
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Affiliation(s)
- Nikolay E Polyakov
- Department of Chemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0336, USA
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48
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Isaev NK, Stelmashook EV, Lukin SV, Freyer D, Mergenthaler P, Zorov DB. Acidosis-induced zinc-dependent death of cultured cerebellar granule neurons. Cell Mol Neurobiol 2010; 30:877-83. [PMID: 20373017 DOI: 10.1007/s10571-010-9516-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Accepted: 03/18/2010] [Indexed: 12/16/2022]
Abstract
Severe acidosis caused death of cultured cerebellar granule neurons (CGNs). Acidosis was accompanied by a progressive increase of the intracellular zinc ions ([Zn(2+)](i)) and decrease of [Ca(2+)](i). Zn(2+) chelator, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), prevented the increase of [Zn(2+)](i) and acidosis-induced neuronal death. However, neuronal death was insensitive to blockade of ASIC1 channels with amiloride, as CGNs display considerably lower expression of ASIC1a than other neurons. The antioxidant trolox and menadione significantly protected neurons from acidotic death. Earlier, we demonstrated that menadione rescues neurons from the deleterious effect of inhibition of mitochondrial complex I (Isaev et al. Neuroreport 15:2227-2231, 2004). We speculate that excessive Zn(2+)-dependent production of reactive oxygen species by mitochondrial complex I may be a general motive for the induction of cell death in CGNs under acidotic conditions.
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Affiliation(s)
- Nikolay K Isaev
- A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia, 119992.
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49
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Berntsen P, Park CY, Rothen-Rutishauser B, Tsuda A, Sager TM, Molina RM, Donaghey TC, Alencar AM, Kasahara DI, Ericsson T, Millet EJ, Swenson J, Tschumperlin DJ, Butler JP, Brain JD, Fredberg JJ, Gehr P, Zhou EH. Biomechanical effects of environmental and engineered particles on human airway smooth muscle cells. J R Soc Interface 2010; 7 Suppl 3:S331-40. [PMID: 20356875 DOI: 10.1098/rsif.2010.0068.focus] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The past decade has seen significant increases in combustion-generated ambient particles, which contain a nanosized fraction (less than 100 nm), and even greater increases have occurred in engineered nanoparticles (NPs) propelled by the booming nanotechnology industry. Although inhalation of these particulates has become a public health concern, human health effects and mechanisms of action for NPs are not well understood. Focusing on the human airway smooth muscle cell, here we show that the cellular mechanical function is altered by particulate exposure in a manner that is dependent upon particle material, size and dose. We used Alamar Blue assay to measure cell viability and optical magnetic twisting cytometry to measure cell stiffness and agonist-induced contractility. The eight particle species fell into four categories, based on their respective effect on cell viability and on mechanical function. Cell viability was impaired and cell contractility was decreased by (i) zinc oxide (40-100 nm and less than 44 microm) and copper(II) oxide (less than 50 nm); cell contractility was decreased by (ii) fluorescent polystyrene spheres (40 nm), increased by (iii) welding fumes and unchanged by (iv) diesel exhaust particles, titanium dioxide (25 nm) and copper(II) oxide (less than 5 microm), although in none of these cases was cell viability impaired. Treatment with hydrogen peroxide up to 500 microM did not alter viability or cell mechanics, suggesting that the particle effects are unlikely to be mediated by particle-generated reactive oxygen species. Our results highlight the susceptibility of cellular mechanical function to particulate exposures and suggest that direct exposure of the airway smooth muscle cells to particulates may initiate or aggravate respiratory diseases.
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Affiliation(s)
- P Berntsen
- Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA
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50
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The critical role of intracellular zinc in adenosine A(2) receptor activation induced cardioprotection against reperfusion injury. J Mol Cell Cardiol 2010; 49:41-7. [PMID: 20144616 DOI: 10.1016/j.yjmcc.2010.02.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2009] [Revised: 01/26/2010] [Accepted: 02/01/2010] [Indexed: 12/19/2022]
Abstract
Exogenous zinc can protect cardiac cells from reperfusion injury, but the exact roles of endogenous zinc in the pathogenesis of reperfusion injury and in adenosine A(2) receptor activation-induced cardioprotection against reperfusion injury remain unknown. Adenosine A(1)/A(2) receptor agonist 5'-(N-ethylcarboxamido) adenosine (NECA) given at reperfusion reduced infarct size in isolated rat hearts subjected to 30min ischemia followed by 2h of reperfusion. This effect of NECA was partially but significantly blocked by the zinc chelator N,N,N',N'-tetrakis-(2-pyridylmethyl) ethylenediamine (TPEN), and ZnCl(2) given at reperfusion mimicked the effect of NECA by reducing infarct size. Total tissue zinc concentrations measured with inductively coupled plasma optical emission spectroscopy (ICPOES) were decreased upon reperfusion in rat hearts and this was reversed by NECA. NECA increased intracellular free zinc during reperfusion in the heart. Confocal imaging study showed a rapid increase in intracellular free zinc in isolated rat cardiomyocytes treated with NECA. Further experiments revealed that NECA increased total zinc levels upon reperfusion in mitochondria isolated from isolated hearts. NECA attenuated mitochondrial swelling upon reperfusion in isolated hearts and this was inhibited by TPEN. Similarly, NECA prevented the loss of mitochondrial membrane potential (DeltaPsim) caused by oxidant stress in cardiomyocytes. Finally, both NECA and ZnCl(2) inhibited the mitochondrial metabolic activity. NECA-induced cardioprotection against reperfusion injury is mediated by intracellular zinc. NECA prevents reperfusion-induced zinc loss and relocates zinc to mitochondria. The inhibitory effects of zinc on both the mPTP opening and the mitochondrial metabolic activity may account for the cardioprotective effect of NECA.
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