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Aydemir MC, Yaman İ, Kilic MA. Membrane Receptor-Mediated Disruption of Cellular Homeostasis: Changes in Intracellular Signaling Pathways Increase the Toxicity of Ochratoxin A. Mol Nutr Food Res 2024:e2300777. [PMID: 38880772 DOI: 10.1002/mnfr.202300777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 04/29/2024] [Indexed: 06/18/2024]
Abstract
Organisms maintain their cellular homeostatic balance by interacting with their environment through the use of their cell surface receptors. Membrane based receptors such as the transforming growth factor β receptor (TGFR), the prolactin receptor (PRLR), and hepatocyte growth factor receptor (HGFR), along with their associated signaling cascade, play significant roles in retaining cellular homeostasis. While these receptors and related signaling pathways are essential for health of cell and organism, their dysregulation can lead to imbalance in cell function with severe pathological conditions such as cell death or cancer. Ochratoxin A (OTA) can disrupt cellular homeostasis by altering expression levels of these receptors and/or receptor-associated intracellular downstream signaling modulators and/or pattern and levels of their phosphorylation/dephosphorylation. Recent studies have shown that the activity of the TGFR, the PRLR, and HGFR and their associated signaling cascades change upon OTA exposure. A critical evaluation of these findings suggests that while increased activity of the HGFR and TGFR signaling pathways leads to an increase in cell survival and fibrosis, decreased activity of the PRLR signaling pathway leads to tissue damage. This review explores the roles of these receptors in OTA-related pathologies and effects on cellular homeostasis.
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Affiliation(s)
- Mesut Cihan Aydemir
- Department of Biology, Institute of Natural and Applied Sciences, Akdeniz University, Antalya, 07070, Turkey
| | - İbrahim Yaman
- Molecular Toxicology and Cancer Research Laboratory, Department of Molecular Biology and Genetics, Bogazici University, Istanbul, Bebek, 34342, Turkey
| | - Mehmet Akif Kilic
- Department of Biology, Molecular Biology Section, Akdeniz University, Antalya, 07070, Turkey
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2
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Kuhn M, Hassan R, González D, Myllys M, Hobloss Z, Degen GH, Humpf HU, Hengstler JG, Cramer B, Ghallab A. Role of albumin in the metabolism and excretion of ochratoxin A. Mycotoxin Res 2024:10.1007/s12550-024-00538-1. [PMID: 38743341 DOI: 10.1007/s12550-024-00538-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/21/2024] [Accepted: 04/29/2024] [Indexed: 05/16/2024]
Abstract
Ochratoxin A (OTA) is known to be strongly bound to serum albumin, but it remains unknown how albumin affects its metabolism and kinetics. To close this gap, we used a mouse model, where heterozygous albumin deletion reduces serum albumin to concentrations similar to hypoalbuminemic patients and completely eliminates albumin by a homozygous knockout. OTA and its potential metabolites (OTα, 4-OH-OTA, 7'-OH-OTA, OTHQ, OP-OTA, OTB-GSH, OTB-NAC, OTB) were time-dependently analyzed in plasma, bile, and urine by LC-MS/MS and were compared to previously published hepatotoxicity and nephrotoxicity data. Homozygous albumin deletion strongly accelerated plasma clearance as well as biliary and urinary excretion of the parent compound and its hydroxylation products. Decreasing albumin in mice by the heterozygous and even more by the homozygous knockout leads to an increase in the parent compound in urine which corresponded to increased nephrotoxicity. The role of albumin in OTA-induced hepatotoxicity is more complex, since heterozygous but not homozygous nor wild-type mice showed a strong biliary increase in the toxic open lactone OP-OTA. Correspondingly, OTA-induced hepatotoxicity was higher in heterozygous than in wild-type and homozygous animals. We present evidence that albumin-mediated retention of OTA in hepatocytes is required for formation of the toxic OP-OTA, while complete albumin elimination leads to rapid biliary clearance of OTA from hepatocytes with less formation of OP-OTA. In conclusion, albumin has a strong influence on metabolism and toxicity of OTA. In hypoalbuminemia, the parent OTA is associated with increased nephrotoxicity and the open lactone with increased hepatotoxicity.
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Affiliation(s)
- Michael Kuhn
- Institute of Food Chemistry, University Münster, Corrensstr. 45, 48149, Münster, Germany
| | - Reham Hassan
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
- Forensic Medicine and Toxicology Department, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
| | - Daniela González
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Maiju Myllys
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Zaynab Hobloss
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Gisela H Degen
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Hans-Ulrich Humpf
- Institute of Food Chemistry, University Münster, Corrensstr. 45, 48149, Münster, Germany
| | - Jan G Hengstler
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany.
| | - Benedikt Cramer
- Institute of Food Chemistry, University Münster, Corrensstr. 45, 48149, Münster, Germany.
| | - Ahmed Ghallab
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany.
- Forensic Medicine and Toxicology Department, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt.
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Das Trisha A, Hafsa JM, Hasan A, Habib A, Tuba HR, Degen GH, Ali N. Occurrence of ochratoxin A in breast milk and urine samples of nursing mothers in Bangladesh. Mycotoxin Res 2024; 40:135-146. [PMID: 38038834 PMCID: PMC10834631 DOI: 10.1007/s12550-023-00510-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 11/09/2023] [Accepted: 11/13/2023] [Indexed: 12/02/2023]
Abstract
The mycotoxin ochratoxin A (OTA) is a potent nephrotoxin with carcinogenic properties and, thus, of concern as a food contaminant. Since food contaminant data are scarce in Bangladesh, we applied human biomonitoring to gain more insights into OTA exposure in the country's population. OTA concentrations in human milk and urine samples of nursing mothers were determined with the aim to assess also exposure to this mycotoxin in breastfed infants. Breastfeeding mothers (n = 74) from three districts of Bangladesh (Sylhet, Cumilla, and Mymensingh region) participated in this study. They provided demographic data, along with breast milk and urine samples. OTA levels were measured by a competitive enzyme-linked immunosorbent assay (ELISA) with a detection limit of 60 ng/L for milk and 30 ng/L for urine.OTA was detected in 62.2% of all breast milk samples (mean 74.8 ± 49.0 ng/L, range < LOD-243.3 ng/L) and in 51.4% of all urine samples (mean 44.3 ± 63.5 ng/L, range < LOD-519.3 ng/L). The differences observed between regions for mean breast milk or for urinary OTA levels were relatively small. No significant correlation was observed between OTA levels in breast milk and food consumption patterns among nursing mothers. Regarding infant exposure, the estimated average daily intake of OTA for all was 15.0 ng/kg bw/day (range 4.5-45 ng/kg bw/day). In 34.5% of these infants, their estimated daily OTA intake exceeded a preliminary TDI value set by EFSA (17 ng/kg bw/day). The mean OTA intake was slightly higher (16.2 ± 7.8 ng/kg bw/day) in 1-2 months babies than in older infants (< 2 to 12 months), although the difference was not significant. Presence of OTA in most milk and urine samples of nursing mothers documents their widespread dietary mycotoxin exposure. Although based on a relatively small number of participants, the present analysis indicates non-negligible exposure of some nursed infants in Bangladesh. Therefore, further biomonitoring studies and investigations on major sources of OTA in food commodities are encouraged.
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Affiliation(s)
- Aporajita Das Trisha
- Department of Biochemistry and Molecular Biology, Shahjalal University of Science and Technology, Sylhet, 3114, Bangladesh
| | - Jaasia Momtahena Hafsa
- Department of Biochemistry and Molecular Biology, Shahjalal University of Science and Technology, Sylhet, 3114, Bangladesh
| | - Akibul Hasan
- Department of Biochemistry and Molecular Biology, Shahjalal University of Science and Technology, Sylhet, 3114, Bangladesh
| | - Ahsan Habib
- Department of Biochemistry and Molecular Biology, Shahjalal University of Science and Technology, Sylhet, 3114, Bangladesh
| | - Humaira Rashid Tuba
- Department of Biochemistry and Molecular Biology, Shahjalal University of Science and Technology, Sylhet, 3114, Bangladesh
| | - Gisela H Degen
- Leibniz-Research Centre for Working Environment and Human Factors (IfADo) at the TU Dortmund, Ardeystr. 67, D-44139, Dortmund, Germany.
| | - Nurshad Ali
- Department of Biochemistry and Molecular Biology, Shahjalal University of Science and Technology, Sylhet, 3114, Bangladesh.
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Bloch D, Diel P, Epe B, Hellwig M, Lampen A, Mally A, Marko D, Villar Fernández MA, Guth S, Roth A, Marchan R, Ghallab A, Cadenas C, Nell P, Vartak N, van Thriel C, Luch A, Schmeisser S, Herzler M, Landsiedel R, Leist M, Marx-Stoelting P, Tralau T, Hengstler JG. Basic concepts of mixture toxicity and relevance for risk evaluation and regulation. Arch Toxicol 2023; 97:3005-3017. [PMID: 37615677 PMCID: PMC10504116 DOI: 10.1007/s00204-023-03565-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 07/26/2023] [Indexed: 08/25/2023]
Abstract
Exposure to multiple substances is a challenge for risk evaluation. Currently, there is an ongoing debate if generic "mixture assessment/allocation factors" (MAF) should be introduced to increase public health protection. Here, we explore concepts of mixture toxicity and the potential influence of mixture regulation concepts for human health protection. Based on this analysis, we provide recommendations for research and risk assessment. One of the concepts of mixture toxicity is additivity. Substances may act additively by affecting the same molecular mechanism within a common target cell, for example, dioxin-like substances. In a second concept, an "enhancer substance" may act by increasing the target site concentration and aggravating the adverse effect of a "driver substance". For both concepts, adequate risk management of individual substances can reliably prevent adverse effects to humans. Furthermore, we discuss the hypothesis that the large number of substances to which humans are exposed at very low and individually safe doses may interact to cause adverse effects. This commentary identifies knowledge gaps, such as the lack of a comprehensive overview of substances regulated under different silos, including food, environmentally and occupationally relevant substances, the absence of reliable human exposure data and the missing accessibility of ratios of current human exposure to threshold values, which are considered safe for individual substances. Moreover, a comprehensive overview of the molecular mechanisms and most susceptible target cells is required. We conclude that, currently, there is no scientific evidence supporting the need for a generic MAF. Rather, we recommend taking more specific measures, which focus on compounds with relatively small ratios between human exposure and doses, at which adverse effects can be expected.
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Affiliation(s)
- Denise Bloch
- Department of Pesticides Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany.
| | - Patrick Diel
- Department of Molecular and Cellular Sports Medicine, Institute of Cardiovascular Research and Sports Medicine, German Sport University Cologne, Cologne, Germany
| | - Bernd Epe
- Institute of Pharmaceutical and Biomedical Sciences, University of Mainz, Mainz, Germany
| | - Michael Hellwig
- Chair of Special Food Chemistry, Technical University Dresden, Dresden, Germany
| | - Alfonso Lampen
- Risk Assessment Strategies, German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Angela Mally
- Department of Toxicology, University of Würzburg, Würzburg, Germany
| | - Doris Marko
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - María A Villar Fernández
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Sabine Guth
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Angelika Roth
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Rosemarie Marchan
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Ahmed Ghallab
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, South Valley University, Qena, 83523, Egypt
| | - Cristina Cadenas
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Patrick Nell
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Nachiket Vartak
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Christoph van Thriel
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | - Andreas Luch
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Sebastian Schmeisser
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Matthias Herzler
- Department of Chemical and Product Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Robert Landsiedel
- Department of Experimental Toxicology and Ecology, BASF SE, Ludwigshafen, Germany
- Pharmacy, Pharmacology and Toxicology, Free University of Berlin, Berlin, Germany
| | - Marcel Leist
- Department of In Vitro Toxicology and Biomedicine, Inaugurated by the Doerenkamp-Zbinden Foundation, University of Konstanz, Constance, Germany
| | - Philip Marx-Stoelting
- Department of Pesticides Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Tewes Tralau
- Department of Pesticides Safety, German Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | - Jan G Hengstler
- Department of Toxicology, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
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5
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Sousa Terada-Nascimento J, Vieira Dantas-Filho J, Temponi-Santos BL, Perez-Pedroti V, de Lima Pinheiro MM, García-Nuñez RY, Mansur Muniz I, Bezerra de Mira Á, Guedes EAC, de Vargas Schons S. Monitoring of Mycotoxigenic Fungi in Fish Farm Water and Fumonisins in Feeds for Farmed Colossoma macropomum. TOXICS 2023; 11:762. [PMID: 37755772 PMCID: PMC10536658 DOI: 10.3390/toxics11090762] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 08/01/2023] [Accepted: 08/27/2023] [Indexed: 09/28/2023]
Abstract
This study aimed to evaluate the occurrence of mycotoxigenic fungi in fish farm water and mycotoxins in feeds for farmed tambaqui (Colossoma macropomum). A total of 40 samples of freshwater from fish farms and 16 samples of feed were collected and analyzed for microbiology. A total of five species of free-living fungi were identified in fish farms: Aspergillus fumigatus, Penicillium citrinum, P. implicatum, Fusarium oxysporum and Alternaria alternata. These fungi species were counted in water samples at 35.14 CFU mL-1 and 24.69 CFU mL-1 in the dry seasons. In all fish farms, there was a higher abundance of fungi species in the rainy season. During visits to the fish farmers, it was possible to verify poor feed storage conditions. Concerning mutations in blood cells, in tambaqui (C. macropomum), a total of 159 anomalies were found, and in Leptodactylus petersii, 299 anomalies were found, with higher incidences in conditions above 1.0 CFU mL-1 in log10(x+1) fungi and in the rainy season. The occurrence of mycotoxicological contamination was confirmed in 81.25% of the analyzed samples. The quantified mycotoxin was Fumonisins B1 + B2 (375 to 1418 μg kg-1). Pearson's correlation analysis showed a significant positive correlation between Fumonisins and feed samples (r = 0.83). There was also a significant positive correlation between the abundance of fungi in water and the quantification of Fumonisins (r = 0.79). Based on the results obtained, it can be concluded that free-living fungi can be used as bioindicators of water quality in fish farms. Consequently, the lack of good management practices caused microbiological contamination of the aquatic environment.
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Affiliation(s)
- Juliana Sousa Terada-Nascimento
- Programa de Pós-Graduação em Ciências Ambientais, Universidade Federal de Rondônia, UNIR, Rolim de Moura 76.940-000, Brazil; (J.S.T.-N.); (S.d.V.S.)
- Grupo de Pesquisa em Patologia Animal no Bioma Amazônico, Centro de Diagnóstico Animal, Universidade Federal de Rondônia, UNIR, Rolim de Moura 76.940-000, Brazil
| | - Jerônimo Vieira Dantas-Filho
- Programa de Pós-Graduação em Ciências Ambientais, Universidade Federal de Rondônia, UNIR, Rolim de Moura 76.940-000, Brazil; (J.S.T.-N.); (S.d.V.S.)
- Grupo de Pesquisa em Patologia Animal no Bioma Amazônico, Centro de Diagnóstico Animal, Universidade Federal de Rondônia, UNIR, Rolim de Moura 76.940-000, Brazil
| | - Bruna Lucieny Temponi-Santos
- Programa de Pós-Graduação em Ciências Ambientais, Universidade Federal de Rondônia, UNIR, Rolim de Moura 76.940-000, Brazil; (J.S.T.-N.); (S.d.V.S.)
| | - Vinícius Perez-Pedroti
- Programa de Pós-Graduação em Ciências Ambientais, Universidade Federal de Rondônia, UNIR, Rolim de Moura 76.940-000, Brazil; (J.S.T.-N.); (S.d.V.S.)
| | - Maria Mirtes de Lima Pinheiro
- Programa de Pós-Graduação em Ciências Ambientais, Universidade Federal de Rondônia, UNIR, Rolim de Moura 76.940-000, Brazil; (J.S.T.-N.); (S.d.V.S.)
| | - Ricardo Ysaac García-Nuñez
- Departamento de Medicina Veterinária—Zootecnia, Universidad Nacional Amazónica de Madre de Dios, UNAMAD, Puerto Maldonado 17.0001-000, Peru
| | - Igor Mansur Muniz
- Grupo de Pesquisa em Patologia Animal no Bioma Amazônico, Centro de Diagnóstico Animal, Universidade Federal de Rondônia, UNIR, Rolim de Moura 76.940-000, Brazil
| | - Átila Bezerra de Mira
- Programa de Pós-Graduação em Ciências Ambientais, Universidade Federal de Rondônia, UNIR, Rolim de Moura 76.940-000, Brazil; (J.S.T.-N.); (S.d.V.S.)
- Grupo de Pesquisa em Patologia Animal no Bioma Amazônico, Centro de Diagnóstico Animal, Universidade Federal de Rondônia, UNIR, Rolim de Moura 76.940-000, Brazil
| | - Elica Amara Cecilia Guedes
- Centro de Ciências Agrárias e Instituto de Ciências Biológicas e da Saúde, Universidade Federal de Alagoas, UFAL, Maceió 57.480-000, Brazil
| | - Sandro de Vargas Schons
- Programa de Pós-Graduação em Ciências Ambientais, Universidade Federal de Rondônia, UNIR, Rolim de Moura 76.940-000, Brazil; (J.S.T.-N.); (S.d.V.S.)
- Grupo de Pesquisa em Patologia Animal no Bioma Amazônico, Centro de Diagnóstico Animal, Universidade Federal de Rondônia, UNIR, Rolim de Moura 76.940-000, Brazil
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Zhang Z, Sun Y, Xie H, Wang J, Zhang X, Shi Z, Liu Y. Protective effect of selenomethionine on kidney injury induced by ochratoxin A in rabbits. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:29874-29887. [PMID: 36417076 DOI: 10.1007/s11356-022-24297-7] [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: 07/18/2022] [Accepted: 11/14/2022] [Indexed: 06/16/2023]
Abstract
The purpose of this study was to investigate the protective effect and mechanism of selenomethionine (SeMet) on ochratoxin A (OTA)-induced nephrotoxicity in rabbits. In total, sixty Ira rabbits were randomly divided into 5 groups (the control group, OTA group, 0. 2 mg/kg SeMet + OTA group, 0. 4 mg/kg SeMet + OTA group, and 0. 6 mg/kg SeMet + OTA group). The rabbits were fed diets supplemented with different doses of SeMet for 21 days and given 0. 2 mg/kg OTA starting on day 15 for a week. The results showed that the SeMet supplementation could improve the changes in blood physiological indices and renal function decline caused by OTA poisoning, and alleviate pathological kidney injury in the rabbits. SeMet also increased the activities of total antioxidant capacity, superoxide dismutase, and glutathione peroxidase, and decreased the contents of malondialdehyde and reactive oxygen species and the expression of interleukin-1β, interleukin-6, and tumor necrosis factor-α in the damaged kidneys of the rabbits. In addition, the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream gene heme oxygenase 1 (HO-1) was also inhibited after OTA poisoning, while SeMet activated the Nrf2 signaling pathway and enhanced the expression of Nrf2 and the downstream gene HO-1. In conclusion, SeMet protected against kidney injury caused by OTA in rabbits, and the mechanism may be the activation of the Nrf2 signaling pathway.
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Affiliation(s)
- Ziqiang Zhang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, Henan, China
| | - Yingying Sun
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, Henan, China
| | - Hui Xie
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, Henan, China
| | - Jiajia Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, Henan, China
| | - Xin Zhang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, Henan, China
| | - Zhangyu Shi
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, Henan, China
| | - Yumei Liu
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, Henan, China.
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7
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Qu J, Liu K, Liu S, Yue D, Zhang P, Mao X, He W, Huang K, Chen X. Taurine alleviates ochratoxin A-induced pyroptosis in PK-15 cells by inhibiting oxidative stress. J Biochem Mol Toxicol 2023; 37:e23249. [PMID: 36281498 DOI: 10.1002/jbt.23249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 09/08/2022] [Accepted: 10/12/2022] [Indexed: 11/06/2022]
Abstract
Ochratoxin A (OTA) is one of the most harmful mycotoxins, which can cause multiple toxicological effects, especially nephrotoxicity in animals and humans. Taurine is an essential amino acid with various biological functions such as anti-inflammatory and anti-oxidation. However, the protective effect of taurine on OTA-induced nephrotoxicity and pyroptosis had not been reported. Our results showed that OTA exposure induced cytotoxicity and oxidative stress in PK-15 cells, including reactive oxygen species (ROS) accumulation, increased mRNA levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2), and decreased mRNA levels of catalase (CAT), glutathione peroxidase 1 (GPx1), and glutathione peroxidase 4 (GPx4). In addition, OTA treatment induced pyroptosis by increasing the expressions of pyroptosis-related proteins NLRP3, GSDMD, Caspase-1 P20, ASC, Pro-caspase-1, and IL-1β. Meanwhile, taurine could alleviate OTA-induced pyroptosis and cytotoxicity, as well as reduce ROS level, COX-2, and iNOS mRNA levels, and increase the mRNA levels of the antioxidant enzyme in PK-15 cells. Taken together, taurine alleviated OTA-induced pyroptosis in PK-15 cells by inhibiting ROS generation and altering the activity of antioxidant enzymes, thereby attenuating its nephrotoxicity.
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Affiliation(s)
- Jie Qu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China.,Institute of Animal Nutritional Health, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Kai Liu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China.,Institute of Animal Nutritional Health, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Shuiping Liu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China.,Institute of Animal Nutritional Health, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Dongmei Yue
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China.,Institute of Animal Nutritional Health, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Ping Zhang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China.,Institute of Animal Nutritional Health, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Xinru Mao
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China.,Institute of Animal Nutritional Health, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Wenmiao He
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China.,Institute of Animal Nutritional Health, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Kehe Huang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China.,Institute of Animal Nutritional Health, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Xingxiang Chen
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu, China.,Institute of Animal Nutritional Health, Nanjing Agricultural University, Nanjing, Jiangsu, China
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8
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Hassan R, González D, Hobloss Z, Brackhagen L, Myllys M, Friebel A, Seddek AL, Marchan R, Cramer B, Humpf HU, Hoehme S, Degen GH, Hengstler JG, Ghallab A. Inhibition of cytochrome P450 enhances the nephro- and hepatotoxicity of ochratoxin A. Arch Toxicol 2022; 96:3349-3361. [PMID: 36227364 PMCID: PMC9584869 DOI: 10.1007/s00204-022-03395-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 10/06/2022] [Indexed: 11/25/2022]
Abstract
The mycotoxin ochratoxin A (OTA) is a contaminant in food that causes nephrotoxicity and to a minor degree hepatotoxicity. Recently, we observed that OTA induces liver damage preferentially to the cytochrome P450 (CYP)-expressing pericentral lobular zone, similar to hepatotoxic substances known to be metabolically toxified by CYP, such as acetaminophen or carbon tetrachloride. To investigate whether CYP influences OTA toxicity, we used a single dose of OTA (7.5 mg/kg; intravenous) with and without pre-treatment with the pan CYP-inhibitor 1-aminobenzotriazole (ABT) 2 h before OTA administration. Blood, urine, as well as liver and kidney tissue samples were collected 24 h after OTA administration for biochemical and histopathological analyses. Inhibition of CYPs by ABT strongly increased the nephro- and hepatotoxicity of OTA. The urinary kidney damage biomarkers kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) were increased > 126-fold and > 20-fold, respectively, in mice treated with ABT and OTA compared to those receiving OTA alone. The blood biomarkers of liver damage, alanine transaminase (ALT) and aspartate transaminase (AST) both increased > 21- and 30-fold, respectively, when OTA was administered to ABT pre-treated mice compared to the effect of OTA alone. Histological analysis of the liver revealed a pericentral lobular damage induced by OTA despite CYP-inhibition by ABT. Administration of ABT alone caused no hepato- or nephrotoxicity. Overall, the results presented are compatible with a scenario where CYPs mediate the detoxification of OTA, yet the mechanisms responsible for the pericental liver damage pattern still remain to be elucidated.
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Affiliation(s)
- Reham Hassan
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany.,Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, South Valley University, Qena, 83523, Egypt
| | - Daniela González
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Zaynab Hobloss
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Lisa Brackhagen
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Maiju Myllys
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Adrian Friebel
- Institute of Computer Science and Saxonian Incubator for Clinical Research (SIKT), University of Leipzig, Haertelstraße 16-18, 04107, Leipzig, Germany
| | - Abdel-Latif Seddek
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, South Valley University, Qena, 83523, Egypt
| | - Rosemarie Marchan
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Benedikt Cramer
- Institute of Food Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstr. 45, 48149, Münster, Germany
| | - Hans-Ulrich Humpf
- Institute of Food Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstr. 45, 48149, Münster, Germany
| | - Stefan Hoehme
- Institute of Computer Science and Saxonian Incubator for Clinical Research (SIKT), University of Leipzig, Haertelstraße 16-18, 04107, Leipzig, Germany
| | - Gisela H Degen
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany.
| | - Jan G Hengstler
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany.
| | - Ahmed Ghallab
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany. .,Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, South Valley University, Qena, 83523, Egypt.
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9
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Hypoalbuminemia affects the spatio-temporal tissue distribution of ochratoxin A in liver and kidneys: consequences for organ toxicity. Arch Toxicol 2022; 96:2967-2981. [PMID: 35962801 PMCID: PMC9525345 DOI: 10.1007/s00204-022-03361-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/03/2022] [Indexed: 11/21/2022]
Abstract
Hypoalbuminemia (HA) is frequently observed in systemic inflammatory diseases and in liver disease. However, the influence of HA on the pharmacokinetics and toxicity of compounds with high plasma albumin binding remained insufficiently studied. The ‘lack-of-delivery-concept’ postulates that HA leads to less carrier mediated uptake of albumin bound substances into hepatocytes and to less glomerular filtration; in contrast, the ‘concept-of-higher-free-fraction’ argues that increased concentrations of non-albumin bound compounds facilitate hepatocellular uptake and enhance glomerular filtration. To address this question, we performed intravital imaging on livers and kidneys of anesthetized mice to quantify the spatio-temporal tissue distribution of the mycotoxin ochratoxin A (OTA) based on its auto-fluorescence in albumin knockout and wild-type mice. HA strongly enhanced the uptake of OTA from the sinusoidal blood into hepatocytes, followed by faster secretion into bile canaliculi. These toxicokinetic changes were associated with increased hepatotoxicity in heterozygous albumin knockout mice for which serum albumin was reduced to a similar extent as in patients with severe hypoalbuminemia. HA also led to a shorter half-life of OTA in renal capillaries, increased glomerular filtration, and to enhanced uptake of OTA into tubular epithelial cells. In conclusion, the results favor the ‘concept-of-higher-free-fraction’ in HA; accordingly, HA causes an increased tissue uptake of compounds with high albumin binding and increased organ toxicity. It should be studied if this concept can be generalized to all compounds with high plasma albumin binding that are substrates of hepatocyte and renal tubular epithelial cell carriers.
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Awuchi CG, Ondari EN, Nwozo S, Odongo GA, Eseoghene IJ, Twinomuhwezi H, Ogbonna CU, Upadhyay AK, Adeleye AO, Okpala COR. Mycotoxins’ Toxicological Mechanisms Involving Humans, Livestock and Their Associated Health Concerns: A Review. Toxins (Basel) 2022; 14:toxins14030167. [PMID: 35324664 PMCID: PMC8949390 DOI: 10.3390/toxins14030167] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/16/2022] [Accepted: 01/25/2022] [Indexed: 12/21/2022] Open
Abstract
Mycotoxins are well established toxic metabolic entities produced when fungi invade agricultural/farm produce, and this happens especially when the conditions are favourable. Exposure to mycotoxins can directly take place via the consumption of infected foods and feeds; humans can also be indirectly exposed from consuming animals fed with infected feeds. Among the hundreds of mycotoxins known to humans, around a handful have drawn the most concern because of their occurrence in food and severe effects on human health. The increasing public health importance of mycotoxins across human and livestock environments mandates the continued review of the relevant literature, especially with regard to understanding their toxicological mechanisms. In particular, our analysis of recently conducted reviews showed that the toxicological mechanisms of mycotoxins deserve additional attention to help provide enhanced understanding regarding this subject matter. For this reason, this current work reviewed the mycotoxins’ toxicological mechanisms involving humans, livestock, and their associated health concerns. In particular, we have deepened our understanding about how the mycotoxins’ toxicological mechanisms impact on the human cellular genome. Along with the significance of mycotoxin toxicities and their toxicological mechanisms, there are associated health concerns arising from exposures to these toxins, including DNA damage, kidney damage, DNA/RNA mutations, growth impairment in children, gene modifications, and immune impairment. More needs to be done to enhance the understanding regards the mechanisms underscoring the environmental implications of mycotoxins, which can be actualized via risk assessment studies into the conditions/factors facilitating mycotoxins’ toxicities.
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Affiliation(s)
- Chinaza Godseill Awuchi
- Department of Biochemistry, Kampala International University, Bushenyi P.O. Box 20000, Uganda; (E.N.O.); (S.N.); (G.A.O.); (I.J.E.)
- Correspondence: (C.G.A.); (C.O.R.O.)
| | - Erick Nyakundi Ondari
- Department of Biochemistry, Kampala International University, Bushenyi P.O. Box 20000, Uganda; (E.N.O.); (S.N.); (G.A.O.); (I.J.E.)
| | - Sarah Nwozo
- Department of Biochemistry, Kampala International University, Bushenyi P.O. Box 20000, Uganda; (E.N.O.); (S.N.); (G.A.O.); (I.J.E.)
| | - Grace Akinyi Odongo
- Department of Biochemistry, Kampala International University, Bushenyi P.O. Box 20000, Uganda; (E.N.O.); (S.N.); (G.A.O.); (I.J.E.)
| | - Ifie Josiah Eseoghene
- Department of Biochemistry, Kampala International University, Bushenyi P.O. Box 20000, Uganda; (E.N.O.); (S.N.); (G.A.O.); (I.J.E.)
| | | | - Chukwuka U. Ogbonna
- Department of Biochemistry, Federal University of Agriculture, P.M.B. 2240, Abeokuta 110124, Ogun State, Nigeria;
| | - Anjani K. Upadhyay
- Heredity Healthcare & Lifesciences, 206-KIIT TBI, Patia, Bhubaneswar 751024, Odisha, India;
| | - Ademiku O. Adeleye
- Faith Heroic Generation, No. 36 Temidire Street, Azure 340251, Ondo State, Nigeria;
| | - Charles Odilichukwu R. Okpala
- Department of Functional Foods Product Development, Wrocław University of Environmental and Life Sciences, 51-630 Wrocław, Poland
- Correspondence: (C.G.A.); (C.O.R.O.)
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11
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Höfs S, Hülagü D, Bennet F, Carl P, Flemig S, Schmid T, Schenk JA, Hodoroaba V, Schneider RJ. Electrochemical Immunomagnetic Ochratoxin A Sensing: Steps Forward in the Application of 3,3’,5,5’‐Tetramethylbenzidine in Amperometric Assays. ChemElectroChem 2021. [DOI: 10.1002/celc.202100446] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Soraya Höfs
- Department of Analytical Chemistry Reference Materials Bundesanstalt für Materialforschung und -prüfung (BAM) Richard-Willstätter-Straße 11 12489 Berlin Germany
- Institute for Biochemistry and Biology University of Potsdam OT-Golm, Karl-Liebknecht-Straße 24–25 14476 Potsdam Germany
| | - Deniz Hülagü
- Department of Materials Chemistry Bundesanstalt für Materialforschung und -prüfung (BAM) Unter den Eichen 44–46 12203 Berlin Germany
| | - Francesca Bennet
- Department of Materials Chemistry Bundesanstalt für Materialforschung und -prüfung (BAM) Unter den Eichen 44–46 12203 Berlin Germany
| | - Peter Carl
- Department of Analytical Chemistry Reference Materials Bundesanstalt für Materialforschung und -prüfung (BAM) Richard-Willstätter-Straße 11 12489 Berlin Germany
| | - Sabine Flemig
- Department of Analytical Chemistry Reference Materials Bundesanstalt für Materialforschung und -prüfung (BAM) Richard-Willstätter-Straße 11 12489 Berlin Germany
| | - Thomas Schmid
- Department of Analytical Chemistry Reference Materials Bundesanstalt für Materialforschung und -prüfung (BAM) Richard-Willstätter-Straße 11 12489 Berlin Germany
- School of Analytical Sciences Adlershof (SALSA) Humboldt-Universität zu Berlin Unter den Linden 6 10099 Berlin Germany
| | | | - Vasile‐Dan Hodoroaba
- Department of Materials Chemistry Bundesanstalt für Materialforschung und -prüfung (BAM) Unter den Eichen 44–46 12203 Berlin Germany
| | - Rudolf J. Schneider
- Department of Analytical Chemistry Reference Materials Bundesanstalt für Materialforschung und -prüfung (BAM) Richard-Willstätter-Straße 11 12489 Berlin Germany
- Technische Universität Berlin Straße des 17. Juni 135 10623 Berlin Germany
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12
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Ghallab A, Hassan R, Myllys M, Albrecht W, Friebel A, Hoehme S, Hofmann U, Seddek AL, Braeuning A, Kuepfer L, Cramer B, Humpf HU, Boor P, Degen GH, Hengstler JG. Subcellular spatio-temporal intravital kinetics of aflatoxin B 1 and ochratoxin A in liver and kidney. Arch Toxicol 2021; 95:2163-2177. [PMID: 34003344 PMCID: PMC8166722 DOI: 10.1007/s00204-021-03073-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/05/2021] [Indexed: 12/14/2022]
Abstract
Local accumulation of xenobiotics in human and animal tissues may cause adverse effects. Large differences in their concentrations may exist between individual cell types, often due to the expression of specific uptake and export carriers. Here we established a two-photon microscopy-based technique for spatio-temporal detection of the distribution of mycotoxins in intact kidneys and livers of anesthetized mice with subcellular resolution. The mycotoxins ochratoxin A (OTA, 10 mg/kg b.w.) and aflatoxin B1 (AFB1, 1.5 mg/kg b.w.), which both show blue auto-fluorescence, were analyzed after intravenous bolus injections. Within seconds after administration, OTA was filtered by glomeruli, and enriched in distal tubular epithelial cells (dTEC). A striking feature of AFB1 toxicokinetics was its very rapid uptake from sinusoidal blood into hepatocytes (t1/2 ~ 4 min) and excretion into bile canaliculi. Interestingly, AFB1 was enriched in the nuclei of hepatocytes with zonal differences in clearance. In the cytoplasm of pericentral hepatocytes, the half-life (t1/2~ 63 min) was much longer compared to periportal hepatocytes of the same lobules (t1/2 ~ 9 min). In addition, nuclear AFB1 from periportal hepatocytes cleared faster compared to the pericentral region. These local differences in AFB1 clearance may be due to the pericentral expression of cytochrome P450 enzymes that activate AFB1 to protein- and DNA-binding metabolites. In conclusion, the present study shows that large spatio-temporal concentration differences exist within the same tissues and its analysis may provide valuable additional information to conventional toxicokinetic studies.
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Affiliation(s)
- Ahmed Ghallab
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany.
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, South Valley University, Qena, 83523, Egypt.
| | - Reham Hassan
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, South Valley University, Qena, 83523, Egypt
| | - Maiju Myllys
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Wiebke Albrecht
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany
| | - Adrian Friebel
- Institute of Computer Science, Saxonian Incubator for Clinical Research (SIKT), University of Leipzig, Haertelstraße 16-18, 04107, Leipzig, Germany
| | - Stefan Hoehme
- Institute of Computer Science, Saxonian Incubator for Clinical Research (SIKT), University of Leipzig, Haertelstraße 16-18, 04107, Leipzig, Germany
| | - Ute Hofmann
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Auerbachstr. 112, 70376, Stuttgart, Germany
| | - Abdel-Latif Seddek
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, South Valley University, Qena, 83523, Egypt
| | - Albert Braeuning
- Department of Food Safety, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589, Berlin, Germany
| | - Lars Kuepfer
- Institute of Systems Medicine with Focus on Organ Interactions, University Hospital RWTH Aachen, Pauwelsstr. 19, 52074, Aachen, Germany
| | - Benedikt Cramer
- Institute of Food Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstr. 45, 48149, Münster, Germany
| | - Hans-Ulrich Humpf
- Institute of Food Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstr. 45, 48149, Münster, Germany
| | - Peter Boor
- Institute of Pathology and Department of Nephrology, University Hospital RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany
| | - Gisela H Degen
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany.
| | - Jan G Hengstler
- Leibniz Research Centre for Working Environment and Human Factors, Technical University Dortmund, Ardeystr. 67, 44139, Dortmund, Germany.
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13
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Transcriptome Analysis Reveals the AhR, Smad2/3, and HIF-1α Pathways as the Mechanism of Ochratoxin A Toxicity in Kidney Cells. Toxins (Basel) 2021; 13:toxins13030190. [PMID: 33800744 PMCID: PMC7999264 DOI: 10.3390/toxins13030190] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/25/2021] [Accepted: 03/05/2021] [Indexed: 12/11/2022] Open
Abstract
Ochratoxin A (OTA) is a mycotoxin occurring in foods consumed by humans. Recently, there has been growing global concern regarding OTA toxicity. The main target organ of OTA is the kidney, but the mechanism underlying renal toxicity is not well known. In this study, human-derived proximal tubular epithelial cells, HK-2 cells, were used for RNA-sequencing (RNA-seq) and transcriptome analysis. In total, 3193 differentially expressed genes were identified upon treatment with 200 nM OTA in HK-2 cells; of these, 2224 were upregulated and 969 were downregulated. Transcriptome analysis revealed that OTA significantly affects hypoxia, epithelial-mesenchymal transition (EMT), apoptosis, and xenobiotic metabolism pathways in kidney cells. Quantitative real-time PCR analysis showed gene expression patterns similar to RNA-seq analysis. Expression of EMT markers (E-cadherin and fibronectin), apoptosis markers (caspase-3 and Bax), and kidney injury molecule-1 (KIM-1) was suppressed by inhibiting AhR expression using siRNA, and the related transcription factors, Smad2/3, and HIF-1α were downregulated. Smad2/3 suppression with siRNA could inhibit fibronetcin, caspase-3, Bax, and KIM-1 expression. Fibronetcin, caspase-3, Bax, and KIM-1 expression could be increased with HIF-1α suppression with siRNA. Taken together, these findings suggest that OTA-mediated kidney toxicity via the AhR-Smad2/3-HIF-1α signaling pathways leads to induction of EMT, apoptosis, and kidney injury.
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Xu R, Karrow NA, Shandilya UK, Sun LH, Kitazawa H. In-Vitro Cell Culture for Efficient Assessment of Mycotoxin Exposure, Toxicity and Risk Mitigation. Toxins (Basel) 2020; 12:E146. [PMID: 32120954 PMCID: PMC7150844 DOI: 10.3390/toxins12030146] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 02/21/2020] [Accepted: 02/25/2020] [Indexed: 12/11/2022] Open
Abstract
Mycotoxins are toxic secondary fungal metabolites that commonly contaminate crops and food by-products and thus, animal feed. Ingestion of mycotoxins can lead to mycotoxicosis in both animals and humans, and at subclinical concentrations may affect animal production and adulterate feed and animal by-products. Mycotoxicity mechanisms of action (MOA) are largely unknown, and co-contamination, which is often the case, raises the likelihood of mycotoxin interactions. Mitigation strategies for reducing the risk of mycotoxicity are diverse and may not necessarily provide protection against all mycotoxins. These factors, as well as the species-specific risk of toxicity, collectively make an assessment of exposure, toxicity, and risk mitigation very challenging and costly; thus, in-vitro cell culture models provide a useful tool for their initial assessment. Since ingestion is the most common route of mycotoxin exposure, the intestinal epithelial barrier comprised of epithelial cells (IECs) and immune cells such as macrophages, represents ground zero where mycotoxins are absorbed, biotransformed, and elicit toxicity. This article aims to review different in-vitro IEC or co-culture models that can be used for assessing mycotoxin exposure, toxicity, and risk mitigation, and their suitability and limitations for the safety assessment of animal foods and food by-products.
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Affiliation(s)
- Ran Xu
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada; (R.X.); (U.K.S.)
| | - Niel A. Karrow
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada; (R.X.); (U.K.S.)
| | - Umesh K. Shandilya
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada; (R.X.); (U.K.S.)
| | - Lv-hui Sun
- Department of Animal Nutrition and Feed Science, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, China;
| | - Haruki Kitazawa
- Food and Feed Immunology Group, Laboratory of Animal Products Chemistry, Graduate School of Agricultural Science, Tohoku University, Sendai 980-8572, Japan;
- Livestock Immunology Unit, International Education and Research Center for Food and Agricultural Immunology (CFAI), Graduate School of Agricultural Science, Tohoku University, Sendai 980-8572, Japan
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15
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Yang X, Li Y, Zheng L, He X, Luo Y, Huang K, Xu W. Glucose-regulated protein 75 in foodborne disease models induces renal tubular necrosis. Food Chem Toxicol 2019; 133:110720. [DOI: 10.1016/j.fct.2019.110720] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 07/04/2019] [Accepted: 07/26/2019] [Indexed: 01/06/2023]
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16
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Klopčič I, Dolenc MS. Chemicals and Drugs Forming Reactive Quinone and Quinone Imine Metabolites. Chem Res Toxicol 2018; 32:1-34. [DOI: 10.1021/acs.chemrestox.8b00213] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Ivana Klopčič
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva 7, 1000 Ljubljana, Slovenia
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17
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Abstract
The important renal tumors that can be induced by exposure of rats to chemical carcinogens are renal tubule tumors (RTTs) derived from tubule epithelium; renal pelvic carcinoma derived from the urothelial lining of the pelvis; renal mesenchymal tumors (RMTs) derived from the interstitial connective tissue; and nephroblastoma derived from the metanephric primordia. However, almost all of our knowledge concerning mechanisms of renal carcinogenesis in the rodent pertains to the adenomas and carcinomas originating from renal tubule epithelium. Currently, nine mechanistic pathways can be identified in either the rat or mouse following chemical exposure. These include direct DNA reactivity, indirect DNA reactivity through free radical formation, multiphase bioactivation involving glutathione conjugation, mitotic disruption, sustained cell proliferation from direct cytotoxicity, sustained cell proliferation by disruption of a physiologic process (alpha 2u-globulin nephropathy), exaggerated pharmacologic response, species-dominant metabolic pathway, and chemical exacerbation of chronic progressive nephropathy. Spontaneous occurrence of RTTs in the rat will be included since one example is a confounder for interpreting kidney tumor results in chemical carcinogenicity studies in rats.
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18
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Abstract
Mycotoxins are the most common contaminants of food and feed worldwide and are considered an important risk factor for human and animal health. Oxidative stress occurs in cells when the concentration of reactive oxygen species exceeds the cell’s antioxidant capacity. Oxidative stress causes DNA damage, enhances lipid peroxidation, protein damage and cell death. This review addresses the toxicity of the major mycotoxins, especially aflatoxin B1, deoxynivalenol, nivalenol, T-2 toxin, fumonisin B1, ochratoxin, patulin and zearalenone, in relation to oxidative stress. It summarises the data associated with oxidative stress as a plausible mechanism for mycotoxin-induced toxicity. Given the contamination caused by mycotoxins worldwide, the protective effects of a variety of natural compounds due to their antioxidant capacities have been evaluated. We review data on the ability of vitamins, flavonoids, crocin, curcumin, green tea, lycopene, phytic acid, L-carnitine, melatonin, minerals and mixtures of anti-oxidants to mitigate the toxic effect of mycotoxins associated with oxidative stress.
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Affiliation(s)
- E.O. da Silva
- Universidade Estadual de Londrina, Laboratory of Animal Pathology, Campus Universitário, Rodovia Celso Garcia Cid, Km 380, Londrina, Paraná 86051-990, Brazil
| | - A.P.F.L. Bracarense
- Universidade Estadual de Londrina, Laboratory of Animal Pathology, Campus Universitário, Rodovia Celso Garcia Cid, Km 380, Londrina, Paraná 86051-990, Brazil
| | - I.P. Oswald
- Université de Toulouse, Toxalim, Research Center in Food Toxicology, INRA, UMR 1331 ENVT, INP-PURPAN, 31076 Toulouse, France
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19
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Kathuria P, Sharma P, Manderville RA, Wetmore SD. Molecular Modeling of the Major DNA Adduct Formed from Food Mutagen Ochratoxin A in NarI Two-Base Deletion Duplexes: Impact of Sequence Context and Adduct Ionization on Conformational Preference and Mutagenicity. Chem Res Toxicol 2017; 30:1582-1591. [PMID: 28719194 DOI: 10.1021/acs.chemrestox.7b00103] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Exposure to ochratoxin A (OTA), a possible human carcinogen, leads to many different DNA mutations. As a first step toward understanding the structural basis of OTA-induced mutagenicity, the present work uses a robust computational approach and a slipped mutagenic intermediate model previously studied for C8-dG aromatic amine adducts to analyze the conformational features of postreplication two-base deletion DNA duplexes containing OT-dG, the major OTA lesion at the C8 position of guanine. Specifically, a total of 960 ns of molecular dynamics simulations (excluding trial simulations) were carried out on four OT-dG ionization states in three sequence contexts within oligomers containing the NarI recognition sequence, a known hotspot for deletion mutations induced by related adducts formed from known carcinogens. Our results indicate that the structural properties and relative stability of the competing "major groove" and "stacked" conformations of OTA adducted two-base deletion duplexes depend on both the OTA ionization state and the sequence context, mainly due to conformation-dependent deviations in discrete local (hydrogen-bonding and stacking) interactions at the lesion site, as well as DNA bending. When the structural characteristics of the OT-dG adducted two-base deletion duplexes are compared to those associated with previously studied C8-dG adducts, a greater understanding of the effects of the nucleobase-carcinogen linkage, and size of the carcinogenic moiety on the conformational preferences of damaged DNA is obtained. Most importantly, our work predicts key structural features for OT-dG-adducted deletion DNA duplexes, which in turn allow us to develop hypotheses regarding OT-dG replication outcomes. Thus, our computational results are valuable for the design and interpretation of future biochemical studies on the potentially carcinogenic OT-dG lesion.
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Affiliation(s)
- Preetleen Kathuria
- Department of Chemistry and Centre for Advanced Studies in Chemistry, Panjab University , Chandigarh 160014, India
| | - Purshotam Sharma
- Department of Chemistry and Centre for Advanced Studies in Chemistry, Panjab University , Chandigarh 160014, India
| | - Richard A Manderville
- Departments of Chemistry and Toxicology, University of Guelph , Guelph, Ontario N1G 2W1, Canada
| | - Stacey D Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge , Lethbridge, Alberta T1K 3M4, Canada
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Ostry V, Malir F, Toman J, Grosse Y. Mycotoxins as human carcinogens-the IARC Monographs classification. Mycotoxin Res 2017; 33:65-73. [PMID: 27888487 DOI: 10.1007/s12550-016-0265-7] [Citation(s) in RCA: 456] [Impact Index Per Article: 65.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/10/2016] [Accepted: 11/14/2016] [Indexed: 10/20/2022]
Abstract
Humans are constantly exposed to mycotoxins (e.g. aflatoxins, ochratoxins), mainly via food intake of plant and animal origin. The health risks stemming from mycotoxins may result from their toxicity, in particular their carcinogenicity. In order to prevent these risks, the International Agency for Research on Cancer (IARC) in Lyon (France)-through its IARC Monographs programme-has performed the carcinogenic hazard assessment of some mycotoxins in humans, on the basis of epidemiological data, studies of cancer in experimental animals and mechanistic studies. The present article summarizes the carcinogenic hazard assessments of those mycotoxins, especially aflatoxins (aflatoxin B1, B2, G1, G2 and M1), fumonisins (fumonisin B1 and B2) and ochratoxin A (OTA). New information regarding the genotoxicity of OTA (formation of OTA-DNA adducts), the role of OTA in oxidative stress and the identification of epigenetic factors involved in OTA carcinogenesis-should they indeed provide strong evidence that OTA carcinogenicity is mediated by a mechanism that also operates in humans-could lead to the reclassification of OTA.
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Affiliation(s)
- Vladimir Ostry
- Center for Health, Nutrition and Food, National Institute of Public Health in Prague, Palackeho 3a, 61242, Brno, Czech Republic.
| | - Frantisek Malir
- Faculty of Science, Department of Biology, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic
| | - Jakub Toman
- Faculty of Science, Department of Biology, University of Hradec Kralove, Rokitanskeho 62, 50003, Hradec Kralove, Czech Republic
| | - Yann Grosse
- International Agency for Research on Cancer, 150 cours Albert Thomas, 69372, Lyon, France
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Stiborová M, Arlt VM, Schmeiser HH. Balkan endemic nephropathy: an update on its aetiology. Arch Toxicol 2016; 90:2595-2615. [PMID: 27538407 PMCID: PMC5065591 DOI: 10.1007/s00204-016-1819-3] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 08/04/2016] [Indexed: 02/02/2023]
Abstract
Balkan endemic nephropathy (BEN) is a unique, chronic renal disease frequently associated with upper urothelial cancer (UUC). It only affects residents of specific farming villages located along tributaries of the Danube River in Bosnia-Herzegovina, Croatia, Macedonia, Serbia, Bulgaria, and Romania where it is estimated that ~100,000 individuals are at risk of BEN, while ~25,000 have the disease. This review summarises current findings on the aetiology of BEN. Over the last 50 years, several hypotheses on the cause of BEN have been formulated, including mycotoxins, heavy metals, viruses, and trace-element insufficiencies. However, recent molecular epidemiological studies provide a strong case that chronic dietary exposure to aristolochic acid (AA) a principal component of Aristolochia clematitis which grows as a weed in the wheat fields of the endemic regions is the cause of BEN and associated UUC. One of the still enigmatic features of BEN that need to be resolved is why the prevalence of BEN is only 3-7 %. This suggests that individual genetic susceptibilities to AA exist in humans. In fact dietary ingestion of AA along with individual genetic susceptibility provides a scenario that plausibly can explain all the peculiarities of BEN such as geographical distribution and high risk of urothelial cancer. For the countries harbouring BEN implementing public health measures to avoid AA exposure is of the utmost importance because this seems to be the best way to eradicate this once mysterious disease to which the residents of BEN villages have been completely and utterly at mercy for so long.
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Affiliation(s)
- Marie Stiborová
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, 128 40, Prague 2, Czech Republic.
| | - Volker M Arlt
- Analytical and Environmental Sciences Division, MRC-PHE Centre for Environmental and Health, King's College London, 150 Stamford Street, London, SE1 9NH, UK
- NIHR Health Protection Research Unit in Health Impact of Environmental Hazards at King's College London in partnership with Public Health England, Franklin-Wilkins Building, 150 Stamford Street, London, SE1 9NH, UK
| | - Heinz H Schmeiser
- Division of Radiopharmaceutical Chemistry (E030), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
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Manderville RA, Wetmore SD. Understanding the Mutagenicity of O-Linked and C-Linked Guanine DNA Adducts: A Combined Experimental and Computational Approach. Chem Res Toxicol 2016; 30:177-188. [DOI: 10.1021/acs.chemrestox.6b00323] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Richard A. Manderville
- Departments
of Chemistry and Toxicology, University of Guelph, Guelph, ON, Canada N1G 2W1
| | - Stacey D. Wetmore
- Department of Chemistry & Biochemistry, University of Lethbridge, Lethbridge, AB, Canada T1K 3M4
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Structure-activity relationship of ochratoxin A and synthesized derivatives: importance of amino acid and halogen moiety for cytotoxicity. Arch Toxicol 2016; 91:1461-1471. [PMID: 27422291 DOI: 10.1007/s00204-016-1799-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 07/07/2016] [Indexed: 10/21/2022]
Abstract
The enigma why the mycotoxin ochratoxin A (OTA) impairs cell and organ function is still not solved. However, an interaction with target molecules is a prerequisite for any observed adverse effect. This interaction depends on characteristics of the target molecule as well as on the OTA molecule itself. OTA has different structural moieties which may be relevant for these interrelations including a halogen (chlorine) and an amino acid group (phenylalanine). To test their importance for the impact of OTA, detailed structure-activity studies with various OTA derivatives were performed. For this, 23 OTA derivatives were available, which were modified by either an exchange of the halogen moiety against another halogen (fluorine, iodine or bromine) or by the amino acid moiety against another one (tyrosine or alanine) or a combination of both. Additionally, the configuration of the 3R carbon atom was changed to 3S. These derivatives were tested in human renal cells for their ability to induce cell death (cytotoxicity, apoptosis, necrosis), their impact on collagen protein secretion and for their influence on gene expression. It turned out that the substitution of the amino acid moiety against tyrosine or alanine almost completely prevented the adverse effects of OTA. The exchange of the halogen moiety had minor effects and the inversion of the stereochemistry at C3 did not prevent the effects of OTA. Therefore, we conclude that the amino acid moiety of OTA is indispensable for the interaction of OTA with its target molecules.
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Malir F, Ostry V, Pfohl-Leszkowicz A, Malir J, Toman J. Ochratoxin A: 50 Years of Research. Toxins (Basel) 2016; 8:E191. [PMID: 27384585 PMCID: PMC4963825 DOI: 10.3390/toxins8070191] [Citation(s) in RCA: 267] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 05/21/2016] [Accepted: 06/13/2016] [Indexed: 12/13/2022] Open
Abstract
Since ochratoxin A (OTA) was discovered, it has been ubiquitous as a natural contaminant of moldy food and feed. The multiple toxic effects of OTA are a real threat for human beings and animal health. For example, OTA can cause porcine nephropathy but can also damage poultries. Humans exposed to OTA can develop (notably by inhalation in the development of acute renal failure within 24 h) a range of chronic disorders such as upper urothelial carcinoma. OTA plays the main role in the pathogenesis of some renal diseases including Balkan endemic nephropathy, kidney tumors occurring in certain endemic regions of the Balkan Peninsula, and chronic interstitial nephropathy occurring in Northern African countries and likely in other parts of the world. OTA leads to DNA adduct formation, which is known for its genotoxicity and carcinogenicity. The present article discusses how renal carcinogenicity and nephrotoxicity cause both oxidative stress and direct genotoxicity. Careful analyses of the data show that OTA carcinogenic effects are due to combined direct and indirect mechanisms (e.g., genotoxicity, oxidative stress, epigenetic factors). Altogether this provides strong evidence that OTA carcinogenicity can also occur in humans.
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Affiliation(s)
- Frantisek Malir
- Department of Biology, Faculty of Science, University of Hradec Kralove, Hradec Kralove 50003, Czech Republic.
| | - Vladimir Ostry
- National Reference Center for Microfungi and Mycotoxins in Food Chains, Center of Health, Nutrition and Food in Brno, National Institute of Public Health in Prague, Brno 61242, Czech Republic.
| | - Annie Pfohl-Leszkowicz
- Department Bioprocess & Microbial Systems, Laboratory Chemical Engineering, INP/ENSA Toulouse, University of Toulouse, UMR 5503 CNRS/INPT/UPS, Auzeville-Tolosane 31320, France.
| | - Jan Malir
- Institute of State and Law, Czech Academy of Sciences, Narodni 18, Prague 11600, Czech Republic.
| | - Jakub Toman
- Department of Biology, Faculty of Science, University of Hradec Kralove, Hradec Kralove 50003, Czech Republic.
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26
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Heussner A, Paget T. Evaluation of renal in vitro models used in ochratoxin research. WORLD MYCOTOXIN J 2016. [DOI: 10.3920/wmj2015.1975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Ochratoxin A (OTA) induces renal carcinomas in rodents with a specific localisation in the S3 segment of proximal tubules and distinct early severe tissue alterations, which have been observed also in other species. Pronounced species- and sex-specific differences in toxicity occur and similar effects cannot be excluded in humans, however precise mechanism(s) remain elusive until today. In such cases, the use of in vitro models for mechanistic investigations can be very useful; in particular if a non-genotoxic mechanism of cancer formation is assumed which include cytotoxic effects. However, potential genotoxic mechanisms can also be investigated in vitro. A crucial issue of in vitro research is the choice of the appropriate cell model. Apparently, the cellular target of OTA is the renal proximal tubular cell; therefore cells from this tissue area are the most reasonable model. Furthermore, cells from affected species should be used and can be compared to cells of human origin. Another important parameter is whether to use primary cultures or to choose a cell line from the huge variety of cell lines available. In any case, important characteristics and quality controls need to be verified beforehand. Therefore, this review discusses the renal in vitro models that have been used for the investigation of renal ochratoxin toxicity. In particular, we discuss the choice of the models and the essential parameters making them suitable models for ochratoxin research together with exemplary results from this research. Furthermore, new promising models such as hTERT-immortalised cells and 3D-cultures are briefly discussed.
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Affiliation(s)
- A.H. Heussner
- Human and Environmental Toxicology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany
- Pharmacy Health and Well-being, University of Sunderland, Sciences Complex, Wharncliffe Street, Sunderland SR1 3SD, United Kingdom
| | - T. Paget
- Pharmacy Health and Well-being, University of Sunderland, Sciences Complex, Wharncliffe Street, Sunderland SR1 3SD, United Kingdom
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Ochratoxin A: Molecular Interactions, Mechanisms of Toxicity and Prevention at the Molecular Level. Toxins (Basel) 2016; 8:111. [PMID: 27092524 PMCID: PMC4848637 DOI: 10.3390/toxins8040111] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 03/31/2016] [Accepted: 04/06/2016] [Indexed: 01/28/2023] Open
Abstract
Ochratoxin A (OTA) is a widely-spread mycotoxin all over the world causing major health risks. The focus of the present review is on the molecular and cellular interactions of OTA. In order to get better insight into the mechanism of its toxicity and on the several attempts made for prevention or attenuation of its toxic action, a detailed description is given on chemistry and toxicokinetics of this mycotoxin. The mode of action of OTA is not clearly understood yet, and seems to be very complex. Inhibition of protein synthesis and energy production, induction of oxidative stress, DNA adduct formation, as well as apoptosis/necrosis and cell cycle arrest are possibly involved in its toxic action. Since OTA binds very strongly to human and animal albumin, a major emphasis is done regarding OTA-albumin interaction. Displacement of OTA from albumin by drugs and by natural flavonoids are discussed in detail, hypothesizing their potentially beneficial effect in order to prevent or attenuate the OTA-induced toxic consequences.
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Cariddi LN, Escobar FM, Sabini MC, Campra NA, Bagnis G, Decote-Ricardo D, Freire-de-Lima CG, Mañas F, Sabini LI, Dalcero AM. Phenolic acid protects of renal damage induced by ochratoxin A in a 28-days-oral treatment in rats. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2016; 43:105-111. [PMID: 26987112 DOI: 10.1016/j.etap.2016.03.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 02/26/2016] [Accepted: 03/03/2016] [Indexed: 06/05/2023]
Abstract
The present study aimed to characterize the chlorogenic acid (ChlA) capacity to reverse the toxic effects induced by ochratoxin A (OTA) in a subacute toxicity test in rats. Male Wistar rats were fed orally by gavage for 28 days with OTA (0.4mg/kg bw/day), ChlA (5mg/kg bw/day) or the combination OTA (0.4mg/kg bw/day)+ChlA (5mg/kg bw/day). No deaths, no decrease in feed intake or body weight in any experimental group were recorded. The negative control group and the animals treated with ChlA alone showed no changes in any parameters evaluated. In OTA-treated group significant changes such as decrease in urine volume, proteinuria, occult blood, increase in serum creatinine values; decrease in absolute and relative kidney weight and characteristics histopathological lesions that indicated kidney damage were observed. However, limited effect on oxidative stress parameters were detected in kidneys of OTA-treated group. Animals treated with the combination OTA+ChlA were showed as negative control group in the evaluation of several parameters of toxicity. In conclusion, ChlA, at given concentration, improved biochemical parameters altered in urine and serum and pathological damages in kidneys induced by OTA exposure, showing a good protective activity, but not by an apparent antioxidant mechanism.
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Affiliation(s)
- L N Cariddi
- Departamento de Microbiología e Inmunología, Universidad Nacional de Río Cuarto, Ruta 36 Km 601, Río Cuarto, CP 5800 Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Rivadavia 1917, Ciudad Autónoma de Buenos Aires, CP C1033AAJ, Argentina.
| | - F M Escobar
- Departamento de Microbiología e Inmunología, Universidad Nacional de Río Cuarto, Ruta 36 Km 601, Río Cuarto, CP 5800 Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Rivadavia 1917, Ciudad Autónoma de Buenos Aires, CP C1033AAJ, Argentina
| | - M C Sabini
- Departamento de Microbiología e Inmunología, Universidad Nacional de Río Cuarto, Ruta 36 Km 601, Río Cuarto, CP 5800 Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Rivadavia 1917, Ciudad Autónoma de Buenos Aires, CP C1033AAJ, Argentina
| | - N A Campra
- Departamento de Microbiología e Inmunología, Universidad Nacional de Río Cuarto, Ruta 36 Km 601, Río Cuarto, CP 5800 Córdoba, Argentina
| | - G Bagnis
- Departamento de Patología Animal, Facultad de Agronomía y Veterinaria, Universidad Nacional de Río Cuarto, Ruta 36 Km 601, Río Cuarto, CP 5800 Córdoba, Argentina
| | - D Decote-Ricardo
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - C G Freire-de-Lima
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - F Mañas
- Cátedra de Farmacología, Universidad Nacional de Río Cuarto, Ruta 36 Km 601, Río Cuarto, CP 5800 Córdoba, Argentina
| | - L I Sabini
- Departamento de Microbiología e Inmunología, Universidad Nacional de Río Cuarto, Ruta 36 Km 601, Río Cuarto, CP 5800 Córdoba, Argentina
| | - A M Dalcero
- Departamento de Microbiología e Inmunología, Universidad Nacional de Río Cuarto, Ruta 36 Km 601, Río Cuarto, CP 5800 Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Rivadavia 1917, Ciudad Autónoma de Buenos Aires, CP C1033AAJ, Argentina
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Toxicology of DNA Adducts Formed Upon Human Exposure to Carcinogens. ADVANCES IN MOLECULAR TOXICOLOGY 2016. [DOI: 10.1016/b978-0-12-804700-2.00007-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Heussner AH, Bingle LEH. Comparative Ochratoxin Toxicity: A Review of the Available Data. Toxins (Basel) 2015; 7:4253-82. [PMID: 26506387 PMCID: PMC4626733 DOI: 10.3390/toxins7104253] [Citation(s) in RCA: 187] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 09/27/2015] [Accepted: 10/15/2015] [Indexed: 11/19/2022] Open
Abstract
Ochratoxins are a group of mycotoxins produced by a variety of moulds. Ochratoxin A (OTA), the most prominent member of this toxin family, was first described by van der Merwe et al. in Nature in 1965. Dietary exposure to OTA represents a serious health issue and has been associated with several human and animal diseases including poultry ochratoxicosis, porcine nephropathy, human endemic nephropathies and urinary tract tumours in humans. More than 30 years ago, OTA was shown to be carcinogenic in rodents and since then extensive research has been performed in order to investigate its mode of action, however, this is still under debate. OTA is regarded as the most toxic family member, however, other ochratoxins or their metabolites and, in particular, ochratoxin mixtures or combinations with other mycotoxins may represent serious threats to human and animal health. This review summarises and evaluates current knowledge about the differential and comparative toxicity of the ochratoxin group.
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Affiliation(s)
- Alexandra H Heussner
- Human and Environmental Toxicology, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.
- Department of Pharmacy, Health and Well-Being, University of Sunderland, City Campus, Sunderland SR1 3SD, UK.
| | - Lewis E H Bingle
- Department of Pharmacy, Health and Well-Being, University of Sunderland, City Campus, Sunderland SR1 3SD, UK.
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Cramer B, Osteresch B, Muñoz KA, Hillmann H, Sibrowski W, Humpf H. Biomonitoring using dried blood spots: detection of ochratoxin A and its degradation product 2'R-ochratoxin A in blood from coffee drinkers. Mol Nutr Food Res 2015; 59:1837-43. [PMID: 26012425 PMCID: PMC4744763 DOI: 10.1002/mnfr.201500220] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 05/15/2015] [Accepted: 05/18/2015] [Indexed: 11/25/2022]
Abstract
SCOPE In this study, human exposure to the mycotoxin ochratoxin A (OTA) and its thermal degradation product 2'R-ochratoxin A (2'R-OTA, previously named as 14R-Ochratoxin A [22]) through coffee consumption was assessed. LC-MS/MS and the dried blood spot (DBS) technique were used for the analysis of blood samples from coffee and noncoffee drinkers (n = 50), and food frequency questionnaires were used to document coffee consumption. METHODS AND RESULTS For the detection of OTA and 2'R-OTA in blood, a new sensitive and efficient sample preparation method based on DBS was established and validated. Using this technique 2'R-OTA was for the first time detected in biological samples. Comparison between coffee drinkers and noncoffee drinkers showed for the first time that 2'R-OTA was only present in blood from the first group while OTA could be found in both groups in a mean concentration of 0.21 μg/L. 2'R-OTA mean concentration was 0.11 μg/L with a maximum concentration of 0.414 μg/L. Thus, in average 2'R-OTA was approx. half the concentration of OTA but in some cases even exceeded OTA levels. No correlation between the amounts of coffee consumption and OTA or 2'R-OTA levels was observed. CONCLUSION The results of this study revealed for the first time a high exposure of coffee consumers to 2'R-OTA, a compound formed from OTA during coffee roasting. Since little information is available regarding toxicity and possible carcinogenicity of this compound, further OTA monitoring in blood including 2'R-OTA is advisable.
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Affiliation(s)
- Benedikt Cramer
- Institute of Food ChemistryWestfälische Wilhelms‐Universität MünsterMünsterGermany
| | - Bernd Osteresch
- Institute of Food ChemistryWestfälische Wilhelms‐Universität MünsterMünsterGermany
| | - Katherine A. Muñoz
- Universität Koblenz‐LandauInstitute for Environmental Sciences, Research Group of Environmental and Soil ChemistryLandau in der PfalzGermany
| | - Hartmut Hillmann
- Institut für Transfusionsmedizin und TransplantationsimmunologieUniversitätsklinikum MünsterMünsterGermany
| | - Walter Sibrowski
- Institut für Transfusionsmedizin und TransplantationsimmunologieUniversitätsklinikum MünsterMünsterGermany
| | - Hans‐Ulrich Humpf
- Institute of Food ChemistryWestfälische Wilhelms‐Universität MünsterMünsterGermany
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Bondy GS, Caldwell DS, Aziz SA, Coady LC, Armstrong CL, Curran IHA, Koffman RL, Kapal K, Lefebvre DE, Mehta R. Effects of Chronic Ochratoxin A Exposure on p53 Heterozygous and p53 Homozygous Mice. Toxicol Pathol 2015; 43:715-29. [DOI: 10.1177/0192623314568391] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Exposure to the mycotoxin ochratoxin A (OTA) causes nephropathy in domestic animals and rodents and renal tumors in rodents and poultry. Humans are exposed to OTA by consuming foods made with contaminated cereal grains and other commodities. Management of human health risks due to OTA exposure depends, in part, on establishing a mode of action (MOA) for OTA carcinogenesis. To further investigate OTA’s MOA, p53 heterozygous (p53+/−) and p53 homozygous (p53+/+) mice were exposed to OTA in diet for 26 weeks. The former are susceptible to tumorigenesis upon chronic exposure to genotoxic carcinogens. OTA-induced renal damage but no tumors were observed in either strain, indicating that p53 heterozygosity conferred little additional sensitivity to OTA. Renal changes included dose-dependent increases in cellular proliferation, apoptosis, karyomegaly, and tubular degeneration in proximal tubules, which were consistent with ochratoxicosis. The lowest observed effect level for renal changes in p53+/− and p53+/+ mice was 200 μg OTA/kg bw/day. Based on the lack of tumors and the severity of renal and body weight changes at a maximum tolerated dose, the results were interpreted as suggestive of a primarily nongenotoxic (epigenetic) MOA for OTA carcinogenesis in this mouse model.
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Affiliation(s)
- Genevieve S. Bondy
- Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada
| | - Donald S. Caldwell
- Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada
| | - Syed A. Aziz
- Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada
| | - Laurie C. Coady
- Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada
| | - Cheryl L. Armstrong
- Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada
| | - Ivan H. A. Curran
- Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada
| | | | - Kamla Kapal
- Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada
| | - David E. Lefebvre
- Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada
| | - Rekha Mehta
- Food Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada
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Vettorazzi A, González-Peñas E, de Cerain AL. Ochratoxin A kinetics: A review of analytical methods and studies in rat model. Food Chem Toxicol 2014; 72:273-88. [DOI: 10.1016/j.fct.2014.07.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 07/04/2014] [Accepted: 07/13/2014] [Indexed: 10/25/2022]
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Sharma P, Manderville RA, Wetmore SD. Structural and energetic characterization of the major DNA adduct formed from the food mutagen ochratoxin A in the NarI hotspot sequence: influence of adduct ionization on the conformational preferences and implications for the NER propensity. Nucleic Acids Res 2014; 42:11831-45. [PMID: 25217592 PMCID: PMC4191402 DOI: 10.1093/nar/gku821] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The nephrotoxic food mutagen ochratoxin A (OTA) produces DNA adducts in rat kidneys, the major lesion being the C8-linked-2′-deoxyguanosine adduct (OTB-dG). Although research on other adducts stresses the importance of understanding the structure of the associated adducted DNA, site-specific incorporation of OTB-dG into DNA has yet to be attempted. The present work uses a robust computational approach to determine the conformational preferences of OTB-dG in three ionization states at three guanine positions in the NarI recognition sequence opposite cytosine. Representative adducted DNA helices were derived from over 2160 ns of simulation and ranked via free energies. For the first time, a close energetic separation between three distinct conformations is highlighted, which indicates OTA-adducted DNA likely adopts a mixture of conformations regardless of the sequence context. Nevertheless, the preferred conformation depends on the flanking bases and ionization state due to deviations in discrete local interactions at the lesion site. The structural characteristics of the lesion thus discerned have profound implications regarding its repair propensity and mutagenic outcomes, and support recent experiments suggesting the induction of double-strand breaks and deletion mutations upon OTA exposure. This combined structural and energetic characterization of the OTB-dG lesion in DNA will encourage future biochemical experiments on this potentially genotoxic lesion.
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Affiliation(s)
- Purshotam Sharma
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, T1K 3M4, Canada
| | - Richard A Manderville
- Department of Chemistry and Toxicology, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | - Stacey D Wetmore
- Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, T1K 3M4, Canada
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Qi X, Yu T, Zhu L, Gao J, He X, Huang K, Luo Y, Xu W. Ochratoxin A induces rat renal carcinogenicity with limited induction of oxidative stress responses. Toxicol Appl Pharmacol 2014; 280:543-9. [PMID: 25218026 DOI: 10.1016/j.taap.2014.08.030] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Revised: 08/27/2014] [Accepted: 08/28/2014] [Indexed: 10/24/2022]
Abstract
Ochratoxin A (OTA) has displayed nephrotoxicity and renal carcinogenicity in mammals, however, no clear mechanisms have been identified detailing the relationship between oxidative stress and these toxicities. This study was performed to clarify the relationship between oxidative stress and the renal carcinogenicity induced by OTA. Rats were treated with 70 or 210 μg/kg b.w. OTA for 4 or 13 weeks. In the rats administrated with OTA for 13 weeks, the kidney was damaged seriously. Cytoplasmic vacuolization was observed in the outer stripe of the outer medulla. Karyomegaly was prominent in the tubular epithelium. Kidney injury molecule-1 (Kim-1) was detected in the outer stripe of the outer medulla in both low- and high-dose groups. OTA increased the mRNA levels of clusterin in rat kidneys. Interestingly, OTA did not significantly alter the oxidative stress level in rat liver and kidney. Yet, some indications related to proliferation and carcinogenicity were observed. A dose-related increase in proliferating cell nuclear antigen (PCNA) was observed at 4 weeks in both liver and kidney, but at 13 weeks, only in the kidney. OTA down-regulated reactive oxygen species (ROS) and up-regulated vimentin and lipocalin 2 in rat kidney at 13 weeks. The p53 gene was decreased in both liver and kidney at 13 weeks. These results suggest that OTA caused apparent kidney damage within 13 weeks but exerted limited effect on oxidative stress parameters. It implies that cell proliferation is the proposed mode of action for OTA-induced renal carcinogenicity.
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Affiliation(s)
- Xiaozhe Qi
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Tao Yu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Liye Zhu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Jing Gao
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Xiaoyun He
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083, China
| | - Kunlun Huang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083, China
| | - Yunbo Luo
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083, China
| | - Wentao Xu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083, China.
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Stoffmonographie Ochratoxin A. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2014. [DOI: 10.1007/s00103-014-1939-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Muñoz K, Blaszkewicz M, Campos V, Vega M, Degen GH. Exposure of infants to ochratoxin A with breast milk. Arch Toxicol 2013; 88:837-46. [DOI: 10.1007/s00204-013-1168-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 11/13/2013] [Indexed: 10/26/2022]
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Malir F, Ostry V, Dofkova M, Roubal T, Dvorak V, Dohnal V. Ochratoxin A levels in blood serum of Czech women in the first trimester of pregnancy and its correspondence with dietary intake of the mycotoxin contaminant. Biomarkers 2013; 18:673-8. [DOI: 10.3109/1354750x.2013.845609] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Micro-solid phase extraction of ochratoxin A, and its determination in urine using capillary electrophoresis. Mikrochim Acta 2013. [DOI: 10.1007/s00604-013-1042-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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A review on ochratoxin A transcriptomic studies. Food Chem Toxicol 2013; 59:766-83. [PMID: 23747715 DOI: 10.1016/j.fct.2013.05.043] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 05/25/2013] [Accepted: 05/28/2013] [Indexed: 10/26/2022]
Abstract
The mycotoxin Ochratoxin A (OTA) is a potent renal carcinogen in male rats. Transcriptomic studies on OTA (4 in vitro, 6 in vivo, 2 in vitro/in vivo) have been reviewed. The aim of 6 of them was mainly mechanistic whereas the rest had mostly predictive (1) or evaluation (5) purposes. An overall tendency towards gene expression downregulation was observed, probably as a result of protein synthesis inhibition. DNA damage response genes were not deregulated in most of the studies. Genes involved in acute renal injury, cell survival and cell proliferation were upregulated in several in vivo studies. Apoptosis genes were deregulated in vitro but less affected in vivo; activation of several MAPKs has been observed. Many genes related to oxidative stress or involved in cell-to-cell interaction pathways (Wnt) or cytoskeleton structure appeared to be deregulated either in vitro or in vivo. Regucalcin was highly downregulated in vivo and other calcium homeostasis genes were significantly deregulated in vitro. Genes related to OTA transport (OATs) and metabolism (CYPs) appeared downregulated in vivo. Overall, the mechanism of action of OTA remains unclear, however transcriptomic data have contributed to new mechanistic hypothesis generation and to in vitro-in vivo comparison.
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Sharma P, Manderville RA, Wetmore SD. Modeling the conformational preference of the carbon-bonded covalent adduct formed upon exposure of 2'-deoxyguanosine to ochratoxin A. Chem Res Toxicol 2013; 26:803-16. [PMID: 23560542 DOI: 10.1021/tx4000864] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The conformational flexibility of the C8-linked guanine adduct formed from attachment of ochratoxin A (OTA) was analyzed using a systematic computational approach and models ranging from the nucleobase to the adducted DNA helix. A focus was placed on the influence of the C8-modification of 2'-deoxyguanosine (dG) on the preferred relative arrangement of the nucleobase and the C8-substituent and, more importantly, the anti/syn conformational preference with respect to the glycosidic bond. Although OTA is twisted with respect to the base in the nucleobase model, addition of the deoxyribose sugar induces a further twist and restricts rotation about the C-C linkage due to close contacts between OTA and the sugar. The nucleoside model preferentially adpots a syn orientation (by 10-20 kJ mol(-1) depending on the OTA conformation) due to the presence of an O5'-H···N3 interaction. However, when this hydrogen bond is eliminated, which better mimics the DNA environment, a small (<5 kJ mol(-1)) anti/syn energy difference is predicted. Inclusion of the 5'-monophosphate group leads to an up to 20 kJ mol(-1) preference for the syn (nucleotide) conformation due to stabilizing base-phosphate interactions involving the amino group of guanine. Nevertheless, MD simulations and free energy analysis predict that both syn- and anti-conformations of OTB-dG are equally stable in helices when paired opposite cytosine. These results indicate that the adduct will likely adopt a syn conformation in an isolated nucleoside and nucleotide, while a mixture of syn and anti conformations will be observed in DNA duplexes. Since the syn conformation could stabilize base mismatches upon DNA replication or Z-DNA structures with varied biological outcomes, future computational and experimental work should elucidate the consequences of the conformational preference of this potentially harmful DNA lesion.
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Affiliation(s)
- Purshotam Sharma
- Department of Chemistry and Biochemistry, University of Lethbridge , 4401 University Drive West, Lethbridge, Alberta T1K 3M4, Canada
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Palabiyik S, Erkekoglu P, Zeybek N, Kızılgun M, Sahin G, Giray BK. Ochratoxin A causes oxidative stress and cell death in rat liver. WORLD MYCOTOXIN J 2012. [DOI: 10.3920/wmj2012.1446] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The effect of ochratoxin A (OTA) on oxidant/antioxidant status and on histopathological changes and apoptotic cell death in livers of male Sprague-Dawley rats has been investigated. OTA (0.5 mg/kg body weight/day) was administered by oral route for 14 days. Plasma biochemical parameters, activities of liver selenoenzymes (glutathione peroxidase-1, thioredoxin reductase) and antioxidant enzymes (catalase, superoxide dismutase, glutathione S-transferase), and levels of total glutathione and thiobarbituric acid reactive substance in hepatic tissue were measured. In addition, histopathological examinations were performed and apoptotic cell death of hepatocytes was evaluated by the TdT-mediated dUTP nick-end labelling (TUNEL) assay. OTA exposure was found to induce focal necrosis of hepatocytes and mononuclear cell infiltration. Besides, exposure to OTA caused an imbalance in oxidant and antioxidant parameters in the rat liver, as evidenced by significant decreases in glutathione S-transferase activity and glutathione levels, and marked increases in concentrations of thiobarbituric acid reactive substances. Furthermore, TUNEL analysis revealed a significant ~2.7-fold increase in the number of TUNEL-positive liver cells of rats exposed to OTA compared to the control group. The results of this study showed that oxidative stress is at least one of the mechanisms underlying the hepatic toxicity of OTA, and that both necrosis and apoptosis are types of cell death in the hepatic toxicity of this mycotoxin.
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Affiliation(s)
- S.S. Palabiyik
- Faculty of Pharmacy, Department of Toxicology, Hacettepe University, 06100 Ankara, Turkey
- Faculty of Pharmacy, Department of Toxicology, Atatürk University, 25240 Erzurum, Turkey
| | - P. Erkekoglu
- Faculty of Pharmacy, Department of Toxicology, Hacettepe University, 06100 Ankara, Turkey
| | - N.D. Zeybek
- Faculty of Medicine, Department of Histology and Embryology, Hacettepe University, 06100 Ankara, Turkey
| | - M. Kızılgun
- Department of Biochemistry, Diskapi Children's Health and Diseases, Hematology, Oncology Training and Research Hospital, 06590 Ankara, Turkey
| | - G. Sahin
- Faculty of Pharmacy, Department of Toxicology, Hacettepe University, 06100 Ankara, Turkey
- Faculty of Pharmacy, Department of Toxicology, Eastern Mediterranean University, Famagusta T.R. North Cyprus via Mersin 10, Turkey
| | - B. Kocer Giray
- Faculty of Pharmacy, Department of Toxicology, Hacettepe University, 06100 Ankara, Turkey
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Jilani K, Lupescu A, Zbidah M, Abed M, Shaik N, Lang F. Enhanced apoptotic death of erythrocytes induced by the mycotoxin ochratoxin A. Kidney Blood Press Res 2012; 36:107-18. [PMID: 23095759 DOI: 10.1159/000341488] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2012] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The mycotoxin ochratoxin A, an agent responsible for endemic Balkan nephropathy is known to trigger apoptosis and thus being toxic to several organs including the kidney. The mechanisms involved in ochratoxin A induced apoptosis include oxidative stress. Sequelae of ochratoxin intoxication include anemia. Similar to apoptosis of nucleated cells, erythrocytes may undergo suicidal cell death or eryptosis, which is characterized by cell shrinkage and cell membrane scrambling resulting in phosphatidylserine-exposure at the cell surface. Eryptosis could be triggered by Ca2+ -entry through oxidant sensitive unspecificcation channels increasing cytosolic Ca2+ activity ([Ca2+]i). The Ca2+ -sensitivity of cell membrane scrambling could be enhanced and eryptosis thus triggered by ceramide. The removal of suicidal erythrocytes may lead to anemia. Moreover, eryptotic erythrocytes could adhere to the vascular wall thus impeding microcirculation. The present study explored, whether ochratoxin A stimulates eryptosis. METHODS Fluo3-fluorescence was utilized to determine [Ca2+]i, forward scatter to estimate cell volume, annexin-V-binding to identify phosphatidylserine-exposing cells, fluorescent antibodies to detect ceramide formation and hemoglobin release to quantify hemolysis. Moreover, adhesion to human vascular endothelial cells (HUVEC) was determined utilizing a flow chamber. RESULTS A 48 h exposure to ochratoxin A was followed by significant increase of Fluo3-fluorescencei (≥ 2.5 µM), increase of ceramide abundance (10 µM), decrease of forward scatter (≥ 5 µM) and increase of annexin-V-binding (≥ 2.5 µM). Ochratoxin A exposure slightly but significantly enhanced hemolysis (10 µM). Ochratoxin (10 µM) enhanced erythrocyte adhesion to HUVEC. Removal of extracellular Ca2+ significantly blunted, but did not abrogate ochratoxin A-induced annexin V binding. CONCLUSIONS Ochratoxin A triggers suicidal erythrocyte death or eryptosis, an effect partially but not fully due to stimulation of Ca2+ -entry.
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Affiliation(s)
- Kashif Jilani
- Department of Physiology, University of Tuebingen, Gmelinstraße 5, 72076 Tuebingen, Germany
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Müller S, Dekant W, Mally A. Fumonisin B1 and the kidney: Modes of action for renal tumor formation by fumonisin B1 in rodents. Food Chem Toxicol 2012; 50:3833-46. [DOI: 10.1016/j.fct.2012.06.053] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 06/28/2012] [Accepted: 06/29/2012] [Indexed: 11/26/2022]
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Comparative immunohistochemical analysis of ochratoxin A tumourigenesis in rats and urinary tract carcinoma in humans; mechanistic significance of p-S6 ribosomal protein expression. Toxins (Basel) 2012; 4:643-62. [PMID: 23105973 PMCID: PMC3475221 DOI: 10.3390/toxins4090643] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 08/20/2012] [Accepted: 08/21/2012] [Indexed: 11/17/2022] Open
Abstract
Ochratoxin A (OTA) is considered to be a possible human urinary tract carcinogen, based largely on a rat model, but no molecular genetic changes in the rat carcinomas have yet been defined. The phosphorylated-S6 ribosomal protein is a marker indicating activity of the mammalian target of rapamycin, which is a serine/threonine kinase with a key role in protein biosynthesis, cell proliferation, transcription, cellular metabolism and apoptosis, while being functionally deregulated in cancer. To assess p-S6 expression we performed immunohistochemistry on formalin-fixed and paraffin-embedded tumours and normal tissues. Marked intensity of p-S6 expression was observed in highly proliferative regions of rat renal carcinomas and a rare angiosarcoma, all of which were attributed to prolonged exposure to dietary OTA. Only very small OTA-generated renal adenomas were negative for p-S6. Examples of rat subcutaneous fibrosarcoma and testicular seminoma, as well as of normal renal tissue, showed no or very weak positive staining. In contrast to the animal model, human renal cell carcinoma, upper urinary tract transitional cell carcinoma from cases of Balkan endemic nephropathy, and a human angiosarcoma were negative for p-S6. The combined findings are reminiscent of constitutive changes in the rat tuberous sclerosis gene complex in the Eker strain correlated with renal neoplasms, Therefore rat renal carcinogenesis caused by OTA does not obviously mimic human urinary tract tumourigenesis.
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Haighton LA, Lynch BS, Magnuson BA, Nestmann ER. A reassessment of risk associated with dietary intake of ochratoxin A based on a lifetime exposure model. Crit Rev Toxicol 2012; 42:147-68. [PMID: 22276591 PMCID: PMC3310481 DOI: 10.3109/10408444.2011.636342] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 10/25/2011] [Accepted: 10/26/2011] [Indexed: 12/23/2022]
Abstract
Mycotoxins, such as ochratoxin A (OTA), can occur from fungal growth on foods. OTA is considered a possible risk factor for adverse renal effects in humans based on renal tumors in male rats. For risk mitigation, Health Canada proposed maximum limits (MLs) for OTA based largely on a comparative risk assessment conducted by Health Canada (Kuiper-Goodman et al., 2010), in which analytical data of OTA in foods were used to determine the possible impact adopting MLs may have on OTA risks. The EU MLs were used for comparison and resultant risk was determined based on age-sex strata groups. These data were reevaluated here to determine comparative risk on a lifetime basis instead of age strata. Also, as there is scientific disagreement over the mechanism of OTA-induced renal tumors, mechanistic data were revisited. On a lifetime basis, risks associated with dietary exposure were found to be negligible, even without MLs, with dietary exposures to OTA three to four orders of magnitude below the pivotal animal LOAEL and the TD(05). Our review of the mechanistic data supported a threshold-based mechanism as the most plausible. In particular, OTA was negative in genotoxicity assays with the highest specificity and levels of DNA adducts were very low and not typical of genotoxic carcinogens. In conclusion, OTA exposures from Canadian foods do not present a significant cancer risk.
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Affiliation(s)
- Lois A Haighton
- Cantox Health Sciences International, An Intertek Company, Mississauga, Ontario, Canada.
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Hadjeba-Medjdoub K, Tozlovanu M, Pfohl-Leszkowicz A, Frenette C, Paugh RJ, Manderville RA. Structure-activity relationships imply different mechanisms of action for ochratoxin A-mediated cytotoxicity and genotoxicity. Chem Res Toxicol 2011; 25:181-90. [PMID: 22126095 DOI: 10.1021/tx200406c] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ochratoxin A (OTA) is a fungal toxin that is classified as a possible human carcinogen based on sufficient evidence for carcinogenicity in animal studies. The toxin is known to promote oxidative DNA damage through production of reactive oxygen species (ROS). The toxin also generates covalent DNA adducts, and it has been difficult to separate the biological effects caused by DNA adduction from that of ROS generation. In the current study, we have derived structure-activity relationships (SAR) for the role of the C5 substituent of OTA (C5-X = Cl) by first comparing the ability of OTA, OTBr (C5-X = Br), OTB (C5-X = H), and OTHQ (C5-X = OH) to photochemically react with GSH and 2'-deoxyguanosine (dG). OTA, OTBr, and OTHQ react covalently with GSH and dG following photoirradiation, while the nonchlorinated OTB does not react photochemically with GSH and dG. These findings correlate with their ability to generate covalent DNA adducts (direct genotoxicity) in human bronchial epithelial cells (WI26) and human kidney (HK2) cells, as evidenced by the (32)P-postlabeling technique. OTB lacks direct genotoxicity, while OTA, OTBr, and OTHQ act as direct genotoxins. In contrast, their cytotoxicity in opossum kidney epithelial cells (OK) and WI26 cells did not show a correlation with photoreactivity. In OK and WI26 cells, OTA, OTBr, and OTB are cytotoxic, while the hydroquinone OTHQ failed to exhibit cytotoxicity. Overall, our data show that the C5-Cl atom of OTA is critical for direct genotoxicity but plays a lesser role in OTA-mediated cytotoxicity. These SARs suggest different mechanisms of action (MOA) for OTA genotoxicity and cytotoxicity and are consistent with recent findings showing OTA mutagenicity to stem from direct genotoxicity, while cytotoxicity is derived from oxidative DNA damage.
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Affiliation(s)
- Kheira Hadjeba-Medjdoub
- Laboratory Chemical Engineering, Department Bioprocess & Microbial System, UMR CNRS/INPT/UPS 5503 , ENSA Toulouse, France
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Jennings P, Weiland C, Limonciel A, Bloch KM, Radford R, Aschauer L, McMorrow T, Wilmes A, Pfaller W, Ahr HJ, Slattery C, Lock EA, Ryan MP, Ellinger-Ziegelbauer H. Transcriptomic alterations induced by Ochratoxin A in rat and human renal proximal tubular in vitro models and comparison to a rat in vivo model. Arch Toxicol 2011; 86:571-89. [DOI: 10.1007/s00204-011-0780-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 11/07/2011] [Indexed: 12/15/2022]
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Pfohl-Leszkowicz A, Manderville RA. An update on direct genotoxicity as a molecular mechanism of ochratoxin a carcinogenicity. Chem Res Toxicol 2011; 25:252-62. [PMID: 22054007 DOI: 10.1021/tx200430f] [Citation(s) in RCA: 163] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Ochratoxin A (OTA) is a naturally occurring chlorophenolic fungal toxin that contaminates a wide range of food products and poses a cancer threat to humans. The mechanism of action (MOA) for OTA renal carcinogenicity is a controversial issue. In 2005, direct genotoxicity (covalent DNA adduct formation) was proposed as a MOA for OTA-mediated carcinogenicity [ Manderville , R. A. ( 2005 ) Chem. Res. Toxicol. 18 , 1091 - 1097 ]. At that time, inconsistent results had been published on OTA genotoxicity/mutagenicity, and conclusive evidence for OTA-mediated DNA adduction had been lacking. In this update, published data from the past 6-7 years are presented that provide new hypotheses for the MOA of OTA-mediated carcinogenicity. While direct genotoxicity remains a controversial issue for OTA, new findings from the Umemura and Nohmi laboratories provide definitive results for the mutagenicity of OTA in the target tissue (outer medulla) of male rat kidney that rules out oxidative DNA damage. These findings, coupled with our own efforts that provide new structural evidence for DNA adduction by OTA, has strengthened the argument for involvement of direct genotoxicity in OTA-mediated renal carcinogenesis. This MOA should be taken into consideration for OTA human risk assessment.
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Affiliation(s)
- Annie Pfohl-Leszkowicz
- Laboratoire de Génie Chimique , UMR CNRS/INPT/UPS 5503, INP/ENSA Toulouse, 1 Avenue Agrobiopole, F-31326 Auzeville-Tolosane, France.
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