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Shimura T, Shiga R, Sasatani M, Kamiya K, Ushiyama A. Melatonin and MitoEbselen-2 Are Radioprotective Agents to Mitochondria. Genes (Basel) 2022; 14:45. [PMID: 36672786 PMCID: PMC9858905 DOI: 10.3390/genes14010045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/13/2022] [Accepted: 12/19/2022] [Indexed: 12/28/2022] Open
Abstract
Mitochondria are responsible for controlling cell death during the early stages of radiation exposure, but their perturbations are associated with late effects of radiation-related carcinogenesis. Therefore, it is important to protect mitochondria to mitigate the harmful effects of radiation throughout life. The glutathione peroxidase (GPx) enzyme is essential for the maintenance of mitochondrial-derived reactive oxygen species (ROS) levels. However, radiation inactivates the GPx, resulting in metabolic oxidative stress and prolonged cell injury in irradiated normal human fibroblasts. Here, we used the GPx activator N-acetyl-5-methoxy-tryptamine (melatonin) and a mitochondria-targeted mimic of GPx MitoEbselen-2 to stimulate the GPx. A commercial GPx activity assay kit was used to measure the GPx activity. ROS levels were determined by using some ROS indicators. Protein expression associated with the response of mitochondria to radiation was assessed using immunostaining. Concurrent pre-administration or post-administration of melatonin or MitoEbselen-2 with radiation maintained GPx activity and ROS levels and suppressed mitochondrial radiation responses associated with cellular damage and radiation-related carcinogenesis. In conclusion, melatonin and MitoEbselen-2 prevented radiation-induced mitochondrial injury and metabolic oxidative stress by targeting mitochondria. These drugs have the potential to protect against acute radiation injury and late effects of carcinogenesis in a variety of radiation scenarios assuming pre-administration or post-administration.
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Affiliation(s)
- Tsutomu Shimura
- Department of Environmental Health, National Institute of Public Health, Wako 351-0197, Japan
| | - Rina Shiga
- Meiji Pharmaceutical University, Kiyose 204-8588, Japan
| | - Megumi Sasatani
- Department of Experimental Oncology, Research Center for Radiation Genome Medicine, Research Institute for Radiation Biology and Medicine (RIRBM), Hiroshima University, Hiroshima 734-8553, Japan
| | - Kenji Kamiya
- Department of Experimental Oncology, Research Center for Radiation Genome Medicine, Research Institute for Radiation Biology and Medicine (RIRBM), Hiroshima University, Hiroshima 734-8553, Japan
| | - Akira Ushiyama
- Department of Environmental Health, National Institute of Public Health, Wako 351-0197, Japan
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Shimura T, Nakashiro C, Fujiwara K, Shiga R, Sasatani M, Kamiya K, Ushiyama A. Radiation affects glutathione redox reaction by reduced glutathione peroxidase activity in human fibroblasts. JOURNAL OF RADIATION RESEARCH 2022; 63:183-191. [PMID: 34977941 PMCID: PMC8944298 DOI: 10.1093/jrr/rrab122] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 10/14/2021] [Indexed: 06/14/2023]
Abstract
The glutathione (GSH) redox control is critical to maintain redox balance in the body's internal environment, and its perturbation leads to a dramatic increase in reactive oxygen species (ROS) levels and oxidative stress which have negative impacts on human health. Although ionizing radiation increases mitochondrial ROS generation, the mechanisms underlying radiation-induced late ROS accumulation are not fully understood. Here we investigated the radiation effect on GSH redox reactions in normal human diploid lung fibroblasts TIG-3 and MRC-5. Superoxide anion probe MitoSOX-red staining and measurement of GSH peroxidase (GPx) activity revealed that high dose single-radiation (SR) exposure (10 Gy) increased mitochondrial ROS generation and overall oxidative stress in parallel with decrease in GSH peroxidase (GPx) activity, while GSH redox control was effective after exposure to moderate doses under standard serum conditions. We used different serum conditions to elucidate the role of serum on GSH redox reaction. Serum starvation, serum deprivation and DNA damage response (DDR) inhibitors-treatment reduced the GPx activity and increased mitochondrial ROS generation regardless of radiation exposure. Fractionated-radiation was used to evaluate the radiation effect on GSH reactions. Repeated fractionated-radiation induced prolonged oxidative stress by down-regulation of GPx activity. In conclusion, radiation affects GSH usage according to radiation dose, irradiation methods and serum concentration. Radiation affected the GPx activity to disrupt fibroblast redox homeostasis.
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Affiliation(s)
- Tsutomu Shimura
- Corresponding author. Department of Environmental Health, National Institute of Public Health 2-3-6 Minami, Wako, Saitama, 351-0197, Japan. Tel. +81-48-458-6261; Fax +81-48-458-6270;
| | - Chinami Nakashiro
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan
| | - Kazusi Fujiwara
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan
| | - Rina Shiga
- Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan
| | - Megumi Sasatani
- Department of Experimental Oncology; Research Center for Radiation Genome Medicine; Research Institute for Radiation Biology and Medicine (RIRBM); Hiroshima University, Hiroshima, 734-8551, Japan
| | - Kenji Kamiya
- Department of Experimental Oncology; Research Center for Radiation Genome Medicine; Research Institute for Radiation Biology and Medicine (RIRBM); Hiroshima University, Hiroshima, 734-8551, Japan
| | - Akira Ushiyama
- Department of Environmental Health; National Institute of Public Health 2-3-6 Minami; Wako, Saitama, 351-0197, Japan
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Shimura T. ATM-Mediated Mitochondrial Radiation Responses of Human Fibroblasts. Genes (Basel) 2021; 12:genes12071015. [PMID: 34208940 PMCID: PMC8305810 DOI: 10.3390/genes12071015] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 01/15/2023] Open
Abstract
Ataxia telangiectasia (AT) is characterized by extreme sensitivity to ionizing radiation. The gene mutated in AT, Ataxia Telangiectasia Mutated (ATM), has serine/threonine protein kinase activity and mediates the activation of multiple signal transduction pathways involved in the processing of DNA double-strand breaks. Reactive oxygen species (ROS) created as a byproduct of the mitochondria's oxidative phosphorylation (OXPHOS) has been proposed to be the source of intracellular ROS. Mitochondria are uniquely vulnerable to ROS because they are the sites of ROS generation. ROS-induced mitochondrial mutations lead to impaired mitochondrial respiration and further increase the likelihood of ROS generation, establishing a vicious cycle of further ROS production and mitochondrial damage. AT patients and ATM-deficient mice display intrinsic mitochondrial dysfunction and exhibit constitutive elevations in ROS levels. ATM plays a critical role in maintaining cellular redox homeostasis. However, the precise mechanism of ATM-mediated mitochondrial antioxidants remains unclear. The aim of this review paper is to introduce our current research surrounding the role of ATM on maintaining cellular redox control in human fibroblasts. ATM-mediated signal transduction is important in the mitochondrial radiation response. Perturbation of mitochondrial redox control elevates ROS which are key mediators in the development of cancer by many mechanisms, including ROS-mediated genomic instability, tumor microenvironment formation, and chronic inflammation.
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Affiliation(s)
- Tsutomu Shimura
- Department of Environmental Health, National Institute of Public Health 2-3-6 Minami, Wako 351-0197, Saitama, Japan
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Vučković AM, Venerando R, Tibaldi E, Bosello Travain V, Roveri A, Bordin L, Miotto G, Cozza G, Toppo S, Maiorino M, Ursini F. Aerobic pyruvate metabolism sensitizes cells to ferroptosis primed by GSH depletion. Free Radic Biol Med 2021; 167:45-53. [PMID: 33711415 DOI: 10.1016/j.freeradbiomed.2021.02.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/10/2021] [Accepted: 02/26/2021] [Indexed: 12/22/2022]
Abstract
Ferroptosis is a non-accidental, regulated form of cell death operated by lipid peroxidation under strict control of GPx4 activity. This is consistent with the notion that lipid peroxidation is initiated by radicals produced from decomposition of traces of pre-existing lipid hydroperoxides. The question, therefore, emerges about the formation of these traces of lipid hydroperoxides interacting with Fe2+. In the most realistic option, they are produced by oxygen activated species generated during aerobic metabolism. Screening for metabolic sources of superoxide supporting ferroptosis induced by GSH depletion, we failed to detect, in our cell model, a role of respiratory chain. We observed instead that the pyruvate dehydrogenase complex -as other α keto acid dehydrogenases already known as a major source of superoxide in mitochondria- supports ferroptosis. The opposite effect on ferroptosis by silencing either the E1 or the E3 subunit of the pyruvate dehydrogenase complex pointed out the autoxidation of dihydrolipoamide as the source of superoxide. We finally observed that GSH depletion activates superoxide production, seemingly through the inhibition of the specific kinase that inhibits pyruvate dehydrogenase. In summary, this set of data is compatible with a scenario where the more electrophilic status produced by GSH depletion not only activates ferroptosis by preventing GPx4 activity, but also favors the formation of lipid hydroperoxides. In an attractive perspective of tissue homeostasis, it is the activation of energetic metabolism associated to a decreased nucleophilic tone that, besides supporting energy demanding proliferation, also sensitizes cells to a regulated form of death.
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Affiliation(s)
- Ana-Marija Vučković
- Department of Molecular Medicine, University of Padova, Viale G. Colombo 3, I-35131, Padova, Italy
| | - Rina Venerando
- Department of Molecular Medicine, University of Padova, Viale G. Colombo 3, I-35131, Padova, Italy
| | - Elena Tibaldi
- Department of Molecular Medicine, University of Padova, Viale G. Colombo 3, I-35131, Padova, Italy
| | | | - Antonella Roveri
- Department of Molecular Medicine, University of Padova, Viale G. Colombo 3, I-35131, Padova, Italy
| | - Luciana Bordin
- Department of Molecular Medicine, University of Padova, Viale G. Colombo 3, I-35131, Padova, Italy
| | - Giovanni Miotto
- Department of Molecular Medicine, University of Padova, Viale G. Colombo 3, I-35131, Padova, Italy
| | - Giorgio Cozza
- Department of Molecular Medicine, University of Padova, Viale G. Colombo 3, I-35131, Padova, Italy
| | - Stefano Toppo
- Department of Molecular Medicine, University of Padova, Viale G. Colombo 3, I-35131, Padova, Italy
| | - Matilde Maiorino
- Department of Molecular Medicine, University of Padova, Viale G. Colombo 3, I-35131, Padova, Italy.
| | - Fulvio Ursini
- Department of Molecular Medicine, University of Padova, Viale G. Colombo 3, I-35131, Padova, Italy
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Bastian P, Dulski J, Roszmann A, Jacewicz D, Kuban-Jankowska A, Slawek J, Wozniak M, Gorska-Ponikowska M. Regulation of Mitochondrial Dynamics in Parkinson's Disease-Is 2-Methoxyestradiol a Missing Piece? Antioxidants (Basel) 2021; 10:248. [PMID: 33562035 PMCID: PMC7915370 DOI: 10.3390/antiox10020248] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 12/15/2022] Open
Abstract
Mitochondria, as "power house of the cell", are crucial players in cell pathophysiology. Beyond adenosine triphosphate (ATP) production, they take part in a generation of reactive oxygen species (ROS), regulation of cell signaling and cell death. Dysregulation of mitochondrial dynamics may lead to cancers and neurodegeneration; however, the fusion/fission cycle allows mitochondria to adapt to metabolic needs of the cell. There are multiple data suggesting that disturbed mitochondrial homeostasis can lead to Parkinson's disease (PD) development. 2-methoxyestradiol (2-ME), metabolite of 17β-estradiol (E2) and potential anticancer agent, was demonstrated to inhibit cell growth of hippocampal HT22 cells by means of nitric oxide synthase (NOS) production and oxidative stress at both pharmacologically and also physiologically relevant concentrations. Moreover, 2-ME was suggested to inhibit mitochondrial biogenesis and to be a dynamic regulator. This review is a comprehensive discussion, from both scientific and clinical point of view, about the influence of 2-ME on mitochondria and its plausible role as a modulator of neuron survival.
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Affiliation(s)
- Paulina Bastian
- Department of Medical Chemistry, Medical University of Gdansk, Debinki 1, 80-211 Gdansk, Poland; (P.B.); (A.K.-J.); (M.W.)
| | - Jaroslaw Dulski
- Department of Neurological-Psychiatric Nursing, Medical University of Gdansk, 80-211 Gdansk, Poland; (J.D.); (A.R.); (J.S.)
- Neurology & Stroke Dpt. St. Adalbert Hospital, “Copernicus” Ltd., 80-462 Gdansk, Poland
| | - Anna Roszmann
- Department of Neurological-Psychiatric Nursing, Medical University of Gdansk, 80-211 Gdansk, Poland; (J.D.); (A.R.); (J.S.)
- Neurology & Stroke Dpt. St. Adalbert Hospital, “Copernicus” Ltd., 80-462 Gdansk, Poland
| | - Dagmara Jacewicz
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308 Gdansk, Poland;
| | - Alicja Kuban-Jankowska
- Department of Medical Chemistry, Medical University of Gdansk, Debinki 1, 80-211 Gdansk, Poland; (P.B.); (A.K.-J.); (M.W.)
| | - Jaroslaw Slawek
- Department of Neurological-Psychiatric Nursing, Medical University of Gdansk, 80-211 Gdansk, Poland; (J.D.); (A.R.); (J.S.)
- Neurology & Stroke Dpt. St. Adalbert Hospital, “Copernicus” Ltd., 80-462 Gdansk, Poland
| | - Michal Wozniak
- Department of Medical Chemistry, Medical University of Gdansk, Debinki 1, 80-211 Gdansk, Poland; (P.B.); (A.K.-J.); (M.W.)
| | - Magdalena Gorska-Ponikowska
- Department of Medical Chemistry, Medical University of Gdansk, Debinki 1, 80-211 Gdansk, Poland; (P.B.); (A.K.-J.); (M.W.)
- Euro-Mediterranean Institute of Science and Technology, 90139 Palermo, Italy
- Department of Biophysics, Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, 70174 Stuttgart, Germany
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6
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Maiorino M, Conrad M, Ursini F. GPx4, Lipid Peroxidation, and Cell Death: Discoveries, Rediscoveries, and Open Issues. Antioxid Redox Signal 2018; 29:61-74. [PMID: 28462584 DOI: 10.1089/ars.2017.7115] [Citation(s) in RCA: 342] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
SIGNIFICANCE Iron-dependent lipid peroxidation is a complex oxidative process where phospholipid hydroperoxides (PLOOH) are produced in membranes and finally transformed into a series of decomposition products, some of which are endowed with biological activity. It is specifically prevented by glutathione peroxidase 4 (GPx4), the selenoenzyme that reduces PLOOH by glutathione (GSH). PLOOH is both a product and the major initiator of peroxidative chain reactions, as well as an activator of lipoxygenases. α-Tocopherol both specifically breaks peroxidative chain propagation and inhibits lipoxygenases. Thus, GPx4, GSH, and α-tocopherol are integrated in a concerted anti-peroxidant mechanism. Recent Advances: Ferroptosis has been recently identified as a cell death subroutine that is specifically activated by missing GPx4 activity and inhibited by iron chelation or α-tocopherol supplementation. Ferroptosis induction may underlie spontaneous human diseases, such as major neurodegeneration and neuroinflammation, causing an excessive cell death. The basic mechanism of ferroptosis, therefore, fits the features of activation of lipid peroxidation. CRITICAL ISSUES Still lacking are convincing proofs that lipoxygenases are involved in ferroptosis. Also, unknown are the molecules eventually killing cells and the mechanisms underlying the drop of the cellular anti-peroxidant capacity. FUTURE DIRECTIONS Molecular events and mechanisms of ferroptosis to be unraveled and validated on animal models are GPx4 inactivation, role of GSH concentration, increased iron availability, and membrane structure and composition. This is expected to drive drug discovery that is aimed at halting cell death in degenerative diseases or boosting it in cancer cells. Antioxid. Redox Signal. 29, 61-74.
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Affiliation(s)
- Matilde Maiorino
- 1 Department of Molecular Medicine, University of Padova , Padova, Italy
| | - Marcus Conrad
- 2 Institute of Developmental Genetics , Helmholtz Zentrum München, Neuherberg, Germany
| | - Fulvio Ursini
- 1 Department of Molecular Medicine, University of Padova , Padova, Italy
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7
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Cozza G, Rossetto M, Bosello-Travain V, Maiorino M, Roveri A, Toppo S, Zaccarin M, Zennaro L, Ursini F. Glutathione peroxidase 4-catalyzed reduction of lipid hydroperoxides in membranes: The polar head of membrane phospholipids binds the enzyme and addresses the fatty acid hydroperoxide group toward the redox center. Free Radic Biol Med 2017; 112:1-11. [PMID: 28709976 DOI: 10.1016/j.freeradbiomed.2017.07.010] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 07/03/2017] [Accepted: 07/06/2017] [Indexed: 12/31/2022]
Abstract
GPx4 is a monomeric glutathione peroxidase, unique in reducing the hydroperoxide group (-OOH) of fatty acids esterified in membrane phospholipids. This reaction inhibits lipid peroxidation and accounts for enzyme's vital role. Here we investigated the interaction of GPx4 with membrane phospholipids. A cationic surface near the GPx4 catalytic center interacts with phospholipid polar heads. Accordingly, SPR analysis indicates cardiolipin as the phospholipid with maximal affinity to GPx4. Consistent with the electrostatic nature of the interaction, KCl increases the KD. Molecular dynamic (MD) simulation shows that a -OOH posed in the core of the membrane as 13 - or 9 -OOH of tetra-linoleoyl cardiolipin or 15 -OOH stearoyl-arachidonoyl-phosphaphatidylcholine moves to the lipid-water interface. Thereby, the -OOH groups are addressed toward the GPx4 redox center. In this pose, however, the catalytic site facing the membrane would be inaccessible to GSH, but the consecutive redox processes facilitate access of GSH, which further primes undocking of the enzyme, because GSH competes for the binding residues implicated in docking. During the final phase of the catalytic cycle, while GSSG is produced, GPx4 is disconnected from the membrane. The observation that GSH depletion in cells induces GPx4 translocation to the membrane, is in agreement with this concept.
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Affiliation(s)
- Giorgio Cozza
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35121 Padova, Italy
| | - Monica Rossetto
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35121 Padova, Italy
| | | | - Matilde Maiorino
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35121 Padova, Italy
| | - Antonella Roveri
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35121 Padova, Italy
| | - Stefano Toppo
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35121 Padova, Italy
| | - Mattia Zaccarin
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35121 Padova, Italy
| | - Lucio Zennaro
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35121 Padova, Italy
| | - Fulvio Ursini
- Department of Molecular Medicine, University of Padova, Viale G. Colombo, 3, I-35121 Padova, Italy.
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8
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Peroxiredoxin 1 (Prx1) is a dual-function enzyme by possessing Cys-independent catalase-like activity. Biochem J 2017; 474:1373-1394. [PMID: 28219939 PMCID: PMC5452528 DOI: 10.1042/bcj20160851] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 02/16/2017] [Accepted: 02/20/2017] [Indexed: 02/01/2023]
Abstract
Peroxiredoxin (Prx) was previously known as a Cys-dependent thioredoxin. However, we unexpectedly observed that Prx1 from the green spotted puffer fish Tetraodon nigroviridis (TnPrx1) was able to reduce H2O2 in a manner independent of Cys peroxidation and reductants. This study aimed to validate a novel function for Prx1, delineate the biochemical features and explore its antioxidant role in cells. We have confirmed that Prx1 from the puffer fish and humans truly possesses a catalase (CAT)-like activity that is independent of Cys residues and reductants, but dependent on iron. We have identified that the GVL motif was essential to the CAT-like activity of Prx1, but not to the Cys-dependent thioredoxin peroxidase (POX) activity, and generated mutants lacking POX and/or CAT-like activities for individual functional validation. We discovered that the TnPrx1 POX and CAT-like activities possessed different kinetic features in the reduction of H2O2. The overexpression of wild-type TnPrx1 and mutants differentially regulated the intracellular levels of reactive oxygen species (ROS) and the phosphorylation of p38 in HEK-293T cells treated with H2O2. Prx1 is a dual-function enzyme by acting as POX and CAT with varied affinities towards ROS. This study extends our knowledge on Prx1 and provides new opportunities to further study the biological roles of this family of antioxidants.
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Sun CC, Dong WR, Zhao J, Nie L, Xiang LX, Zhu G, Shao JZ. Cysteine-independent Catalase-like Activity of Vertebrate Peroxiredoxin 1 (Prx1). J Biol Chem 2015; 290:19942-54. [PMID: 26088136 DOI: 10.1074/jbc.m115.659011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Indexed: 11/06/2022] Open
Abstract
Peroxiredoxins (Prxs) are a ubiquitous family of antioxidant proteins that are known as thioredoxin peroxidases. Here we report that Prx1 proteins from Tetraodon nigroviridis and humans also possess a previously unknown catalase-like activity that is independent of Cys residues and reductants but dependent on iron. We identified that the GVL motif was essential to the catalase (CAT)-like activity of Prx1 but not to the Cys-dependent thioredoxin peroxidase (POX) activity, and we generated mutants lacking POX and/or CAT activities for individually delineating their functional features. We discovered that the TnPrx1 POX and CAT activities possessed different kinetic features in reducing H2O2. The overexpression of wild-type TnPrx1 and mutants differentially regulated the intracellular levels of reactive oxygen species and p38 phosphorylation in HEK-293T cells treated with H2O2. These observations suggest that the dual antioxidant activities of Prx1 may be crucial for organisms to mediate intracellular redox homeostasis.
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Affiliation(s)
- Cen-Cen Sun
- From the College of Life Sciences, Zhejiang University and Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China and
| | - Wei-Ren Dong
- From the College of Life Sciences, Zhejiang University and Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China and
| | - Jing Zhao
- From the College of Life Sciences, Zhejiang University and Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China and
| | - Li Nie
- From the College of Life Sciences, Zhejiang University and Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China and
| | - Li-Xin Xiang
- From the College of Life Sciences, Zhejiang University and Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China and
| | - Guan Zhu
- From the College of Life Sciences, Zhejiang University and Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China and the Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas 77843
| | - Jian-Zhong Shao
- From the College of Life Sciences, Zhejiang University and Key Laboratory for Cell and Gene Engineering of Zhejiang Province, Hangzhou 310058, China and
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10
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Holley AK, Miao L, St Clair DK, St Clair WH. Redox-modulated phenomena and radiation therapy: the central role of superoxide dismutases. Antioxid Redox Signal 2014; 20:1567-89. [PMID: 24094070 PMCID: PMC3942704 DOI: 10.1089/ars.2012.5000] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
SIGNIFICANCE Ionizing radiation is a vital component in the oncologist's arsenal for the treatment of cancer. Approximately 50% of all cancer patients will receive some form of radiation therapy as part of their treatment regimen. DNA is considered the major cellular target of ionizing radiation and can be damaged directly by radiation or indirectly through reactive oxygen species (ROS) formed from the radiolysis of water, enzyme-mediated ROS production, and ROS resulting from altered aerobic metabolism. RECENT ADVANCES ROS are produced as a byproduct of oxygen metabolism, and superoxide dismutases (SODs) are the chief scavengers. ROS contribute to the radioresponsiveness of normal and tumor tissues, and SODs modulate the radioresponsiveness of tissues, thus affecting the efficacy of radiotherapy. CRITICAL ISSUES Despite its prevalent use, radiation therapy suffers from certain limitations that diminish its effectiveness, including tumor hypoxia and normal tissue damage. Oxygen is important for the stabilization of radiation-induced DNA damage, and tumor hypoxia dramatically decreases radiation efficacy. Therefore, auxiliary therapies are needed to increase the effectiveness of radiation therapy against tumor tissues while minimizing normal tissue injury. FUTURE DIRECTIONS Because of the importance of ROS in the response of normal and cancer tissues to ionizing radiation, methods that differentially modulate the ROS scavenging ability of cells may prove to be an important method to increase the radiation response in cancer tissues and simultaneously mitigate the damaging effects of ionizing radiation on normal tissues. Altering the expression or activity of SODs may prove valuable in maximizing the overall effectiveness of ionizing radiation.
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Affiliation(s)
- Aaron K Holley
- 1 Graduate Center for Toxicology, University of Kentucky , Lexington, Kentucky
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11
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Hauser DN, Dukes AA, Mortimer AD, Hastings TG. Dopamine quinone modifies and decreases the abundance of the mitochondrial selenoprotein glutathione peroxidase 4. Free Radic Biol Med 2013; 65:419-427. [PMID: 23816523 PMCID: PMC4043454 DOI: 10.1016/j.freeradbiomed.2013.06.030] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Revised: 06/07/2013] [Accepted: 06/17/2013] [Indexed: 12/21/2022]
Abstract
Oxidative stress and mitochondrial dysfunction are known to contribute to the pathogenesis of Parkinson's disease. Dopaminergic neurons may be more sensitive to these stressors because they contain dopamine (DA), a molecule that oxidizes to the electrophilic dopamine quinone (DAQ) which can covalently bind nucleophilic amino acid residues such as cysteine. The identification of proteins that are sensitive to covalent modification and functional alteration by DAQ is of great interest. We have hypothesized that selenoproteins, which contain a highly nucleophilic selenocysteine residue and often play vital roles in the maintenance of neuronal viability, are likely targets for the DAQ. Here we report the findings of our studies on the effect of DA oxidation and DAQ on the mitochondrial antioxidant selenoprotein glutathione peroxidase 4 (GPx4). Purified GPx4 could be covalently modified by DAQ, and the addition of DAQ to rat testes lysate resulted in dose-dependent decreases in GPx4 activity and monomeric protein levels. Exposing intact rat brain mitochondria to DAQ resulted in similar decreases in GPx4 activity and monomeric protein levels as well as detection of multiple forms of DA-conjugated GPx4 protein. Evidence of both GPx4 degradation and polymerization was observed following DAQ exposure. Finally, we observed a dose-dependent loss of mitochondrial GPx4 in differentiated PC12 cells treated with dopamine. Our findings suggest that a decrease in mitochondrial GPx4 monomer and a functional loss of activity may be a contributing factor to the vulnerability of dopaminergic neurons in Parkinson's disease.
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Affiliation(s)
- David N Hauser
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15260
| | - April A Dukes
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15260
| | - Amanda D Mortimer
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15260
| | - Teresa G Hastings
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15260; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15260; Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260.
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Rodríguez-Martínez E, Martínez F, Espinosa-García M, Maldonado P, Rivas-Arancibia S. Mitochondrial dysfunction in the hippocampus of rats caused by chronic oxidative stress. Neuroscience 2013; 252:384-95. [DOI: 10.1016/j.neuroscience.2013.08.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 08/09/2013] [Accepted: 08/12/2013] [Indexed: 12/23/2022]
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13
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Holley AK, Dhar SK, St Clair DK. Curbing cancer's sweet tooth: is there a role for MnSOD in regulation of the Warburg effect? Mitochondrion 2013; 13:170-88. [PMID: 22820117 PMCID: PMC4604438 DOI: 10.1016/j.mito.2012.07.104] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 07/04/2012] [Accepted: 07/10/2012] [Indexed: 01/27/2023]
Abstract
Reactive oxygen species (ROS), while vital for normal cellular function, can have harmful effects on cells, leading to the development of diseases such as cancer. The Warburg effect, the shift from oxidative phosphorylation to glycolysis, even in the presence of adequate oxygen, is an important metabolic change that confers many growth and survival advantages to cancer cells. Reactive oxygen species are important regulators of the Warburg effect. The mitochondria-localized antioxidant enzyme manganese superoxide dismutase (MnSOD) is vital to survival in our oxygen-rich atmosphere because it scavenges mitochondrial ROS. MnSOD is important in cancer development and progression. However, the significance of MnSOD in the regulation of the Warburg effect is just now being revealed, and it may significantly impact the treatment of cancer in the future.
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Affiliation(s)
- Aaron K. Holley
- Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536
| | - Sanjit Kumar Dhar
- Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536
| | - Daret K. St Clair
- Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536
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14
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Venditti P, Di Stefano L, Di Meo S. Mitochondrial metabolism of reactive oxygen species. Mitochondrion 2013; 13:71-82. [DOI: 10.1016/j.mito.2013.01.008] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Revised: 01/16/2013] [Accepted: 01/22/2013] [Indexed: 11/16/2022]
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15
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Yao P, Lu W, Meng F, Wang X, Xu B, Guo X. Molecular cloning, expression and oxidative stress response of a mitochondrial thioredoxin peroxidase gene (AccTpx-3) from Apis cerana cerana. JOURNAL OF INSECT PHYSIOLOGY 2013; 59:273-282. [PMID: 23220190 DOI: 10.1016/j.jinsphys.2012.11.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Revised: 11/22/2012] [Accepted: 11/26/2012] [Indexed: 06/01/2023]
Abstract
Thioredoxin peroxidase (Tpxs) plays an important role in maintaining redox homeostasis and in protecting organisms from the accumulation of toxic reactive oxygen species (ROS). Here, we isolated a mitochondrial thioredoxin peroxidase gene from Apis cerana cerana, AccTpx-3. The open reading frame (ORF) of AccTpx-3 is 729 bp in length and encodes a predicted protein of 242 amino acids, 27.084 kDa and an isoelectric point of 8.70. Furthermore, the 980 bp 5' flanking region was cloned, and the transcription factor binding sites were predicted. A quantitative RT-PCR (Q-PCR) analysis indicated that AccTpx-3 was expressed higher in muscle than other tissues, with its highest expression occurring on the fourth day of the larval stage, followed by the fifteenth day of the adult stage. Moreover, the expression of the AccTpx-3 transcript was upregulated by such abiotic stresses as 4°C, 42°C, H(2)O(2), cyhalothrin, acaricide and phoxime treatments. In contrast, AccTpx-3 transcription was downregulated by other abiotic stresses, including 16°C, 25°C, ultraviolet light and HgCl(2). Recombinant AccTpx-3 protein acted as a potent antioxidant that resisted paraquat-induced oxidative stress and protected DNA from oxidative damage. Taken together, these results suggest that the AccTpx-3 protein is an antioxidant enzyme that may protect organisms from oxidative stress.
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Affiliation(s)
- Pengbo Yao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, PR China
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16
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Abstract
Many proteins contain free thiols that can be modified by the reversible formation of mixed disulfides with glutathione. Protein glutathionylation is of significance for defense against oxidative damage and in redox signaling. Here we outline the mechanisms and possible significance of protein glutathionylation.
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17
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Pandey AK, Patnaik R, Muresanu DF, Sharma A, Sharma HS. Quercetin in hypoxia-induced oxidative stress: novel target for neuroprotection. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2012; 102:107-46. [PMID: 22748828 DOI: 10.1016/b978-0-12-386986-9.00005-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Oxidative stress in the central nervous system is one of the key players for neurodegeneration. Thus, antioxidants could play important roles in treating several neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, and aging-related brain disorders. This review is focused on the new developments in oxidative stress-induced neurodegeneration. Further, based on our own investigations, new roles of quercetin, an antioxidant compound in hypoxia and ischemia induced neuroprotection in relation to suppression of oxidative stress, improvement in behavioral function, reduction in infarct volume, brain swelling, and cellular injury in both in vivo and in vitro models are discussed. Our new findings clearly suggest that antioxidant compounds have potential role in therapeutic strategies to treat neurodegenerative diseases in clinical settings.
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Affiliation(s)
- Anand Kumar Pandey
- School of Biomedical Engineering, Institute of Technology, Banaras Hindu University, Varanasi, India
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18
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Holley AK, Bakthavatchalu V, Velez-Roman JM, St. Clair DK. Manganese superoxide dismutase: guardian of the powerhouse. Int J Mol Sci 2011; 12:7114-62. [PMID: 22072939 PMCID: PMC3211030 DOI: 10.3390/ijms12107114] [Citation(s) in RCA: 198] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 09/28/2011] [Accepted: 10/08/2011] [Indexed: 12/18/2022] Open
Abstract
The mitochondrion is vital for many metabolic pathways in the cell, contributing all or important constituent enzymes for diverse functions such as β-oxidation of fatty acids, the urea cycle, the citric acid cycle, and ATP synthesis. The mitochondrion is also a major site of reactive oxygen species (ROS) production in the cell. Aberrant production of mitochondrial ROS can have dramatic effects on cellular function, in part, due to oxidative modification of key metabolic proteins localized in the mitochondrion. The cell is equipped with myriad antioxidant enzyme systems to combat deleterious ROS production in mitochondria, with the mitochondrial antioxidant enzyme manganese superoxide dismutase (MnSOD) acting as the chief ROS scavenging enzyme in the cell. Factors that affect the expression and/or the activity of MnSOD, resulting in diminished antioxidant capacity of the cell, can have extraordinary consequences on the overall health of the cell by altering mitochondrial metabolic function, leading to the development and progression of numerous diseases. A better understanding of the mechanisms by which MnSOD protects cells from the harmful effects of overproduction of ROS, in particular, the effects of ROS on mitochondrial metabolic enzymes, may contribute to the development of novel treatments for various diseases in which ROS are an important component.
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Affiliation(s)
- Aaron K. Holley
- Graduate Center for Toxicology, University of Kentucky, 454 HSRB, 1095 VA Drive, Lexington, KY 40536, USA; E-Mails: (A.K.H.); (V.B.); (J.M.V.-R.)
| | - Vasudevan Bakthavatchalu
- Graduate Center for Toxicology, University of Kentucky, 454 HSRB, 1095 VA Drive, Lexington, KY 40536, USA; E-Mails: (A.K.H.); (V.B.); (J.M.V.-R.)
| | - Joyce M. Velez-Roman
- Graduate Center for Toxicology, University of Kentucky, 454 HSRB, 1095 VA Drive, Lexington, KY 40536, USA; E-Mails: (A.K.H.); (V.B.); (J.M.V.-R.)
| | - Daret K. St. Clair
- Graduate Center for Toxicology, University of Kentucky, 454 HSRB, 1095 VA Drive, Lexington, KY 40536, USA; E-Mails: (A.K.H.); (V.B.); (J.M.V.-R.)
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19
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Song IS, Kim HK, Jeong SH, Lee SR, Kim N, Rhee BD, Ko KS, Han J. Mitochondrial peroxiredoxin III is a potential target for cancer therapy. Int J Mol Sci 2011; 12:7163-85. [PMID: 22072940 PMCID: PMC3211031 DOI: 10.3390/ijms12107163] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 09/30/2011] [Accepted: 10/20/2011] [Indexed: 01/01/2023] Open
Abstract
Mitochondria are involved either directly or indirectly in oncogenesis and the alteration of metabolism in cancer cells. Cancer cells contain large numbers of abnormal mitochondria and produce large amounts of reactive oxygen species (ROS). Oxidative stress is caused by an imbalance between the production of ROS and the antioxidant capacity of the cell. Several cancer therapies, such as chemotherapeutic drugs and radiation, disrupt mitochondrial homeostasis and release cytochrome c, leading to apoptosome formation, which activates the intrinsic pathway. This is modulated by the extent of mitochondrial oxidative stress. The peroxiredoxin (Prx) system is a cellular defense system against oxidative stress, and mitochondria in cancer cells are known to contain high levels of Prx III. Here, we review accumulating evidence suggesting that mitochondrial oxidative stress is involved in cancer, and discuss the role of the mitochondrial Prx III antioxidant system as a potential target for cancer therapy. We hope that this review will provide the basis for new strategic approaches in the development of effective cancer treatments.
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Affiliation(s)
- In-Sung Song
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-7-5, Korea; E-Mails: (I.-S.S.); (H.-K.K.); (S.-H.J.); (S.-R.L.); (N.K.); (B.D.R.); (K.S.K.)
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20
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Van der Eecken V, Clippe A, Van Veldhoven PP, Knoops B. Mitochondrial targeting of peroxiredoxin 5 is preserved from annelids to mammals but is absent in pig Sus scrofa domesticus. Mitochondrion 2011; 11:973-81. [PMID: 21763786 DOI: 10.1016/j.mito.2011.06.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 05/13/2011] [Accepted: 06/29/2011] [Indexed: 11/19/2022]
Abstract
Peroxiredoxin 5 (PRDX5) is a thioredoxin peroxidase able to reduce hydrogen peroxide, alkyl hydroperoxides and peroxynitrite. In human, PRDX5 was reported to be localized in the cytosol, the mitochondria, the peroxisomes and the nucleus. Mitochondrial localization results from the presence of an N-terminal mitochondrial targeting sequence (MTS). Here, we examined the conservation of mitochondrial localization of PRDX5 in animal species. We found that PRDX5 MTS is present and functional in the annelid lugworm Arenicola marina. Surprisingly, although mitochondrial targeting is well conserved among animals, PRDX5 is missing in mitochondria of domestic pig. Thus, it appears that mitochondrial targeting of PRDX5 may have been lost throughout evolution in animal species, including pig, with unknown functional consequences.
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Affiliation(s)
- Valérie Van der Eecken
- Université catholique de Louvain, Institut des Sciences de la Vie, 4-5 place Croix du Sud, B-1348 Louvain-la-Neuve, Belgium
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21
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Holley AK, Dhar SK, St Clair DK. Manganese superoxide dismutase versus p53: the mitochondrial center. Ann N Y Acad Sci 2010; 1201:72-8. [PMID: 20649542 DOI: 10.1111/j.1749-6632.2010.05612.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Mitochondria are important sites of myriad metabolic activities. The actions of mitochondria must be carefully synchronized with other processes in the cell to maintain cellular homeostasis. Interorganellar communication between mitochondria and the nucleus is key for coordination of these cellular functions. Numerous signaling proteins and transcription factors are affected by reactive oxygen species and aid interorganellar communication. p53 is an important tumor suppressing protein that regulates many cellular activities, such as cell cycle regulation, DNA repair, and programmed cell death. p53 carries out these functions through both transcription-dependent and transcription-independent routes at mitochondria and the nucleus. Manganese superoxide dismutase (MnSOD), a p53-regulated gene that is a vital antioxidant enzyme localized in the matrix of mitochondria, scavenges reactive oxygen species. Recent studies suggest that mitochondria can regulate p53 activity and that assaults on the cell that affect mitochondrial ROS production and mitochondrial function can influence p53 activity. Cross-talk between mitochondria and p53 is important in normal cellular functions, and a breakdown in communication among mitochondria, p53, and the nucleus may have serious consequences in disease development.
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Affiliation(s)
- Aaron K Holley
- Graduate Center for Toxicology, University of Kentucky, Lexington, Kentucky 40536, USA
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22
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Holley AK, Dhar SK, St Clair DK. Manganese superoxide dismutase vs. p53: regulation of mitochondrial ROS. Mitochondrion 2010; 10:649-61. [PMID: 20601193 DOI: 10.1016/j.mito.2010.06.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Revised: 06/18/2010] [Accepted: 06/22/2010] [Indexed: 01/10/2023]
Abstract
Coordination of mitochondrial and nuclear activities is vital for cellular homeostasis, and many signaling molecules and transcription factors are regulated by mitochondria-derived reactive oxygen species (ROS) to carry out this interorganellar communication. The tumor suppressor p53 regulates myriad cellular functions through transcription-dependent and -independent mechanisms at both the nucleus and mitochondria. p53 affect mitochondrial ROS production, in part, by regulating the expression of the mitochondrial antioxidant enzyme manganese superoxide dismutase (MnSOD). Recent evidence suggests mitochondrial regulation of p53 activity through mechanisms that affect ROS production, and a breakdown of communication amongst mitochondria, p53, and the nucleus can have broad implications in disease development.
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Affiliation(s)
- Aaron K Holley
- Graduate Center for Toxicology, University of Kentucky, Lexington, KY 40536, United States
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23
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Malik SG, Irwanto KA, Ostrow JD, Tiribelli C. Effect of bilirubin on cytochrome c oxidase activity of mitochondria from mouse brain and liver. BMC Res Notes 2010; 3:162. [PMID: 20534120 PMCID: PMC2901210 DOI: 10.1186/1756-0500-3-162] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 06/09/2010] [Indexed: 12/04/2022] Open
Abstract
Background The unbound, free concentration (Bf) of unconjugated bilirubin (UCB), and not the total UCB level, has been shown to correlate with bilirubin cytotoxicity, but the key molecular mechanisms accounting for the toxic effects of UCB are largely unknown. Findings Mouse liver mitochondria increase unbound UCB oxidation, consequently increasing the apparent rate constant for unbound UCB oxidation by HRP (Kp), higher than in control and mouse brain mitochondria, emphasizing the importance of determining Kp in complete systems containing the organelles being studied. The in vitro effects of UCB on cytochrome c oxidase activity in mitochondria isolated from mouse brain and liver were studied at Bf ranging from 22 to 150 nM. The results show that UCB at Bf up to 60 nM did not alter mitochondrial cytochrome c oxidase activity, while the higher concentrations significantly inhibited the enzyme activity by 20% in both liver and brain mitochondria. Conclusions We conclude that it is essential to include the organelles being studied in the medium used in measuring both Kp and Bf. A moderately elevated, pathophysiologically-relevant Bf impaired the cytochrome c oxidase activity modestly in mitochondria from mouse brain and liver.
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Affiliation(s)
- Safarina G Malik
- Eijkman Institute for Molecular Biology, Jl, Diponegoro 69, Jakarta 10430, Indonesia.
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24
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Chen L, Na R, Gu M, Salmon AB, Liu Y, Liang H, Qi W, Van Remmen H, Richardson A, Ran Q. Reduction of mitochondrial H2O2 by overexpressing peroxiredoxin 3 improves glucose tolerance in mice. Aging Cell 2008; 7:866-78. [PMID: 18778410 DOI: 10.1111/j.1474-9726.2008.00432.x] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
H(2)O(2) is a major reactive oxygen species produced by mitochondria that is implicated to be important in aging and pathogenesis of diseases such as diabetes; however, the cellular and physiological roles of mitochondrial H(2)O(2) remain poorly understood. Peroxiredoxin 3 (Prdx3/Prx3) is a thioredoxin peroxidase localized in mitochondria. To understand the cellular and physiological roles of mitochondrial H(2)O(2) in aging and pathogenesis of age-associated diseases, we generated transgenic mice overexpressing Prdx3 (Tg(PRDX3) mice). Tg(PRDX3) mice overexpress Prdx3 in a broad range of tissues, and the Prdx3 overexpression occurs exclusively in the mitochondria. As a result of increased Prdx3 expression, mitochondria from Tg(PRDX3) mice produce significantly reduced amount of H(2)O(2), and cells from Tg(PRDX3) mice have increased resistance to stress-induced cell death and apoptosis. Interestingly, Tg(PRDX3) mice show improved glucose homeostasis, as evidenced by their reduced levels of blood glucose and increased glucose clearance. Tg(PRDX3) mice are also protected against hyperglycemia and glucose intolerance induced by high-fat diet feeding. Our results further show that the inhibition of GSK3 may play a role in mediating the improved glucose tolerance phenotype in Tg(PRDX3) mice. Thus, our results indicate that reduction of mitochondrial H(2)O(2) by overexpressing Prdx3 improves glucose tolerance.
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Affiliation(s)
- Liuji Chen
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, Texas 78229, USA
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25
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Savaskan NE, Ufer C, Kühn H, Borchert A. Molecular biology of glutathione peroxidase 4: from genomic structure to developmental expression and neural function. Biol Chem 2008; 388:1007-17. [PMID: 17937614 DOI: 10.1515/bc.2007.126] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Selenoproteins have been recognized as modulators of brain function and signaling. Phospholipid hydroperoxide glutathione peroxidase (GPx4/PHGPx) is a unique member of the selenium-dependent glutathione peroxidases in mammals with a pivotal role in brain development and function. GPx4 exists as a cytosolic, mitochondrial, and nuclear isoform derived from a single gene. In mice, the GPx4 gene is located on chromosome 10 in close proximity to a functional retrotransposome that is expressed under the control of captured regulatory elements. Elucidation of crystallographic data uncovered structural peculiarities of GPx4 that provide the molecular basis for its unique enzymatic properties and substrate specificity. Monomeric GPx4 is multifunctional: it acts as a reducing enzyme of peroxidized phospholipids and thiols and as a structural protein. Transcriptional regulation of the different GPx4 isoforms requires several isoform-specific cis-regulatory sequences and trans-activating factors. Cytosolic and mitochondrial GPx4 are the major isoforms exclusively expressed by neurons in the developing brain. In stark contrast, following brain trauma, GPx4 is specifically upregulated in non-neuronal cells, i.e., reactive astrocytes. Molecular approaches to genetic modification in mice have revealed an essential and isoform-specific function for GPx4 in development and disease. Here we review recent findings on GPx4 with emphasis on its molecular structure and function and consider potential mechanisms that underlie neural development and neuropathological conditions.
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Affiliation(s)
- Nicolai E Savaskan
- Division of Cellular Biochemistry, The Netherlands Cancer Institute, NL-1066 CX Amsterdam, The Netherlands.
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26
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Zafiriou MP, Deva R, Ciccoli R, Siafaka-Kapadai A, Nigam S. Biological role of hepoxilins: upregulation of phospholipid hydroperoxide glutathione peroxidase as a cellular response to oxidative stress? Prostaglandins Leukot Essent Fatty Acids 2007; 77:209-15. [PMID: 17997296 DOI: 10.1016/j.plefa.2007.08.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2007] [Revised: 08/08/2007] [Accepted: 08/14/2007] [Indexed: 10/22/2022]
Abstract
The 12S-lipoxygenase (12S-LOX) pathway of arachidonic acid (AA) metabolism is bifurcated at 12(S)-hydroperoxy-5Z,8Z,10E (12S-HpETE) in the reduction route to form 12S-hydroxy-eicosatetraenoic acid (12S-HETE) and in 8(S/R)-hydroxy-11(S),12S-trans-epoxyeicosa-5Z,9E,14Z-trienoic acid (HXA3) synthase pathway, previously known as isomerization route, to form hepoxilins. Earlier we showed that the HXA3 formation is restricted to cellular systems devoid of hydroperoxide reducing enzymes, e.g. GPxs, thus causing a persistent oxidative stress situation. Here, we show that HXA3 at as low as 100 nM concentration upregulates phospholipid hydroperoxide glutathione peroxidase (PHGPx) mRNA and protein expressions, whereas other metabolites of AA metabolism 12S-HpETE and 12S-HETE failed to stimulate the PHGPx. Moreover, the decrease in 12S-HpETE below a threshold value of the hydroperoxide tone causes both suppression of the overall 12S-LOX activity and a shift from HXA3 formation towards 12S-HETE formation. We therefore propose that under persistent oxidative stress the formation of HXA3 and the HXA3-induced upregulation of PHGPx constitute a compensatory defense response to protect the vitality and functionality of the cell.
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Affiliation(s)
- M P Zafiriou
- Centre for Experimental Gynecology & Breast Research and Eicosanoid Research Division, Charité - Campus University Medical Centre Benjamin Franklin, Berlin, D-12200 Berlin, German.
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27
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Cao Z, Bhella D, Lindsay JG. Reconstitution of the mitochondrial PrxIII antioxidant defence pathway: general properties and factors affecting PrxIII activity and oligomeric state. J Mol Biol 2007; 372:1022-1033. [PMID: 17707404 DOI: 10.1016/j.jmb.2007.07.018] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2006] [Revised: 07/04/2007] [Accepted: 07/10/2007] [Indexed: 10/23/2022]
Abstract
The mitochondrial 2-Cys peroxiredoxin PrxIII serves as a thioredoxin-dependent peroxidase operating in tandem with its cognate partners, an organelle-specific thioredoxin (Trx2) and NADP-linked thioredoxin reductase (TRR2). This PrxIII pathway is emerging as a primary regulator of intracellular H(2)O(2) levels with dual roles in antioxidant defence and H(2)O(2)-mediated signalling. Here we describe the reconstitution of the mammalian PrxIII pathway in vitro from its purified recombinant components and investigate some of its overall properties. Employing the site-directed PrxIII mutants C47S, C66S and C168S, the putative N and C-terminal catalytic cysteine residues are shown to be essential for function whereas the C66S mutant retains full activity. The pathway attains maximal capacity at low H(2)O(2) concentrations (<10 microM) and is progressively inhibited in the range 0.1 mM to 1.0 mM peroxide. Damage to PrxIII caused by over-oxidation is confirmed by the appearance of abnormal oxidised species of PrxIII on SDS-PAGE at elevated H(2)O(2) levels. The presence of an N-terminal His-tag on PrxIII markedly enhances dodecamer stability, particularly apparent in its oxidised state. Its removal promotes oxidised PrxIII dissociation into dimers and leads to a 3.0-3.5-fold stimulation in peroxidase activity. The unusual concatenated crystal structure of PrxIII consisting of two-interlocked dodecameric rings is also evident in dilute solution employing transmission electron microscopy; however, it represents only 3-5% of the population with most molecules present as single toroids. Moreover, concatenated PrxIII C168S reverts to single toroids on crystal dissolution indicating that these higher-order structures are produced dynamically during the crystallisation process.
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Affiliation(s)
- Zhenbo Cao
- Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
| | - David Bhella
- Medical Research Council Virology Unit, Church Street, Glasgow G11 5JR, Scotland, UK
| | - J Gordon Lindsay
- Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK.
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28
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Savaskan NE, Borchert A, Bräuer AU, Kuhn H. Role for glutathione peroxidase-4 in brain development and neuronal apoptosis: specific induction of enzyme expression in reactive astrocytes following brain injury. Free Radic Biol Med 2007; 43:191-201. [PMID: 17603929 DOI: 10.1016/j.freeradbiomed.2007.03.033] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2007] [Accepted: 03/31/2007] [Indexed: 01/18/2023]
Abstract
Glutathione peroxidase-4 (GPx4) is a multifunctional selenoprotein expressed as mitochondrial, cytosolic, or nuclear isoforms. As a catalytically active enzyme it has been implicated in antioxidative defense, but during sperm development it functions as a structural protein. GPx4 null mice die in utero at midgestation and knockdown of GPx4 during embryogenesis disturbs brain development. To explore the cerebral function of GPx4 we profiled cell-specific enzyme expression at various stages of perinatal brain maturation and investigated its regulation following brain injury by immunohistochemistry, in situ hybridization, and quantitative RT-PCR. Large amounts of GPx4 mRNA were detected in all neuronal layers during perinatal brain development but expression became restricted during postnatal maturation. In adult brain mitochondrial and cytosolic GPx4 isoforms were detected in neurons of cerebral cortex, hippocampus, and cerebellum whereas glial cells were devoid of GPx4. Following selective brain injury expression of the enzyme was upregulated in reactive astrocytes of lesioned areas and deafferented regions but not in neurons. Selective knockdown of GPx4 by small interfering RNA induced depletion of phosphatidylinositol-(4,5)-bisphosphate in the neuronal plasma membrane and subsequently apoptosis as indicated by caspase-3 activation. We hypothesize that astrocytic upregulation of GPx4 in response to injury is part of a protective cascade counteracting further cell damage.
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Affiliation(s)
- Nicolai E Savaskan
- Division of Cellular Biochemistry, The Netherlands Cancer Institute, 1066 CX Amsterdam, The Netherlands.
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29
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Baek IJ, Seo DS, Yon JM, Lee SR, Jin Y, Nahm SS, Jeong JH, Choo YK, Kang JK, Lee BJ, Yun YW, Nam SY. Tissue expression and cellular localization of phospholipid hydroperoxide glutathione peroxidase (PHGPx) mRNA in male mice. J Mol Histol 2007; 38:237-44. [PMID: 17503194 DOI: 10.1007/s10735-007-9092-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Accepted: 04/13/2007] [Indexed: 01/17/2023]
Abstract
Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is an ubiquitous antioxidant enzyme, but the exact expression pattern in mammalian tissues is still unknown. The expression and cellular localization of PHGPx mRNA were examined in male mice using real time-polymerase chain reaction and in situ hybridization techniques. The rank order of PHGPx mRNA expression across tissues exhibiting substantial levels of expression was:testes >> heart > cerebrum > or = ileum > stomach = liver = jejunum > or = epididymis. In testes, PHGPx mRNA was highly expressed in spermiogenic cells and Leydig cells. The signal was also expressed in the molecular layer, Purkinje cell layer, and white matter of cerebellum, the pituicytes of neurohypophysis, the parafollicular cells and follicular basement membrane of thyroid, the exocrine portion of pancreas, the tubular epithelium of kidney, the smooth muscle cells of arteries, and the red pulp of spleen. In the gastrointestinal tract, PHGPx mRNA expression was mainly observed in the keratinized surface epithelium of forestomach, the submucosal glands and serosa layers, and further the Paneth cells of intestines. PHGPx mRNA appeared to be ubiquitously expressed in the parenchyma of heart, liver, and lung. These results indicate that PHGPx exhibits a cell- and tissue-specific expression pattern in mice.
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Affiliation(s)
- In-Jeoung Baek
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University, Cheongju 361-763, Korea
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30
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Abstract
A large number of proteins contain free thiols that can be modified by the formation of internal disulphides or by mixed disulphides with low-molecular-mass thiols. The majority of these latter modifications result from the interaction of protein thiols with the endogenous glutathione pool. Protein glutathionylation and disulphide formation are of significance both for defence against oxidative damage and in redox signalling. As mitochondria are central to both oxidative damage and redox signalling within the cell, these modifications of mitochondrial proteins are of particular importance. In the present study, we review the mechanisms and physiological significance of these processes.
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31
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Zeevalk GD, Bernard LP, Song C, Gluck M, Ehrhart J. Mitochondrial inhibition and oxidative stress: reciprocating players in neurodegeneration. Antioxid Redox Signal 2005; 7:1117-39. [PMID: 16115016 DOI: 10.1089/ars.2005.7.1117] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Although the etiology for many neurodegenerative diseases is unknown, the common findings of mitochondrial defects and oxidative damage posit these events as contributing factors. The temporal conundrum of whether mitochondrial defects lead to enhanced reactive oxygen species generation, or conversely, if oxidative stress is the underlying cause of the mitochondrial defects remains enigmatic. This review focuses on evidence to show that either event can lead to the evolution of the other with subsequent neuronal cell loss. Glutathione is a major antioxidant system used by cells and mitochondria for protection and is altered in a number of neurodegenerative and neuropathological conditions. This review also addresses the multiple roles for glutathione during mitochondrial inhibition or oxidative stress. Protein aggregation and inclusions are hallmarks of a number of neurodegenerative diseases. Recent evidence that links protein aggregation to oxidative stress and mitochondrial dysfunction will also be examined. Lastly, current therapies that target mitochondrial dysfunction or oxidative stress are discussed.
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Affiliation(s)
- G D Zeevalk
- Department of Neurology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
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32
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Andreyev AY, Kushnareva YE, Starkov AA. Mitochondrial metabolism of reactive oxygen species. BIOCHEMISTRY (MOSCOW) 2005; 70:200-14. [PMID: 15807660 DOI: 10.1007/s10541-005-0102-7] [Citation(s) in RCA: 830] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Oxidative stress is considered a major contributor to etiology of both "normal" senescence and severe pathologies with serious public health implications. Mitochondria generate reactive oxygen species (ROS) that are thought to augment intracellular oxidative stress. Mitochondria possess at least nine known sites that are capable of generating superoxide anion, a progenitor ROS. Mitochondria also possess numerous ROS defense systems that are much less studied. Studies of the last three decades shed light on many important mechanistic details of mitochondrial ROS production, but the bigger picture remains obscure. This review summarizes the current knowledge about major components involved in mitochondrial ROS metabolism and factors that regulate ROS generation and removal. An integrative, systemic approach is applied to analysis of mitochondrial ROS metabolism, which is now dissected into mitochondrial ROS production, mitochondrial ROS removal, and mitochondrial ROS emission. It is suggested that mitochondria augment intracellular oxidative stress due primarily to failure of their ROS removal systems, whereas the role of mitochondrial ROS emission is yet to be determined and a net increase in mitochondrial ROS production in situ remains to be demonstrated.
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Affiliation(s)
- A Yu Andreyev
- Alumni of Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia
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33
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Siler-Marsiglio KI, Pan Q, Paiva M, Madorsky I, Khurana NC, Heaton MB. Mitochondrially targeted vitamin E and vitamin E mitigate ethanol-mediated effects on cerebellar granule cell antioxidant defense systems. Brain Res 2005; 1052:202-11. [PMID: 16024002 DOI: 10.1016/j.brainres.2005.06.030] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2004] [Revised: 06/10/2005] [Accepted: 06/10/2005] [Indexed: 10/25/2022]
Abstract
Ethanol (EtOH) disrupts the structure and function of the developing nervous system, sometimes leading to birth defects associated with fetal alcohol syndrome (FAS). Animal FAS models indicate that cellular membrane peroxidation, intracellular oxidant accumulation, and suppression of endogenous antioxidant enzymes contribute to the toxic effects of EtOH. Mitochondrially targeted vitamin E (MitoVit E), a chemically engineered form of vitamin E (VE) designed to accumulate in the mitochondria, has been shown to inhibit intracellular oxidant accumulation and cell death more effectively than VE. In previous investigations, we have shown that, in vivo, VE reduces neuronal death in the developing cerebellum of EtOH-exposed animals, and, in vitro, VE prevents apoptotic and necrotic death of EtOH-exposed cerebellar granule cells (CGCs). The present investigation shows that, in a FAS CGC model, 1 nM MitoVit E renders significant neuroprotection against EtOH concentrations as high as 1600 mg/dL. The present study also demonstrates that, in this same model, MitoVit E mitigates EtOH-induced accumulation of intracellular oxidants and counteracts suppression of glutathione peroxidase/glutathione reductase (GSH-Px/GSSG-R) functions, protein expression of gamma-glutamylcysteine synthetase (gamma-GCS), and total cellular glutathione (GSH) levels. In the presence and absence of EtOH, VE amplifies the protein expression levels of gamma-GCS, an enzyme that performs the rate-limiting step for GSH synthesis, and total GSH levels. These results suggest that MitoVit E and VE ameliorate EtOH toxicity through non-oxidant mechanisms-modulations of endogenous cellular proteins-and antioxidant means.
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Affiliation(s)
- Kendra I Siler-Marsiglio
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, 32611, USA.
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34
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Hurd TR, Costa NJ, Dahm CC, Beer SM, Brown SE, Filipovska A, Murphy MP. Glutathionylation of mitochondrial proteins. Antioxid Redox Signal 2005; 7:999-1010. [PMID: 15998254 DOI: 10.1089/ars.2005.7.999] [Citation(s) in RCA: 165] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Many proteins contain free thiols that can be modified by the reversible formation of mixed disulfides with low-molecular-weight thiols through a process called S-thiolation. As the majority of these modifications result from the interaction of protein thiols with the endogenous glutathione pool, protein glutathionylation is the predominant alteration. Protein glutathionylation is of significance both for defense against oxidative damage and in redox signaling. As mitochondria are at the heart of both oxidative damage and redox signaling within the cell, the glutathionylation of mitochondrial proteins is of particular importance. Here we review the mechanisms and physiological significance of the glutathionylation of mitochondrial thiol proteins.
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35
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Rhee SG, Kang SW, Jeong W, Chang TS, Yang KS, Woo HA. Intracellular messenger function of hydrogen peroxide and its regulation by peroxiredoxins. Curr Opin Cell Biol 2005; 17:183-9. [PMID: 15780595 DOI: 10.1016/j.ceb.2005.02.004] [Citation(s) in RCA: 550] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Hydrogen peroxide (H2O2) accumulates transiently in various cell types stimulated with peptide growth factors and participates in receptor signaling by oxidizing the essential cysteine residues of protein tyrosine phosphatases and the lipid phosphatase PTEN. The reversible inactivation of these phosphatases by H2O2 is likely required to prevent futile cycles of phosphorylation-dephosphorylation of proteins and phosphoinositides. The accumulation of H2O2 is possible even in the presence of large amounts of the antioxidant enzymes peroxiredoxin I and II in the cytosol, probably because of a built-in mechanism of peroxiredoxin inactivation that is mediated by H2O2 and reversed by an ATP-dependent reduction reaction catalyzed by sulfiredoxin.
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Affiliation(s)
- Sue Goo Rhee
- Laboratory of Cell Signaling, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
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36
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Kwon J, Lee SR, Yang KS, Ahn Y, Kim YJ, Stadtman ER, Rhee SG. Reversible oxidation and inactivation of the tumor suppressor PTEN in cells stimulated with peptide growth factors. Proc Natl Acad Sci U S A 2004; 101:16419-24. [PMID: 15534200 PMCID: PMC534546 DOI: 10.1073/pnas.0407396101] [Citation(s) in RCA: 499] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Stimulation of cells with various peptide growth factors induces the production of phosphatidylinositol 3,4,5-trisphosphate (PIP3) through activation of phosphatidylinositol 3-kinase. The action of this enzyme is reversed by that of the tumor suppressor PTEN. With the use of cells overexpressing NADPH oxidase 1 or peroxiredoxin II, we have now shown that H2O2 produced in response to stimulation of cells with epidermal growth factor or platelet-derived growth factor potentiates PIP3 generation and activation of the protein kinase Akt induced by these growth factors. We also show that a small fraction of PTEN molecules is transiently inactivated as a result of oxidation of the essential cysteine residue of this phosphatase in various cell types stimulated with epidermal growth factor, platelet-derived growth factor, or insulin. These results suggest that the activation of phosphatidylinositol 3-kinase by growth factors might not be sufficient to induce the accumulation of PIP3 because of the opposing activity of PTEN and that the concomitant local inactivation of PTEN by H2O2 might be needed to increase the concentration of PIP3 sufficiently to trigger downstream signaling events. Furthermore, together with previous observations, our data indicate that peroxiredoxin likely participates in PIP3 signaling by modulating the local concentration of H2O2.
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Affiliation(s)
- Jaeyul Kwon
- Laboratories of Cell Signaling and Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8015, USA
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37
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Chang TS, Cho CS, Park S, Yu S, Kang SW, Rhee SG. Peroxiredoxin III, a mitochondrion-specific peroxidase, regulates apoptotic signaling by mitochondria. J Biol Chem 2004; 279:41975-84. [PMID: 15280382 DOI: 10.1074/jbc.m407707200] [Citation(s) in RCA: 303] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Various proapoptotic stimuli increase the production of superoxide and H(2)O(2) by mitochondria. Whereas superoxide impairs mitochondrial function and is removed by Mn(2+)-dependent superoxide dismutase, the role and metabolism of mitochondrial H(2)O(2) during apoptosis have remained unclear. The effects on apoptotic signaling of depletion of peroxiredoxin (Prx) III, a mitochondrion-specific H(2)O(2)-scavenging enzyme, have now been investigated by RNA interference in HeLa cells. Depletion of Prx III resulted in increased intracellular levels of H(2)O(2) and sensitized cells to induction of apoptosis by staurosporine or TNF-alpha. The rates of mitochondrial membrane potential collapse, cytochrome c release, and caspase activation were increased in Prx III-depleted cells, and these effects were reversed by ectopic expression of Prx III or mitochondrion-targeted catalase. Depletion of Prx III also exacerbated damage to mitochondrial macromolecules induced by the proapoptotic stimuli. Our results suggest that Prx III is a critical regulator of the abundance of mitochondrial H(2)O(2), which itself promotes apoptosis in cooperation with other mediators of apoptotic signaling.
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Affiliation(s)
- Tong-Shin Chang
- Laboratory of Cell Signaling, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, USA
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38
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Rossi L, Lombardo MF, Ciriolo MR, Rotilio G. Mitochondrial dysfunction in neurodegenerative diseases associated with copper imbalance. Neurochem Res 2004; 29:493-504. [PMID: 15038597 DOI: 10.1023/b:nere.0000014820.99232.8a] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Copper is an essential transition metal ion for the function of key metabolic enzymes, but its uncontrolled redox reactivity is source of reactive oxygen species. Therefore a network of transporters strictly controls the trafficking of copper in living systems. Deficit, excess, or aberrant coordination of copper are conditions that may be detrimental, especially for neuronal cells, which are particularly sensitive to oxidative stress. Indeed, the genetic disturbances of copper homeostasis, Menkes' and Wilson's diseases, are associated with neurodegeneration. Furthermore, copper interacts with the proteins that are the hallmarks of neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, prion diseases, and familial amyotrophic lateral sclerosis. In all cases, copper-mediated oxidative stress is linked to mitochondrial dysfunction, which is a common feature of neurodegeneration. In particular we recently demonstrated that in copper deficiency, mitochondrial function is impaired due to decreased activity of cytochrome c oxidase, leading to production of reactive oxygen species, which in turn triggers mitochondria-mediated apoptotic neurodegeneration.
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Affiliation(s)
- Luisa Rossi
- Department of Biology, "Tor Vergata" University of Rome, Via della Ricerca Scientifica, 00133 Rome, Italy
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39
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Costa NJ, Dahm CC, Hurrell F, Taylor ER, Murphy MP. Interactions of mitochondrial thiols with nitric oxide. Antioxid Redox Signal 2003; 5:291-305. [PMID: 12880484 DOI: 10.1089/152308603322110878] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The interaction of nitric oxide (NO) with mitochondria is of pathological significance and is also a potential mechanism for the regulation of mitochondrial function. Some of the ways in which NO may affect mitochondria are by reacting with low-molecular-weight thiols such as glutathione and with protein thiols. However, the detailed mechanisms and the consequences of these interactions for mitochondria are uncertain. Here we review mitochondrial thiol metabolism, outline how NO and its metabolites interact with thiols, and discuss the implications of these reactions for mitochondrial and cell function.
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Affiliation(s)
- Nikola J Costa
- Human Nutrition Unit, Wellcome Trust/MRC Building, Cambridge, UK
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40
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Tabuchi A, Funaji K, Nakatsubo J, Fukuchi M, Tsuchiya T, Tsuda M. Inactivation of aconitase during the apoptosis of mouse cerebellar granule neurons induced by a deprivation of membrane depolarization. J Neurosci Res 2003; 71:504-15. [PMID: 12548706 DOI: 10.1002/jnr.10505] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
During the excitotoxic neuronal cell death which accompanies an overflow of extracellular Ca(2+) into neurons, aconitase, an oxidative stress-sensitive enzyme of the tricarboxylic acid (TCA)-cycle in mitochondria, is inactivated due to the generation of oxidative stress (Patel et al. [1996] Neuron 16:345-355). In this study, we investigated whether aconitase could be inactivated during the apoptosis of mouse cerebellar granule cells (CGCs), which was caused by a deprivation of membrane depolarization followed by a stoppage of Ca(2+) influx into CGCs. Upon lowering the potassium (K(+)) concentration in medium from 25 to 5 mM (low K(+)), aconitase was inactivated in accordance with the decrease in methylthiazoletetrazolium (MTT)-reducing activity although its mRNA expression did not change. The blockade of Ca(2+) influx into CGCs mediated by nicardipine at 25 mM KCl also caused the inactivation of aconitase, accompanying induction of the apoptosis of CGCs. Suppression of the apoptosis of CGCs mediated by the Ca(2+) influx or neurotrophic factors such as brain-derived neurotrophic factor (BDNF) and adenylate cyclase activating polypeptide-38 (PACAP-38) attenuated the aconitase inactivation as well as the lactate dehydrogenase (LDH)-release and the decrease in MTT reduction. On the other hand, the levels of intracellular glutathione and manganese superoxide dismutase-2 mRNA decreased under the low K(+) condition, supporting a cause for oxidative stress at low K(+) due to a loss of anti-oxidant activity. Thus, the inactivation of aconitase is also caused by a deprivation of Ca(2+) influx into neurons, suggesting that aconitase is a key mitochondrial enzyme influencing the viability of neurons in response to oxidative stress.
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Affiliation(s)
- Akiko Tabuchi
- Toyama Medical and Pharmaceutical University, Department of Biological Chemistry, Faculty of Pharmaceutical Sciences, Toyama, Japan.
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41
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Abstract
During the course of normal metabolism, reactive oxygen species (ROS) are produced from within the respiratory chain of the mitochondria. These ROS have the capacity to oxidize and damage a variety of cellular constituents including lipids, DNA, and proteins. We have taken a genetic and pharmacological approach in delineating the range of molecular targets that can be oxidatively damaged by mitochondrial ROS. Specifically, we use mice that are lacking the mitochondrial form of superoxide dismutase (sod 2(-/-) mice) to better understand the possible phenotypes that can arise from mitochondrial oxidative stress. sod 2(-/-) mice can be used to test the efficacy of antioxidants, and more generally the efficacy of antioxidants against mitochondrial oxidative stress. We have evaluated superoxide dismutase/catalase mimetics in this mammalian model of mitochondrial oxidative stress, and have shown a high degree of efficacy in protecting against ROS produced within the mitochondria. Similarly, we have employed the nematode Caenorhabditis elegans to test the hypothesis that effective antioxidant therapy can prolong the life span of an invertebrate.
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Affiliation(s)
- Simon Melov
- Buck Institute for Age Research, Novato, California 94945, USA.
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42
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Rigobello MP, Donella-Deana A, Cesaro L, Bindoli A. Distribution of protein disulphide isomerase in rat liver mitochondria. Biochem J 2001; 356:567-70. [PMID: 11368786 PMCID: PMC1221870 DOI: 10.1042/0264-6021:3560567] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Here we report the localization of protein disulphide isomerase (PDI) in the mitochondrial compartments, comparing it with that of thioredoxin reductase. The latter enzyme is present mostly in the matrix, whereas PDI is located at the level of the outer membrane. We characterize the different submitochondrial fractions with specific marker enzymes. PDI, whether isolated from whole mitochondria or from purified outer membranes, exhibits the same electrophoretic mobility, indicating identical molecular masses. Moreover, immunoblot analysis with monoclonal anti-PDI antibody shows immunoreactivity only with the microsomal PDI, indicating the specificity of the mitochondrial isoform. The significance of these findings is discussed with reference to the potential role of PDI and thioredoxin reductase in regulating the mitochondrial functions dependent on the thiol-disulphide transition.
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Affiliation(s)
- M P Rigobello
- Dipartimento di Chimica Biologica, Università di Padova, Viale G. Colombo 3, 35121 Padova, Italy
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43
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Han D, Williams E, Cadenas E. Mitochondrial respiratory chain-dependent generation of superoxide anion and its release into the intermembrane space. Biochem J 2001; 353:411-6. [PMID: 11139407 PMCID: PMC1221585 DOI: 10.1042/0264-6021:3530411] [Citation(s) in RCA: 261] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
It has been generally accepted that superoxide anion generated by the mitochondrial respiratory transport chain are vectorially released into the mitochondrial matrix, where they are converted to hydrogen peroxide through the catalytic action of Mn-superoxide dismutase. Release of superoxide anion into the intermembrane space is a controversial topic, partly unresolved by the reaction of superoxide anion with cytochrome c, which faces the intermembrane space and is present in this compartment at a high concentration. This study was aimed at assessing the topological site(s) of release of superoxide anion during respiratory chain activity. To address this issue, mitoplasts were prepared from isolated mitochondria by digitonin treatment to remove portions of the outer membrane along with portions of cytochrome c. EPR analysis in conjunction with spin traps of antimycin-supplemented mitoplasts revealed the formation of a spin adduct of superoxide anion. The EPR signal was (i) abrogated by superoxide dismutase, (ii) decreased competitively by exogenous ferricytochrome c and (iii) broadened by the membrane-impermeable spin-broadening agent chromium trioxalate. These results confirm the production and release of superoxide anion towards the cytosolic side of the inner mitochondrial membrane. In addition, co-treatment of mitoplasts with myxothiazol and antimycin A, resulting in an inhibition of the oxidation of ubiquinol to ubisemiquinone, abolished the EPR signal, thus suggesting that ubisemiquinone autoxidation at the outer site of the complex-III ubiquinone pool is a pathway for superoxide anion formation and subsequent release into the intermembrane space. The generation of superoxide anion towards the intermembrane space requires consideration of the mitochondrial steady-state values for superoxide anion and hydrogen peroxide, the decay pathways of these oxidants in this compartment and the implications of these processes for cytosolic events.
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Affiliation(s)
- D Han
- Department of Molecular Pharmacology and Toxicology, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA 90089-9121, U.S.A
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44
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Abstract
During the last 10 years, the theory known as the "free radical theory of aging" has achieved prominence as one of the most compelling explanations for many of the degenerative changes associated with aging. Although its appeal derives from a long-standing body of supporting correlative data, the theory was only recently more rigorously tested. Ongoing researches in the study of free radical biochemistry and the genetics of aging have been at the forefront of this work. First, transgenic approaches in invertebrate models with candidate genes such as superoxide dismutase (SOD) involved in the detoxification of reactive oxygen species (ROS) have shown that the endogenous production of ROS due to normal physiologic processes is a major limiter of life span. Genes involved in ROS detoxification are highly conserved among eukaryotes; hence, the physiologic processes that limit life span in invertebrates are likely to be similar in higher eukaryotes. Secondly, transgenic mice deficient in the antioxidant enzyme mitochondrial superoxide dismutase (SOD2) die within their first week of life, demonstrating the importance of limiting endogenous mitochondrial free radicals in mammals. Together, data from studies using transgenic invertebrates and those using sod2 mutant mice demonstrate that modulation of metabolic ROS can have a profound effect on life span. We show here that the effects of mitochondrial ROS can be modulated through appropriate catalytic antioxidant intervention. These catalytic antioxidants are discussed in the context of mitochondrial oxidative stress and their potential role in intervening in mitochondrial oxidative stress and aging.
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Affiliation(s)
- S Melov
- Buck Center for Research in Aging, Novato, California 94948-0638, USA.
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45
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Abstract
Mitochondria play a central role in the survival and death of neurons. The detailed bioenergetic mechanisms by which isolated mitochondria generate ATP, sequester Ca(2+), generate reactive oxygen species, and undergo Ca(2+)-dependent permeabilization of their inner membrane are currently being applied to the function of mitochondria in situ within neurons under physiological and pathophysiological conditions. Here we review the functional bioenergetics of isolated mitochondria, with emphasis on the chemiosmotic proton circuit and the application (and occasional misapplication) of these principles to intact neurons. Mitochondria play an integral role in both necrotic and apoptotic neuronal cell death, and the bioenergetic principles underlying current studies are reviewed.
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Affiliation(s)
- D G Nicholls
- Department of Pharmacology, University of Dundee, Dundee, Scotland.
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46
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Abstract
Mitochondrial defects encompassing complexes I-IV of the electron transport chain characterize a relatively large number of neurodegenerative diseases. The relationships between mitochondrial lesions and recently described genetic alterations have not yet been defined. We describe a general mechanism whereby the enzymatic metabolism of neurotransmitters by monoamine oxidase (MAO) damages mitochondria, altering their protein thiol status and suppressing respiration. In these experiments, incubation of rat brain mitochondria with tyramine (a mixed MAO-A/MAO-B substrate) for 15 min at 27 degrees C suppressed state 3 respiration by 32.8% and state 5 respiration by 40.1%. These changes were accompanied by a 10-fold rise in protein-glutathione mixed disulfides. Direct comparison of effects on respiration and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] dye reduction during electron flow gave similar results. It is suggested that certain mitochondrial lesions may derive from the natural turnover of monoamine neurotransmitters in susceptible individuals.
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Affiliation(s)
- G Cohen
- Department of Neurology and Center for Neurobiology, Mount Sinai School of Medicine, New York, New York 10029, USA
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47
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Vogel R, Wiesinger H, Hamprecht B, Dringen R. The regeneration of reduced glutathione in rat forebrain mitochondria identifies metabolic pathways providing the NADPH required. Neurosci Lett 1999; 275:97-100. [PMID: 10568508 DOI: 10.1016/s0304-3940(99)00748-x] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Metabolic pathways underlying the regeneration of reduced glutathione were investigated in acutely isolated metabolically active mitochondria from rat forebrain. The application of hydrogen peroxide to the organelles was accompanied by a transient increase in glutathione disulfide. The recovery of reduced glutathione was significantly improved in the presence of alternatively succinate, malate, citrate, isocitrate, or beta-hydroxybutyrate. Inhibition of succinate dehydrogenase by malonate abolished the beneficial effect of succinate on the reduction of glutathione disulfide but did not influence the effect of isocitrate. Fluorocitrate, an inhibitor of aconitase, blocked the effect exerted by citrate but did not inhibit the effects of malate or beta-hydroxybutyrate. Uncoupling of the respiratory chain by carbonyl cyanide m-chlorophenylhydrazone prevented the beneficial effect of beta-hydroxybutyrate but did not abolish the improved reduction of mitochondrial glutathione disulfide in the presence of malate and isocitrate. These results suggest that NADP+-dependent isocitrate dehydrogenase as well as malic enzyme and nicotinamide nucleotide transhydrogenase contribute to the regeneration of NADPH required for the reduction of glutathione disulfide in brain mitochondria.
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Affiliation(s)
- R Vogel
- Physiologisch-chemisches Institut der Universität Tübingen, Germany
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48
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Cohen G, Farooqui R, Kesler N. Parkinson disease: a new link between monoamine oxidase and mitochondrial electron flow. Proc Natl Acad Sci U S A 1997; 94:4890-4. [PMID: 9144160 PMCID: PMC24601 DOI: 10.1073/pnas.94.10.4890] [Citation(s) in RCA: 222] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Two factors that contribute to the progression of Parkinson disease are a brain defect in mitochondrial respiration and the generation of hydrogen peroxide (H2O2) by monoamine oxidase (MAO). Here we show that the two are linked. Metabolism of the neurotransmitter dopamine, or other monoamines (benzylamine, tyramine), by intact rat brain mitochondria suppresses pyruvate- and succinate-dependent electron transport. MAO inhibitors prevent this action. Mitochondrial damage is also reversed during electron flow. A probable explanation is that MAO-generated H2O2 oxidizes glutathione to glutathione disulfide (GSSG), which undergoes thiol-disulfide interchange to form protein mixed disulfides, thereby interfering reversibly with thiol-dependent enzymatic function. In agreement with this premise, direct addition of GSSG to mitochondria resulted in similar reversible inhibition of electron transport. In addition, the monoamines induced an elevation in protein mixed disulfides within mitochondria. These observations imply that (i) heightened activity and metabolism of neurotransmitter by monoamine neurons may affect neuronal function, and (ii) apparent defects in mitochondrial respiration associated with Parkinson disease may reflect, in part, an established increase in dopamine turnover. The experimental results also target mitochondrial repair mechanisms for further investigation and may, in time, lead to newer forms of therapy.
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Affiliation(s)
- G Cohen
- Department of Neurology and Fishberg Center for Neurobiology, Mount Sinai School of Medicine, New York, NY 10029, USA
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Esworthy RS, Ho YS, Chu FF. The Gpx1 gene encodes mitochondrial glutathione peroxidase in the mouse liver. Arch Biochem Biophys 1997; 340:59-63. [PMID: 9126277 DOI: 10.1006/abbi.1997.9901] [Citation(s) in RCA: 125] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Mitochondria have GPX and PHGPX activity. It has been an unsettled issue whether mitochondrial GPX is encoded by Gpx1. Unlike the Gpx4 gene which encodes PHGPX with alternative transcription and translation start sites determining the subcellular localization of PHGPX, the Gpx1 gene appears to have a single translation start site. Additionally, mitochondrial GPX has been shown to have different chromatographic and kinetic properties from the cytosolic GPX1. We studied mouse liver mitochondrial GPX activity in homozygous Gpx1-knockout mice. Mitochondria were enriched at the density of 1.10 g/ml in the Percoll gradients as shown by electron microscopy. The H2O2-reducing GPX activity in the highly enriched mitochondrial fraction of wild-type mouse liver is 2700 mU/mg which is about one-half of specific activity found in cytosol. There is less than 0.5% GPX activity in the cytosol and no GPX activity in the mitochondria of Gpx1-knockout mouse liver compared to the cytosol of wild-type mouse liver using H2O2 or cumene hydroperoxide as the substrate. The fact that the knockout mice express normal levels of plasma GPX as well as testis and liver PHGPX activity indicates that animals are not selenium-deficient. Based on these observations, we concluded that mitochondrial GPX is the product of the Gpx1 gene.
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Affiliation(s)
- R S Esworthy
- Department of Medical Oncology and Therapeutics Research, City of Hope National Medical Center, Duarte, California 91010, USA
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Lai CT, Yu PH. Dopamine- and L-beta-3,4-dihydroxyphenylalanine hydrochloride (L-Dopa)-induced cytotoxicity towards catecholaminergic neuroblastoma SH-SY5Y cells. Effects of oxidative stress and antioxidative factors. Biochem Pharmacol 1997; 53:363-72. [PMID: 9065740 DOI: 10.1016/s0006-2952(96)00731-9] [Citation(s) in RCA: 155] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Enhanced oxidative stress has been suggested to be involved in the degeneration of nigrostriatal dopaminergic neurons in Parkinson's disease. The high turnover rate of dopamine and/or unsequestered dopamine may cause an increase of formation of hydrogen peroxide via either oxidative deamination of dopamine by monoamine oxidase or autoxidation. Hydrogen peroxide would be converted to more toxic hydroxyl free radicals. L-beta-3,4-Dihydroxyphenylalanine hydrochloride (L-DOPA), the most useful drug in the symptomatic treatment of Parkinson's disease, has been considered to possess deteriorating degenerative side-effects. The catecholaminergic neuroblastoma SH-SY5Y cells were chosen to investigate the cytotoxic effect of dopamine and L-DOPA. Both dopamine and L-DOPA were found to be cytotoxic towards SH-SY5Y cells. Such toxic effects were accompanied by an increase of oxidative stress in the cell cultures and could be reversed effectively by catalase and to a lesser extent by superoxide dismutase. The non-enzymatic antioxidants L-ascorbic acid, glutathione, N-acetyl-L-cysteine, but not (+)-alpha-tocopherol, also completely protected SH-SY5Y cells against the cytotoxic effects induced by dopamine and L-DOPA. Antioxidative factors, namely free radical scavengers (including N-tert-butyl-alpha-phenylnitrone, salicylic acid, and D-mannitol) and a strong iron chelator, deferoxamine, however, did not protect the SH-SY5Y cells against dopamine and L-DOPA. The generation of reactive oxygen species and the resulting enhanced oxidative stress was clearly involved in the dopamine- and L-DOPA-induced cytotoxic effects. Hydrogen peroxide played the most important role related to cytotoxicity of dopamine and L-DOPA.
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Affiliation(s)
- C T Lai
- Department of Psychiatry, University of Saskatchewan, Saskatoon, Canada
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