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Adomako-Bonsu AG, Jacobsen J, Maser E. Metabolic activation of 2,4,6-trinitrotoluene; a case for ROS-induced cell damage. Redox Biol 2024; 72:103082. [PMID: 38527399 PMCID: PMC10979124 DOI: 10.1016/j.redox.2024.103082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 03/27/2024] Open
Abstract
The explosive compound 2,4,6-trinitrotoluene (TNT) is well known as a major component of munitions. In addition to its potential carcinogenicity and mutagenicity in humans, recent reports have highlighted TNT toxicities in diverse organisms due to its occurrence in the environment. These toxic effects have been linked to the intracellular metabolism of TNT, which is generally characterised by redox cycling and the generation of noxious reactive molecules. The reactive intermediates formed, such as nitroso and hydroxylamine compounds, also interact with oxygen molecules and cellular components to cause macromolecular damage and oxidative stress. The current review aims to highlight the crucial role of TNT metabolism in mediating TNT toxicity, via increased generation of reactive oxygen species. Cellular proliferation of reactive species results in depletion of cellular antioxidant enzymes, DNA and protein adduct formation, and oxidative stress. While TNT toxicity is well known, its ability to induce oxidative stress, resulting from its reductive activation, suggests that some of its toxic effects may be caused by its reactive metabolites. Hence, further research on TNT metabolism is imperative to elucidate TNT-induced toxicities.
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Affiliation(s)
- Amma Gyapomah Adomako-Bonsu
- Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein Campus Kiel, Brunswiker Str. 10, 24105, Kiel, Germany
| | - Jana Jacobsen
- Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein Campus Kiel, Brunswiker Str. 10, 24105, Kiel, Germany
| | - Edmund Maser
- Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein Campus Kiel, Brunswiker Str. 10, 24105, Kiel, Germany.
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2
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Lesanavičius M, Boucher JL, Čėnas N. Reactions of Recombinant Neuronal Nitric Oxide Synthase with Redox Cycling Xenobiotics: A Mechanistic Study. Int J Mol Sci 2022; 23:ijms23020980. [PMID: 35055166 PMCID: PMC8781745 DOI: 10.3390/ijms23020980] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 01/10/2022] [Accepted: 01/14/2022] [Indexed: 12/16/2022] Open
Abstract
Neuronal nitric oxide synthase (nNOS) catalyzes single-electron reduction of quinones (Q), nitroaromatic compounds (ArNO2) and aromatic N-oxides (ArN → O), and is partly responsible for their oxidative stress-type cytotoxicity. In order to expand a limited knowledge on the enzymatic mechanisms of these processes, we aimed to disclose the specific features of nNOS in the reduction of such xenobiotics. In the absence or presence of calmodulin (CAM), the reactivity of Q and ArN → O increases with their single-electron reduction midpoint potential (E17). ArNO2 form a series with lower reactivity. The calculations according to an "outer-sphere" electron transfer model show that the binding of CAM decreases the electron transfer distance from FMNH2 to quinone by 1-2 Å. The effects of ionic strength point to the interaction of oxidants with a negatively charged protein domain close to FMN, and to an increase in accessibility of the active center induced by high ionic strength. The multiple turnover experiments of nNOS show that, in parallel with reduced FAD-FMN, duroquinone reoxidizes the reduced heme, in particular its Fe2+-NO form. This finding may help to design the heme-targeted bioreductively activated agents and contribute to the understanding of the role of P-450-type heme proteins in the bioreduction of quinones and other prooxidant xenobiotics.
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Affiliation(s)
- Mindaugas Lesanavičius
- Department of Xenobiotics Biochemistry, Institute of Biochemistry of Vilnius University, Saulėtekio 7, LT-10257 Vilnius, Lithuania;
| | - Jean-Luc Boucher
- Laboratoire de Chimie & Biochimie Pharmacologiques et Toxicologiques, CNRS UMR 8601, Université Paris Descartes, 45 rue de Saints Pères, CEDEX 06, 75270 Paris, France;
| | - Narimantas Čėnas
- Department of Xenobiotics Biochemistry, Institute of Biochemistry of Vilnius University, Saulėtekio 7, LT-10257 Vilnius, Lithuania;
- Correspondence: ; Tel.: +370-223-4392
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3
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Jacobsen J, Adomako-Bonsu AG, Maser E. Induction of carbonyl reductase 1 (CR1) gene expression in Daphnia magna by TNT, but not its key metabolites 2-ADNT and 4-ADNT. Chem Biol Interact 2022; 351:109752. [PMID: 34801537 DOI: 10.1016/j.cbi.2021.109752] [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: 08/05/2021] [Revised: 10/16/2021] [Accepted: 11/16/2021] [Indexed: 11/03/2022]
Abstract
2,4,6-trinitrotoluene (TNT) is a known source of reactive oxygen species (ROS), which cause oxidative stress in aquatic ecosystems. Carbonyl reductases (CRs) are one of several possible defense mechanisms induced against ROS products, especially those that result in the 'so-called' carbonyl stress. Daphnia magna, a freshwater organism living in stagnant freshwater bodies, expresses four copies of the CR gene (Dma_CR1, Dma_CR2, Dma_CR3 and Dma_CR4). In this study, induction of all four copies of Dma_CR by 2-amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT), was investigated. Reverse transcription polymerase chain reaction (RT-PCR) analysis of treated daphnids revealed up-regulation of Dma_CR1 alone in response to TNT, but not 2-ADNT and 4-ADNT (which are key metabolites of TNT). This concentration- and time-dependent up-regulation in mRNA-expression was observed both in the presence and absence of light, in the same magnitude. Moreover, significant change in mRNA-expression could be observed 8 h after treatment with TNT. In the presence of TNT, the antioxidant N-acetylcysteine (NAc) could not reverse TNT-induced up-regulation of Dma_CR1 mRNA-expression. On the other hand, withdrawal of TNT from the culture medium caused a significant reduction in the TNT-induced mRNA-expression of Dma_CR1 within 24 h. These findings highlight the potential of Dma_CR1 as a biomarker for biomonitoring of TNT levels in freshwater bodies.
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Affiliation(s)
- Jana Jacobsen
- Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein, Kiel, Germany
| | - Amma G Adomako-Bonsu
- Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein, Kiel, Germany
| | - Edmund Maser
- Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein, Kiel, Germany.
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Čėnas N, Nemeikaitė-Čėnienė A, Kosychova L. Single- and Two-Electron Reduction of Nitroaromatic Compounds by Flavoenzymes: Mechanisms and Implications for Cytotoxicity. Int J Mol Sci 2021; 22:ijms22168534. [PMID: 34445240 PMCID: PMC8395237 DOI: 10.3390/ijms22168534] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/30/2021] [Accepted: 08/04/2021] [Indexed: 12/14/2022] Open
Abstract
Nitroaromatic compounds (ArNO2) maintain their importance in relation to industrial processes, environmental pollution, and pharmaceutical application. The manifestation of toxicity/therapeutic action of nitroaromatics may involve their single- or two-electron reduction performed by various flavoenzymes and/or their physiological redox partners, metalloproteins. The pivotal and still incompletely resolved questions in this area are the identification and characterization of the specific enzymes that are involved in the bioreduction of ArNO2 and the establishment of their contribution to cytotoxic/therapeutic action of nitroaromatics. This review addresses the following topics: (i) the intrinsic redox properties of ArNO2, in particular, the energetics of their single- and two-electron reduction in aqueous medium; (ii) the mechanisms and structure-activity relationships of reduction in ArNO2 by flavoenzymes of different groups, dehydrogenases-electrontransferases (NADPH:cytochrome P-450 reductase, ferredoxin:NADP(H) oxidoreductase and their analogs), mammalian NAD(P)H:quinone oxidoreductase, bacterial nitroreductases, and disulfide reductases of different origin (glutathione, trypanothione, and thioredoxin reductases, lipoamide dehydrogenase), and (iii) the relationships between the enzymatic reactivity of compounds and their activity in mammalian cells, bacteria, and parasites.
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Affiliation(s)
- Narimantas Čėnas
- Institute of Biochemistry of Vilnius University, Saulėtekio 7, LT-10257 Vilnius, Lithuania;
- Correspondence: ; Tel.: +370-5-223-4392
| | - Aušra Nemeikaitė-Čėnienė
- State Research Institute Center for Innovative Medicine, Santariškių St. 5, LT-08406 Vilnius, Lithuania;
| | - Lidija Kosychova
- Institute of Biochemistry of Vilnius University, Saulėtekio 7, LT-10257 Vilnius, Lithuania;
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Yang H, Zhou M, Li H, Wei T, Tang C, Zhou Y, Long X. Effects of Low-level Lipid Peroxidation on the Permeability of Nitroaromatic Molecules across a Membrane: A Computational Study. ACS OMEGA 2020; 5:4798-4806. [PMID: 32201765 PMCID: PMC7081259 DOI: 10.1021/acsomega.9b03462] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 12/18/2019] [Indexed: 05/31/2023]
Abstract
Lipid peroxidation (LPO) in cellular membranes can cause severe membrane damage and potential cell death. Although oxidized phospholipids have been proved to lead to great changes in the structures and properties of membranes, effects of low-level LPO on membrane permeability have not yet been fully understood. Here, we explored the molecular mechanism of low-level LPO changing the permeability of nitroaromatic molecules across a lipid bilayer by all-atom molecular dynamics simulations. The results reveal that the enhanced passive transport of nitroaromatic molecules lies in the size of defects (i.e., water "finger" and "cone"), which is further dependent on the extent of LPO and the structural feature of solutes. In detail, if the solute can form more hydrogen bonds with water, which stabilizes the water into a large-size cone, there is a greater permeability coefficient (P). Otherwise, a small-size finger only results in a small increase of P. For example, the presence of 15% oxidized lipids could result in an increase of 2,4,6-trinitrotoluene (TNT's) P by more than 2 orders of magnitude (from 1.7 × 10-2 to 2.39 cm·s-1). The result suggests that the membrane permeability can be greatly promoted in the physiologically relevant environment with low-level LPO, and more importantly, clarifies the contributions of both the hydrophobicity of the membrane interior and the structural feature of solutes to such enhanced permeability. This work may provide significant insight into the toxic effects of nitroaromatic molecules and the pharmaceutical characteristics of tissues with oxidative damage.
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Affiliation(s)
- Hong Yang
- School
of Materials Science and Engineering, Tsinghua
University, Beijing 100084, China
- Institute
of Chemical Materials, China Academy of
Engineering and Physics, Mianyang 621900, China
| | - Mi Zhou
- Institute
of Chemical Materials, China Academy of
Engineering and Physics, Mianyang 621900, China
| | - Huarong Li
- Institute
of Chemical Materials, China Academy of
Engineering and Physics, Mianyang 621900, China
| | - Tong Wei
- Institute
of Chemical Materials, China Academy of
Engineering and Physics, Mianyang 621900, China
| | - Can Tang
- Institute
of Chemical Materials, China Academy of
Engineering and Physics, Mianyang 621900, China
| | - Yang Zhou
- Institute
of Chemical Materials, China Academy of
Engineering and Physics, Mianyang 621900, China
| | - Xinping Long
- Institute
of Chemical Materials, China Academy of
Engineering and Physics, Mianyang 621900, China
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Liao HY, Chien CC, Tang P, Chen CC, Chen CY, Chen SC. The integrated analysis of transcriptome and proteome for exploring the biodegradation mechanism of 2, 4, 6-trinitrotoluene by Citrobacter sp. JOURNAL OF HAZARDOUS MATERIALS 2018; 349:79-90. [PMID: 29414755 DOI: 10.1016/j.jhazmat.2018.01.039] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 01/16/2018] [Accepted: 01/21/2018] [Indexed: 06/08/2023]
Abstract
Citrobacter sp. has been shown to degrade 2,4,6-trinitrotoluene (TNT). However, the mechanism of its TNT biodegradation is poorly understood. An integrated proteome and transcriptome analysis was performed for investigating the differential genes and differential proteins in bacterial growth at the onset of experiments and after 12 h treatment with TNT. With the RNA sequencing, we found a total of 3792 transcripts and 569 differentially expressed genes (≥2 fold, P < 0.05) by. Genes for amino acid transport, cellular metabolism and stress-shock proteins were up-regulated, while carbohydrate transport and metabolism were down-regulated. A total of 42 protein spots (≥1.5 fold, P < 0.05) showed differential expression on two-dimensional gel electrophoresis and these proteins were identified by mass spectrometry. The most prominent proteins up-regulated were involved in energy production and conversion, amino acid transport and metabolism, posttranslational modification, protein turnover and chaperones. Proteins involved in carbohydrate transport and metabolism were down-regulated. Most notably, we observed that nemA encoding N-ethylmaleimide reductase was the most up-regulated gene involved in TNT degradation, and further proved that it can transform TNT to 4-amino-2,6-dinitrotoluene (4-ADNT) and 2-amino-4,6-dinitrotoluene (2-ADNT). This study highlights the molecular mechanisms of Citrobacter sp. for TNT removal.
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Affiliation(s)
- Hung-Yu Liao
- Department of Life Sciences, National Central University, No. 300, Jhing-da Rd., Jhongli City, Taoyuan, 32001, Taiwan
| | - Chih-Ching Chien
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, No. 135, Yuantung Rd., Jhongli City, Taoyuan, 32003, Taiwan
| | - Petrus Tang
- Department of Parasitology, Chang Gung University, No.259, Wenhua 1st Rd., Guishan Dis., Taoyuan City, 33302, Taiwan
| | - Chien-Cheng Chen
- Department of Biotechnology, National Kaohsiung Normal University, No.116, Heping 1st Rd., Lingya District, Kaohsiung City, 80201, Taiwan
| | - Chin-Yu Chen
- Department of Life Sciences, National Central University, No. 300, Jhing-da Rd., Jhongli City, Taoyuan, 32001, Taiwan
| | - Ssu-Ching Chen
- Department of Life Sciences, National Central University, No. 300, Jhing-da Rd., Jhongli City, Taoyuan, 32001, Taiwan.
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7
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Khilyas IV, Lochnit G, Ilinskaya ON. Proteomic Analysis of 2,4,6-Trinitrotoluene Degrading Yeast Yarrowia lipolytica. Front Microbiol 2017; 8:2600. [PMID: 29312267 PMCID: PMC5744042 DOI: 10.3389/fmicb.2017.02600] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 12/13/2017] [Indexed: 11/28/2022] Open
Abstract
2,4,6-trinitrotoluene (TNT) is a common component of many explosives. The overproduction and extensive usage of TNT significantly contaminates the environment. TNT accumulates in soils and aquatic ecosystems and can primarily be destroyed by microorganisms. Current work is devoted to investigation of Yarrowia lipolytica proteins responsible for TNT transformation through the pathway leading to protonated Meisenheimer complexes and nitrite release. Here, we identified a unique set of upregulated membrane and cytosolic proteins of Y. lipolytica, which biosynthesis increased during TNT transformation through TNT-monohydride-Meisenheimer complexes in the first step of TNT degradation, through TNT-dihydride-Meisenheimer complexes in the second step, and the aromatic ring denitration and degradation in the last step. We established that the production of oxidoreductases, namely, NADH flavin oxidoreductases and NAD(P)+-dependent aldehyde dehydrogenases, as well as transferases was enhanced at all stages of the TNT transformation by Y. lipolytica. The up-regulation of several stress response proteins (superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase) was also detected. The involvement of intracellular nitric oxide dioxygenase in NO formation during nitrite oxidation was shown. Our results present at the first time the full proteome analysis of Y. lipolytica yeast, destructor of TNT.
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Affiliation(s)
- Irina V Khilyas
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan, Russia
| | - Guenter Lochnit
- Protein Analytics, Institute of Biochemistry, Faculty of Medicine, Justus Liebig University Giessen, Giessen, Germany
| | - Olga N Ilinskaya
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan, Russia
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Naumenko EA, Ahlemeyer B, Baumgart-Vogt E. Species-specific differences in peroxisome proliferation, catalase, and SOD2 upregulation as well as toxicity in human, mouse, and rat hepatoma cells induced by the explosive and environmental pollutant 2,4,6-trinitrotoluene. ENVIRONMENTAL TOXICOLOGY 2017; 32:989-1006. [PMID: 27322098 DOI: 10.1002/tox.22299] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 05/11/2016] [Accepted: 05/21/2016] [Indexed: 06/06/2023]
Abstract
2,4,6-Trinitrotoluene (TNT) has been widely used as an explosive substance and its toxicity is still of interest as it persisted in polluted areas. TNT is metabolized in hepatocytes which are prone to its toxicity. Since analysis of the human liver or hepatocytes is restricted due to ethical reasons, we investigated the effects of TNT on cell viability, reactive oxygen species (ROS) production, peroxisome proliferation, and antioxidative enzymes in human (HepG2), mouse (Hepa 1-6), and rat (H4IIEC3) hepatoma cell lines. Under control conditions, hepatoma cells of all three species were highly comparable exhibiting identical proliferation rates and distribution of their cell cycle phases. However, we found strong differences in TNT toxicity with the lowest IC50 values (highest cell death rate) for rat cells, whereas human and mouse cells were three to sevenfold less sensitive. Moreover, a strong decrease in cellular dehydrogenase activity (MTT assay) and increased ROS levels were noted. TNT caused peroxisome proliferation with rat hepatoma cells being most responsive followed by those from mouse and human. Under control conditions, rat cells contained fivefold higher peroxisomal catalase and mitochondrial SOD2 activities and a twofold higher capacity to reduce MTT than human and mouse cells. TNT treatment caused an increase in catalase and SOD2 mRNA and protein levels in human and mouse, but not in rat cells. Similarly, human and mouse cells upregulated SOD2 activity, whereas rat cells failed therein. We conclude that TNT induced oxidative stress, peroxisome proliferation and mitochondrial damage which are highest in rat cells rendering them most susceptible toward TNT. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 989-1006, 2017.
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Affiliation(s)
- Ekaterina Anatolevna Naumenko
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kremlevskaya 18, Kazan, 420008, Russia
- Institute for Anatomy and Cell Biology, Division of Medical Cell Biology, Justus Liebig University Giessen, Aulweg 123, Giessen, 35385, Germany
| | - Barbara Ahlemeyer
- Institute for Anatomy and Cell Biology, Division of Medical Cell Biology, Justus Liebig University Giessen, Aulweg 123, Giessen, 35385, Germany
| | - Eveline Baumgart-Vogt
- Institute for Anatomy and Cell Biology, Division of Medical Cell Biology, Justus Liebig University Giessen, Aulweg 123, Giessen, 35385, Germany
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Prasath A, Panneerselvan L, Provatas A, Naidu R, Megharaj M. Genotoxicity assessment of acute exposure of 2, 4-dinitroanisole, its metabolites and 2, 4, 6-trinitrotoluene to Daphnia carinata. ECOTOXICOLOGY (LONDON, ENGLAND) 2016; 25:1873-1879. [PMID: 27650370 DOI: 10.1007/s10646-016-1709-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/11/2016] [Indexed: 06/06/2023]
Abstract
The insensitive munition ingredient, 2, 4-dinitroanisole has emerged as an alternative ingredient to 2, 4, 6-trinitro toluene in melt pourable high explosive formulations mainly due to its improved insensitiveness properties. As a result, production of 2, 4-dinitroanisole has increased and as a consequence 2, 4-dinitroanisole has emerged as a potential ingredient to enter the environment and possibly persist in water and soil ecosystems. The present study showed that 2, 4-dinitroanisole, its metabolites (2-amino 4-nitroanisole and 2,4-dinitroanisole) and 2, 4, 6-trinitro toluene were found to induce DNA damages in a freshwater crustacean Daphnia carinata exposed for 48 h and which was investigated by the alkaline single-cell gel electrophoresis (comet assay) method. The value of LC50-48 h of 2, 4-dinitroanisole was determined as 14.87 ± 1.70 (mg L-1) and its metabolites exhibited the similar toxic range although the toxicity of 2, 4, 6-trinitro toluene was seven-fold more toxic (2.32 ± 0.29 mg L-1) than 2, 4-dinitroanisole and its metabolites. Exposure to sub-acute toxicity concentration ranges of 2, 4-dinitroanisole and its metabolites and 2, 4, 6-trinitro toluene showed significant (P < 0.01) DNA damage. The higher concentration of each test chemical exhibited higher tail DNA per cent and increased olive tail moment. The results from this study can be used to identify genotoxic biomarkers for the risk assessment of insensitive munitions exposure in aquatic invertebrates.
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Affiliation(s)
- Annamalai Prasath
- Global Centre for Environmental Remediation, Faculty of Science and Information Technology, The University of Newcastle, ATC Building, University Drive, Callaghan, NSW 2308, Australia
- Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA5095, Australia
- Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, The University of Newcastle, ATC Building, Callaghan, NSW 2308, Australia
| | - Logeshwaran Panneerselvan
- Global Centre for Environmental Remediation, Faculty of Science and Information Technology, The University of Newcastle, ATC Building, University Drive, Callaghan, NSW 2308, Australia
- Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA5095, Australia
- Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, The University of Newcastle, ATC Building, Callaghan, NSW 2308, Australia
| | - Arthur Provatas
- Weapons and Combat Systems Division, Defence Science and Technology Organisation, Edinburgh, SA 5111, Australia
| | - Ravi Naidu
- Global Centre for Environmental Remediation, Faculty of Science and Information Technology, The University of Newcastle, ATC Building, University Drive, Callaghan, NSW 2308, Australia
- Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, The University of Newcastle, ATC Building, Callaghan, NSW 2308, Australia
| | - Mallavarapu Megharaj
- Global Centre for Environmental Remediation, Faculty of Science and Information Technology, The University of Newcastle, ATC Building, University Drive, Callaghan, NSW 2308, Australia.
- Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA5095, Australia.
- Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, The University of Newcastle, ATC Building, Callaghan, NSW 2308, Australia.
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10
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Johnston EJ, Rylott EL, Beynon E, Lorenz A, Chechik V, Bruce NC. Monodehydroascorbate reductase mediates TNT toxicity in plants. Science 2015; 349:1072-5. [DOI: 10.1126/science.aab3472] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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11
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Ziganshin AM, Ziganshina EE, Byrne J, Gerlach R, Struve E, Biktagirov T, Rodionov A, Kappler A. Fe(III) mineral reduction followed by partial dissolution and reactive oxygen species generation during 2,4,6-trinitrotoluene transformation by the aerobic yeast Yarrowia lipolytica. AMB Express 2015; 5:8. [PMID: 25852985 PMCID: PMC4314830 DOI: 10.1186/s13568-014-0094-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 12/29/2014] [Indexed: 11/23/2022] Open
Abstract
Understanding the factors that influence pollutant transformation in the presence of ferric (oxyhydr)oxides is crucial to the efficient application of different remediation strategies. In this study we determined the effect of goethite, hematite, magnetite and ferrihydrite on the transformation of 2,4,6-trinitrotoluene (TNT) by Yarrowia lipolytica AN-L15. The presence of ferric (oxyhydr)oxides led to a small decrease in the rate of TNT removal. In all cases, a significant release of NO2− from TNT and further NO2− oxidation to NO3− was observed. A fraction of the released NO2− was abiotically decomposed to NO and NO2, and then NO was likely oxidized abiotically to NO2 by O2. ESR analysis revealed the generation of superoxide in the culture medium; its further protonation at low pH resulted in the formation of hydroperoxyl radical. Presumably, a fraction of NO released during TNT degradation reacted with superoxide and formed peroxynitrite, which was further rearranged to NO3− at the acidic pH values observed in this study. A transformation and reduction of ferric (oxyhydr)oxides followed by partial dissolution (in the range of 7–86% of the initial Fe(III)) were observed in the presence of cells and TNT. Mössbauer spectroscopy showed some minor changes for goethite, magnetite and ferrihydrite samples during their incubation with Y. lipolytica and TNT. This study shows that i) reactive oxygen and nitrogen species generated during TNT transformation by Y. lipolytica participate in the abiotic conversion of TNT and ii) the presence of iron(III) minerals leads to a minor decrease in TNT transformation.
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Stanley JK, Perkins EJ, Habib T, Sims JG, Chappell P, Escalon BL, Wilbanks M, Garcia-Reyero N. The good, the bad, and the toxic: approaching hormesis in Daphnia magna exposed to an energetic compound. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:9424-33. [PMID: 23898970 PMCID: PMC4120942 DOI: 10.1021/es401115q] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A hormetic response is characterized by an opposite effect in small and large doses of chemical exposure, often resulting in seemingly beneficial effects at low doses. Here, we examined the potential mechanisms underlying the hormetic response of Daphnia magna to the energetic trinitrotoluene (TNT). Daphnia magna were exposed to TNT for 21 days, and a significant increase in adult length and number of neonates was identified at low concentrations (0.002-0.22 mg/L TNT), while toxic effects were identified at high concentrations (0.97 mg/L TNT and above). Microarray analysis of D. magna exposed to 0.004, 0.12, and 1.85 mg/L TNT identified effects on lipid metabolism as a potential mechanism underlying hormetic effects. Lipidomic analysis of exposed D. magna supported the hypothesis that TNT exposure affected lipid and fatty acid metabolism, showing that hormetic effects could be related to changes in polyunsaturated fatty acids known to be involved in Daphnia growth and reproduction. Our results show that Daphnia exposed to low levels of TNT presented hormetic growth and reproduction enhancement, while higher TNT concentrations had an opposite effect. Our results also show how a systems approach can help elucidate potential mechanisms of action and adverse outcomes.
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Affiliation(s)
- Jacob K. Stanley
- U.S. Army Engineer Research and Development Center, Environmental Laboratory 3909 Halls Ferry Road, Vicksburg, MS 39180
| | - Edward J. Perkins
- U.S. Army Engineer Research and Development Center, Environmental Laboratory 3909 Halls Ferry Road, Vicksburg, MS 39180
| | - Tanwir Habib
- Badger Technical Services, 12500 San Pedro Avenue, Suite 450, San Antonio, TX 78216
| | - Jerre G. Sims
- U.S. Army Engineer Research and Development Center, Environmental Laboratory 3909 Halls Ferry Road, Vicksburg, MS 39180
| | - Pornsawan Chappell
- Badger Technical Services, 12500 San Pedro Avenue, Suite 450, San Antonio, TX 78216
| | - B. Lynn Escalon
- U.S. Army Engineer Research and Development Center, Environmental Laboratory 3909 Halls Ferry Road, Vicksburg, MS 39180
| | - Mitchell Wilbanks
- U.S. Army Engineer Research and Development Center, Environmental Laboratory 3909 Halls Ferry Road, Vicksburg, MS 39180
| | - Natàlia Garcia-Reyero
- Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Starkville, MS
- Corresponding author: , phone: +1-601-634-3764; fax: 601-634-4017
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Peptide secondary structure modulates single-walled carbon nanotube fluorescence as a chaperone sensor for nitroaromatics. Proc Natl Acad Sci U S A 2011; 108:8544-9. [PMID: 21555544 DOI: 10.1073/pnas.1005512108] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A class of peptides from the bombolitin family, not previously identified for nitroaromatic recognition, allows near-infrared fluorescent single-walled carbon nanotubes to transduce specific changes in their conformation. In response to the binding of specific nitroaromatic species, such peptide-nanotube complexes form a virtual "chaperone sensor," which reports modulation of the peptide secondary structure via changes in single-walled carbon nanotubes, near-infrared photoluminescence. A split-channel microscope constructed to image quantized spectral wavelength shifts in real time, in response to nitroaromatic adsorption, results in the first single-nanotube imaging of solvatochromic events. The described indirect detection mechanism, as well as an additional exciton quenching-based optical nitroaromatic detection method, illustrate that functionalization of the carbon nanotube surface can result in completely unique sites for recognition, resolvable at the single-molecule level.
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Fuchs J, Piola L, González EP, Oneto ML, Basack S, Kesten E, Casabé N. Coelomocyte biomarkers in the earthworm Eisenia fetida exposed to 2,4,6-trinitrotoluene (TNT). ENVIRONMENTAL MONITORING AND ASSESSMENT 2011; 175:127-137. [PMID: 20512622 DOI: 10.1007/s10661-010-1499-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Accepted: 05/06/2010] [Indexed: 05/29/2023]
Abstract
Contamination by 2,4,6-trinitrotoluene (TNT) is a global environmental problem at sites of former explosive production, handling, or storage, and could have deleterious consequences for human and ecological health. We investigated its sublethal effects to Eisenia fetida, using two nonspecific biomarkers. In coelomocytes of earthworms exposed 24, 48, or 72 h, we evaluated DNA damage (comet assay) and neutral red retention time (NRRT), using the filter paper contact test. Both percentage of damage (D%) and calculated damage index showed significant DNA damage at almost all concentrations, at all time points assayed. Along exposure time, two different patterns were observed. At the lower TNT concentrations (0.25-0.5 μg/cm2) an increased DNA migration at 48 h, with a decrease close to initial levels after 72 h exposure, was observed. This decrease could be attributed to activation of the DNA repair system. At higher concentrations (1.0-2.0 μg/cm2), the high DNA damage observed remained constant during the 72 h exposure, suggesting that the rate of DNA repair was not enough to compensate such damage. Analysis of NRRT results showed a significant interaction between time and treatment. After 48 h, a significant decrease was observed at 4.0 μg/cm2. After 72 h, NRRT presented a concentration-dependent decrease, significantly different with respect to control at 0.5, 1.0, 2.0, and 4.0 μg/cm2. The two assayed methods, performed on the same sample, showed clear responses to sublethal TNT exposure in E. fetida, providing sensitive unspecific biomarkers of cell injury and DNA damage.
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Affiliation(s)
- Julio Fuchs
- Toxicology and Legal Chemistry, Department of Biological Chemistry, Faculty of Exact and Natural Sciences, University of Buenos Aires, Ciudad Universitaria, Pabellón 2, 4° piso, 1428, Buenos Aires, Argentina
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Involvement of NOX2 in the development of behavioral and pathologic alterations in isolated rats. Biol Psychiatry 2009; 66:384-92. [PMID: 19559404 DOI: 10.1016/j.biopsych.2009.04.033] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 04/06/2009] [Accepted: 04/16/2009] [Indexed: 01/30/2023]
Abstract
BACKGROUND Social stress leads to oxidative stress in the central nervous system, contributing to the development of mental disorders. Loss of parvalbumin in interneurons is an important feature of these diseases. We studied the role of the superoxide-producing nicotinamide adenosine dinucleotide phosphate (NADPH) oxidase 2 (NOX2) in rats exposed to social isolation. METHODS Male rats were kept for 7 weeks in group or in social isolation (n = 6-10 per group). Behavioral tests, immunohistochemistry, and analysis of NOX2 expression were performed at the end of social isolation. Apocynin was given in the drinking water (5 mg/kg/day). RESULTS NOX2 was below detection level in the brains of control animals, whereas it was highly expressed in isolated rats, particularly in nucleus accumbens and prefrontal cortex. Indirect markers of oxidative stress (oxidized nucleic acid 8-hydroxy-2'-deoxyguanosine, redox-sensitive transcription factor c-fos, and hypoxia-inducible factor-1alpha) were increased after social isolation in brain areas with high NOX2 expression. An increase in immunoreactive microglia suggested that oxidative stress could be in part due to NOX2 activation in microglia. In response to social isolation, rats showed increased locomotor activity, decreased discrimination, signs of oxidative stress in neurons, and loss of parvalbumin-immunoreactivity. Treatment of isolated rats with the antioxidant/NOX inhibitor apocynin prevented the behavioral and histopathological alterations induced by social isolation. CONCLUSIONS Our data suggest that NOX2-derived oxidative stress is involved in loss of parvalbumin immunoreactivity and development of behavioral alterations after social isolation. These results provide a molecular mechanism for the coupling between social stress and brain oxidative stress, as well as potential new therapeutic avenues.
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Naumenko EA, Naumov AV, Suvorova ES, Gerlach R, Ziganshin AM, Lozhkin AP, Silkin NI, Naumova RP. Participation of oxygen in the bacterial transformation of 2,4,6-trinitrotoluene. BIOCHEMISTRY (MOSCOW) 2008; 73:463-9. [PMID: 18457577 DOI: 10.1134/s0006297908040123] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The exposure of Bacillus cereus ZS18 cell suspensions to 2,4,6-trinitrotoluene (TNT) in the absence of other oxidizable substrates increases oxygen uptake, exceeding the basal level of respiration of the bacterium 1.5- and 2-fold with 50 and 100 mg/liter of TNT, respectively. The interaction of both living and to less extent dead bacterial cells with TNT results in the accumulation of superoxide anion (O2*-) in the extracellular medium, which was revealed by the EPR spectroscopy. The accumulation of O2*- decreased by 50-70% in the presence of Cu,Zn-superoxide dismutase of animal origin. In the presence of living bacterial cells, the level of TNT decreased progressively, yielding hydroxylaminodinitrotoluenes together with O2*-. In the presence of heat-killed cells, a moderate decrease in TNT was observed, and the appearance of O2*- was not accompanied by the production of any detectable TNT metabolites. Chelating agents inhibited the transformation of TNT and decreased the formation of O2*-. The demonstrated generation of O2*- during the interaction of TNT with K4[Fe(CN)6] together with the observed effects of chelating agents suggest the participation of iron in the one-electron reduction of TNT and the functioning of an extracellular redox cycle with the involvement of molecular oxygen.
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Gong P, Guan X, Inouye LS, Pirooznia M, Indest KJ, Athow RS, Deng Y, Perkins EJ. Toxicogenomic analysis provides new insights into molecular mechanisms of the sublethal toxicity of 2,4,6-trinitrotoluene in Eisenia fetida. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:8195-8202. [PMID: 18186358 DOI: 10.1021/es0716352] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Xenobiotics such as explosives and pesticides released into the environment can have lethal and sublethal impacts on soil organisms such as earthworms with potential subsequent impacts at highertrophic levels. To better understand the molecular toxicological mechanisms of 2,4,6-trinitrotoluene (TNT), a commonly used explosive, in Eisenia fetida, earthworms were exposed to a gradient of TNT-spiked soils for 28 days and impacts on gene expression were examined using a 4032 cDNA microarray. Reproduction was increased at low doses of TNT, whereas high doses of TNT reduced juvenile production. On the basis of reproduction responses to TNT, four treatments, that is, control, 2, 10.6, and 38.7 mg/kg, were selected for gene expression studies in a balanced interwoven loop design microarray experiment in which the expression of 311 transcripts was significantly affected. Reverse-transcription quantitative polymerase chain reaction (RT-QPCR) data on 68 selected differentially and nondifferentially expressed transcripts showed a significant correlation with microarray results. The expression of genes involved in multiple biological processes was altered, including muscle contraction, neuronal signaling and growth, ubiquitinylation, fibrinolysis and coagulation, iron and calcium homeostasis, oxygen transport, and immunity. Chitinase activity assays confirmed down-regulation of chitinase genes as indicated by array and RT-QPCR data. An acute toxicity test provided evidence that dermal contact with TNT can cause bleeding, inflammation, and constriction, which may be explained by gene expression results. Sublethal doses of TNT affected the nervous system, caused blood disorders similar to methemoglobinemia, and weakened immunity in E. fetida.
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Affiliation(s)
- Ping Gong
- SpecPro Inc., 3909 Halls Ferry Road, Vicksburg, Mississippi 39180, USA.
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Tognetti VB, Monti MR, Valle EM, Carrillo N, Smania AM. Detoxification of 2,4-dinitrotoluene by transgenic tobacco plants expressing a bacterial flavodoxin. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2007; 41:4071-6. [PMID: 17612192 DOI: 10.1021/es070015y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Significant effort has been directed in recent times to the use of plants to extract and detoxify nitroaromatics from polluted industrial facilities. We have explored the possibility of overcoming the phytotoxicity of the highly toxic and recalcitrant nitroderivative 2,4-dinitrotoluene (2,4-DNT) by expressing a cyanobacterial flavodoxin (Fld) in tobacco plants. We demonstrate here that transformants accumulating Fld in plastids display a remarkable increase in the ability to tolerate, take up, and transform 2,4-DNT, as compared to their wild-type siblings. We also show that Fld mediates one-electron reduction of 2,4-DNT in the presence of oxygen and especially in anaerobiosis. Moreover, Fld-loaded chloroplasts are able to convert 2,4-DNT into its aminoderivatives in the presence of light. The results suggest that expression of Fld in landscape plants could facilitate effective cleanup of sites contaminated with this class of pollutants.
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Affiliation(s)
- Vanesa B Tognetti
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, División Biología Molecular, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, S2002LRK Rosario, Argentina
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Escames G, López LC, Ortiz F, López A, García JA, Ros E, Acuña-Castroviejo D. Attenuation of cardiac mitochondrial dysfunction by melatonin in septic mice. FEBS J 2007; 274:2135-47. [PMID: 17371545 DOI: 10.1111/j.1742-4658.2007.05755.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The existence of an inducible mitochondrial nitric oxide synthase has been recently related to the nitrosative/oxidative damage and mitochondrial dysfunction that occurs during endotoxemia. Melatonin inhibits both inducible nitric oxide synthase and inducible mitochondrial nitric oxide synthase activities, a finding related to the antiseptic properties of the indoleamine. Hence, we examined the changes in inducible nitric oxide synthase/inducible mitochondrial nitric oxide synthase expression and activity, bioenergetics and oxidative stress in heart mitochondria following cecal ligation and puncture-induced sepsis in wild-type (iNOS(+/+)) and inducible nitric oxide synthase-deficient (iNOS(-/-)) mice. We also evaluated whether melatonin reduces the expression of inducible nitric oxide synthase/inducible mitochondrial nitric oxide synthase, and whether this inhibition improves mitochondrial function in this experimental paradigm. The results show that cecal ligation and puncture induced an increase of inducible mitochondrial nitric oxide synthase in iNOS(+/+) mice that was accompanied by oxidative stress, respiratory chain impairment, and reduced ATP production, although the ATPase activity remained unchanged. Real-time PCR analysis showed that induction of inducible nitric oxide synthase during sepsis was related to the increase of inducible mitochondrial nitric oxide synthase activity, as both inducible nitric oxide synthase and inducible mitochondrial nitric oxide synthase were absent in iNOS(-/-) mice. The induction of inducible mitochondrial nitric oxide synthase was associated with mitochondrial dysfunction, because heart mitochondria from iNOS(-/-) mice were unaffected during sepsis. Melatonin treatment blunted sepsis-induced inducible nitric oxide synthase/inducible mitochondrial nitric oxide synthase isoforms, prevented the impairment of mitochondrial homeostasis under sepsis, and restored ATP production. These properties of melatonin should be considered in clinical sepsis.
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Affiliation(s)
- Germaine Escames
- Instituto de Biotecnología, Departamento de Fisiología, Universidad de Granada, Spain
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Sun Y, Sumi D, Kumagai Y. Serine 1179 phosphorylation of endothelial nitric oxide synthase caused by 2,4,6-trinitrotoluene through PI3K/Akt signaling in endothelial cells. Toxicol Appl Pharmacol 2006; 214:55-60. [PMID: 16516256 DOI: 10.1016/j.taap.2006.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2005] [Revised: 12/20/2005] [Accepted: 01/05/2006] [Indexed: 11/23/2022]
Abstract
Although 2,4,6-trinitrotoluene (TNT) has been found to uncouple nitric oxide synthase (NOS), thereby leading to reactive oxygen species (ROS), cellular response against TNT still remains unclear. Exposure of bovine aortic endothelial cells (BAECs) to TNT (100 microM) resulted in serine 1179 phosphorylation of endothelial NOS (eNOS). With specific inhibitors (wortmannin and LY294002), we found that PI3K/Akt signaling participated in the eNOS phosphorylation caused by TNT, whereas the ERK pathway did not. ROS were generated following exposure of BAECs to TNT. However, TNT-mediated phosphorylation of either eNOS or Akt was drastically blocked by NAC and PEG-CAT. Interestingly, pretreatment with apocynin, a specific inhibitor for NADPH oxidase, diminished the phosphorylation of eNOS and Akt. These results suggest that TNT affects NADPH oxidase, thereby generating hydrogen peroxide, which is capable of activating PI3K/Akt signaling associated with eNOS Ser 1179 phosphorylation.
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Affiliation(s)
- Yang Sun
- Doctoral Programs in Medical Sciences, Graduate School of Comprehensive Sciences, University of Tsukuba, Japan
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Sun Y, Iemitsu M, Shimojo N, Miyauchi T, Amamiya M, Sumi D, Hayashi T, Sun G, Shimojo N, Kumagai Y. 2,4,6-Trinitrotoluene inhibits endothelial nitric oxide synthase activity and elevates blood pressure in rats. Arch Toxicol 2005; 79:705-10. [PMID: 16025313 DOI: 10.1007/s00204-005-0003-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2005] [Accepted: 06/01/2005] [Indexed: 10/25/2022]
Abstract
2,4,6-Trinitrotoluene (TNT), which is widely used in explosives, is an important occupational and environmental pollutant. Human exposure to TNT has been reported to be associated with cardiovascular dysfunction, but the mechanism is not well understood. In this study, we examine the endothelial nitric oxide synthase (eNOS) activity and blood pressure value following TNT exposure. With a crude enzyme preparation, we found that TNT inhibited the enzyme activity of eNOS in a concentration-dependent manner (IC50 value = 49.4 microM). With an intraperitoneal administration of TNT (10 and 30 mg/kg) to rats, systolic blood pressure was significantly elevated 1 h after TNT exposure (1.2- and 1.3-fold of that of the control, respectively). Under the conditions, however, experiments with the inducible NOS inhibitor aminoguanidine revealed that an adaptive response against hypertension caused by TNT occurs. These results suggest that TNT is an environmental chemical that acts as an uncoupler of constitutive NOS isozymes, resulting in decreased nitric oxide formation associated with hypertension in rats.
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Affiliation(s)
- Yang Sun
- Doctoral Programs in Medicine Sciences, Graduate School of Comprehensive Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
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