1
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Veal EA, Kritsiligkou P. How are hydrogen peroxide messages relayed to affect cell signalling? Curr Opin Chem Biol 2024; 81:102496. [PMID: 38959751 DOI: 10.1016/j.cbpa.2024.102496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 06/07/2024] [Accepted: 06/09/2024] [Indexed: 07/05/2024]
Abstract
H2O2 signals trigger adaptive responses affecting cell division, differentiation, migration, and survival. These signals are transduced by selective oxidation of cysteines on specific target proteins, with redox-sensitive cysteines now identified in many proteins, including both kinases and phosphatases. Assessing the contribution of these oxidation events to cell signalling presents several challenges including understanding how and when the selective oxidation of specific proteins takes place in vivo. In recent years, a combination of biochemical, structural, genetic, and computational approaches in fungi, plants, and animals have revealed different ways in which thiol peroxidases (peroxiredoxins) are bypassed or utilised in relaying these signals. Together, these mechanisms provide a conceptual framework for selectively oxidising proteins that will further advance understanding of how redox modifications contribute to health and disease.
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Affiliation(s)
- Elizabeth A Veal
- Newcastle University Biosciences Institute, Newcastle upon Tyne, NE2 4HH, UK.
| | - Paraskevi Kritsiligkou
- Division of Redox Regulation, German Cancer Research Center (DKFZ), DKFZ-ZMBH Alliance, 69120, Heidelberg, Germany; Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
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2
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Villar SF, Ferrer-Sueta G, Denicola A. The multifaceted nature of peroxiredoxins in chemical biology. Curr Opin Chem Biol 2023; 76:102355. [PMID: 37385138 DOI: 10.1016/j.cbpa.2023.102355] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 05/27/2023] [Accepted: 05/30/2023] [Indexed: 07/01/2023]
Abstract
Peroxiredoxins (Prx), thiol-dependent peroxidases, were first identified as H2O2 detoxifiers, and more recently as H2O2 sensors, intermediates in redox-signaling pathways, metabolism modulators, and chaperones. The multifaceted nature of Prx is not only dependent on their peroxidase activity but also strongly associated with specific protein-protein interactions that are being identified, and where the Prx oligomerization dynamics plays a role. Their oxidation by a peroxide substrate forms a sulfenic acid that opens a route to channel the redox signal to diverse protein targets. Recent research underscores the importance of different Prx isoforms in the cellular processes behind disease development with potential therapeutic applications.
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Affiliation(s)
- Sebastián F Villar
- Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Montevideo, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay
| | - Gerardo Ferrer-Sueta
- Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Montevideo, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay
| | - Ana Denicola
- Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Montevideo, Uruguay; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay.
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3
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Sadowska-Bartosz I, Bartosz G. Peroxiredoxin 2: An Important Element of the Antioxidant Defense of the Erythrocyte. Antioxidants (Basel) 2023; 12:antiox12051012. [PMID: 37237878 DOI: 10.3390/antiox12051012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/14/2023] [Accepted: 04/24/2023] [Indexed: 05/28/2023] Open
Abstract
Peroxiredoxin 2 (Prdx2) is the third most abundant erythrocyte protein. It was known previously as calpromotin since its binding to the membrane stimulates the calcium-dependent potassium channel. Prdx2 is present mostly in cytosol in the form of non-covalent dimers but may associate into doughnut-like decamers and other oligomers. Prdx2 reacts rapidly with hydrogen peroxide (k > 107 M-1 s-1). It is the main erythrocyte antioxidant that removes hydrogen peroxide formed endogenously by hemoglobin autoxidation. Prdx2 also reduces other peroxides including lipid, urate, amino acid, and protein hydroperoxides and peroxynitrite. Oxidized Prdx2 can be reduced at the expense of thioredoxin but also of other thiols, especially glutathione. Further reactions of Prdx2 with oxidants lead to hyperoxidation (formation of sulfinyl or sulfonyl derivatives of the peroxidative cysteine). The sulfinyl derivative can be reduced by sulfiredoxin. Circadian oscillations in the level of hyperoxidation of erythrocyte Prdx2 were reported. The protein can be subject to post-translational modifications; some of them, such as phosphorylation, nitration, and acetylation, increase its activity. Prdx2 can also act as a chaperone for hemoglobin and erythrocyte membrane proteins, especially during the maturation of erythrocyte precursors. The extent of Prdx2 oxidation is increased in various diseases and can be an index of oxidative stress.
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Affiliation(s)
- Izabela Sadowska-Bartosz
- Laboratory of Analytical Biochemistry, Institute of Food Technology and Nutrition, College of Natural Sciences, University of Rzeszow, 4 Zelwerowicza St., 35-601 Rzeszow, Poland
| | - Grzegorz Bartosz
- Department of Bioenergetics, Food Analysis and Microbiology, Institute of Food Technology and Nutrition, College of Natural Sciences, University of Rzeszów, 4 Zelwerowicza St., 35-601 Rzeszow, Poland
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4
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Fuentes-Lemus E, Davies MJ. Effect of crowding, compartmentalization and nanodomains on protein modification and redox signaling - current state and future challenges. Free Radic Biol Med 2023; 196:81-92. [PMID: 36657730 DOI: 10.1016/j.freeradbiomed.2023.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/21/2022] [Accepted: 01/10/2023] [Indexed: 01/19/2023]
Abstract
Biological milieus are highly crowded and heterogeneous systems where organization of macromolecules within nanodomains (e.g. membraneless compartments) is vital to the regulation of metabolic processes. There is an increasing interest in understanding the effects that such packed environments have on different biochemical and biological processes. In this context, the redox biochemistry and redox signaling fields are moving towards investigating oxidative processes under conditions that exhibit these key features of biological systems in order to solve existing paradigms including those related to the generation and transmission of specific redox signals within and between cells in both normal physiology and under conditions of oxidative stress. This review outlines the effects that crowding, nanodomain formation and altered local viscosities can have on biochemical processes involving proteins, and then discusses some of the reactions and pathways involving proteins and oxidants that may, or are known to, be modulated by these factors. We postulate that knowledge of protein modification processes (e.g. kinetics, pathways and product formation) under conditions that mimic biological milieus, will provide a better understanding of the response of cells to endogenous and exogenous stressors, and their role in ageing, signaling, health and disease.
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Affiliation(s)
- Eduardo Fuentes-Lemus
- Department of Biomedical Sciences, Panum Institute, Blegdamsvej 3, University of Copenhagen, Copenhagen, 2200, Denmark.
| | - Michael J Davies
- Department of Biomedical Sciences, Panum Institute, Blegdamsvej 3, University of Copenhagen, Copenhagen, 2200, Denmark
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5
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Taylor MF, Black MA, Hampton MB, Ledgerwood EC. Insights into H 2O 2-induced signaling in Jurkat cells from analysis of gene expression. Free Radic Res 2022; 56:666-676. [PMID: 36630571 DOI: 10.1080/10715762.2023.2165073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Hydrogen peroxide (H2O2) is a ubiquitous oxidant produced in a regulated manner by various enzymes in mammalian cells. H2O2 reversibly oxidizes thiol groups of cysteine residues to mediate intracellular signaling. While examples of H2O2-dependent signaling have been reported, the exact molecular mechanism(s) of signaling and the pathways affected are not well understood. Here, the transcriptomic response of Jurkat T cells to H2O2 was investigated to determine global effects on gene expression. With a low H2O2 concentration (10 µM) that did not induce an oxidative stress response or cell death, extensive changes in gene expression occurred after 4 h (6803 differentially expressed genes). Of the genes with a greater then 2-fold change in expression, 85% were upregulated suggesting that in a physiological setting H2O2 predominantly activates gene expression. Pathway analysis identified gene expression signatures associated with FOXO and NTRK signaling. These signatures were associated with an overlapping set of transcriptional regulators. Overall, our results provide a snapshot of gene expression changes in response to H2O2, which, along with further studies, will lead to new insights into the specific pathways that are activated in response to endogenous production of H2O2, and the molecular mechanisms of H2O2 signaling.
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Affiliation(s)
- Megan F Taylor
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Michael A Black
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Mark B Hampton
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago Christchurch, New Zealand
| | - Elizabeth C Ledgerwood
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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6
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Luo T, Pueyo JM, Wahni K, Yvanoff C, Lazar T, Pyr Dit Ruys S, Vertommen D, Ezeriņa D, Messens J. Thiol-disulphide independent in-cell trapping for the identification of peroxiredoxin 2 interactors. Redox Biol 2021; 46:102066. [PMID: 34340028 PMCID: PMC8346688 DOI: 10.1016/j.redox.2021.102066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/05/2021] [Accepted: 07/06/2021] [Indexed: 10/28/2022] Open
Abstract
Hydrogen peroxide (H2O2) acts as a signalling molecule by oxidising cysteine thiols in proteins. Recent evidence has established a role for cytosolic peroxiredoxins in transmitting H2O2-based oxidation to a multitude of target proteins. Moreover, it is becoming clear that peroxiredoxins fulfil their function in organised microdomains, where not all interactors are covalently bound. However, most studies aimed at identifying peroxiredoxin interactors were based on methods that only detect covalently linked partners. Here, we explore the applicability of two thiol-disulphide independent in-cell trapping methodological approaches in combination with mass spectrometry for the identification of interaction partners of peroxiredoxin 2 (Prdx2). The first is biotin-dependent proximity-labelling (BioID) with a biotin ligase A (BirA*)-fused Prdx2, which has never been applied on redox-active proteins. The second is crosslinker co-immunoprecipitation with an N-terminally His-tagged Prdx2. During the initial characterisation of the tagged Prdx2 constructs, we found that the His-tag, but not BirA*, compromises the peroxidase and signalling activities of Prdx2. Further, the Prdx2 interactors identified with each approach showed little overlap. We therefore concluded that BioID is a more reliable method than crosslinker co-immunoprecipitation. After a stringent mass spec data filtering, BioID identified 13 interactors under elevated H2O2 conditions, including subunit five of the COP9 signalosome complex (CSN5). The Prdx2:CSN5 interaction was further confirmed in a proximity ligation assay. Taken together, our results demonstrate that BioID can be used as a method for the identification of interactors of Prdxs, and that caution should be exercised when interpreting protein-protein interaction results using tagged Prdxs.
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Affiliation(s)
- Ting Luo
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, B-1050, Brussels, Belgium; Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050, Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, B-1050, Brussels, Belgium
| | - Julia Malo Pueyo
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, B-1050, Brussels, Belgium; Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050, Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, B-1050, Brussels, Belgium
| | - Khadija Wahni
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, B-1050, Brussels, Belgium; Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050, Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, B-1050, Brussels, Belgium
| | - Charlotte Yvanoff
- Structural Biology Brussels, Vrije Universiteit Brussel, B-1050, Brussels, Belgium; International Joint Research Group VUB-EPFL NanoBiotechnology & NanoMedicine (NANO), Vrije Universiteit Brussel, Brussels, Belgium and Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Tamas Lazar
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, B-1050, Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, B-1050, Brussels, Belgium
| | | | - Didier Vertommen
- de Duve Institute, Université Catholique de Louvain, 1200, Brussels, Belgium
| | - Daria Ezeriņa
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, B-1050, Brussels, Belgium; Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050, Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, B-1050, Brussels, Belgium.
| | - Joris Messens
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, B-1050, Brussels, Belgium; Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050, Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel, B-1050, Brussels, Belgium.
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7
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Vo TN, Malo Pueyo J, Wahni K, Ezeriņa D, Bolduc J, Messens J. Prdx1 Interacts with ASK1 upon Exposure to H 2O 2 and Independently of a Scaffolding Protein. Antioxidants (Basel) 2021; 10:antiox10071060. [PMID: 34209102 PMCID: PMC8300624 DOI: 10.3390/antiox10071060] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 06/18/2021] [Accepted: 06/25/2021] [Indexed: 01/02/2023] Open
Abstract
Hydrogen peroxide (H2O2) is a key redox signaling molecule that selectively oxidizes cysteines on proteins. It can accomplish this even in the presence of highly efficient and abundant H2O2 scavengers, peroxiredoxins (Prdxs), as it is the Prdxs themselves that transfer oxidative equivalents to specific protein thiols on target proteins via their redox-relay functionality. The first evidence of a mammalian cytosolic Prdx-mediated redox-relay—Prdx1 with the kinase ASK1—was presented a decade ago based on the outcome of a co-immunoprecipitation experiment. A second such redox-relay—Prdx2:STAT3—soon followed, for which further studies provided insights into its specificity, organization, and mechanism. The Prdx1:ASK1 redox-relay, however, has never undergone such a characterization. Here, we combine cellular and in vitro protein–protein interaction methods to investigate the Prdx1:ASK1 interaction more thoroughly. We show that, contrary to the Prdx2:STAT3 redox-relay, Prdx1 interacts with ASK1 at elevated H2O2 concentrations, and that this interaction can happen independently of a scaffolding protein. We also provide evidence of a Prdx2:ASK1 interaction, and demonstrate that it requires a facilitator that, however, is not annexin A2. Our results reveal that cytosolic Prdx redox-relays can be organized in different ways and yet again highlight the differentiated roles of Prdx1 and Prdx2.
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Affiliation(s)
- Trung Nghia Vo
- VIB-VUB Center for Structural Biology, Vlaams Instituut Voor Biotechnologie, B-1050 Brussels, Belgium; (T.N.V.); (J.M.P.); (K.W.); (D.E.); (J.B.)
- Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050 Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, B-1050 Brussels, Belgium
| | - Julia Malo Pueyo
- VIB-VUB Center for Structural Biology, Vlaams Instituut Voor Biotechnologie, B-1050 Brussels, Belgium; (T.N.V.); (J.M.P.); (K.W.); (D.E.); (J.B.)
- Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050 Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, B-1050 Brussels, Belgium
| | - Khadija Wahni
- VIB-VUB Center for Structural Biology, Vlaams Instituut Voor Biotechnologie, B-1050 Brussels, Belgium; (T.N.V.); (J.M.P.); (K.W.); (D.E.); (J.B.)
- Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050 Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, B-1050 Brussels, Belgium
| | - Daria Ezeriņa
- VIB-VUB Center for Structural Biology, Vlaams Instituut Voor Biotechnologie, B-1050 Brussels, Belgium; (T.N.V.); (J.M.P.); (K.W.); (D.E.); (J.B.)
- Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050 Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, B-1050 Brussels, Belgium
| | - Jesalyn Bolduc
- VIB-VUB Center for Structural Biology, Vlaams Instituut Voor Biotechnologie, B-1050 Brussels, Belgium; (T.N.V.); (J.M.P.); (K.W.); (D.E.); (J.B.)
- Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050 Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, B-1050 Brussels, Belgium
| | - Joris Messens
- VIB-VUB Center for Structural Biology, Vlaams Instituut Voor Biotechnologie, B-1050 Brussels, Belgium; (T.N.V.); (J.M.P.); (K.W.); (D.E.); (J.B.)
- Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050 Brussels, Belgium
- Structural Biology Brussels, Vrije Universiteit Brussel, B-1050 Brussels, Belgium
- Correspondence:
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8
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Seriani R, Paula CPD, Cunha AFD, Oliveira MAD, Krempel PG, Frias DP, Negri EM, Mauad T, Macchione M. Expression patterns of peroxiredoxin genes in bronchial epithelial cells exposed to diesel exhaust particles. Exp Mol Pathol 2021; 120:104641. [PMID: 33901418 DOI: 10.1016/j.yexmp.2021.104641] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 03/07/2021] [Accepted: 04/21/2021] [Indexed: 11/18/2022]
Abstract
Several mechanisms have been suggested to explain the adverse effects of air pollutants on airway cells. One such explanation is the presence of high concentrations of oxidants and pro-oxidants in environmental pollutants. All animal and plant cells have developed several mechanisms to prevent damage by oxidative molecules. Among these, the peroxiredoxins (PRDXs) are of interest due to a high reactivity with reactive oxygen species (ROS) through the functioning of the thioredoxin/thioredoxin reductase system. This study aimed to verify the gene expression patterns of the PRDX family in bronchial epithelial airway cells (BEAS-2B) cells exposed to diesel exhaust particles (DEPs) at a concentration of 15 μg/mL for 1 or 2 h because this it is a major component of particulate matter in the atmosphere. There was a significant decrease in mRNA fold changes of PRDX2 (0.43 ± 0.34; *p = 0.0220), PRDX5 (0.43 ± 0.34; *p = 0.0220), and PRDX6 (0.33 ± 0.25; *p = 0.0069) after 1 h of exposure to DEPs. The reduction in mRNA levels may consequently lead to a decrease in the levels of PRDX proteins, increasing oxidative stress in bronchial epithelial cells BEAS-2B and thus, negatively affecting cellular functions.
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Affiliation(s)
- Robson Seriani
- Laboratory of Experimental Air Pollution (LIM05), Department of Pathology, School of Medicine, University of São Paulo, FMUSP- Av. Dr. Arnaldo 455, 1°floor, room 1150, São Paulo, SP 01246-903, Brazil; PROSCED - Consulting, Training and Development, Rua Alto Belo, 742, room 01, São Paulo, SP 03478-040, Brazil.
| | - Carla Peres de Paula
- Genetic and Evolution Department, Federal University of São Carlos, UFSCar- Av. Washington Luiz Km 235, São Carlos, SP 13565-905, Brazil
| | - Anderson Ferreira da Cunha
- Genetic and Evolution Department, Federal University of São Carlos, UFSCar- Av. Washington Luiz Km 235, São Carlos, SP 13565-905, Brazil
| | - Marcos Antonio de Oliveira
- Biosciences Institute, Coastal Campus, São Paulo State University, Structural and Functional Molecular Biology, UNESP- Praça Infante Dom Henrique s/n°, São Vicente, SP 11330-900, Brazil
| | - Paloma Gava Krempel
- Laboratory for Investigations in Ophthalmology (LIM-33), University of São Paulo Medical School São Paulo, FMUSP - Dr. Arnaldo 455, 5° floorr, São Paulo, SP 01246-903, Brazil
| | - Daniela Perroni Frias
- Laboratory of Experimental Air Pollution (LIM05), Department of Pathology, School of Medicine, University of São Paulo, FMUSP- Av. Dr. Arnaldo 455, 1°floor, room 1150, São Paulo, SP 01246-903, Brazil
| | - Elnara Marcia Negri
- Laboratory of Experimental Air Pollution (LIM05), Department of Pathology, School of Medicine, University of São Paulo, FMUSP- Av. Dr. Arnaldo 455, 1°floor, room 1150, São Paulo, SP 01246-903, Brazil
| | - Thais Mauad
- Laboratory of Experimental Air Pollution (LIM05), Department of Pathology, School of Medicine, University of São Paulo, FMUSP- Av. Dr. Arnaldo 455, 1°floor, room 1150, São Paulo, SP 01246-903, Brazil
| | - Mariangela Macchione
- Laboratory of Experimental Air Pollution (LIM05), Department of Pathology, School of Medicine, University of São Paulo, FMUSP- Av. Dr. Arnaldo 455, 1°floor, room 1150, São Paulo, SP 01246-903, Brazil
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9
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Peskin AV, Winterbourn CC. The Enigma of 2-Cys Peroxiredoxins: What Are Their Roles? BIOCHEMISTRY (MOSCOW) 2021; 86:84-91. [PMID: 33705284 DOI: 10.1134/s0006297921010089] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
2-Cys peroxiredoxins are abundant thiol proteins that react efficiently with a wide range of peroxides. Unlike other enzymes, their exceptionally high reactivity does not rely on cofactors. The mechanism of oxidation and reduction of peroxiredoxins places them in a good position to act as antioxidants as well as key players in redox signaling. Understanding of the intimate details of peroxiredoxin functioning is important for translational research.
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Affiliation(s)
- Alexander V Peskin
- Centre for Free Radical Research, University of Otago Christchurch, Christchurch, Otago, 8140, New Zealand.
| | - Christine C Winterbourn
- Centre for Free Radical Research, University of Otago Christchurch, Christchurch, Otago, 8140, New Zealand
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10
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Stretton C, Pugh JN, McDonagh B, McArdle A, Close GL, Jackson MJ. 2-Cys peroxiredoxin oxidation in response to hydrogen peroxide and contractile activity in skeletal muscle: A novel insight into exercise-induced redox signalling? Free Radic Biol Med 2020; 160:199-207. [PMID: 32784030 PMCID: PMC7718083 DOI: 10.1016/j.freeradbiomed.2020.06.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/05/2020] [Accepted: 06/06/2020] [Indexed: 12/15/2022]
Abstract
Skeletal muscle generates superoxide during contractions which is rapidly converted to H2O2. This molecule has been proposed to activate signalling pathways and transcription factors that regulate key adaptive responses to exercise but the concentration of H2O2 required to oxidise and activate key signalling proteins in vitro is much higher than the intracellular concentration in muscle fibers following exercise. We hypothesised that Peroxiredoxins (Prx), which reacts with H2O2 at the low intracellular concentrations found in muscle, would be rapidly oxidised in contracting muscle and hence potentially transmit oxidising equivalents to downstream signalling proteins as a method for their oxidation and activation. The aim of this study was to characterise the effects of muscle contractile activity on the oxidation of Prx1, 2 and 3 and determine if these were affected by aging. Prx1, 2 and 3 were all rapidly and reversibly oxidised following treatment with low micromolar concentrations of H2O2 in C2C12 myotubes and also in isolated mature flexor digitalis brevis fibers from adult mice following a protocol of repeated isometric contractions. Significant oxidation of Prx2 was seen within 1 min (i.e. after 12 contractions), whereas significant oxidation was seen after 2 min for Prx1 and 3. In muscle fibers from old mice, Prx2 oxidation was significantly attenuated following contractile activity. Thus we show for the first time that Prx are rapidly and reversibly oxidised in response to contractile activity in skeletal muscle and hypothesise that these proteins act as effectors of muscle redox signalling pathways which are key to adaptations to exercise that are attenuated during aging.
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Affiliation(s)
- Clare Stretton
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool and MRC- Arthritis Research UK Centre for Integrated Research Into Musculoskeletal Ageing (CIMA), UK
| | - Jamie N Pugh
- School of Sport and Exercise Sciences, Tom Reilly Building, Byrom Street, Liverpool John Moores University, Liverpool, UK
| | - Brian McDonagh
- Discipline of Physiology, School of Medicine, National University of Ireland Galway, Ireland
| | - Anne McArdle
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool and MRC- Arthritis Research UK Centre for Integrated Research Into Musculoskeletal Ageing (CIMA), UK
| | - Graeme L Close
- School of Sport and Exercise Sciences, Tom Reilly Building, Byrom Street, Liverpool John Moores University, Liverpool, UK
| | - Malcolm J Jackson
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool and MRC- Arthritis Research UK Centre for Integrated Research Into Musculoskeletal Ageing (CIMA), UK.
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11
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Kim EJ, Kim YJ, Lee HI, Jeong SH, Nam HJ, Cho JH. Upregulation of Peroxiredoxin-2 in Well-Differentiated Pancreatic Neuroendocrine Tumors and Its Utility as a Biomarker for Predicting the Response to Everolimus. Antioxidants (Basel) 2020; 9:antiox9111104. [PMID: 33182509 PMCID: PMC7696978 DOI: 10.3390/antiox9111104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/04/2020] [Accepted: 11/06/2020] [Indexed: 01/12/2023] Open
Abstract
Pancreatic neuroendocrine neoplasms (pNENs) account for 2–3% of pancreatic malignancies. Peroxiredoxins (Prdxs), which are major cellular antioxidants, are involved in multiple oncogenic signaling pathways. We investigated the role of peroxiredoxin-2 in QGP-1 human pNEN cell line and patient-derived pNEN tissue. To validate the cancer stem cell-like cell characteristics of QGP-1 cells in spheroid culture, in vitro analyses and xenografting were performed. Furthermore, immunohistochemical staining was conducted to verify the overexpression of Prdx2 in pNEN tissue. Prdx2 expression was high at the mRNA and protein levels in QGP-1 cells. Prdx2 was also overexpressed in patient-derived pNEN tissue. Silencing of Prdx2 using siRNA induced overexpression and phosphorylation of ERK and AKT in QGP-1. Cell proliferation was increased by treating QGP-1 cells with siPrdx2, and the IC50 of everolimus increased suggesting resistance to everolimus. Interestingly, QGP-1 spheroid cells, which exhibited cancer stem cell-like features, exhibited lower expression of Prdx2 and mTOR. The results suggest that Prdx2 expression level and its activity may be a potential predictive biomarker for therapeutic response or resistance to everolimus in pNEN.
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Affiliation(s)
- Eui Joo Kim
- Division of Gastroenterology, Department of Internal Medicine, Gil Medical Center, College of Medicine Gachon University, Incheon 21565, Korea; (E.J.K.); (Y.J.K.); (H.J.N.)
| | - Yoon Jae Kim
- Division of Gastroenterology, Department of Internal Medicine, Gil Medical Center, College of Medicine Gachon University, Incheon 21565, Korea; (E.J.K.); (Y.J.K.); (H.J.N.)
| | - Hye In Lee
- Division of Gastroenterology, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea;
| | - Seok-Hoo Jeong
- Division of Gastroenterology, Department of Internal Medicine, Catholic Kwandong University International St. Mary’s Hospital, Incheon 22711, Korea;
| | - Hyo Jung Nam
- Division of Gastroenterology, Department of Internal Medicine, Gil Medical Center, College of Medicine Gachon University, Incheon 21565, Korea; (E.J.K.); (Y.J.K.); (H.J.N.)
| | - Jae Hee Cho
- Division of Gastroenterology, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea;
- Correspondence: ; Tel.: +82-2-2019-3310
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12
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Talwar D, Messens J, Dick TP. A role for annexin A2 in scaffolding the peroxiredoxin 2-STAT3 redox relay complex. Nat Commun 2020; 11:4512. [PMID: 32908147 PMCID: PMC7481202 DOI: 10.1038/s41467-020-18324-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 08/12/2020] [Indexed: 11/19/2022] Open
Abstract
Hydrogen peroxide (H2O2) is recognized to act as a signaling molecule. Peroxiredoxins (Prxs) have the ability to transfer H2O2-derived oxidizing equivalents to redox-regulated target proteins, thus facilitating the transmission of H2O2 signals. It has remained unclear how Prxs and their target proteins are brought together to allow for target-specific protein thiol oxidation. Addressing the specific case of Prx2-dependent STAT3 oxidation, we here show that the association of the two proteins occurs prior to Prx oxidation and depends on a scaffolding protein, the membrane chaperone annexin A2. Deletion or depletion of annexin A2 interrupts the transfer of oxidizing equivalents from Prx2 to STAT3, which is observed to take place on membranes. These findings support the notion that the Prx2-STAT3 redox relay is part of a highly organized membrane signaling domain. Peroxiredoxin 2 (Prx2) was previously shown to transfer H2O2-derived oxidative equivalents to STAT3, generating disulfide-linked dimers and tetramers. Here the authors show that the interaction between Prx2 and STAT3 at the plasma membrane is mediated by the membrane chaperone annexin A2; suggesting that the redox relay complex is part of a membrane signaling domain.
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Affiliation(s)
- Deepti Talwar
- Division of Redox Regulation, DKFZ-ZMBH Alliance, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, 69120, Heidelberg, Germany
| | - Joris Messens
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie, B-1050 Brussels, Belgium.,Brussels Center for Redox Biology, Vrije Universiteit Brussel, B-1050, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, B-1050, Brussels, Belgium
| | - Tobias P Dick
- Division of Redox Regulation, DKFZ-ZMBH Alliance, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.
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Vallés PG, Bocanegra V, Costantino VV, Gil Lorenzo AF, Benardon ME, Cacciamani V. The renal antioxidative effect of losartan involves heat shock protein 70 in proximal tubule cells. Cell Stress Chaperones 2020; 25:753-766. [PMID: 32447546 PMCID: PMC7479660 DOI: 10.1007/s12192-020-01119-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 04/30/2020] [Accepted: 05/06/2020] [Indexed: 02/07/2023] Open
Abstract
Angiotensin II exerts a cardinal role in the pathogenesis of hypertension and renal injury via action of angiotensin II type 1 (AT1) receptors. Local renin-angiotensin system (RAS) activity is essential for the mechanisms mediating pathophysiological functions. Proximal tubular angiotensinogen and tubular AT1 receptors are augmented by intrarenal angiotensin II. Caveolin 1 plays an important role as a regulatory molecule for the compartmentalization of redox signaling events through angiotensin II-induced NADPH oxidase activation in the kidney. A role for the renin-angiotensin system in the development and/or maintenance of hypertension has been demonstrated in spontaneously hypertensive rats (SHRs). Many effects of angiotensin II are dependent on the AT1 stimulation of reactive oxygen species (ROS) production by NADPH oxidase. Angiotensin II upregulation stimulates oxidative stress in proximal tubules from SHR. The NADPH oxidase 4 (Nox4) is abundantly expressed in kidney proximal tubule cells. Induction of the stress response includes synthesis of heat shock protein 70, a molecular chaperone that has a critical role in the recovery of cells from stress and in cytoprotection, guarding cells from subsequent insults. HSP70 chaperones function in part by driving the molecular triage decision, which determines whether proteins enter the productive folding pathway or result in client substrate ubiquitination and proteasomal degradation. This review examines regulation of losartan-mediated antioxidative stress responses by the chaperone HSP70 in proximal tubule cells of spontaneously hypertensive rats.
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Affiliation(s)
- Patricia G Vallés
- Área de Fisiopatología, Departamento de Patología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina.
- IMBECU CONICET (National Council of Scientific and Technical Research of Argentina), Mendoza, Argentina.
| | - Victoria Bocanegra
- IMBECU CONICET (National Council of Scientific and Technical Research of Argentina), Mendoza, Argentina
| | - Valeria V Costantino
- IMBECU CONICET (National Council of Scientific and Technical Research of Argentina), Mendoza, Argentina
| | - Andrea F Gil Lorenzo
- Área de Fisiopatología, Departamento de Patología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - María Eugenia Benardon
- Área de Fisiopatología, Departamento de Patología, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Valeria Cacciamani
- IMBECU CONICET (National Council of Scientific and Technical Research of Argentina), Mendoza, Argentina
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14
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Redox signalling and regulation of the blood-brain barrier. Int J Biochem Cell Biol 2020; 125:105794. [PMID: 32562769 DOI: 10.1016/j.biocel.2020.105794] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 06/08/2020] [Accepted: 06/15/2020] [Indexed: 02/07/2023]
Abstract
Neurological disorders are associated with increased oxidative stress. Reactive oxidants damage tissue and promote cell death, but it is apparent that oxidants can have more subtle effects on cell function through the modulation of redox-sensitive signalling pathways. Cells of the blood-brain barrier regulate the brain microenvironment but become dysfunctional during neurological disease. The blood-brain barrier is maintained by many cell types, and is modulated by redox-sensitive pathways, ranging from the cytoskeletal elements responsible for establishing a barrier, to growth factor and cytokine signalling pathways that influence neurovascular cells. During neurological disease, blood-brain barrier cells are exposed to exogenously generated oxidants from immune cells, as well as increasing endogenously oxidant production. These oxidants impair the function of the blood-brain barrier, leading to increased leakage and reduced blood flow. Reducing the impact of oxidants on the function of blood-brain barrier cells may provide new strategies for delaying the progression of neurological disease.
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15
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Moutal A, White KA, Chefdeville A, Laufmann RN, Vitiello PF, Feinstein D, Weimer JM, Khanna R. Dysregulation of CRMP2 Post-Translational Modifications Drive Its Pathological Functions. Mol Neurobiol 2019; 56:6736-6755. [PMID: 30915713 PMCID: PMC6728212 DOI: 10.1007/s12035-019-1568-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/15/2019] [Indexed: 12/13/2022]
Abstract
Collapsin response mediator proteins (CRMPs) are a family of ubiquitously expressed, homologous phosphoproteins best known for coordinating cytoskeletal formation and regulating cellular division, migration, polarity, and synaptic connection. CRMP2, the most studied of the five family members, is best known for its affinity for tubulin heterodimers and function in regulating the microtubule network. These functions are tightly regulated by post-translational modifications including phosphorylation, SUMOylation, oxidation, and O-GlcNAcylation. While CRMP2's physiological functions rely mostly on its non-phosphorylated state, dysregulation of CRMP2 phosphorylation and SUMOylation has been reported to be involved in the pathophysiology of multiple diseases including cancer, chronic pain, spinal cord injury, neurofibromatosis type 1, and others. Here, we provide a consolidated update on what is known about CRMP2 signaling and function, first focusing on axonal growth and neuronal polarity, then illustrating the link between dysregulated CRMP2 post-translational modifications and diseases. We additionally discuss the roles of CRMP2 in non-neuronal cells, both in the CNS and regions of the periphery. Finally, we offer thoughts on the therapeutic implications of modulating CRMP2 function in a variety of diseases.
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Affiliation(s)
- Aubin Moutal
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Drive, P.O. Box 245050, Tucson, AZ, 85724, USA
| | - Katherine A White
- Pediatrics and Rare Diseases Group, Sanford Research, 2301 E 60th St N, Sioux Falls, SD, 57104, USA
| | - Aude Chefdeville
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Drive, P.O. Box 245050, Tucson, AZ, 85724, USA
| | - Rachel N Laufmann
- Pediatrics and Rare Diseases Group, Sanford Research, 2301 E 60th St N, Sioux Falls, SD, 57104, USA
| | - Peter F Vitiello
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Drive, P.O. Box 245050, Tucson, AZ, 85724, USA
- Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD, USA
| | - Douglas Feinstein
- Department of Veterans Affairs, Jesse Brown VA Medical Center, University of Illinois at Chicago, Chicago, IL, USA
| | - Jill M Weimer
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Drive, P.O. Box 245050, Tucson, AZ, 85724, USA.
- Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD, USA.
| | - Rajesh Khanna
- Department of Pharmacology, College of Medicine, University of Arizona, 1501 North Campbell Drive, P.O. Box 245050, Tucson, AZ, 85724, USA.
- Pediatrics and Rare Diseases Group, Sanford Research, 2301 E 60th St N, Sioux Falls, SD, 57104, USA.
- Department of Anesthesiology, University of Arizona, Tucson, AZ, USA.
- The Center for Innovation in Brain Sciences, The University of Arizona Health Sciences, Tucson, AZ, USA.
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16
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Randall LM, Dalla Rizza J, Parsonage D, Santos J, Mehl RA, Lowther WT, Poole LB, Denicola A. Unraveling the effects of peroxiredoxin 2 nitration; role of C-terminal tyrosine 193. Free Radic Biol Med 2019; 141:492-501. [PMID: 31323313 PMCID: PMC6749834 DOI: 10.1016/j.freeradbiomed.2019.07.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/12/2019] [Accepted: 07/15/2019] [Indexed: 12/19/2022]
Abstract
Peroxiredoxins (Prx) are enzymes that efficiently reduce hydroperoxides through active participation of cysteine residues (CP, CR). The first step in catalysis, the reduction of peroxide substrate, is fast, 107 - 108 M-1s-1 for human Prx2. In addition, the high intracellular concentration of Prx positions them not only as good antioxidants but also as central players in redox signaling pathways. These biological functions can be affected by post-translational modifications that could alter the peroxidase activity and/or interaction with other proteins. In particular, inactivation by hyperoxidation of CP, which occurs when a second molecule of peroxide reacts with the CP in the sulfenic acid form, modulates their participation in redox signaling pathways. The higher sensitivity to hyperoxidation of some Prx has been related to the presence of structural motifs that disfavor disulfide formation at the active site, making the CP sulfenic acid more available for hyperoxidation or interaction with a redox protein target. We previously reported that treatment of human Prx2 with peroxynitrite results in tyrosine nitration, a post-translational modification on non-catalytic residues, yielding a more active peroxidase with higher resistance to hyperoxidation. In this work, studies on various mutants of hPrx2 confirm that the presence of the tyrosyl side-chain of Y193, belonging to the C-terminal YF motif of eukaryotic Prx, is necessary to observe the increase in Prx2 resistance to hyperoxidation. Moreover, our results underline the critical role of this structural motif on the rate of disulfide formation that determines the differential participation of Prx in redox signaling pathways.
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Affiliation(s)
- Lía M Randall
- Laboratorio I+D de Moléculas Bioactivas, CENUR Litoral Norte, Universidad de la República, Paysandú, Uruguay; Laboratorio de Fisicoquímica Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Centro de Investigaciones Biomédicas, Universidad de la República, Uruguay
| | - Joaquín Dalla Rizza
- Laboratorio de Fisicoquímica Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Centro de Investigaciones Biomédicas, Universidad de la República, Uruguay
| | - Derek Parsonage
- Department of Biochemistry and Center for Redox Biology and Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Javier Santos
- Departamento de Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina; Instituto de Química y Fisicoquímica Biológicas (UBA-CONICET), Buenos Aires, Argentina
| | - Ryan A Mehl
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR, USA
| | - W Todd Lowther
- Department of Biochemistry and Center for Redox Biology and Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Leslie B Poole
- Department of Biochemistry and Center for Redox Biology and Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA.
| | - Ana Denicola
- Laboratorio de Fisicoquímica Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay; Centro de Investigaciones Biomédicas, Universidad de la República, Uruguay.
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17
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Potential of Mitochondria-Targeted Antioxidants to Prevent Oxidative Stress in Pancreatic β-cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:1826303. [PMID: 31249641 PMCID: PMC6556329 DOI: 10.1155/2019/1826303] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/02/2019] [Accepted: 04/10/2019] [Indexed: 12/12/2022]
Abstract
Pancreatic β-cells are vulnerable to oxidative stress due to their low content of redox buffers, such as glutathione, but possess a rich content of thioredoxin, peroxiredoxin, and other proteins capable of redox relay, transferring redox signaling. Consequently, it may be predicted that cytosolic antioxidants could interfere with the cytosolic redox signaling and should not be recommended for any potential therapy. In contrast, mitochondrial matrix-targeted antioxidants could prevent the primary oxidative stress arising from the primary superoxide sources within the mitochondrial matrix, such as at the flavin (IF) and ubiquinone (IQ) sites of superoxide formation within respiratory chain complex I and the outer ubiquinone site (IIIQ) of complex III. Therefore, using time-resolved confocal fluorescence monitoring with MitoSOX Red, we investigated various effects of mitochondria-targeted antioxidants in model pancreatic β-cells (insulinoma INS-1E cells) and pancreatic islets. Both SkQ1 (a mitochondria-targeted plastoquinone) and a suppressor of complex III site Q electron leak (S3QEL) prevented superoxide production released to the mitochondrial matrix in INS-1E cells with stimulatory glucose, where SkQ1 also exhibited an antioxidant role for UCP2-silenced cells. SkQ1 acted similarly at nonstimulatory glucose but not in UCP2-silenced cells. Thus, UCP2 can facilitate the antioxidant mechanism based on SkQ1+ fatty acid anion− pairing. The elevated superoxide formation induced by antimycin A was largely prevented by S3QEL, and that induced by rotenone was decreased by SkQ1 and S3QEL and slightly by S1QEL, acting at complex I site Q. Similar results were obtained with the MitoB probe, for the LC-MS-based assessment of the 4 hr accumulation of reactive oxygen species within the mitochondrial matrix but for isolated pancreatic islets. For 2 hr INS-1E incubations, some samples were influenced by the cell death during the experiment. Due to the frequent dependency of antioxidant effects on metabolic modes, we suggest a potential use of mitochondria-targeted antioxidants for the treatment of prediabetic states after cautious nutrition-controlled tests. Their targeted delivery might eventually attenuate the vicious spiral leading to type 2 diabetes.
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