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Damasceno FC, Condeles AL, Lopes AKB, Facci RR, Linares E, Truzzi DR, Augusto O, Toledo JC. The labile iron pool attenuates peroxynitrite-dependent damage and can no longer be considered solely a pro-oxidative cellular iron source. J Biol Chem 2018; 293:8530-8542. [PMID: 29661935 DOI: 10.1074/jbc.ra117.000883] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 04/12/2018] [Indexed: 01/01/2023] Open
Abstract
The ubiquitous cellular labile iron pool (LIP) is often associated with the production of the highly reactive hydroxyl radical, which forms through a redox reaction with hydrogen peroxide. Peroxynitrite is a biologically relevant peroxide produced by the recombination of nitric oxide and superoxide. It is a strong oxidant that may be involved in multiple pathological conditions, but whether and how it interacts with the LIP are unclear. Here, using fluorescence spectroscopy, we investigated the interaction between the LIP and peroxynitrite by monitoring peroxynitrite-dependent accumulation of nitrosated and oxidized fluorescent intracellular indicators. We found that, in murine macrophages, removal of the LIP with membrane-permeable iron chelators sustainably accelerates the peroxynitrite-dependent oxidation and nitrosation of these indicators. These observations could not be reproduced in cell-free assays, indicating that the chelator-enhancing effect on peroxynitrite-dependent modifications of the indicators depended on cell constituents, presumably including LIP, that react with these chelators. Moreover, neither free nor ferrous-complexed chelators stimulated intracellular or extracellular oxidative and nitrosative chemistries. On the basis of these results, LIP appears to be a relevant and competitive cellular target of peroxynitrite or its derived oxidants, and thereby it reduces oxidative processes, an observation that may change the conventional notion that the LIP is simply a cellular source of pro-oxidant iron.
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Affiliation(s)
- Fernando Cruvinel Damasceno
- From the Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, CEP 14040-901 and
| | - André Luis Condeles
- From the Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, CEP 14040-901 and
| | - Angélica Kodama Bueno Lopes
- From the Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, CEP 14040-901 and
| | - Rômulo Rodrigues Facci
- From the Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, CEP 14040-901 and
| | - Edlaine Linares
- the Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, CEP 05508-000, Brazil
| | - Daniela Ramos Truzzi
- the Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, CEP 05508-000, Brazil
| | - Ohara Augusto
- the Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, CEP 05508-000, Brazil
| | - José Carlos Toledo
- From the Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, CEP 14040-901 and
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Forman HJ, Finch CE. A critical review of assays for hazardous components of air pollution. Free Radic Biol Med 2018; 117:202-217. [PMID: 29407794 PMCID: PMC5845809 DOI: 10.1016/j.freeradbiomed.2018.01.030] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 01/22/2018] [Accepted: 01/25/2018] [Indexed: 12/11/2022]
Abstract
Increased mortality and diverse morbidities are globally associated with exposure to ambient air pollution (AAP), cigarette smoke (CS), and household air pollution (HAP). The AAP-CS-HAP aerosols present heterogeneous particulate matter (PM) of diverse chemical and physical characteristics. Some epidemiological models have assumed the same health hazards by PM weight for AAP, CS, and HAP regardless of the composition. While others have recognized that biological activities and toxicity will vary with components, we focus particularly on oxidation because of its major role in assay outcomes. Our review of PM assays considers misinterpretations of some chemical measures used for oxidative activity. Overall, there is low consistency across chemical and cell-based assays for oxidative and inflammatory activity. We also note gaps in understanding how much airborne PM of various sizes enter cells and organs. For CS, the body burden per cigarette may be much below current assumptions. Synergies shown for health hazards of AAP and CS suggest crosstalk in detoxification pathways mediated by AHR, NF-κB, and Nrf2. These complex genomic and biochemical interactions frustrate resolution of the toxicity of specific AAP components. We propose further strategies based on targeted gene expression based on cell-type differences.
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Affiliation(s)
- Henry Jay Forman
- Leonard Davis School of Gerontology, The University of Southern California, Los Angeles, CA, United States; School of Natural Sciences, University of California, Merced, CA, United States.
| | - Caleb Ellicott Finch
- Leonard Davis School of Gerontology, The University of Southern California, Los Angeles, CA, United States; Dornsife College, The University of Southern California, Los Angeles, CA, United States
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Hofer T, Jørgensen TØ, Olsen RL. Comparison of food antioxidants and iron chelators in two cellular free radical assays: strong protection by luteolin. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:8402-8410. [PMID: 25070170 DOI: 10.1021/jf5022779] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Liver (HepG2) cells were incubated with 21 edible flavonoids, carotenoids, polyunsaturated fatty acid (PUFA) chromones, and metal chelators for 1 h, washed in PBS, and challenged in the cellular antioxidant activity (CAA) and the cellular lipid peroxidation antioxidant activity (CLPAA) assays. These microplate format assays assess the compounds' ability to protect against cytosolic peroxyl radicals (CAA) and induced membrane lipid peroxidation (CLPAA), respectively. Incubation encompassing a broad compound concentration range determined half-maximal inhibitory concentrations (IC(50)) by using sigmoidal curve fits. Overall, considering both assays, luteolin offered the greatest protection. The carotenoid astaxanthin offered only modest protection, whereas β-carotene was ineffective. Subtle structural differences between flavonoids were found to have amplified effects on protective abilities, and mechanisms of flavonoid antioxidant action are discussed. Membrane-permeable iron chelators (deferasirox and SIH) offered strong protective effects in CLPAA, but not in CAA, suggesting that CLPAA is dependent on membrane-associated free iron ions.
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Affiliation(s)
- Tim Hofer
- Department of Chemicals and Radiation, Division of Environmental Medicine, The Norwegian Institute of Public Health , N-0403 Oslo, Norway
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Borkowska A, Knap N, Antosiewicz J. Diallyl trisulfide is more cytotoxic to prostate cancer cells PC-3 than to noncancerous epithelial cell line PNT1A: a possible role of p66Shc signaling axis. Nutr Cancer 2014; 65:711-7. [PMID: 23859039 DOI: 10.1080/01635581.2013.789115] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Diallyl trisulfide (DATS) is an organosulfur compound isolated from garlic, and has been shown to have anticancer activity both in vitro and in vivo. The aim of this study was to compare cytotoxic effects of DATS on prostate cancer cells PC-3 and noncancerous human prostate epithelial cells PNT1A. PC-3 prostate cancer and noncancerous human prostate epithelial cells PNT1A were used in the study. We observed that PNT1A cells had higher resistance to DATS-induced cell death than PC-3 cells. Investigating signaling pathways involved in the cell death we observed that p66Shc phosphorylation at serine 36 and extracellular signal-regulated kinase 1/2 activation induced by DATS, were significantly attenuated in PNT1A cells as compared to PC-3 cells. Moreover, DATS-induced Akt inactivation was also significantly reduced in PNT1A cells. In addition to that, DATS-induced reactive oxygen species generation was nearly completely abolished in PNT1A cells. Interestingly, DATS induced only slight decrease in the level of ferritin H, whereas ferritin L was elevated. These data suggest that cytotoxicity of DATS toward PNT1A cells is strongly reduced as opposed to PC-3 cancer cells, which corresponds to the lower activation of prodeath signaling pathway mediated by the adaptor protein p66Shc in the noncancerous PNT1A cells.
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Affiliation(s)
- Andzelika Borkowska
- Department of Bioenergetics and Physiology of Exercise, Medical University of Gdansk, Gdansk, Poland
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