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Caro-Astorga J, Meyerowitz JT, Stork DA, Nattermann U, Piszkiewicz S, Vimercati L, Schwendner P, Hocher A, Cockell C, DeBenedictis E. Polyextremophile engineering: a review of organisms that push the limits of life. Front Microbiol 2024; 15:1341701. [PMID: 38903795 PMCID: PMC11188471 DOI: 10.3389/fmicb.2024.1341701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 05/16/2024] [Indexed: 06/22/2024] Open
Abstract
Nature exhibits an enormous diversity of organisms that thrive in extreme environments. From snow algae that reproduce at sub-zero temperatures to radiotrophic fungi that thrive in nuclear radiation at Chernobyl, extreme organisms raise many questions about the limits of life. Is there any environment where life could not "find a way"? Although many individual extremophilic organisms have been identified and studied, there remain outstanding questions about the limits of life and the extent to which extreme properties can be enhanced, combined or transferred to new organisms. In this review, we compile the current knowledge on the bioengineering of extremophile microbes. We summarize what is known about the basic mechanisms of extreme adaptations, compile synthetic biology's efforts to engineer extremophile organisms beyond what is found in nature, and highlight which adaptations can be combined. The basic science of extremophiles can be applied to engineered organisms tailored to specific biomanufacturing needs, such as growth in high temperatures or in the presence of unusual solvents.
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Affiliation(s)
| | | | - Devon A. Stork
- Pioneer Research Laboratories, San Francisco, CA, United States
| | - Una Nattermann
- Pioneer Research Laboratories, San Francisco, CA, United States
| | | | - Lara Vimercati
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, United States
| | | | - Antoine Hocher
- London Institute of Medical Sciences, London, United Kingdom
| | - Charles Cockell
- UK Centre for Astrobiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Erika DeBenedictis
- The Francis Crick Institute, London, United Kingdom
- Pioneer Research Laboratories, San Francisco, CA, United States
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2
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Aryal A, Harmon AC, Varner KJ, Noël A, Cormier SA, Nde DB, Mottram P, Maxie J, Dugas TR. Inhalation of particulate matter containing environmentally persistent free radicals induces endothelial dysfunction mediated via AhR activation at the air-blood interface. Toxicol Sci 2024; 199:246-260. [PMID: 38310335 DOI: 10.1093/toxsci/kfae007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2024] Open
Abstract
Particulate matter (PM) containing environmentally persistent free radicals (EPFR) is formed by the incomplete combustion of organic wastes, resulting in the chemisorption of pollutants to the surface of PM containing redox-active transition metals. In prior studies in mice, EPFR inhalation impaired endothelium-dependent vasodilation. These findings were associated with aryl hydrocarbon receptor (AhR) activation in the alveolar type-II (AT-II) cells that form the air-blood interface in the lung. We thus hypothesized that AhR activation in AT-II cells promotes the systemic release of mediators that promote endothelium dysfunction peripheral to the lung. To test our hypothesis, we knocked down AhR in AT-II cells of male and female mice and exposed them to 280 µg/m3 EPFR lo (2.7e + 16 radicals/g) or EPFR (5.5e + 17 radicals/g) compared with filtered air for 4 h/day for 1 day or 5 days. AT-II-AhR activation-induced EPFR-mediated endothelial dysfunction, reducing endothelium-dependent vasorelaxation by 59%, and eNOS expression by 50%. It also increased endothelin-1 mRNA levels in the lungs and peptide levels in the plasma in a paracrine fashion, along with soluble vascular cell adhesion molecule-1 and iNOS mRNA expression, possibly via NF-kB activation. Finally, AhR-dependent increases in antioxidant response signaling, coupled to increased levels of 3-nitrotyrosine in the lungs of EPFR-exposed littermate control but not AT-II AhR KO mice suggested that ATII-specific AhR activation promotes oxidative and nitrative stress. Thus, AhR activation at the air-blood interface mediates endothelial dysfunction observed peripheral to the lung, potentially via release of systemic mediators.
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Affiliation(s)
- Ankit Aryal
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, USA
| | - Ashlyn C Harmon
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, USA
| | - Kurt J Varner
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA
| | - Alexandra Noël
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, USA
| | - Stephania A Cormier
- Department of Biological Sciences, Louisiana State University A&M College and Pennington Biomedical Research Institute, Baton Rouge, Louisiana 70803, USA
| | - Divine B Nde
- Department of Chemistry, Louisiana State University A&M College, Baton Rouge, Louisiana 70803, USA
| | - Peter Mottram
- Department of Pathobiological Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, USA
| | - Jemiah Maxie
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, USA
| | - Tammy R Dugas
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, USA
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3
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Silva-Parra J, Ramírez-Martínez L, Palafox-Gómez C, Sandu C, López-Bayghen E, Vega L, Elizondo G, Loaeza-Loaeza J, Hernández-Sotelo D, Hernández-Kelly LC, Felder-Schmittbuhl MP, Ortega A. Aryl Hydrocarbon Receptor Involvement in the Sodium-Dependent Glutamate/Aspartate Transporter Regulation in Cerebellar Bergmann Glia Cells. ACS Chem Neurosci 2024; 15:1276-1285. [PMID: 38454572 PMCID: PMC10958506 DOI: 10.1021/acschemneuro.4c00046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/22/2024] [Accepted: 02/27/2024] [Indexed: 03/09/2024] Open
Abstract
Glutamate, the major excitatory neurotransmitter in the vertebrate brain, exerts its functions through the activation of specific plasma membrane receptors and transporters. Overstimulation of glutamate receptors results in neuronal cell death through a process known as excitotoxicity. A family of sodium-dependent glutamate plasma membrane transporters is responsible for the removal of glutamate from the synaptic cleft, preventing an excitotoxic insult. Glial glutamate transporters carry out more than 90% of the brain glutamate uptake activity and are responsible for glutamate recycling through the GABA/Glutamate/Glutamine shuttle. The aryl hydrocarbon receptor is a ligand-dependent transcription factor that integrates environmental clues through its ability to heterodimerize with different transcription factors. Taking into consideration the fundamental role of glial glutamate transporters in glutamatergic synapses and that these transporters are regulated at the transcriptional, translational, and localization levels in an activity-dependent fashion, in this contribution, we explored the involvement of the aryl hydrocarbon receptor, as a model of environmental integrator, in the regulation of the glial sodium-dependent glutamate/aspartate transporter. Using the model of chick cerebellar Bergmann glia cells, we report herein that the aryl hydrocarbon receptors exert a time-dependent decrease in the transporter mRNA levels and a diminution of its uptake activity. The nuclear factor kappa light chain enhancer of the activated B cell signaling pathway is involved in this regulation. Our results favor the notion of an environmentally dependent regulation of glutamate removal in glial cells and therefore strengthen the notion of the involvement of glial cells in xenobiotic neurotoxic effects.
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Affiliation(s)
- Janisse Silva-Parra
- Departamento
de Toxicología, Centro de Investigación
y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado Postal 14-740, Ciudad de México 07360, Mexico
| | - Leticia Ramírez-Martínez
- Departamento
de Toxicología, Centro de Investigación
y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado Postal 14-740, Ciudad de México 07360, Mexico
| | - Cecilia Palafox-Gómez
- Departamento
de Toxicología, Centro de Investigación
y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado Postal 14-740, Ciudad de México 07360, Mexico
| | - Cristina Sandu
- Centre
National de la Recherche Scientifique, Université
de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg 00000, France
| | - Esther López-Bayghen
- Departamento
de Toxicología, Centro de Investigación
y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado Postal 14-740, Ciudad de México 07360, Mexico
| | - Libia Vega
- Departamento
de Toxicología, Centro de Investigación
y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado Postal 14-740, Ciudad de México 07360, Mexico
| | - Guillermo Elizondo
- Departamento
de Biología Celular, Centro de Investigación
y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado Postal 14-740, Ciudad de México 07360, Mexico
| | - Jaqueline Loaeza-Loaeza
- Departamento
de Toxicología, Centro de Investigación
y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado Postal 14-740, Ciudad de México 07360, Mexico
| | - Daniel Hernández-Sotelo
- Facultad
de Ciencias Químico-Biológicas, Universidad Autónoma de Guerrero, Chilpancingo 39070, Guerrero, Mexico
| | - Luisa C. Hernández-Kelly
- Departamento
de Toxicología, Centro de Investigación
y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado Postal 14-740, Ciudad de México 07360, Mexico
| | - Marie-Paule Felder-Schmittbuhl
- Centre
National de la Recherche Scientifique, Université
de Strasbourg, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg 00000, France
| | - Arturo Ortega
- Departamento
de Toxicología, Centro de Investigación
y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado Postal 14-740, Ciudad de México 07360, Mexico
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Cholico GN, Fling RR, Sink WJ, Nault R, Zacharewski T. Inhibition of the urea cycle by the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin increases serum ammonia levels in mice. J Biol Chem 2024; 300:105500. [PMID: 38013089 PMCID: PMC10731612 DOI: 10.1016/j.jbc.2023.105500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/26/2023] [Accepted: 11/18/2023] [Indexed: 11/29/2023] Open
Abstract
The aryl hydrocarbon receptor is a ligand-activated transcription factor known for mediating the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds. TCDD induces nonalcoholic fatty liver disease (NAFLD)-like pathologies including simple steatosis that can progress to steatohepatitis with fibrosis and bile duct proliferation in male mice. Dose-dependent progression of steatosis to steatohepatitis with fibrosis by TCDD has been associated with metabolic reprogramming, including the disruption of amino acid metabolism. Here, we used targeted metabolomic analysis to reveal dose-dependent changes in the level of ten serum and eleven hepatic amino acids in mice upon treatment with TCDD. Bulk RNA-seq and protein analysis showed TCDD repressed CPS1, OTS, ASS1, ASL, and GLUL, all of which are associated with the urea cycle and glutamine biosynthesis. Urea and glutamine are end products of the detoxification and excretion of ammonia, a toxic byproduct of amino acid catabolism. Furthermore, we found that the catalytic activity of OTC, a rate-limiting step in the urea cycle was also dose dependently repressed. These results are consistent with an increase in circulating ammonia. Collectively, the repression of the urea and glutamate-glutamine cycles increased circulating ammonia levels and the toxicity of TCDD.
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Affiliation(s)
- Giovan N Cholico
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA; Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan, USA
| | - Russell R Fling
- Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan, USA; Microbiology & Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Warren J Sink
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA; Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan, USA
| | - Rance Nault
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA; Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan, USA
| | - Tim Zacharewski
- Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA; Institute for Integrative Toxicology, Michigan State University, East Lansing, Michigan, USA.
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Aryal A, Noël A, Khachatryan L, Cormier SA, Chowdhury PH, Penn A, Dugas TR, Harmon AC. Environmentally persistent free radicals: Methods for combustion generation, whole-body inhalation and assessing cardiopulmonary consequences. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 334:122183. [PMID: 37442324 PMCID: PMC10528481 DOI: 10.1016/j.envpol.2023.122183] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 07/04/2023] [Accepted: 07/10/2023] [Indexed: 07/15/2023]
Abstract
Particulate matter (PM) containing environmentally persistent free radicals (EPFRs) results from the incomplete combustion of organic wastes which chemisorb to transition metals. This process generates a particle-pollutant complex that continuously redox cycles to produce reactive oxygen species. EPFRs are well characterized, but their cardiopulmonary effects remain unknown. This publication provides a detailed approach to evaluating these effects and demonstrates the impact that EPFRs have on the lungs and vasculature. Combustion-derived EPFRs were generated (EPFR lo: 2.1e-16 radical/g, EPFR hi: 5.5e-17 radical/g), characterized, and verified as representative of those found in urban areas. Dry particle aerosolization and whole-body inhalation were established for rodent exposures. To verify that these particles and exposures recapitulate findings relevant to known PM-induced cardiopulmonary effects, male C57BL6 mice were exposed to filtered air, ∼280 μg/m3 EPFR lo or EPFR hi for 4 h/d for 5 consecutive days. Compared to filtered air, pulmonary resistance was increased in mice exposed to EPFR hi. Mice exposed to EPFR hi also exhibited increased plasma endothelin-1 (44.6 vs 30.6 pg/mL) and reduced nitric oxide (137 nM vs 236 nM), suggesting vascular dysfunction. Assessment of vascular response demonstrated an impairment in endothelium-dependent vasorelaxation, with maximum relaxation decreased from 80% to 62% in filtered air vs EPFR hi exposed mice. Gene expression analysis highlighted fold changes in aryl hydrocarbon receptor (AhR) and antioxidant response genes including increases in lung Cyp1a1 (8.7 fold), Cyp1b1 (9 fold), Aldh3a1 (1.7 fold) and Nqo1 (2.4 fold) and Gclc (1.3 fold), and in aortic Cyp1a1 (5.3 fold) in mice exposed to EPFR hi vs filtered air. We then determined that lung AT2 cells were the predominate locus for AhR activation. Together, these data suggest the lung and vasculature as particular targets for the health impacts of EPFRs and demonstrate the importance of additional studies investigating the cardiopulmonary effects of EPFRs.
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Affiliation(s)
- Ankit Aryal
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana, 70803, USA
| | - Alexandra Noël
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana, 70803, USA
| | - Lavrent Khachatryan
- Department of Chemistry, Louisiana State University A&M College, Baton Rouge, Louisiana, 70803, USA
| | - Stephania A Cormier
- Department of Biological Sciences, Louisiana State University A&M College and the Pennington Biomedical Research Institute, Baton Rouge, Louisiana, 70803, USA
| | - Pratiti H Chowdhury
- Department of Biological Sciences, Louisiana State University A&M College and the Pennington Biomedical Research Institute, Baton Rouge, Louisiana, 70803, USA
| | - Arthur Penn
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana, 70803, USA
| | - Tammy R Dugas
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana, 70803, USA
| | - Ashlyn C Harmon
- Department of Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana, 70803, USA.
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Mohammadkhani MA, Shahrzad S, Haghighi M, Ghanbari R, Mohamadkhani A. Insights into Organochlorine Pesticides Exposure in the Development of Cardiovascular Diseases: A Systematic Review. ARCHIVES OF IRANIAN MEDICINE 2023; 26:592-599. [PMID: 38310416 PMCID: PMC10862093 DOI: 10.34172/aim.2023.86] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 07/22/2023] [Indexed: 02/05/2024]
Abstract
Many human diseases such as cancer, neurological diseases, autism and diabetes are associated with exposure to pesticides, especially organochlorine pesticides. However, pesticide exposure is also associated with cardiovascular disease (CVD) as the leading cause of death worldwide. In this systematic review, results on the link between organochlorine pesticide pollution and CVD were collected from databases (Medline (PubMed), Scopus and Science Direct) in May 2022 from studies published between 2010 and 2022. A total of 24 articles were selected for this systematic review. Sixteen articles were extracted by reviewers using a standardized form that included cross-sectional, cohort, and ecological studies that reported exposure to organochlorine pesticides in association with increased CVD risk. In addition, eight articles covering molecular mechanisms organochlorine pesticides and polychlorinated biphenyls (PCBs) on cardiovascular effects were retrieved for detailed evaluation. Based on the findings of the study, it seems elevated circulating levels of organochlorine pesticides and PCBs increase the risk of coronary heart disease, especially in early life exposure to these pesticides and especially in men. Changes in the regulatory function of peroxisome proliferator-activated γ receptor (PPARγ), reduction of paroxonase activity (PON1), epigenetic changes of histone through induction of reactive oxygen species, vascular endothelial inflammation with miR-expression 126 and miR-31, increased collagen synthesis enzymes in the extracellular matrix and left ventricular hypertrophy (LVH) and fibrosis are mechanisms by which PCBs increase the risk of CVD. According to this systematic review, organochlorine pesticide exposure is associated with increased risk of CVD and CVD mortality through the atherogenic and inflammatory molecular mechanism involving fatty acid and glucose metabolism.
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Affiliation(s)
| | - Soraya Shahrzad
- Department of Cardiology, Shariati Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehrdad Haghighi
- Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Reza Ghanbari
- Gene Therapy Research Center, Digestive Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Ashraf Mohamadkhani
- Liver and Pancreatobiliary Diseases Research Center, Digestive Diseases Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
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Aryl Hydrocarbon Receptor Repressor Is Hypomethylated in Psoriasis and Promotes Psoriasis-like Inflammation in HaCaT Cells. Int J Mol Sci 2021; 22:ijms222312715. [PMID: 34884515 PMCID: PMC8657998 DOI: 10.3390/ijms222312715] [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: 10/18/2021] [Revised: 11/17/2021] [Accepted: 11/17/2021] [Indexed: 11/17/2022] Open
Abstract
It is known that DNA hypomethylation of aryl hydrocarbon receptor repressor (AhRR), one of the epigenetic markers of environmental pollutants, causes skin diseases. However, the function and mechanisms are still unknown. We aimed to determine whether AhRR is hypomethylated in PBMC of psoriasis patients, as well as to examine the expression of psoriasis-related inflammatory cytokines and antimicrobial peptides after 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) treatment in HaCaT cells overexpressing or silencing AhRR. AhRR was determined by qPCR, Western blot, immunohistochemistry, and immunocytochemistry in skin tissue and HaCaT cells. DNA methylation of AhRR was performed by Infinium Human Methylation450 BeadChip in PBMC of psoriasis patients and methylation-specific PCR (MSP) in HaCaT cells. NF-κB pp50 translocation and activity were performed by immunocytochemistry and luciferase reporter assay, respectively. We verified AhRR gene expression in the epidermis from psoriasis patients and healthy controls. AhRR hypomethylation in PBMC of psoriasis patients and pAhRR-HaCaT cells was confirmed. The expression level of AhRR was increased in both TCDD-treated HaCaT cells and pAhRR-HaCaT cells. NF-κB pp50 translocation and activity increased with TCDD. Our results showed that AhRR was hypomethylated and overexpressed in the lesional skin of patients with psoriasis, thereby increasing AhRR gene expression and regulating pro-inflammatory cytokines through the NF-κB signaling pathway in TCDD-treated HaCaT cells.
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Doğan MF, Başak Türkmen N, Taşlıdere A, Şahin Y, Çiftçi O. The protective effects of capsaicin on oxidative damage-induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in rats. Drug Chem Toxicol 2021; 45:2463-2470. [PMID: 34308744 DOI: 10.1080/01480545.2021.1957912] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The present study aimed to investigate the protective role of capsaicin in a rat model of 2,3,7,8-tetracholorodibenzo-p-dioxin (TCDD)-induced toxicity. Exposure to TCDD which is an environmental toxicant causes severe toxic effects in the animal and human tissues. Therefore, the potential protective effect of capsaicin in TCDD-induced organ damage was investigated in rats by measuring thiobarbituric acid reactive substances (TBARS) level, superoxide dismutase (SOD) activity, and glutathione (GSH) level in the heart, liver, and kidney tissues for oxidant/antioxidant balance. Thirty-two healthy adults (250-300 g weight and 3-4 months old) male Wistar albino rats were randomly distributed into four equal groups (n = 8): Control, CAP, TCDD, TCDD + CAP. A dose of 2 μg/kg TCDD or a dose of 25 mg/kg capsaicin were dissolved in corn oil and orally administered to the rats for 30 days. The results indicated that TCDD-induced oxidative stress by increasing the level of TBARS and by decreasing the levels of GSH, and SOD activity in the tissues of rats. However, capsaicin treatment was significantly decreased TBARS levels and was significantly increased GSH level and SOD activity (p < 0.05). In addition, capsaicin (25 mg/kg) significantly attenuated TCDD-induced histopathological alteration associated with oxidative stress in the heart, liver, and kidney tissues (p < 0.05). As capsaicin regulates oxidative imbalance and attenuates histopathological alterations in the rat tissues, it may be preventing agents in TCDD toxicity.
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Affiliation(s)
- Muhammed Fatih Doğan
- Department of Pharmacology, Faculty of Medicine, University of Pamukkale, Denizli, Turkey
| | - Neşe Başak Türkmen
- Department of Pharmaceutical Toxicology, Faculty of Pharmacy, University of Inonu, Malatya, Turkey
| | - Aslı Taşlıdere
- Department of Histology and Embryology, Faculty of Medicine, University of Inonu, Malatya, Turkey
| | - Yasemin Şahin
- Department of Pharmacology, Faculty of Medicine, University of Pamukkale, Denizli, Turkey
| | - Osman Çiftçi
- Department of Pharmacology, Faculty of Medicine, University of Pamukkale, Denizli, Turkey
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9
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Shankar P, Dasgupta S, Hahn ME, Tanguay RL. A Review of the Functional Roles of the Zebrafish Aryl Hydrocarbon Receptors. Toxicol Sci 2020; 178:215-238. [PMID: 32976604 PMCID: PMC7706399 DOI: 10.1093/toxsci/kfaa143] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Over the last 2 decades, the zebrafish (Danio rerio) has emerged as a stellar model for unraveling molecular signaling events mediated by the aryl hydrocarbon receptor (AHR), an important ligand-activated receptor found in all eumetazoan animals. Zebrafish have 3 AHRs-AHR1a, AHR1b, and AHR2, and studies have demonstrated the diversity of both the endogenous and toxicological functions of the zebrafish AHRs. In this contemporary review, we first highlight the evolution of the zebrafish ahr genes, and the characteristics of the receptors including developmental and adult expression, their endogenous and inducible roles, and the predicted ligands from homology modeling studies. We then review the toxicity of a broad spectrum of AHR ligands across multiple life stages (early stage, and adult), discuss their transcriptomic and epigenetic mechanisms of action, and report on any known interactions between the AHRs and other signaling pathways. Through this article, we summarize the promising research that furthers our understanding of the complex AHR pathway through the extensive use of zebrafish as a model, coupled with a large array of molecular techniques. As much of the research has focused on the functions of AHR2 during development and the mechanism of TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) toxicity, we illustrate the need to address the considerable knowledge gap in our understanding of both the mechanistic roles of AHR1a and AHR1b, and the diverse modes of toxicity of the various AHR ligands.
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Affiliation(s)
- Prarthana Shankar
- Department of Environmental and Molecular Toxicology, The Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, Oregon 97331
| | - Subham Dasgupta
- Department of Environmental and Molecular Toxicology, The Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, Oregon 97331
| | - Mark E Hahn
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543
| | - Robyn L Tanguay
- Department of Environmental and Molecular Toxicology, The Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, Oregon 97331
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Hexachloronaphthalene Induces Mitochondrial-Dependent Neurotoxicity via a Mechanism of Enhanced Production of Reactive Oxygen Species. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:2479234. [PMID: 32685088 PMCID: PMC7335409 DOI: 10.1155/2020/2479234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 06/09/2020] [Indexed: 12/30/2022]
Abstract
Hexachloronaphthalene (PCN67) is one of the most toxic among polychlorinated naphthalenes. Despite the known high bioaccumulation and persistence of PCN67 in the environment, it is still unclear to what extent exposure to these substances may interfere with normal neuronal physiology and lead to neurotoxicity. Therefore, the primary goal of this study was to assess the effect of PCN67 in neuronal in vitro models. Neuronal death was assessed upon PCN67 treatment using differentiated PC12 cells and primary hippocampal neurons. At 72 h postexposure, cell viability assays showed an IC50 value of 0.35 μg/ml and dose-dependent damage of neurites and concomitant downregulation of neurofilaments L and M. Moreover, we found that younger primary neurons (DIV4) were much more sensitive to PCN67 toxicity than mature cultures (DIV14). Our comprehensive analysis indicated that the application of PCN67 at the IC50 concentration caused necrosis, which was reflected by an increase in LDH release, HMGB1 protein export to the cytosol, nuclear swelling, and loss of homeostatic control of energy balance. The blockage of mitochondrial calcium uniporter partially rescued the cell viability, loss of mitochondrial membrane potential (ΔΨm), and the overproduction of reactive oxygen species, suggesting that the underlying mechanism of neurotoxicity involved mitochondrial calcium accumulation. Increased lipid peroxidation as a consequence of oxidative stress was additionally seen for 0.1 μg/ml of PCN67, while this concentration did not affect ΔΨm and plasma membrane permeability. Our results show for the first time that neuronal mitochondria act as a target for PCN67 and indicate that exposure to this drug may result in neuron loss via mitochondrial-dependent mechanisms.
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11
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Tarnow P, Zordick C, Bottke A, Fischer B, Kühne F, Tralau T, Luch A. Characterization of Quinoline Yellow Dyes As Transient Aryl Hydrocarbon Receptor Agonists. Chem Res Toxicol 2020; 33:742-750. [PMID: 31957441 DOI: 10.1021/acs.chemrestox.9b00351] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The aryl hydrocarbon receptor (AHR) and estrogen receptor alpha (ERα) are two ligand activated transcription factors that are targeted by a wide range of anthropogenic compounds. Crosstalk between both receptors is well established but little understood. We previously developed a dual color luciferase assay (i.e., XEER) which allows time dissolved monitoring of the activation of both receptors in situ. The system was now used in conjunction with HPLC-qTOF to identify several quinophthalone dyes as transient receptor agonists of the AHR. Altogether the approach identified three widely used dyes, that is the plastic colorant latyl yellow 3G (LY), the structurally related textile dye disperse yellow 64 (DY), and the cosmetic dye quinoline yellow (QY). The latter was the most potent agonist followed by LY and DY as confirmed by the XEER assay and CYP1A1 gene induction in MCF7 cells. In addition QY, LY, and DY also inhibited ER signaling in an AHR-dependent manner. This establishes some evidence for quinoline yellow dyes as potential disruptors of AHR/ER signaling, raising potential toxicological concern. Although none of the dyes featured any signs of genotoxicity in vitro, our data point to the need for a systematic approach when screening for substances of potential toxicological and endocrine relevance.
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Affiliation(s)
- Patrick Tarnow
- German Federal Institute for Risk Assessment, Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Catrin Zordick
- German Federal Institute for Risk Assessment, Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Alex Bottke
- German Federal Institute for Risk Assessment, Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Berit Fischer
- German Federal Institute for Risk Assessment, Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Friederike Kühne
- German Federal Institute for Risk Assessment, Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Tewes Tralau
- German Federal Institute for Risk Assessment, Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
| | - Andreas Luch
- German Federal Institute for Risk Assessment, Department of Chemical and Product Safety, Max-Dohrn-Strasse 8-10, 10589 Berlin, Germany
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12
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Singh J, Mumford SL, Pollack AZ, Schisterman EF, Weisskopf MG, Navas-Acien A, Kioumourtzoglou MA. Tampon use, environmental chemicals and oxidative stress in the BioCycle study. Environ Health 2019; 18:11. [PMID: 30744632 PMCID: PMC6371574 DOI: 10.1186/s12940-019-0452-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 02/05/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Tampons are used by up to 86% of US women and are a rarely considered potential source of pesticide and metal exposure. Tampons may be of particular concern given the likely higher absorption that occurs in the vagina. Our objective was to examine the potential associations between tampon use and metal concentrations, and biomarkers of inflammation and oxidative stress among healthy women. METHODS We used information from a prospective cohort of 259 regularly menstruating women, aged 18-44, followed for two menstrual cycles. Tampon use was assessed using information provided in participant study diaries. Metal concentrations were measured from a blood sample collected at enrollment. Oxidative stress and inflammation biomarker concentrations were determined from blood samples collected at up to 8 clinic visits for each cycle. Linear regression models were used to estimate associations of tampon use with metal exposure, and linear mixed models to estimate associations of tampon use with inflammation and oxidative stress biomarkers at different times during the menstrual cycle. RESULTS We observed non-significantly higher mean levels of mercury for tampon users compared to non-tampon users (exp(β) = 1.25, 95% CI = 0.93, 1.68). We found no evidence of an association between tampon use and inflammation biomarkers. We observed consistently higher isoprostane levels, an oxidative stress biomarker, among tampon users compared to non-tampon users (e.g. exp.(β) = 1.05, 95%CI = 0.96, 1.16, for the average isoprostane during the menstruating week); however, these results were not statistically significant. CONCLUSIONS While our results are not statistically significant, we observed suggestive associations between tampon use and elevated levels of mercury and oxidative stress biomarkers. Although our finding should be interpreted in light of our limitations, they indicate that tampons may be a source of exposure to metals and chemicals that have been largely ignored, and any related health effects are an important public health concern.
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Affiliation(s)
- Jessica Singh
- Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY, USA
| | - Sunni L Mumford
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, Epidemiology Branch, Bethesda, MD, USA
| | - Anna Z Pollack
- Department of Global and Community Health, College of Health and Human Services, George Mason University, Fairfax, Virginia, USA
| | - Enrique F Schisterman
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, Epidemiology Branch, Bethesda, MD, USA
| | - Marc G Weisskopf
- Department of Environmental Health, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - Ana Navas-Acien
- Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY, USA
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13
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Ulin A, Henderson J, Pham MT, Meyo J, Chen Y, Karchner SI, Goldstone JV, Hahn ME, Williams LM. Developmental Regulation of Nuclear Factor Erythroid-2 Related Factors (nrfs) by AHR1b in Zebrafish (Danio rerio). Toxicol Sci 2019; 167:536-545. [PMID: 30321412 PMCID: PMC6358246 DOI: 10.1093/toxsci/kfy257] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Interactions between regulatory pathways allow organisms to adapt to their environment and respond to stress. One interaction that has been recently identified occurs between the aryl hydrocarbon receptor (AHR) and the nuclear factor erythroid-2 related factor (NRF) family. Each transcription factor regulates numerous downstream genes involved in the cellular response to toxicants and oxidative stress; they are also implicated in normal developmental pathways. The zebrafish model was used to explore the role of AHR regulation of nrf genes during development and in response to toxicant exposure. To determine if AHR1b is responsible for transcriptional regulation of 6 nrf genes during development, a loss-of-function experiment using morpholino-modified oligonucleotides was conducted followed by a chromatin immunoprecipitation study at the beginning of the pharyngula period (24 h postfertilization). The expression of nrf1a was AHR1b dependent and its expression was directly regulated through specific XREs in its cis-promoter. However, nrf1a expression was not altered by exposure to 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), a toxicant and prototypic AHR agonist. The expression of nrf1b, nrf2a, and nfe2 was induced by TCDD, and AHR1b directly regulated their expression by binding to cis-XRE promoter elements. Last, nrf2b and nrf3 were neither induced by TCDD nor regulated by AHR1b. These results show that AHR1b transcriptionally regulates nrf genes under toxicant modulation via binding to specific XREs. These data provide a better understanding of how combinatorial molecular signaling potentially protects embryos from embryotoxic events following toxicant exposure.
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Affiliation(s)
- Alexandra Ulin
- Department of biology, Bates College, Lewiston, Maine 04240
| | - Jake Henderson
- Department of biology, Bates College, Lewiston, Maine 04240
| | - Minh-Tam Pham
- Department of biology, Bates College, Lewiston, Maine 04240
| | - James Meyo
- Department of biology, Bates College, Lewiston, Maine 04240
| | - Yuying Chen
- Department of biology, Bates College, Lewiston, Maine 04240
| | - Sibel I Karchner
- Department of biology, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543
| | - Jared V Goldstone
- Department of biology, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543
| | - Mark E Hahn
- Department of biology, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543
| | - Larissa M Williams
- Department of biology, Bates College, Lewiston, Maine 04240
- Department of biology, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543
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14
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Aluru N, Karchner SI, Krick KS, Zhu W, Liu J. Role of DNA methylation in altered gene expression patterns in adult zebrafish ( Danio rerio) exposed to 3, 3', 4, 4', 5-pentachlorobiphenyl (PCB 126). ENVIRONMENTAL EPIGENETICS 2018; 4:dvy005. [PMID: 29686887 PMCID: PMC5905506 DOI: 10.1093/eep/dvy005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 02/09/2018] [Accepted: 03/08/2018] [Indexed: 05/08/2023]
Abstract
There is growing evidence that environmental toxicants can affect various physiological processes by altering DNA methylation patterns. However, very little is known about the impact of toxicant-induced DNA methylation changes on gene expression patterns. The objective of this study was to determine the genome-wide changes in DNA methylation concomitant with altered gene expression patterns in response to 3, 3', 4, 4', 5-pentachlorobiphenyl (PCB126) exposure. We used PCB126 as a model environmental chemical because the mechanism of action is well-characterized, involving activation of aryl hydrocarbon receptor, a ligand-activated transcription factor. Adult zebrafish were exposed to 10 nM PCB126 for 24 h (water-borne exposure) and brain and liver tissues were sampled at 7 days post-exposure in order to capture both primary and secondary changes in DNA methylation and gene expression. We used enhanced Reduced Representation Bisulfite Sequencing and RNAseq to quantify DNA methylation and gene expression, respectively. Enhanced reduced representation bisulfite sequencing analysis revealed 573 and 481 differentially methylated regions in the liver and brain, respectively. Most of the differentially methylated regions are located more than 10 kilobases upstream of transcriptional start sites of the nearest neighboring genes. Gene Ontology analysis of these genes showed that they belong to diverse physiological pathways including development, metabolic processes and regeneration. RNAseq results revealed differential expression of genes related to xenobiotic metabolism, oxidative stress and energy metabolism in response to polychlorinated biphenyl exposure. There was very little correlation between differentially methylated regions and differentially expressed genes suggesting that the relationship between methylation and gene expression is dynamic and complex, involving multiple layers of regulation.
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Affiliation(s)
- Neelakanteswar Aluru
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
- Correspondence address. Department of Biology, Woods Hole Oceanographic Institution, 45 Water Street, Woods Hole, MA 02543, USA. Tel: 508-289-3607; Fax: 508-457-2134; E-mail:
| | - Sibel I Karchner
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Keegan S Krick
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Wei Zhu
- CAS Key Laboratory of Genomic Sciences and Information, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, CAS, Beijing 100101, China
| | - Jiang Liu
- CAS Key Laboratory of Genomic Sciences and Information, Collaborative Innovation Center of Genetics and Development, Beijing Institute of Genomics, CAS, Beijing 100101, China
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15
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Gao L, Mutlu E, Collins LB, Walker NJ, Hartwell HJ, Olson JR, Sun W, Gold A, Ball LM, Swenberg JA. DNA Product Formation in Female Sprague-Dawley Rats Following Polyhalogenated Aromatic Hydrocarbon (PHAH) Exposure. Chem Res Toxicol 2017; 30:794-803. [PMID: 28207250 PMCID: PMC5363288 DOI: 10.1021/acs.chemrestox.6b00368] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Indexed: 01/16/2023]
Abstract
DNA oxidation damage has been regarded as one of the possible mechanisms for the hepatic carcinogenesis of dioxin-like compounds (DLCs). In this study, we evaluated the toxic equivalency factor (TEF) from the standpoint of induced DNA oxidation products and their relationship to toxicity and carcinogenicity. Nine DNA oxidation products were analyzed in the liver of female Sprague-Dawley rats exposed to 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD) alone or the tertiary mixture of TCDD, 3,3',4,4',5-pentachlorobiphenyl (PCB 126), and 2,3,4,7,8-pentachlorodibenzofuran (PeCDF) by gavage for 14, 31, and 53 weeks (5 days/week) by LC-MS/MS: 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dGuo); 1,N6-etheno-2'-deoxyadenosine (1,N6-εdAdo); N2,3-ethenoguanine (N2,3-εG); 7-(2-oxoethly)guanine (7-OEG); 1,N2-etheno-2'-deoxyguanosine (1,N2-εdGuo); malondialdehyde (M1dGuo); acrolein (AcrdGuo); crotonaldehyde (CrdGuo); and 4-hydroxynonenal (HNEdGuo) derived 2'-deoxyguanosine adducts. Exposure to TCDD (100 ng/kg/day) significantly induced 1,N6-εdAdo at 31 and 53 weeks, while no increase of 8-oxo-dGuo was observed. Significant increases were observed for 8-oxo-dGuo and 1,N6-εdAdo at all time points following exposure to the tertiary mixture (TEQ 100 ng/kg/day). Exposure to TCDD for 53 weeks only significantly increased 1,N6-εdAdo, while increases of N2,3-εG and 7-OEG were only found in the highest dose group (100 ng/kg/day). Exposure to the tertiary mixture for 53 weeks had no effect on N2,3-εG in any exposure group (TEQ 0, 22, 46, or 100 ng/kg/day), while significant increases were observed for 1,N6-εdAdo (all dose groups), 8-oxo-dGuo (46 and 100 ng/kg/day), and 7-OEG (100 ng/kg/day). While no significant increase was observed at 53 weeks for 1,N2-εdGuo, M1dGuo, AcrdGuo, or CrdGuo following exposure to TCDD (100 ng/kg/day), all of them were significantly induced in animals exposed to the tertiary mixture (TEQ 100 ng/kg/day). This oxidation DNA product data suggest that the simple TEF methodology cannot be applied to evaluate the diverse patterns of toxic effects induced by DLCs.
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Affiliation(s)
- Lina Gao
- Department of Environmental Sciences and Engineering and Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Esra Mutlu
- National
Toxicology Program, National Institute of
Environmental Health Sciences, NIH, RTP, Durham, North Carolina 27709, United States
| | - Leonard B. Collins
- Department of Environmental Sciences and Engineering and Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Nigel J. Walker
- National
Toxicology Program, National Institute of
Environmental Health Sciences, NIH, RTP, Durham, North Carolina 27709, United States
| | - Hadley J. Hartwell
- Department of Environmental Sciences and Engineering and Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - James R. Olson
- Department
of Pharmacology and Toxicology, State University
of New York at Buffalo, Buffalo, New York 14214, United States
| | - Wei Sun
- Department of Environmental Sciences and Engineering and Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Avram Gold
- Department of Environmental Sciences and Engineering and Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Louise M. Ball
- Department of Environmental Sciences and Engineering and Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - James A. Swenberg
- Department of Environmental Sciences and Engineering and Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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16
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Brinkmann M, Koglin S, Eisner B, Wiseman S, Hecker M, Eichbaum K, Thalmann B, Buchinger S, Reifferscheid G, Hollert H. Characterisation of transcriptional responses to dioxins and dioxin-like contaminants in roach (Rutilus rutilus) using whole transcriptome analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 541:412-423. [PMID: 26410716 DOI: 10.1016/j.scitotenv.2015.09.087] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2015] [Revised: 09/16/2015] [Accepted: 09/16/2015] [Indexed: 05/10/2023]
Abstract
There is significant concern regarding the contamination of riverine sediments with dioxins and dioxin-like compounds (DLCs), including polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and some polycyclic aromatic hydrocarbons (PAHs). The majority of studies investigating the ecotoxicology of DLCs in fish have focused on a few standard model species. However, there is significant uncertainty as to whether these model species are representative of native river fish, particularly in Europe. In this study, the transcriptional responses following exposure to equipotent concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), PCB 156 or the dioxin-like PAH, benzo[k]fluoranthene (BkF), were investigated in juvenile roach (Rutilus rutilus), a fish species that constitutes a large proportion of the fish biomass in freshwater bodies throughout Europe. To this end, RNA sequencing analysis was used to comprehensively characterise the molecular mechanisms and pathways of toxicity of these DLCs. Whole transcriptome analyses using ClueGO software revealed that DLCs have the potential to disrupt a number of important processes, including energy metabolism, oogenesis, the immune system, apoptosis and the response to oxidative stress. However, despite using equipotent concentrations, there was very little conservation of the transcriptional responses observed in fish exposed to different DLCs. TCDD provoked significant specific changes in the levels of transcripts related to immunotoxicity and carbohydrate metabolism, while PCB 156 caused virtually no specific effects. Exposure to BkF affected the most diverse suite of molecular functions and biological processes, including blood coagulation, oxidative stress responses, unspecific responses to organic or inorganic substances/stimuli, cellular redox homeostasis and specific receptor pathways. To our knowledge, this is the first study of the transcriptome-wide effects of different classes of DLCs in fish. These findings represent an important step towards describing complete toxicity pathways of DLCs, which will be important in the context of informing risk assessments of DLC toxicity in native fish species.
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Affiliation(s)
- Markus Brinkmann
- Department of Ecosystem Analysis, Institute for Environmental Research, ABBt - Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Sven Koglin
- Department of Ecosystem Analysis, Institute for Environmental Research, ABBt - Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Bryanna Eisner
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - Steve Wiseman
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - Markus Hecker
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada; School of the Environment & Sustainability, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - Kathrin Eichbaum
- Department of Ecosystem Analysis, Institute for Environmental Research, ABBt - Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Beat Thalmann
- Department of Ecosystem Analysis, Institute for Environmental Research, ABBt - Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Sebastian Buchinger
- Federal Institute of Hydrology (BfG), Department G3: Biochemistry, Ecotoxicology, Am Mainzer Tor 1, 56068 Koblenz, Germany
| | - Georg Reifferscheid
- Federal Institute of Hydrology (BfG), Department G3: Biochemistry, Ecotoxicology, Am Mainzer Tor 1, 56068 Koblenz, Germany
| | - Henner Hollert
- Department of Ecosystem Analysis, Institute for Environmental Research, ABBt - Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany; College of Resources and Environmental Science, Chongqing University, 1 Tiansheng Road Beibei, Chongqing 400715, China; College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, 1239 Siping Road, Shanghai, China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, China.
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17
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Pahlke G, Tiessen C, Domnanich K, Kahle N, Groh IAM, Schreck I, Weiss C, Marko D. Impact of Alternaria toxins on CYP1A1 expression in different human tumor cells and relevance for genotoxicity. Toxicol Lett 2015; 240:93-104. [PMID: 26474839 DOI: 10.1016/j.toxlet.2015.10.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 10/05/2015] [Accepted: 10/08/2015] [Indexed: 10/22/2022]
Abstract
The Alternaria toxins alternariol (AOH) and alternariol monomethyl ether (AME) have been reported previously to act as activators of the aryl hydrocarbon receptor (AhR) in murine hepatoma cells, thus enhancing the expression of cytochrome P450 (CYP) 1A monooxygenases. Concomitantly, both benzopyrones represent substrates of CYP1A, giving rise to catecholic metabolites. The impact of AOH and AME on CYP1A expression in human cells of different tissue origin colon (HT29), esophagus (KYSE510), liver (HepG2) and their effects on cell viability, generation of reactive oxygen species (ROS) and DNA integrity were investigated. ROS production was induced by both mycotoxins in all cell lines with AOH exhibiting the highest potency in esophageal cells concomitant with the most prominent CYP1A induction level. Of note, altertoxin-II (ATX-II), the more potent DNA-damaging mutagen formed by Alternaria alternata, induces CYP1A even at significant lower concentrations. AhR-siRNA knockdown in human esophageal cells supported the hypothesis of AhR-mediated CYP1A1 induction by AOH. However, DNA damage was minor at CYP1A1-inducing AOH concentrations. AhR-depletion did not affect the DNA-damaging properties of AOH indicating no substantial impact of AhR in this regard. However, in combination with xenobiotics prone to metabolic activation by CYP1A the induction of CYP1A by Alternaria toxins deserves further attention.
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Affiliation(s)
- G Pahlke
- Department of Food Chemistry and Toxicology, University of Vienna, Waehringer Str. 38, A-1090 Vienna, Austria.
| | - C Tiessen
- Department of Food Chemistry and Toxicology, University of Vienna, Waehringer Str. 38, A-1090 Vienna, Austria
| | - K Domnanich
- Department of Food Chemistry and Toxicology, University of Vienna, Waehringer Str. 38, A-1090 Vienna, Austria
| | - N Kahle
- Department of Food Chemistry and Toxicology, University of Vienna, Waehringer Str. 38, A-1090 Vienna, Austria
| | - I A M Groh
- Department of Food Chemistry and Toxicology, University of Vienna, Waehringer Str. 38, A-1090 Vienna, Austria
| | - I Schreck
- Institute of Toxicology and Genetics (ITG), Karlsruhe Institute of Technology (KIT), Germany
| | - C Weiss
- Institute of Toxicology and Genetics (ITG), Karlsruhe Institute of Technology (KIT), Germany
| | - D Marko
- Department of Food Chemistry and Toxicology, University of Vienna, Waehringer Str. 38, A-1090 Vienna, Austria
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18
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McLean LS, Watkins CN, Campbell P, Zylstra D, Rowland L, Amis LH, Scott L, Babb CE, Livingston WJ, Darwanto A, Davis WL, Senthil M, Sowers LC, Brantley E. Aryl Hydrocarbon Receptor Ligand 5F 203 Induces Oxidative Stress That Triggers DNA Damage in Human Breast Cancer Cells. Chem Res Toxicol 2015; 28:855-71. [PMID: 25781201 DOI: 10.1021/tx500485v] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Breast tumors often show profound sensitivity to exogenous oxidative stress. Investigational agent 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (5F 203) induces aryl hydrocarbon receptor (AhR)-mediated DNA damage in certain breast cancer cells. Since AhR agonists often elevate intracellular oxidative stress, we hypothesize that 5F 203 increases reactive oxygen species (ROS) to induce DNA damage, which thwarts breast cancer cell growth. We found that 5F 203 induced single-strand break formation. 5F 203 enhanced oxidative DNA damage that was specific to breast cancer cells sensitive to its cytotoxic actions, as it did not increase oxidative DNA damage or ROS formation in nontumorigenic MCF-10A breast epithelial cells. In contrast, AhR agonist and procarcinogen benzo[a]pyrene and its metabolite, 1,6-benzo[a]pyrene quinone, induced oxidative DNA damage and ROS formation, respectively, in MCF-10A cells. In sensitive breast cancer cells, 5F 203 activated ROS-responsive kinases: c-Jun-N-terminal kinase (JNK) and p38 mitogen activated protein kinase (p38). AhR antagonists (alpha-naphthoflavone, CH223191) or antioxidants (N-acetyl-l-cysteine, EUK-134) attenuated 5F 203-mediated JNK and p38 activation, depending on the cell type. Pharmacological inhibition of AhR, JNK, or p38 attenuated 5F 203-mediated increases in intracellular ROS, apoptosis, and single-strand break formation. 5F 203 induced the expression of cytoglobin, an oxidative stress-responsive gene and a putative tumor suppressor, which was diminished with AhR, JNK, or p38 inhibition. Additionally, 5F 203-mediated increases in ROS production and cytoglobin were suppressed in AHR100 cells (AhR ligand-unresponsive MCF-7 breast cancer cells). Our data demonstrate 5F 203 induces ROS-mediated DNA damage at least in part via AhR, JNK, or p38 activation and modulates the expression of oxidative stress-responsive genes such as cytoglobin to confer its anticancer action.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Lawrence C Sowers
- ⊥Department of Pharmacology and Toxicology, University of Texas Medical Branch at Galveston, Galveston, Texas 77555, United States
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19
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Girolami F, Spalenza V, Manzini L, Carletti M, Nebbia C. Constitutive expression of the AHR signaling pathway in a bovine mammary epithelial cell line and modulation by dioxin-like PCB and other AHR ligands. Toxicol Lett 2015; 232:98-105. [DOI: 10.1016/j.toxlet.2014.09.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 09/15/2014] [Accepted: 09/16/2014] [Indexed: 12/20/2022]
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20
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The transcriptional response to oxidative stress during vertebrate development: effects of tert-butylhydroquinone and 2,3,7,8-tetrachlorodibenzo-p-dioxin. PLoS One 2014; 9:e113158. [PMID: 25402455 PMCID: PMC4234671 DOI: 10.1371/journal.pone.0113158] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 10/20/2014] [Indexed: 01/12/2023] Open
Abstract
Oxidative stress is an important mechanism of chemical toxicity, contributing to teratogenesis and to cardiovascular and neurodegenerative diseases. Developing animals may be especially sensitive to chemicals causing oxidative stress. The developmental expression and inducibility of anti-oxidant defenses through activation of NF-E2-related factor 2 (NRF2) affect susceptibility to oxidants, but the embryonic response to oxidants is not well understood. To assess the response to chemically mediated oxidative stress and how it may vary during development, zebrafish embryos, eleutheroembryos, or larvae at 1, 2, 3, 4, 5, and 6 days post fertilization (dpf) were exposed to DMSO (0.1%), tert-butylhydroquinone (tBHQ; 10 µM) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 2 nM) for 6 hr. Transcript abundance was assessed by real-time qRT-PCR and microarray. qRT-PCR showed strong (4- to 5-fold) induction of gstp1 by tBHQ as early as 1 dpf. tBHQ also induced gclc (2 dpf), but not sod1, nqo1, or cyp1a. TCDD induced cyp1a but none of the other genes. Microarray analysis showed that 1477 probes were significantly different among the DMSO-, tBHQ-, and TCDD-treated eleutheroembryos at 4 dpf. There was substantial overlap between genes induced in developing zebrafish and a set of marker genes induced by oxidative stress in mammals. Genes induced by tBHQ in 4-dpf zebrafish included those involved in glutathione synthesis and utilization, signal transduction, and DNA damage/stress response. The strong induction of hsp70 determined by microarray was confirmed by qRT-PCR and by use of transgenic zebrafish expressing enhanced green fluorescent protein (EGFP) under control of the hsp70 promoter. Genes strongly down-regulated by tBHQ included mitfa, providing a molecular explanation for the loss of pigmentation in tBHQ-exposed embryos. These data show that zebrafish embryos are responsive to oxidative stress as early as 1 dpf, that responsiveness varies with development in a gene-specific manner, and that the oxidative stress response is substantially conserved in vertebrate animals.
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Human urinary biomarkers of dioxin exposure: Analysis by metabolomics and biologically driven data dimensionality reduction. Toxicol Lett 2014; 230:234-43. [DOI: 10.1016/j.toxlet.2013.10.031] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 10/16/2013] [Accepted: 10/26/2013] [Indexed: 12/31/2022]
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Niittynen M, Simanainen U, Pohjanvirta R, Sankari S, Tuomisto JT. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) increases bilirubin formation but hampers quantitative hepatic conversion of biliverdin to bilirubin in rats with wild-type AH receptor. Basic Clin Pharmacol Toxicol 2014; 114:497-509. [PMID: 24418412 DOI: 10.1111/bcpt.12191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 12/30/2013] [Indexed: 11/29/2022]
Abstract
In haem degradation, haem oxygenase-1 (HO-1) first cleaves haem to biliverdin, which is reduced to bilirubin by biliverdin IXα reductase (BVR-A). The environmental pollutant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes hepatic accumulation of biliverdin in moderately TCDD-resistant line B (Kuopio) rats. Using line B and two TCDD-sensitive rat strains, the present study set out to probe the dose-response and biochemical mechanisms of this accumulation. At 28 days after exposure to 3-300 μg/kg TCDD in line B rats, already the lowest dose of TCDD tested, 3 μg/kg, affected serum bilirubin conjugates, and after doses ≥100 μg/kg, the liver content of bilirubin, biliverdin and their conjugates (collectively 'bile pigments') as well as HO-1 was elevated. BVR-A activity and serum bile acids were increased only by the doses of 100 and 300 μg/kg TCDD, respectively. Biliverdin conjugates correlated best with biliverdin suggesting it to be their immediate precursor. TCDD (100 μg/kg, 10 days) increased hepatic bilirubin and biliverdin levels also in TCDD-sensitive Long-Evans (Turku/AB; L-E) rats. Hepatic bilirubin and bile acids, but not biliverdin, were increased in feed-restricted L-E control rats. In TCDD-sensitive line C (Kuopio) rats, 10 μg/kg of TCDD increased the body-weight-normalized biliary excretion of bilirubin. Altogether, the results suggest that at acutely toxic doses, TCDD induces the formation of bilirubin in rats. However, concurrently, TCDD seems to hamper the quantitative conversion of biliverdin to bilirubin in line B and L-E rats' liver. Biliverdin conjugates are most likely formed as secondary products of biliverdin.
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Affiliation(s)
- Marjo Niittynen
- Department of Environmental Health, National Institute for Health and Welfare, Kuopio, Finland
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Budinsky RA, Schrenk D, Simon T, Van den Berg M, Reichard JF, Silkworth JB, Aylward LL, Brix A, Gasiewicz T, Kaminski N, Perdew G, Starr TB, Walker NJ, Rowlands JC. Mode of action and dose–response framework analysis for receptor-mediated toxicity: The aryl hydrocarbon receptor as a case study. Crit Rev Toxicol 2013; 44:83-119. [DOI: 10.3109/10408444.2013.835787] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Wang Y, Shen D, Wang VM, Yu CR, Wang RX, Tuo J, Chan CC. Enhanced apoptosis in retinal pigment epithelium under inflammatory stimuli and oxidative stress. Apoptosis 2012; 17:1144-55. [PMID: 22911474 PMCID: PMC3469765 DOI: 10.1007/s10495-012-0750-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Age-related macular degeneration (AMD) is a neurodegenerative disease that causes irreversible central vision loss in the elderly. Retinal pigment epithelium (RPE) has been found to be a key component in AMD pathogenesis. The Ccl2(-/-)/Cx3cr1(-/-) (DKO) mouse on Crb1(rd8) background is created as an AMD model, developing AMD-like retinal lesions. Our study aimed to examine RPE apoptosis in DKO mouse and human ARPE-19 cell line. DKO RPE expressed higher apoptotic proteins when compared with age-matched wild type (WT) RPE in physiological conditions. Apoptosis of primary cultured mouse RPE was evaluated under stimulation with lipopolysaccharide for inflammatory stimulation and 2,3,7,8-tetrachlorodibenzo-p-dioxin or H(2)O(2) for oxidative stress. Compared with WT RPE, DKO RPE was more susceptible to Fas ligand (FasL)-mediated apoptosis under both inflammatory and oxidative stress, with less cell viability and higher expression of apoptotic transcripts and proteins. Decreased cell viability was also observed in ARPE-19 cells under each stimulus. Furthermore, we also investigated the anti-apoptotic effects of decoy receptor 3 (DcR3), a decoy receptor for FasL, on ARPE-19 cells under inflammatory and oxidative stress. DcR3 pre-incubated ARPE-19 cells showed decreased apoptosis, with increased cell viability and decreased expression of apoptotic transcripts and proteins under the stimuli. On the contrary, knockdown of DcR3 in ARPE-19 cells showed totally opposite results. Our study demonstrates that FasL-mediated RPE apoptosis may play a pivotal role in AMD pathogenesis.
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Affiliation(s)
- Yujuan Wang
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Defen Shen
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Vinson M. Wang
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Cheng-Rong Yu
- Molecular Immunology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ren-Xi Wang
- Molecular Immunology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jingsheng Tuo
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chi-Chao Chan
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Chen Y, Krishan M, Nebert DW, Shertzer HG. Glutathione-deficient mice are susceptible to TCDD-Induced hepatocellular toxicity but resistant to steatosis. Chem Res Toxicol 2011; 25:94-100. [PMID: 22082335 DOI: 10.1021/tx200242a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) generates both hepatocellular injury and steatosis, processes that involve oxidative stress. Herein, we evaluated the role of the antioxidant glutathione (GSH) in TCDD-induced hepatotoxicity. Glutamate-cysteine ligase (GCL), comprising catalytic (GCLC) and modifier (GCLM) subunits, is rate limiting in de novo GSH biosynthesis; GCLM maintains GSH homeostasis by optimizing the catalytic efficiency of GCL holoenzyme. Gclm(-/-) transgenic mice exhibit 10-20% of normal tissue GSH levels. Gclm(-/-) and Gclm(+/+) wild-type (WT) female mice received TCDD for 3 consecutive days and were then examined 21 days later. As compared with WT littermates, Gclm(-/-) mice were more sensitive to TCDD-induced hepatocellular toxicity, exhibiting lower reduction potentials for GSH, lower ATP levels, and elevated levels of plasma glutamic oxaloacetic transaminase (GOT) and γ-glutamyl transferase (GGT). However, the histopathology showed that TCDD-mediated steatosis, which occurs in WT mice, was absent in Gclm(-/-) mice. This finding was consistent with cDNA microarray expression analysis, revealing striking deficiencies in lipid biosynthesis pathways in Gclm(-/-) mice; qrt-PCR analysis confirmed that Gclm(-/-) mice are deficient in expression of several lipid metabolism genes including Srebp2, Elovl6, Fasn, Scd1/2, Ppargc1a, and Ppara. We suggest that whereas GSH protects against TCDD-mediated hepatocellular damage, GSH deficiency confers resistance to TCDD-induced steatosis due to impaired lipid metabolism.
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Affiliation(s)
- Ying Chen
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Denver , Aurora, Colorado 80045, United States
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Jennen D, Ruiz-Aracama A, Magkoufopoulou C, Peijnenburg A, Lommen A, van Delft J, Kleinjans J. Integrating transcriptomics and metabonomics to unravel modes-of-action of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in HepG2 cells. BMC SYSTEMS BIOLOGY 2011; 5:139. [PMID: 21880148 PMCID: PMC3231768 DOI: 10.1186/1752-0509-5-139] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 08/31/2011] [Indexed: 12/30/2022]
Abstract
BACKGROUND The integration of different 'omics' technologies has already been shown in several in vivo studies to offer a complementary insight into cellular responses to toxic challenges. Being interested in developing in vitro cellular models as alternative to animal-based toxicity assays, we hypothesize that combining transcriptomics and metabonomics data improves the understanding of molecular mechanisms underlying the effects caused by a toxic compound also in vitro in human cells. To test this hypothesis, and with the focus on non-genotoxic carcinogenesis as an endpoint of toxicity, in the present study, the human hepatocarcinoma cell line HepG2 was exposed to the well-known environmental carcinogen 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). RESULTS Transcriptomics as well as metabonomics analyses demonstrated changes in TCDD-exposed HepG2 in common metabolic processes, e.g. amino acid metabolism, of which some of the changes only being confirmed if both 'omics' were integrated. In particular, this integrated analysis identified unique pathway maps involved in receptor-mediated mechanisms, such as the G-protein coupled receptor protein (GPCR) signaling pathway maps, in which the significantly up-regulated gene son of sevenless 1 (SOS1) seems to play an important role. SOS1 is an activator of several members of the RAS superfamily, a group of small GTPases known for their role in carcinogenesis. CONCLUSIONS The results presented here were not only comparable with other in vitro studies but also with in vivo studies. Moreover, new insights on the molecular responses caused by TCDD exposure were gained by the cross-omics analysis.
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Affiliation(s)
- Danyel Jennen
- Department of Toxicogenomics, Maastricht University, PO Box 616, 6200 MD Maastricht, the Netherlands
- Netherlands Toxicogenomics Centre, PO Box 616, 6200 MD Maastricht, the Netherlands
| | - Ainhoa Ruiz-Aracama
- RIKILT-Institute of Food Safety, Wageningen University and Research Centre, PO Box 230, 6700 AE Wageningen, the Netherlands
- Netherlands Toxicogenomics Centre, PO Box 616, 6200 MD Maastricht, the Netherlands
| | - Christina Magkoufopoulou
- Department of Toxicogenomics, Maastricht University, PO Box 616, 6200 MD Maastricht, the Netherlands
| | - Ad Peijnenburg
- RIKILT-Institute of Food Safety, Wageningen University and Research Centre, PO Box 230, 6700 AE Wageningen, the Netherlands
- Netherlands Toxicogenomics Centre, PO Box 616, 6200 MD Maastricht, the Netherlands
| | - Arjen Lommen
- RIKILT-Institute of Food Safety, Wageningen University and Research Centre, PO Box 230, 6700 AE Wageningen, the Netherlands
- Netherlands Toxicogenomics Centre, PO Box 616, 6200 MD Maastricht, the Netherlands
| | - Joost van Delft
- Department of Toxicogenomics, Maastricht University, PO Box 616, 6200 MD Maastricht, the Netherlands
- Netherlands Toxicogenomics Centre, PO Box 616, 6200 MD Maastricht, the Netherlands
| | - Jos Kleinjans
- Department of Toxicogenomics, Maastricht University, PO Box 616, 6200 MD Maastricht, the Netherlands
- Netherlands Toxicogenomics Centre, PO Box 616, 6200 MD Maastricht, the Netherlands
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Romer EJ, Sulentic CEW. Hydrogen peroxide modulates immunoglobulin expression by targeting the 3'Igh regulatory region through an NFκB-dependent mechanism. Free Radic Res 2011; 45:796-809. [PMID: 21599461 DOI: 10.3109/10715762.2011.581280] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Reactive oxygen species such as hydrogen peroxide (H(2)O(2)) appear to play a role in signal transduction in immune cells and have been shown to be synthesized upon antigen-mediated activation and to facilitate cellular activation in B- and T-cells. However, an effect of H(2)O(2) on B-cell function (i.e. immunoglobulin (Ig) expression) has been less well-characterized. The effects of H(2)O(2) exposure on lymphocytes may be partly mediated by oxidative modulation of the NFκB signal transduction pathway, which also plays a role in Ig heavy chain (Igh) gene expression. Igh transcription in B lymphocytes is an essential step in antibody production and is governed through a complex interaction of several regulatory elements, including the 3'Igh regulatory region (3'IghRR). Utilizing an in vitro mouse B-cell line model, this study demonstrates that exposure to low μM concentrations of H(2)O(2) can enhance 3'IghRR-regulated transcriptional activity and Igh gene expression, while either higher concentrations of H(2)O(2) or the expression of a degradation resistant inhibitory κB (IκBα super-repressor) can abrogate this effect. Furthermore, suppressive H(2)O(2) concentrations increased protein levels of the p50 NFκB sub-unit, IκBα, and an IκBα immunoreactive band which was previously characterized as an IκBα cleavage product exhibiting stronger inhibitory function than native IκBα. Taken together, these observations suggest that exposure of B lymphocytes to H(2)O(2) can alter Igh transcriptional activity and Ig expression in a complex biphasic manner which appears to be mediated by NFκB and altered 3'IghRR activity. These results may have significant implications to disease states previously associated with the 3'IghRR.
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Affiliation(s)
- Eric J Romer
- Department of Pharmacology & Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio 45435, USA
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Inhibition of Soluble Epoxide Hydrolase Confers Cardioprotection and Prevents Cardiac Cytochrome P450 Induction by Benzo(a)pyrene. J Cardiovasc Pharmacol 2011; 57:273-81. [DOI: 10.1097/fjc.0b013e3182055baf] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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External influences on the immune system via activation of the aryl hydrocarbon receptor. Semin Immunol 2011; 23:99-105. [PMID: 21288737 DOI: 10.1016/j.smim.2011.01.008] [Citation(s) in RCA: 135] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 01/10/2011] [Indexed: 02/06/2023]
Abstract
The aryl hydrocarbon receptor (AhR), subject of intensive research over three decades by the pharmacology/toxicology field has recently made its entry into mainstream immunology research and is set to continue to intrigue with ever more complex modes of modulating immune responses. The discovery of high and selective AhR expression on Th17 cells and its role in induction of the cytokine IL-22 attributed new immunological functions to this transcription factor and stimulated further research into physiological functions of the AhR in the immune system. A number of recent reviews have highlighted potential new avenues of research. This review addresses recent new insight into physiological roles of AhR in the immune system.
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Teraoka H, Ogawa A, Kubota A, Stegeman JJ, Peterson RE, Hiraga T. Malformation of certain brain blood vessels caused by TCDD activation of Ahr2/Arnt1 signaling in developing zebrafish. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2010; 99:241-7. [PMID: 20554057 PMCID: PMC3040289 DOI: 10.1016/j.aquatox.2010.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 04/20/2010] [Accepted: 05/04/2010] [Indexed: 05/07/2023]
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes various signs of toxicity in early life stages of vertebrates through activation of the aryl hydrocarbon receptor (AHR). The AHR also plays important roles in normal development in mice, and AHR(-/-) mice show abnormal development of vascular structures in various blood vessels. Our previous studies revealed that Ahr type 2 (Ahr2) activation by TCDD and beta-naphthoflavone (BNF) caused a significant decrease in blood flow in the dorsal midbrain of zebrafish embryos. Here we report effects of TCDD exposure on the morphology of some blood vessels in the head of developing zebrafish. TCDD caused concentration-dependent anatomical rearrangements in the shape of the prosencephalic artery in zebrafish larvae. In contrast, no major vascular defects were recognized in the trunk and tail regions following exposure to TCDD at least at the concentrations used. Essentially, the same observations were also confirmed in BNF-exposed larvae. Knock-down of either Ahr2 or Ahr nuclear translocator type 1 (Arnt1) by morpholino oligonucleotides (MOs) protected larvae against abnormal shape of the prosencephalic artery caused by TCDD and BNF. On the other hand, knock-down of Ahr2 or Arnt1 in vehicle-exposed zebrafish larvae had no clear effect on morphology of the prosencephalic artery or trunk vessels. Ascorbic acid, an antioxidant, protected against the TCDD-induced decrease in blood flow through the prosencephalic artery, but not the abnormal morphological changes in the shape of this artery. These results indicate that activation of Ahr2/Arnt1 pathway by TCDD and BNF affects the shape of certain blood vessels in the brain of developing zebrafish.
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Affiliation(s)
- Hiroki Teraoka
- School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501, Japan.
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Søfteland L, Holen E, Olsvik PA. Toxicological application of primary hepatocyte cell cultures of Atlantic cod (Gadus morhua)--effects of BNF, PCDD and Cd. Comp Biochem Physiol C Toxicol Pharmacol 2010; 151:401-11. [PMID: 20067845 DOI: 10.1016/j.cbpc.2010.01.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 01/04/2010] [Accepted: 01/07/2010] [Indexed: 10/20/2022]
Abstract
Fish primary hepatocyte cultures are commonly used for toxicological assessment of contaminants. So far no one has described a protocol on how to use Atlantic cod hepatocytes in bioassays. In this work we describe an experiment in which we were able to isolate intact liver cells from mature individuals. Hepatic cytochrome P450 1A (CYP1A) expression in the isolated cells was evaluated with in situ hybridization after intraperitoneal injection with the strong CYP1A inducer ss-naphthoflavone (BNF). Cod hepatocytes were further exposed to 1,2,3,7,8-polychlorinated dibenzo-p-dioxin (PCDD) and cadmium (Cd). Transcriptional responses of 11 genes were quantified (CYP1A, metallothionein (MT), aryl hydrocarbon receptor 2 (AhR2), UDP-glucuronosyltransferase (UGT), glutathione S-transferase (GST), vitellogenin B (VTGB), hypoxia-inducible factor 1 (HIF1), heme oxygenase 1 (HO-1), transferrin, glutathione peroxidase (GPx) and heat shock protein 70 (HSP70)). Immunohistochemisty evaluation clearly showed elevated CYP1A mRNA expression in primary hepatocytes isolated from BNF-exposed fish. The transcriptional results showed that PCDD exposure resulted in a 311-fold up-regulation of CYP1A and Cd a 1.82-fold increase of MT. Unexpectedly, AhR2 and UGT mRNA levels were not significantly up-regulated in PCDD-exposed cod hepatocytes. HO-1 and transferrin showed a dose-dependent transcriptional response to Cd exposure. Cd appears to act as an endocrine-disrupting metal in exposed primary Atlantic cod hepatocytes. This study demonstrates the use of Atlantic cod primary hepatocyte cultures in toxicological research.
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Affiliation(s)
- Liv Søfteland
- National Institute of Nutrition and Seafood Research, PO Box 2029 Nordnes, N-5817 Bergen, Norway.
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Henkler F, Brinkmann J, Luch A. The role of oxidative stress in carcinogenesis induced by metals and xenobiotics. Cancers (Basel) 2010; 2:376-96. [PMID: 24281075 PMCID: PMC3835083 DOI: 10.3390/cancers2020376] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 04/02/2010] [Accepted: 04/06/2010] [Indexed: 12/21/2022] Open
Abstract
In addition to a wide range of adverse effects on human health, toxic metals such as cadmium, arsenic and nickel can also promote carcinogenesis. The toxicological properties of these metals are partly related to generation of reactive oxygen species (ROS) that can induce DNA damage and trigger redox-dependent transcription factors. The precise mechanisms that induce oxidative stress are not fully understood. Further, it is not yet known whether chronic exposures to low doses of arsenic, cadmium or other metals are sufficient to induce mutations in vivo, leading to DNA repair responses and/or tumorigenesis. Oxidative stress can also be induced by environmental xenobiotics, when certain metabolites are generated that lead to the continuous release of superoxide, as long as the capacity to reduce the resulting dions (quinones) into hydroquinones is maintained. However, the specific significance of superoxide-dependent pathways to carcinogenesis is often difficult to address, because formation of DNA adducts by mutagenic metabolites can occur in parallel. Here, we will review both mechanisms and toxicological consequences of oxidative stress triggered by metals and dietary or environmental pollutants in general. Besides causing DNA damage, ROS may further induce multiple intracellular signaling pathways, notably NF-kB, JNK/SAPK/p38, as well as Erk/MAPK. These signaling routes can lead to transcriptional induction of target genes that could promote proliferation or confer apoptosis resistance to exposed cells. The significance of these additional modes depends on tissue, cell-type and is often masked by alternate oncogenic mechanisms being activated in parallel.
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Affiliation(s)
- Frank Henkler
- German Federal Institute for Risk Assessment, Thielallee 88-92, 14195 Berlin, Germany; E-Mail:
| | | | - Andreas Luch
- German Federal Institute for Risk Assessment, Thielallee 88-92, 14195 Berlin, Germany; E-Mail:
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Wells PG, Lee CJJ, McCallum GP, Perstin J, Harper PA. Receptor- and reactive intermediate-mediated mechanisms of teratogenesis. Handb Exp Pharmacol 2010:131-162. [PMID: 20020262 DOI: 10.1007/978-3-642-00663-0_6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Drugs and environmental chemicals can adversely alter the development of the fetus at critical periods during pregnancy, resulting in death, or in structural and functional birth defects in the surviving offspring. This process of teratogenesis may not be evident until a decade or more after birth. Postnatal functional abnormalities include deficits in brain function, a variety of metabolic diseases, and cancer. Due to the high degree of fetal cellular division and differentiation, and to differences from the adult in many biochemical pathways, the fetus is highly susceptible to teratogens, typically at low exposure levels that do not harm the mother. Insights into the mechanisms of teratogenesis come primarily from animal models and in vitro systems, and involve either receptor-mediated or reactive intermediate-mediated processes. Receptor-mediated mechanisms involving the reversible binding of xenobiotic substrates to a specific receptor are exemplified herein by the interaction of the environmental chemical 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or "dioxin") with the cytosolic aryl hydrocarbon receptor (AHR), which translocates to the nucleus and, in association with other proteins, binds to AH-responsive elements (AHREs) in numerous genes, initiating changes in gene transcription that can perturb development. Alternatively, many xenobiotics are bioactivated by fetal enzymes like the cytochromes P450 (CYPs) and prostaglandin H synthases (PHSs) to highly unstable electrophilic or free radical reactive intermediates. Electrophilic reactive intermediates can covalently (irreversibly) bind to and alter the function of essential cellular macromolecules (proteins, DNA), causing developmental anomalies. Free radical reactive intermediates can enhance the formation of reactive oxygen species (ROS), resulting in oxidative damage to cellular macromolecules and/or altered signal transduction. The teratogenicity of reactive intermediates is determined to a large extent by the balance among embryonic and fetal pathways of xenobiotic bioactivation, detoxification of the xenobiotic reactive intermediate, detoxification of ROS, and repair of oxidative macromolecular damage.
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Affiliation(s)
- Peter G Wells
- Division of Biomolecular Sciences, University of Toronto, Toronto, Ontario, Canada.
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Zordoky BNM, El-Kadi AOS. 2,3,7,8-Tetrachlorodibenzo-p-dioxin and beta-naphthoflavone induce cellular hypertrophy in H9c2 cells by an aryl hydrocarbon receptor-dependant mechanism. Toxicol In Vitro 2009; 24:863-71. [PMID: 19969063 DOI: 10.1016/j.tiv.2009.12.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 11/11/2009] [Accepted: 12/01/2009] [Indexed: 11/30/2022]
Abstract
Cigarette smoke is a major risk factor for cardiovascular diseases. It contains thousands of compounds that activate the aryl hydrocarbon receptor (AhR). In addition, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most potent AhR ligand, has been shown to cause cardiotoxic effects in several in vivo models. Although induction of CYP1 family is the most important effect of AhR activation, the role of CYP1 induction in mediating the cardiotoxic effect of TCDD is usually overlooked. Therefore, we investigated whether AhR activation causes a hypertrophic effect in H9c2 cells and we related this effect to changes in CYP gene expression. In the current study, the cardiac derived H9c2 cells were treated with two AhR ligands, TCDD and beta-naphthoflavone (BNF), for 24 and 48h. The expression of the hypertrophic markers, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), and several CYP genes were measured by real-time PCR. Treatment of H9c2 cells with TCDD or BNF for 24h caused a significant induction of CYP1A1, CYP1B1, and CYP4A1; however, there was no change in the expression of other genes. On the other hand, treatment of the cells with TCDD or BNF for 48h caused a significant induction of the hypertrophic markers, ANP and BNP, and several CYP genes such as CYP1A1, CYP1B1, CYP2E1, CYP2J3, and CYP4F4 parallel to a significant increase in the cell surface area. Neither TCDD nor BNF increased the oxidative stress in H9c2 cells at all concentrations tested. Interestingly, resveratrol, an AhR antagonist, protected the cells from TCDD-induced hypertrophy. In conclusion, AhR ligands caused a hypertrophic effect in H9c2 cells which was associated with induction of several CYP genes which can be prevented by resveratrol.
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Affiliation(s)
- Beshay N M Zordoky
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2N8
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Protective Effects of the Antioxidant 4b,5,9b,10-Tetrahydroindeno[1,2-b]indole Against TCDD Toxicity in C57BL/6J Mice. Int J Toxicol 2009; 29:40-8. [DOI: 10.1177/1091581809352885] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The protection against 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD; 5 µg/kg body weight) toxicity by the antioxidant 4b,5,9b,10-tetrahydroindeno[1,2- b]indole (THII) was examined in female C57BL/6J mice. TCDD produced increases in the levels of hepatic lipid-derived aldehydes, rates of mitochondrial production of hydrogen peroxide and superoxide, and the oxidation state of cytosolic GSH. In contrast, mitochondrial GSH increased in reduction state, correlating with an increase in mitochondrial membrane potential. Systemically, TCDD lowered body weight gain, percentage body fat, and hepatic ATP levels, parameters prevented by concomitant administration of 100 µM THII in drinking water. However, TCDD-induced increases in mitochondrial respiration and decreased mitochondrial membrane fluidity were not prevented by THII. These results suggest that TCDD-mediated oxidative stress was not responsible for changes in mitochondrial respiration or membrane fluidity. Furthermore, although TCDD produced a large increase in mitochondrial oxygen consumption, this was not associated with the poor gain in weight produced by TCDD.
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Lu CF, Wang YM, Peng SQ, Zou LB, Tan DH, Liu G, Fu Z, Wang QX, Zhao J. Combined effects of repeated administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin and polychlorinated biphenyls on kidneys of male rats. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2009; 57:767-776. [PMID: 19373505 DOI: 10.1007/s00244-009-9323-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Accepted: 03/30/2009] [Indexed: 05/26/2023]
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls (PCBs) are persistent environmental contaminants that exist as complex mixtures in the environment, but the possible interactions of TCDD and PCBs have not been systematically investigated. The main objective of this study was to investigate the combined nephrotoxic effects of TCDD and PCBs on rats and to reveal the potential interactions between TCDD and PCBs. Male Sprague-Dawley rats were intragastrically administered TCDD (10 microg/kg), PCBs (Aroclor 1254, 10 mg/kg), or the combination (10 microg/kg TCDD + 10 mg/kg Aroclor 1254). After 12 consecutive days of exposure, all treatments induced nephrotoxicity, as evidenced by significant increases in the levels of serum creatinine and blood urea nitrogen, changes of kidney histopathology, and significant renal oxidative stress. Most of these effects were more remarkable in the combined-exposure group. Furthermore, all treatments induced renal cytochrome P450 1A1 (CYP1A1) protein expression, and the induction was more conspicuous in the combined-exposure group. These findings suggested that the nephrotoxicity induced by TCDD and PCBs in the present study might be attributable to the high expression of CYP1A1. In addition, the result of the two-way analysis of variance revealed that the combined effects of TCDD and PCBs were complicated, being additive, synergistic, or antagonistic depending on the selection of toxicity end points under the present experimental condition. This study demonstrates that combined exposure to TCDD and PCBs induced significant nephrotoxicity in rats, and there were complicated interactions between the two pollutants on the nephrotoxicity.
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Affiliation(s)
- Chun-Feng Lu
- Evaluation and Research Center for Toxicology, Institute of Disease Control and Prevention of PLA, Academy of Military Medical Sciences, 20 Dongdajie Street, Fengtai District, Beijing, 100071, People's Republic of China
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Simon T, Aylward LL, Kirman CR, Rowlands JC, Budinsky RA. Estimates of Cancer Potency of 2,3,7,8-Tetrachlorodibenzo(p)dioxin Using Linear and Nonlinear Dose-Response Modeling and Toxicokinetics. Toxicol Sci 2009; 112:490-506. [DOI: 10.1093/toxsci/kfp232] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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Dehydroascorbate protection against dioxin-induced toxicity in the beta-cell line INS-1E. Toxicol Lett 2009; 189:27-34. [PMID: 19414064 DOI: 10.1016/j.toxlet.2009.04.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Accepted: 04/27/2009] [Indexed: 11/22/2022]
Abstract
Oxidative stress has been proposed as a mechanism of the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The aim of this research was to evaluate the protective effects of increased intracellular ascorbate levels against TCDD acute toxicity in the insulin-secreting beta-cell line INS-1E. Ascorbate is considered a potent antioxidant, but its therapeutic efficacy is greatly limited by its slow achievement of high intracellular levels. This might be circumvented by administration of dehydroascorbate (DHA), which is transported at a much higher rate and undergoes rapid intracellular reduction to ascorbate. Indeed, 30 min incubation of INS-1E cells with various concentrations of DHA caused a remarkable, dose-related increase of the intracellular ascorbate levels. INS-1E cells preincubated with 0.5 and 1.0mM DHA showed a greater viability than control cells after 1h exposition to cytotoxic TCDD concentrations. In our experimental conditions, TCDD surprisingly failed to increase ROS production in INS-1E cells, but induced a dose-related mitochondrial depolarisation which was significantly improved by DHA preincubation. Furthermore, DHA preincubation completely prevented the low dose TCDD-induced inhibition of glucose-stimulated insulin secretion. Thus, our results suggest that DHA preincubation protects INS-1E cells against TCDD acute toxicity by partially preserving mitochondrial function.
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Hernández-Ochoa I, Karman BN, Flaws JA. The role of the aryl hydrocarbon receptor in the female reproductive system. Biochem Pharmacol 2009; 77:547-59. [PMID: 18977336 PMCID: PMC2657805 DOI: 10.1016/j.bcp.2008.09.037] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2008] [Revised: 09/24/2008] [Accepted: 09/25/2008] [Indexed: 11/28/2022]
Abstract
In recent years, many studies have emphasized how changes in aryl hydrocarbon receptor (AHR)-mediated gene expression result in biological effects, raising interest in this receptor as a regulator of normal biological function. This review focuses on what is known about the role of the AHR in the female reproductive system, which includes the ovaries, Fallopian tubes or oviduct, uterus and vagina. This review also focuses on the role of the AHR in reproductive outcomes such as cyclicity, senescence, and fertility. Specifically, studies using potent AHR ligands, as well as transgenic mice lacking the AHR-signaling pathway are discussed from a viewpoint of understanding the endogenous role of this ligand-activated transcription factor in the female reproductive lifespan. Based on findings highlighted in this paper, it is proposed that the AHR has a role in physiological functions including ovarian function, establishment of an optimum environment for fertilization, nourishing the embryo and maintaining pregnancy, as well as in regulating reproductive lifespan and fertility. The mechanisms by which the AHR regulates female reproduction are poorly understood, but it is anticipated that new models and the ability to generate specific gene deletions will provide powerful experimental tools for better understanding how alterations in AHR pathways result in functional changes in the female reproductive system.
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Affiliation(s)
- Isabel Hernández-Ochoa
- Department of Veterinary Biosciences, University of Illinois Urbana-Champaign, Urbana, IL 61802, USA
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