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Ohtani S, Ushiyama A, Wada K, Suzuki Y, Hattori K. In vivo genotoxicity of high-intensity intermediate frequency magnetic fields in somatic cells and germ cells. JOURNAL OF RADIATION RESEARCH 2023; 64:250-260. [PMID: 36579461 PMCID: PMC10036096 DOI: 10.1093/jrr/rrac081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/31/2022] [Indexed: 06/17/2023]
Abstract
Intermediate frequency magnetic fields (IF-MFs) at ~85 kHz are one of the components of wireless power transfer (WPT) systems. However, the available data needed for the assessment of the safety of organisms from IF-MF exposure are scarce. Thus, there is an imminent need to accumulate evidence-based assessment data. In particular, if humans are exposed to IF-MF due to an accident or trouble, they are at increased risk of being exposed to high-intensity IF-MF within a short period. The already existing exposure system was improved to a system that could intermittently expose animals at 3 s intervals. This system allows the exposure of a mouse to high-intensity IF-MF (frequency: 82.3 kHz; induced electric field: 87 V/m, which was 3.8 times the basic restriction level for occupational exposure in the ICNIRP guideline), while regulating the heat generated by the coil. In vivo genotoxicity after IF-MF exposure was assessed using micronucleus (MN) test, Pig-a assay, and gpt assay. The results of MN test and Pig-a assay in hematopoietic cells revealed that neither the reticulocytes nor the mature erythrocytes exhibited significant increases in the IF-MF-exposed group compared with that in the sham-exposed group. In germ cells, MN test and gpt assay outcomes showed that IF-MF exposure did not cause any genetic or chromosomal abnormality. Based on these data, there was no genotoxic effect of our set IF-MF exposure on somatic and germ cells. These findings can contribute to the widespread use of WPT systems as effective data of IF-MF safety assessment.
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Affiliation(s)
- Shin Ohtani
- Department of Environmental Toxicology, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan
| | - Akira Ushiyama
- Corresponding author. Department of Environmental Health, National Institute of Public Health, 2-3-6 Minami, Wako, Saitama, 351-0197, Japan. Phone: +81-48-458-6254; Fax: +81-48-458-6270. E-mail:
| | - Keiji Wada
- Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan
| | - Yukihisa Suzuki
- Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan
| | - Kenji Hattori
- Department of Environmental Toxicology, Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo, 204-8588, Japan
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Peanlikhit T, Honikel L, Liu J, Zimmerman T, Rithidech K. Countermeasure efficacy of apigenin for silicon-ion-induced early damage in blood and bone marrow of exposed C57BL/6J mice. LIFE SCIENCES IN SPACE RESEARCH 2022; 35:44-52. [PMID: 36336369 DOI: 10.1016/j.lssr.2022.05.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 05/09/2022] [Accepted: 05/25/2022] [Indexed: 06/16/2023]
Abstract
We investigated the countermeasure efficacy of apigenin (AP), given as a diet supplement, for radiation-induced damage in the hematopoietic tissues collected on day 7 after a total-body exposure of male C57BL/6J mice to 0 or 0.5 Gy of 260 MeV/n silicon (28Si) ions. We gave food with AP at the concentration of 20 mg/kg body weight (bw) (AP20) or without AP (AP0) to mice before and after irradiation. There were four groups of mice (six mice in each): Group 1- Control, i.e. No Radiation (0 Gy) with AP0; Group 2 - Radiation (0.5 Gy) with AP0; Group 3 - No Radiation (0 Gy) with AP20; and Group 4 - Radiation (0.5 Gy) with AP20. The complete blood count (CBC) and differential blood count were performed for each mouse. In the same mouse, an anti-clastogenic activity of AP was evaluated using the in vivo blood-erythrocyte micronucleus (MN) assay. Further in each mouse, bone marrow (BM) cells were collected and used for measuring the levels of activated nuclear factor-kappa B (NF-κB), and pro-inflammatory cytokines (i.e. tumor necrotic factor-alpha (TNF-α), interleukin-1α (IL-1α), IL-1 beta (IL-1β), and IL-6). We used the colony-forming unit assay (CFU-A) as a tool to study the countermeasure efficacy of AP against the harmful effects of 28Si ions on the proliferation of the hematopoietic stem/progenitor cells (HSPCs). Our results showed that AP is highly effective not only in the prevention of leukopenia and thrombocytopenia but also in the enhancement of erythropoiesis and the proliferation of HSPCs. We also observed the potent anti-clastogenic activity of AP given to mice as a diet supplement. Further, we found that AP is very effective in the suppression of activated NF-κB and pro-inflammatory cytokines, suggesting that AP given as a diet supplement protects mice from 28Si-ion-induced damage in the hematopoietic tissues of irradiated male C57BL/6J mice via its anti-inflammation activity.
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Affiliation(s)
- Tanat Peanlikhit
- Pathology Department, Stony Brook University, Stony Brook, NY 11794-8691, USA
| | - Louise Honikel
- Pathology Department, Stony Brook University, Stony Brook, NY 11794-8691, USA
| | - Jingxuan Liu
- Pathology Department, Stony Brook University, Stony Brook, NY 11794-8691, USA
| | - Thomas Zimmerman
- Pathology Department, Stony Brook University, Stony Brook, NY 11794-8691, USA; Division of Laboratory Animal Resources, Stony Brook University, Stony Brook, NY 11794-8611, USA
| | - Kanokporn Rithidech
- Pathology Department, Stony Brook University, Stony Brook, NY 11794-8691, USA
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Castañeda-Yslas IY, Torres-Bugarín O, García-Ramos JC, Toledano-Magaña Y, Radilla-Chávez P, Bogdanchikova N, Pestryakov A, Ruiz-Ruiz B, Arellano-García ME. AgNPs Argovit™ Modulates Cyclophosphamide-Induced Genotoxicity on Peripheral Blood Erythrocytes In Vivo. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2096. [PMID: 34443926 PMCID: PMC8399516 DOI: 10.3390/nano11082096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/05/2021] [Accepted: 08/13/2021] [Indexed: 11/16/2022]
Abstract
Silver nanoparticles (AgNPs) have been studied worldwide for their potential biomedical applications. Specifically, they are proposed as a novel alternative for cancer treatment. However, the determination of their cytotoxic and genotoxic effects continues to limit their application. The commercially available silver nanoparticle Argovit™ has shown antineoplastic, antiviral, antibacterial, and tissue regenerative properties, activities triggered by its capacity to promote the overproduction of reactive oxygen species (ROS). Therefore, in this work, we evaluated the genotoxic and cytotoxic potential of the Argovit™ formulation (average size: 35 nm) on BALB/c mice using the micronucleus in a peripheral blood erythrocytes model. Besides, we evaluated the capability of AgNPs to modulate the genotoxic effect induced by cyclophosphamide (CP) after the administration of the oncologic agent. To achieve this, 5-6-week-old male mice with a mean weight of 20.11 ± 2.38 g were treated with water as negative control (Group 1), an single intraperitoneal dose of CP (50 mg/kg of body weight, Group 2), a daily oral dose of AgNPs (6 mg/kg of weight, Group 3) for three consecutive days, or a combination of these treatment schemes: one day of CP doses (50 mg/kg of body weight) followed by three doses of AgNPs (one dose per day, Group 4) and three alternate doses of CP and AgNPs (six days of exposure, Group 5). Blood samples were taken just before the first administration (0 h) and every 24 h for seven days. Our results show that Argovit™ AgNPs induced no significant cytotoxic or acute genotoxic damage. The observed cumulative genotoxic damage in this model could be caused by the accumulation of AgNPs due to administered consecutive doses. Furthermore, the administration of AgNPs after 24 h of CP seems to have a protective effect on bone marrow and reduces by up to 50% the acute genotoxic damage induced by CP. However, this protection is not enough to counteract several doses of CP. To our knowledge, this is the first time that the exceptional chemoprotective capacity produced by a non-cytotoxic silver nanoparticle formulation against CP genotoxic damage has been reported. These findings raise the possibility of using AgNPs as an adjuvant agent with current treatments, reducing adverse effects.
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Affiliation(s)
- Idalia Yazmin Castañeda-Yslas
- Programa de Maestría y Doctorado en Ciencias e Ingeniería (MyDCI), Facultad de Ciencias, Universidad Autónoma de Baja California, Ensenada 22860, Baja California, Mexico;
| | - Olivia Torres-Bugarín
- Departamento de Ciclo de Vida y Medicina Interna II, Decanato Ciencias de la Salud, Universidad Autónoma de Guadalajara, Zapopan 45129, Jalisco, Mexico;
| | - Juan Carlos García-Ramos
- Escuela de Ciencias de la Salud Unidad Valle Dorado, Universidad Autónoma de Baja California, Ensenada 22890, Baja California, Mexico; (Y.T.-M.); (P.R.-C.)
| | - Yanis Toledano-Magaña
- Escuela de Ciencias de la Salud Unidad Valle Dorado, Universidad Autónoma de Baja California, Ensenada 22890, Baja California, Mexico; (Y.T.-M.); (P.R.-C.)
| | - Patricia Radilla-Chávez
- Escuela de Ciencias de la Salud Unidad Valle Dorado, Universidad Autónoma de Baja California, Ensenada 22890, Baja California, Mexico; (Y.T.-M.); (P.R.-C.)
| | - Nina Bogdanchikova
- Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada 22860, Baja California, Mexico;
| | - Alexey Pestryakov
- Research School of Chemistry and Applied Biomedical Sciences, Tomsk Polytechnic University, 634050 Tomsk, Russia;
| | - Balam Ruiz-Ruiz
- Departamento de Ciencias de la Salud, Unidad Regional Los Mochis, Universidad Autónoma de Occidente, Los Mochis 81223, Sinaloa, Mexico;
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Toxicity studies of Aspergillus fumigatus administered by inhalation to B6C3F1/N mice (revised). TOXICITY REPORT SERIES 2021:NTP-TOX-100. [PMID: 34283822 PMCID: PMC8436148 DOI: 10.22427/ntp-tox-100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Aspergillus fumigatus is a thermotolerant, soil-borne fungal species that is ubiquitous in the environment. Mold was nominated to the National Toxicology Program (NTP) by a private individual due to suspected adverse health effects associated with personal exposure in indoor and occupational settings. A. fumigatus is of particular concern in the biowaste industry as the species can contaminate self-heating compost piles. Because of this potential for personal and occupational exposure and the lack of available toxicity data, toxicity studies were conducted in which male and female B6C3F1/N mice were exposed to A. fumigatus conidia (spores) two times a week for 3 months. All in-life procedures, including inhalation exposure, test article preparation, and hematology analysis, were completed by the National Institute for Occupational Safety and Health (NIOSH, Morgantown, WV). Battelle (Columbus, OH) conducted terminal necropsies, measured terminal body and organ weights, and evaluated gross lesions on-site at NIOSH. Tissue processing and histopathology were completed at Battelle. Grocott's methenamine silver (GMS) staining was performed at NIOSH. Genetic toxicology studies on mouse peripheral blood erythrocytes were conducted by Integrated Laboratory Systems, LLC (Research Triangle Park, NC). (Abstract Abridged).
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Rithidech KN, Jangiam W, Tungjai M, Reungpatthanaphong P, Gordon C, Honikel L. Early- and late-occurring damage in bone marrow cells of male CBA/Ca mice exposed whole-body to 1 GeV/n 48Ti ions. Int J Radiat Biol 2021; 97:517-528. [PMID: 33591845 DOI: 10.1080/09553002.2021.1884312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 10/20/2020] [Accepted: 01/21/2021] [Indexed: 12/22/2022]
Abstract
PURPOSE To determine the early- and late-occurring damage in the bone marrow (BM) and peripheral blood cells of male CBA/Ca mice after exposure to 0, 0.1, 0.25, or 0.5 Gy of 1 GeV/n titanium (48Ti) ions (one type of space radiation). METHOD We used the mouse in vivo blood-erythrocyte micronucleus (MN) assay for evaluating the cytogenetic effects of various doses of 1 GeV/n 48Ti ions. The MN assay was coupled with the characterization of epigenetic alterations (the levels of global 5-methylcytosine and 5-hydroxymethylcytosine) in DNA samples isolated from BM cells. These analyses were performed in samples collected at an early time-point (1 week) and a late time-point (6 months) post-irradiation. RESULTS Our results showed that 48Ti ions induced genomic instability in exposed mice. Significant dose-dependent loss of global 5-hydroxymethylcytosine was found but there were no changes in global 5-methylcytosine levels. CONCLUSION Since persistent genomic instability and loss of global 5-hydroxymethylcytosine are linked to cancer, our findings suggest that exposure to 48Ti ions may pose health risks.
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Affiliation(s)
| | - Witawat Jangiam
- Pathology Department, Stony Brook University, Stony Brook, NY, USA
- Department of Chemical Engineering, Faculty of Engineering, Burapha University, Chonburi, Thailand
| | - Montree Tungjai
- Pathology Department, Stony Brook University, Stony Brook, NY, USA
- Department of Radiologic Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Paiboon Reungpatthanaphong
- Pathology Department, Stony Brook University, Stony Brook, NY, USA
- Department of Applied Radiation and Isotopes, Faculty of Sciences, Kasetsart University, Bangkok, Thailand
| | - Chris Gordon
- Pathology Department, Stony Brook University, Stony Brook, NY, USA
| | - Louise Honikel
- Pathology Department, Stony Brook University, Stony Brook, NY, USA
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Shipkowski KA, Cora MC, Cesta MF, Robinson VG, Waidyanatha S, Witt KL, Vallant MK, Fallacara DM, Hejtmancik MR, Masten SA, Cooper SD, Fernando RA, Blystone CR. Comparison of sulfolane effects in Sprague Dawley rats, B6C3F1/N mice, and Hartley guinea pigs after 28 days of exposure via oral gavage. Toxicol Rep 2021; 8:581-591. [PMID: 33777704 PMCID: PMC7985713 DOI: 10.1016/j.toxrep.2021.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 02/02/2021] [Accepted: 02/04/2021] [Indexed: 01/27/2023] Open
Abstract
Sulfolane is a solvent used in industrial refining with identified environmental exposure in drinking water. Due to potential large species differences, the National Toxicology Program (NTP) conducted 28-day toxicity studies in male and female Hsd:Sprague Dawley® SD® rats, B6C3F1/N mice, and Hartley guinea pigs. A wide dose range of 0, 1, 10, 30, 100, 300, and 800 mg/kg was administered via gavage. Histopathology, clinical pathology, and organ weights were evaluated after 28 days of exposure. In addition, plasma concentrations of sulfolane were evaluated 2 and 24 h after the last dose. Increased mortality was observed in the highest dose group of guinea pigs and mice while decreased body weight was observed in rats compared to controls. Histopathological lesions were observed in the kidney (male rat), stomach (male mice), esophagus (male and female guinea pigs), and nose (male guinea pigs). Plasma concentrations were generally higher in rats and guinea pigs compared to mice with evidence of saturated clearance at higher doses. Male rats appear to be the most sensitive with hyaline droplet accumulation occurring at all doses, although the human relevance of this finding is questionable.
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Affiliation(s)
- K A Shipkowski
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - M C Cora
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - M F Cesta
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - V G Robinson
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - S Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - K L Witt
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - M K Vallant
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | | | | | - S A Masten
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - S D Cooper
- RTI International, Research Triangle Park, NC, USA
| | - R A Fernando
- RTI International, Research Triangle Park, NC, USA
| | - C R Blystone
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
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No evidence for genotoxicity in mice due to exposure to intermediate-frequency magnetic fields used for wireless power-transfer systems. Mutat Res 2021; 863-864:503310. [PMID: 33678242 DOI: 10.1016/j.mrgentox.2021.503310] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 01/09/2021] [Accepted: 01/11/2021] [Indexed: 11/23/2022]
Abstract
Time varying magnetic fields (MFs) are used for the wireless power-transfer (WPT) technology. Especially, 85 kHz band MFs, which are included in the intermediate frequency (IF) band (300 Hz - 10 MHz), are commonly used WPT system for charging electric vehicles. Those applications of WPT technology have elicited public concern about health effects of IF-MF. However, existing data from health risk assessments are insufficient and additional data are needed. We assessed the genotoxic effects of IF-MF exposure on erythroid differentiation in mice. A high-intensity IF-MF mouse exposure system was constructed to induce an average whole-body electric field of 54.1 V/m. Blood samples were obtained from male mice before and after a 2-week IF-MF exposure (1 h/day, total: 10 h); X-irradiated mice were used as positive controls. We analyzed the blood samples with the micronucleus (MN) test and the Pig-a mutation assay. No significant differences were seen between IF-MF-exposed and sham-exposed mice in the frequencies of either MN or Pig-a mutations in mature erythrocytes and reticulocytes. IF-MF exposure did not induce genotoxicity in vivo under the study conditions (2.36× the basic restriction for occupational exposure, 22.9 V/m, in the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines). The absence of significant biological effects due to IF-MF exposure supports the practical application of this technology.
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Smith‐Roe SL, Wyde ME, Stout MD, Winters JW, Hobbs CA, Shepard KG, Green AS, Kissling GE, Shockley KR, Tice RR, Bucher JR, Witt KL. Evaluation of the genotoxicity of cell phone radiofrequency radiation in male and female rats and mice following subchronic exposure. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:276-290. [PMID: 31633839 PMCID: PMC7027901 DOI: 10.1002/em.22343] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/04/2019] [Accepted: 10/16/2019] [Indexed: 05/03/2023]
Abstract
The National Toxicology Program tested two common radiofrequency radiation (RFR) modulations emitted by cellular telephones in a 2-year rodent cancer bioassay that included interim assessments of additional animals for genotoxicity endpoints. Male and female Hsd:Sprague Dawley SD rats and B6C3F1/N mice were exposed from Gestation day 5 or Postnatal day 35, respectively, to code division multiple access (CDMA) or global system for mobile modulations over 18 hr/day, at 10-min intervals, in reverberation chambers at specific absorption rates of 1.5, 3, or 6 W/kg (rats, 900 MHz) or 2.5, 5, or 10 W/kg (mice, 1,900 MHz). After 19 (rats) or 14 (mice) weeks of exposure, animals were examined for evidence of RFR-associated genotoxicity using two different measures. Using the alkaline (pH > 13) comet assay, DNA damage was assessed in cells from three brain regions, liver cells, and peripheral blood leukocytes; using the micronucleus assay, chromosomal damage was assessed in immature and mature peripheral blood erythrocytes. Results of the comet assay showed significant increases in DNA damage in the frontal cortex of male mice (both modulations), leukocytes of female mice (CDMA only), and hippocampus of male rats (CDMA only). Increases in DNA damage judged to be equivocal were observed in several other tissues of rats and mice. No significant increases in micronucleated red blood cells were observed in rats or mice. In conclusion, these results suggest that exposure to RFR is associated with an increase in DNA damage. Environ. Mol. Mutagen. 61:276-290, 2020. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Stephanie L. Smith‐Roe
- Division of the National Toxicology ProgramNational Institute of Environmental Health SciencesResearch Triangle ParkNorth Carolina
| | - Michael E. Wyde
- Division of the National Toxicology ProgramNational Institute of Environmental Health SciencesResearch Triangle ParkNorth Carolina
| | - Matthew D. Stout
- Division of the National Toxicology ProgramNational Institute of Environmental Health SciencesResearch Triangle ParkNorth Carolina
| | - John W. Winters
- Integrated Laboratory Systems, Inc.Research Triangle ParkNorth Carolina
| | - Cheryl A. Hobbs
- Integrated Laboratory Systems, Inc.Research Triangle ParkNorth Carolina
| | - Kim G. Shepard
- Integrated Laboratory Systems, Inc.Research Triangle ParkNorth Carolina
| | - Amanda S. Green
- Integrated Laboratory Systems, Inc.Research Triangle ParkNorth Carolina
| | - Grace E. Kissling
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health SciencesResearch Triangle ParkNorth Carolina
| | - Keith R. Shockley
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health SciencesResearch Triangle ParkNorth Carolina
| | - Raymond R. Tice
- Division of the National Toxicology ProgramNational Institute of Environmental Health SciencesResearch Triangle ParkNorth Carolina
| | - John R. Bucher
- Division of the National Toxicology ProgramNational Institute of Environmental Health SciencesResearch Triangle ParkNorth Carolina
| | - Kristine L. Witt
- Division of the National Toxicology ProgramNational Institute of Environmental Health SciencesResearch Triangle ParkNorth Carolina
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Dertinger SD, Avlasevich SL, Torous DK, Singh P, Khanal S, Kirby C, Drake A, MacGregor JT, Bemis JC. 3Rs friendly study designs facilitate rat liver and blood micronucleus assays and Pig-a gene mutation assessments: Proof-of-concept with 13 reference chemicals. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2019; 60:704-739. [PMID: 31294869 PMCID: PMC8600442 DOI: 10.1002/em.22312] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/31/2019] [Accepted: 06/11/2019] [Indexed: 05/16/2023]
Abstract
Regulatory guidance documents stress the value of assessing the most appropriate endpoints in multiple tissues when evaluating the in vivo genotoxic potential of chemicals. However, conducting several independent studies to evaluate multiple endpoints and/or tissue compartments is resource intensive. Furthermore, when dependent on visual detection, conventional approaches for scoring genotoxicity endpoints can be slow, tedious, and less objective than the ideal. To address these issues with current practices we attempted to (1) devise resource sparing treatment and harvest schedules that are compatible with liver and blood micronucleus endpoints, as well as the Pig-a gene mutation assay, and (2) utilize flow cytometry-based methods to score each of these genotoxicity biomarkers. Proof-of-principle experiments were performed with 4-week-old male and female Crl:CD(SD) rats exposed to aristolochic acids I/II, benzo[a]pyrene, cisplatin, cyclophosphamide, diethylnitrosamine, 1,2-dimethylhydrazine, dimethylnitrosamine, 2,6-dinitrotoluene, hydroxyurea, melphalan, temozolomide, quinoline, or vinblastine. These 13 chemicals were each tested in two treatment regimens: one 3-day exposure cycle, and three 3-day exposure cycles. Each exposure, blood collection, and liver harvest was accomplished during a standard Monday-Friday workweek. Key findings are that even these well-studied, relatively potent genotoxicants were not active in both tissues and all assays (indeed only cisplatin was clearly positive in all three assays); and whereas the sensitivity of the Pig-a assay clearly benefitted from three versus one treatment cycle, micronucleus assays yielded qualitatively similar results across both study designs. Collectively, these results suggest it is possible to significantly reduce animal and other resource requirements while improving assessments of in vivo genotoxicity potential by simultaneously evaluating three endpoints and two important tissue compartments using fit-for-purpose study designs in conjunction with flow cytometric scoring approaches. Environ. Mol. Mutagen., 60:704-739, 2019. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Stephen D. Dertinger
- Litron Laboratories, Rochester, New York
- Correspondence to: Stephen D. Dertinger and Jeffrey C. Bemis, Litron Laboratories, 3500 Winton Place, Rochester, NY 14623, and
| | | | | | | | | | | | | | | | - Jeffrey C. Bemis
- Litron Laboratories, Rochester, New York
- Correspondence to: Stephen D. Dertinger and Jeffrey C. Bemis, Litron Laboratories, 3500 Winton Place, Rochester, NY 14623, and
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Font-Ribera L, Marco E, Grimalt JO, Pastor S, Marcos R, Abramsson-Zetterberg L, Pedersen M, Grummt T, Junek R, Barreiro E, Heederik D, Spithoven J, Critelli R, Naccarati A, Schmalz C, Zwiener C, Liu J, Zhang X, Mitch W, Gracia-Lavedan E, Arjona L, de Bont J, Tarès L, Vineis P, Kogevinas M, Villanueva CM. Exposure to disinfection by-products in swimming pools and biomarkers of genotoxicity and respiratory damage - The PISCINA2 Study. ENVIRONMENT INTERNATIONAL 2019; 131:104988. [PMID: 31323486 DOI: 10.1016/j.envint.2019.104988] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 06/28/2019] [Accepted: 06/30/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Swimming in pools is a healthy activity that entails exposure to disinfection by-products (DBPs), some of which are irritant and genotoxic. OBJECTIVES We evaluated exposure to DBPs during swimming in a chlorinated pool and the association with short-term changes in genotoxicity and lung epithelium permeability biomarkers. METHODS Non-smoker adults (N = 116) swimming 40 min in an indoor pool were included. We measured a range of biomarkers before and at different times after swimming: trihalomethanes (THMs) in exhaled breath (5 min), trichloroacetic acid (TCAA) in urine (30 min), micronuclei in lymphocytes (1 h), serum club cell protein (CC16) (1 h), urine mutagenicity (2 h) and micronuclei in reticulocytes (4 days in a subset, N = 19). Several DBPs in water and trichloramine in air were measured, and physical activity was extensively assessed. We estimated interactions with polymorphisms in genes related to DBP metabolism. RESULTS Median level of chloroform, brominated and total THMs in water was 37.3, 9.5 and 48.5, μg/L, respectively, and trichloramine in air was 472.6 μg/m3. Median exhaled chloroform, brominated and total THMs increased after swimming by 10.9, 2.6 and 13.4, μg/m3, respectively. Creatinine-adjusted urinary TCAA increased by 3.1 μmol/mol. Micronuclei in lymphocytes and reticulocytes, urine mutagenicity and serum CC16 levels remained unchanged after swimming. Spearman correlation coefficients showed no association between DBP exposure and micronuclei in lymphocytes, urine mutagenicity and CC16. Moderate associations were observed for micronuclei in reticulocytes and DBP exposure. CONCLUSIONS The unchanged levels of the short-term effect biomarkers after swimming and null associations with personal estimates of exposure to DBPs suggest no measurable effect on genotoxicity in lymphocytes, urine mutagenicity and lung epithelium permeability at the observed exposure levels. The moderate associations with micronuclei in reticulocytes require cautious interpretation given the reduced sample size.
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Affiliation(s)
- Laia Font-Ribera
- ISGlobal, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Carlos III Institute of Health, Madrid, Spain; IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain
| | - Esther Marco
- Institute of Environmental Assessment and Water Research (IDÆA-CSIC), Barcelona, Spain
| | - Joan O Grimalt
- Institute of Environmental Assessment and Water Research (IDÆA-CSIC), Barcelona, Spain
| | - Susana Pastor
- Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Carlos III Institute of Health, Madrid, Spain; Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | - Ricard Marcos
- Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Carlos III Institute of Health, Madrid, Spain; Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
| | | | - Marie Pedersen
- Department of Public Health, Section of Epidemiology, University of Copenhagen, Denmark; Danish Cancer Society Research Center, Diet, Genes and Environment, Copenhagen, Denmark
| | | | - Ralf Junek
- German Environment Agency, Bad Elster, Germany
| | - Esther Barreiro
- Universitat Pompeu Fabra (UPF), Barcelona, Spain; Pulmonology Department-Lung Cancer & Muscle Research Group, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Barcelona, Spain
| | - Dick Heederik
- Institute for Risk Assessment Sciences (IRAS), Utrecht, the Netherlands
| | - Jack Spithoven
- Institute for Risk Assessment Sciences (IRAS), Utrecht, the Netherlands
| | - Rossana Critelli
- Italian Institute for Genomic Medicine (IIGM), Torino, Italy; Department of Medical Science, University of Turin, Turin, Italy
| | | | - Christina Schmalz
- Environmental Analytical Chemistry, Center for Applied Geoscience, University of Tübingen, Tübingen, Germany
| | - Christian Zwiener
- Environmental Analytical Chemistry, Center for Applied Geoscience, University of Tübingen, Tübingen, Germany
| | - Jiaqi Liu
- Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong, China
| | - Xiangru Zhang
- Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong, China
| | - William Mitch
- Department of Civil and Environmental Engineering, Stanford University, Palo Alto, CA, USA
| | - Esther Gracia-Lavedan
- ISGlobal, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Carlos III Institute of Health, Madrid, Spain
| | - Lourdes Arjona
- ISGlobal, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Carlos III Institute of Health, Madrid, Spain; IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain
| | - Jeroen de Bont
- ISGlobal, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Carlos III Institute of Health, Madrid, Spain
| | - Lluïsa Tarès
- ISGlobal, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Carlos III Institute of Health, Madrid, Spain
| | - Paolo Vineis
- School of Public Health, Imperial College London, UK
| | - Manolis Kogevinas
- ISGlobal, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Carlos III Institute of Health, Madrid, Spain; IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain
| | - Cristina M Villanueva
- ISGlobal, Barcelona, Spain; Universitat Pompeu Fabra (UPF), Barcelona, Spain; Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Carlos III Institute of Health, Madrid, Spain; IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain.
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Szeleszczuk O, Gleindek M, Grzesiakowska A, Kuchta-Gładysz M, Otwinowska-Mindur A. Evaluation of chromosomal instability in somatic cells of farmed foxes. Arch Anim Breed 2018; 61:405-412. [PMID: 32175447 PMCID: PMC7065389 DOI: 10.5194/aab-61-405-2018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 09/28/2018] [Indexed: 11/11/2022] Open
Abstract
The micronucleus
(MN) test is a common tool used to evaluate cellular genetic instability at
the chromosomal level. It determines the effect of physical, chemical and
environmental factors on DNA, and thus the body's individual resistance to
harmful substances. The karyotypes of blue and silver foxes and their
interspecific hybrids are characterized by morphological and structural
variation. This variation is partly attributable to the presence of
chromosomal polymorphism, which may significantly influence the stability of
genetic material in the cells of these species. The objective of the study
was to evaluate genetic material stability in selected Canidae species. To
this end, analyses using the MN test were performed. Binucleated cells (BNCs)
were analysed in microscopic preparations, and the number of micronuclei was
determined within these cells. For the proportions of both MN and BNCs,
highly significant differences were observed between the fox species. The
interspecific hybrids differed from the other fox species in MN percentage.
The lowest average was noted in blue foxes (3.33) and the highest in
interspecific hybrids (15.21).
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Affiliation(s)
- Olga Szeleszczuk
- Department of Animal Anatomy, Institute of Veterinary Sciences, University of Agriculture in Krakow, Krakow 30-059, Poland
| | - Magdalena Gleindek
- Department of Animal Anatomy, Institute of Veterinary Sciences, University of Agriculture in Krakow, Krakow 30-059, Poland
| | - Anna Grzesiakowska
- Department of Animal Anatomy, Institute of Veterinary Sciences, University of Agriculture in Krakow, Krakow 30-059, Poland
| | - Marta Kuchta-Gładysz
- Department of Animal Anatomy, Institute of Veterinary Sciences, University of Agriculture in Krakow, Krakow 30-059, Poland
| | - Agnieszka Otwinowska-Mindur
- Department of Genetics and Animal Breeding, Faculty of Animal Science, University of Agriculture in Krakow, Krakow 30-059, Poland
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Rana SVS, Verma Y, Singh GD. Assessment of genotoxicity amongst smokers, alcoholics, and tobacco chewers of North India using micronucleus assay and urinary 8-hydroxyl-2'-deoxyguanosine, as biomarkers. ENVIRONMENTAL MONITORING AND ASSESSMENT 2017; 189:391. [PMID: 28702879 DOI: 10.1007/s10661-017-6103-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 06/23/2017] [Indexed: 06/07/2023]
Abstract
The main objective of the present study was to screen the genotoxicity caused by individual and combined habits of smoking, tobacco chewing, and alcohol consumption in human population of North India. Study recruited 67 male subjects aged 25 to 65 years. Buccal mucosal cells were subjected to micronucleus (MN) assay, and 8-hydroxyl-2-deoxyguanosine (8-OHdG) was estimated in their urine samples. Number and shape of the MN cells varied in the buccal epithelium of different groups. Maximum number of MN (0.47%) were found in tobacco chewers followed by smokers (0.45%) and alcoholics (0.44%) (P < 0.05). These results reciprocated the concentration of urinary 8-OHdG. Maximum value for 8-OHdG was also recorded in tobacco chewers (21.07 ± 5.51 mg/mg creatinine) followed by smokers (20.25 ± 3.96 mg/mg creatinine) and alcoholics (19.06 ± 3.41 mg/mg creatinine) (P < 0.05). Combined effects of these agents were found to be statistically different from individual effects. Carcinogenic compounds present in cigarette smoke, nitrosamines found in solid tobacco, and acetaldehyde, a metabolic product of alcohol, induce oxidative stress that manifests into genotoxicity. In conclusion, demographical differences occur in the genotoxicity caused by these three habits. MN assay and urinary 8-OHdG are simple, noninvasive, and reliable biomarkers of genotoxicity.
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Affiliation(s)
- S V S Rana
- Department of Zoology, Toxicology Laboratory, Ch. Charan Singh University, Meerut, UP, 250004, India.
| | - Yeshvandra Verma
- Department of Zoology, Toxicology Laboratory, Ch. Charan Singh University, Meerut, UP, 250004, India
| | - Gagan Deep Singh
- Department of Zoology, Toxicology Laboratory, Ch. Charan Singh University, Meerut, UP, 250004, India
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13
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Thybaud V, Lorge E, Levy DD, van Benthem J, Douglas GR, Marchetti F, Moore MM, Schoeny R. Main issues addressed in the 2014-2015 revisions to the OECD Genetic Toxicology Test Guidelines. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2017; 58:284-295. [PMID: 28266061 DOI: 10.1002/em.22079] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 02/10/2017] [Indexed: 05/23/2023]
Abstract
The Organization for Economic Cooperation and Development (OECD) recently revised the test guidelines (TGs) for genetic toxicology. This article describes the main issues addressed during the revision process, and the new and consistent recommendations made in the revised TGs for: (1) demonstration of laboratory proficiency; (2) generation and use of robust historical control data; (3) improvement of the statistical power of the tests; (4) selection of top concentration for in vitro assays; (5) consistent data interpretation and determination of whether the result is clearly positive, clearly negative or needs closer consideration; and, (6) consideration of 3R's for in vivo assay design. The revision process resulted in improved consistency among OECD TGs (including the newly developed ones) and more comprehensive recommendations for the conduct and the interpretation of the assays. Altogether, the recommendations made during the revision process should improve the efficiency, by which the data are generated, and the quality and reliability of test results. Environ. Mol. Mutagen. 58:284-295, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
| | | | - Dan D Levy
- US Food and Drug Administration Center for Food Safety and Applied Nutrition, College Park, Maryland
| | - Jan van Benthem
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - George R Douglas
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | - Francesco Marchetti
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
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Manservisi F, Marquillas CB, Buscaroli A, Huff J, Lauriola M, Mandrioli D, Manservigi M, Panzacchi S, Silbergeld EK, Belpoggi F. An Integrated Experimental Design for the Assessment of Multiple Toxicological End Points in Rat Bioassays. ENVIRONMENTAL HEALTH PERSPECTIVES 2017; 125:289-295. [PMID: 27448388 PMCID: PMC5332192 DOI: 10.1289/ehp419] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 04/27/2016] [Accepted: 06/20/2016] [Indexed: 05/03/2023]
Abstract
BACKGROUND For nearly five decades long-term studies in rodents have been the accepted benchmark for assessing chronic long-term toxic effects, particularly carcinogenicity, of chemicals. The European Food Safety Authority (EFSA) and the World Health Organization (WHO) have pointed out that the current set of internationally utilized test methods capture only some of the potential adverse effects associated with exposures to these agents over the lifetime. OBJECTIVES In this paper, we propose the adaption of the carcinogenicity bioassay to integrate additional protocols for comprehensive long-term toxicity assessment that includes developmental exposures and long-term outcomes, capable of generating information on a broad spectrum of different end points. DISCUSSION An integrated study design based on a stepwise process is described that includes the priority end points of the Economic Co-operation and Development and the National Toxicology Program guidelines on carcinogenicity and chronic toxicity and developmental and reproductive toxicity. Integrating a comprehensive set of relevant toxicological end points in a single protocol represents an opportunity to optimize animal use in accordance with the 3Rs (replacement, reduction and refinement). This strategy has the potential to provide sufficient data on multiple windows of susceptibility of specific interest for risk assessments and public health decision-making by including prenatal, lactational, neonatal exposures and evaluating outcomes over the lifespan. CONCLUSION This integrated study design is efficient in that the same generational cohort of rats used for evaluating long-term outcomes can be monitored in satellite parallel experiments to measure biomarkers and other parameters related to system-specific responses including metabolic alterations and endocrine disturbances. Citation: Manservisi F, Babot Marquillas C, Buscaroli A, Huff J, Lauriola M, Mandrioli D, Manservigi M, Panzacchi S, Silbergeld EK, Belpoggi F. 2017. An integrated experimental design for the assessment of multiple toxicological end points in rat bioassays. Environ Health Perspect 125:289-295; http://dx.doi.org/10.1289/EHP419.
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Affiliation(s)
- Fabiana Manservisi
- Cesare Maltoni Cancer Research Center, Ramazzini Institute, Bentivoglio, Bologna, Italy
| | - Clara Babot Marquillas
- Leonardo da Vinci Programme at the Cesare Maltoni Cancer Research Center, Ramazzini Institute, Bentivoglio, Bologna, Italy
| | - Annalisa Buscaroli
- Cesare Maltoni Cancer Research Center, Ramazzini Institute, Bentivoglio, Bologna, Italy
| | - James Huff
- National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Michelina Lauriola
- Cesare Maltoni Cancer Research Center, Ramazzini Institute, Bentivoglio, Bologna, Italy
| | - Daniele Mandrioli
- Cesare Maltoni Cancer Research Center, Ramazzini Institute, Bentivoglio, Bologna, Italy
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Marco Manservigi
- Cesare Maltoni Cancer Research Center, Ramazzini Institute, Bentivoglio, Bologna, Italy
| | - Simona Panzacchi
- Cesare Maltoni Cancer Research Center, Ramazzini Institute, Bentivoglio, Bologna, Italy
| | - Ellen K. Silbergeld
- Leonardo da Vinci Programme at the Cesare Maltoni Cancer Research Center, Ramazzini Institute, Bentivoglio, Bologna, Italy
| | - Fiorella Belpoggi
- Cesare Maltoni Cancer Research Center, Ramazzini Institute, Bentivoglio, Bologna, Italy
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Roberts DJ, McKeon M, Xu Y, Stankowski LF. Comparison of integrated genotoxicity endpoints in rats after acute and subchronic oral doses of 4-nitroquinoline-1-oxide. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2016; 57:17-27. [PMID: 26407646 PMCID: PMC7362388 DOI: 10.1002/em.21981] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 08/17/2015] [Indexed: 05/16/2023]
Abstract
During interlaboratory validation trials for the Pig-a gene mutation assay we assessed the genotoxicity of 4-nitroquinoline-1-oxide (4NQO) across endpoints in multiple tissues: induction of Pig-a mutant red blood cells (RBCs) and reticulocytes (RETs); micronucleated RETs (MN RETs); and DNA damage in blood and liver via the alkaline Comet assay (%tail intensity [TI]). In a previous subchronic toxicity study with 28 daily doses, biologically meaningful increases were observed only for Pig-a mutant RBCs/RETs while marginal increases in the frequency of MN RET were observed, and other clastogenic endpoints were negative. Follow up acute studies were performed using the same cumulative doses (0, 35, 70, 105, and 140 mg/kg) administered in a bolus, or split over three equal daily doses, with samples collected up to 1 month after the last dose. Both of the acute dosing regimens produced similar results, in that endpoints were either positive or negative, regardless of 1 or 3 daily doses, but the three consecutive daily dose regimen yielded more potent responses in TI (in liver and blood) and Pig-a mutant frequencies. In these acute studies the same cumulative doses of 4NQO induced positive responses in clastogenic endpoints that were negative or inconclusive using a subchronic study design. Additionally, a positive control group using combination doses of cyclophosphamide and ethyl methanesulfonate was employed to assess assay validity and potentially identify a future positive control treatment for integrated genetic toxicity studies.
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Affiliation(s)
- Daniel J Roberts
- Bristol-Myers Squibb, New Brunswick, NJ, USA
- Joint Graduate Program of Toxicology, Rutgers, NJ, USA
| | | | - Yong Xu
- BioReliance Corporation, Rockville, MD, USA
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Stankowski LF, Aardema MJ, Lawlor TE, Pant K, Roy S, Xu Y, Elbekai R. Integration of Pig-a, micronucleus, chromosome aberration and comet assay endpoints in a 28-day rodent toxicity study with urethane. Mutagenesis 2015; 30:335-42. [PMID: 25934985 PMCID: PMC4506322 DOI: 10.1093/mutage/gev013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
As part of the international Pig-a validation trials, we examined the induction of Pig-a mutant reticulocytes and red blood cells (RET(CD59-) and RBC(CD59-), respectively) in peripheral blood of male Sprague Dawley(®) rats treated with urethane (25, 100 and 250mg/kg/day) or saline by oral gavage for 29 days. Additional endpoints integrated into this study were: micronucleated reticulocytes (MN-RET) in peripheral blood; chromosome aberrations (CAb) and DNA damage (%tail intensity via the comet assay) in peripheral blood lymphocytes (PBL); micronucleated polychromatic erythrocytes (MN-PCE) in bone marrow; and DNA damage (comet) in various organs at termination (the 29th dose was added for the comet endpoint at sacrifice). Ethyl methanesulfonate (EMS; 200mg/kg/day on Days 3, 4, 13, 14, 15, 27, 28 and 29) was evaluated as the concurrent positive control (PC). All animals survived to termination and none exhibited overt toxicity, but there were significant differences in body weight and body weight gain in the 250-mg/kg/day urethane group, as compared with the saline control animals. Statistically significant, dose-dependent increases were observed for urethane for: RET(CD59-) and RBC(CD59-) (on Days 15 and 29); MN-RET (on Days 4, 15 and 29); and MN-PCE (on Day 29). The comet assay yielded positive results in PBL (Day 15) and liver (Day 29), but negative results for PBL (Days 4 and 29) and brain, kidney and lung (Day 29). No significant increases in PBL CAb were observed at any sample time. Except for PBL CAb (likely due to excessive cytotoxicity), EMS-induced significant increases in all endpoints/tissues. These results compare favorably with earlier in vivo observations and demonstrate the utility and sensitivity of the Pig-a in vivo gene mutation assay, and its ability to be easily integrated, along with other standard genotoxicity endpoints, into 28-day rodent toxicity studies.
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Affiliation(s)
| | - Marilyn J Aardema
- BioReliance Corporation, Rockville, MD 20850, USA, Marilyn Aardema Consulting LLC, Fairfield, OH 45014, USA
| | | | - Kamala Pant
- BioReliance Corporation, Rockville, MD 20850, USA
| | - Shambhu Roy
- BioReliance Corporation, Rockville, MD 20850, USA
| | - Yong Xu
- BioReliance Corporation, Rockville, MD 20850, USA
| | - Reem Elbekai
- BioReliance Corporation, Rockville, MD 20850, USA
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17
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French JE, Gatti DM, Morgan DL, Kissling GE, Shockley KR, Knudsen GA, Shepard KG, Price HC, King D, Witt KL, Pedersen LC, Munger SC, Svenson KL, Churchill GA. Diversity Outbred Mice Identify Population-Based Exposure Thresholds and Genetic Factors that Influence Benzene-Induced Genotoxicity. ENVIRONMENTAL HEALTH PERSPECTIVES 2015; 123:237-45. [PMID: 25376053 PMCID: PMC4348743 DOI: 10.1289/ehp.1408202] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 10/31/2014] [Indexed: 05/20/2023]
Abstract
BACKGROUND Inhalation of benzene at levels below the current exposure limit values leads to hematotoxicity in occupationally exposed workers. OBJECTIVE We sought to evaluate Diversity Outbred (DO) mice as a tool for exposure threshold assessment and to identify genetic factors that influence benzene-induced genotoxicity. METHODS We exposed male DO mice to benzene (0, 1, 10, or 100 ppm; 75 mice/exposure group) via inhalation for 28 days (6 hr/day for 5 days/week). The study was repeated using two independent cohorts of 300 animals each. We measured micronuclei frequency in reticulocytes from peripheral blood and bone marrow and applied benchmark concentration modeling to estimate exposure thresholds. We genotyped the mice and performed linkage analysis. RESULTS We observed a dose-dependent increase in benzene-induced chromosomal damage and estimated a benchmark concentration limit of 0.205 ppm benzene using DO mice. This estimate is an order of magnitude below the value estimated using B6C3F1 mice. We identified a locus on Chr 10 (31.87 Mb) that contained a pair of overexpressed sulfotransferases that were inversely correlated with genotoxicity. CONCLUSIONS The genetically diverse DO mice provided a reproducible response to benzene exposure. The DO mice display interindividual variation in toxicity response and, as such, may more accurately reflect the range of response that is observed in human populations. Studies using DO mice can localize genetic associations with high precision. The identification of sulfotransferases as candidate genes suggests that DO mice may provide additional insight into benzene-induced genotoxicity.
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Affiliation(s)
- John E French
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Resources (DHHS), Research Triangle Park, North Carolina, USA
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18
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Yadav L, Khan S, Shekh K, Jena G. Influence of 3-aminobenzamide, an inhibitor of poly(ADP-ribose)polymerase, in the evaluation of the genotoxicity of doxorubicin, cyclophosphamide and zidovudine in female mice. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2014; 770:6-15. [DOI: 10.1016/j.mrgentox.2014.04.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 02/22/2014] [Accepted: 04/05/2014] [Indexed: 11/29/2022]
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Jiang M, Zhao L, Gamez M, Imperiale MJ. Roles of ATM and ATR-mediated DNA damage responses during lytic BK polyomavirus infection. PLoS Pathog 2012; 8:e1002898. [PMID: 22952448 PMCID: PMC3431332 DOI: 10.1371/journal.ppat.1002898] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Accepted: 07/24/2012] [Indexed: 12/18/2022] Open
Abstract
BK polyomavirus (BKPyV) is an emerging pathogen whose reactivation causes severe disease in transplant patients. Unfortunately, there is no specific anti-BKPyV treatment available, and host cell components that affect the infection outcome are not well characterized. In this report, we examined the relationship between BKPyV productive infection and the activation of the cellular DNA damage response (DDR) in natural host cells. Our results showed that both the ataxia-telangiectasia mutated (ATM)- and ATM and Rad-3-related (ATR)-mediated DDR were activated during BKPyV infection, accompanied by the accumulation of polyploid cells. We assessed the involvement of ATM and ATR during infection using small interfering RNA (siRNA) knockdowns. ATM knockdown did not significantly affect viral gene expression, but reduced BKPyV DNA replication and infectious progeny production. ATR knockdown had a slightly more dramatic effect on viral T antigen (TAg) and its modified forms, DNA replication, and progeny production. ATM and ATR double knockdown had an additive effect on DNA replication and resulted in a severe reduction in viral titer. While ATM mainly led to the activation of pChk2 and ATR was primarily responsible for the activation of pChk1, knockdown of all three major phosphatidylinositol 3-kinase-like kinases (ATM, ATR, and DNA-PKcs) did not abolish the activation of γH2AX during BKPyV infection. Finally, in the absence of ATM or ATR, BKPyV infection caused severe DNA damage and aberrant TAg staining patterns. These results indicate that induction of the DDR by BKPyV is critical for productive infection, and that one of the functions of the DDR is to minimize the DNA damage which is generated during BKPyV infection. BK polyomavirus (BKPyV) is a human pathogen that establishes a persistent sub-clinical infection in healthy humans. When patients are immunosuppressed, particularly in kidney and bone marrow transplantation, the virus can reactivate and result in severe disease. BKPyV-related disease has risen due to the use of newer immunosuppressive regimens and an increase in the number of transplants performed each year. We are interested in understanding the interactions between BKPyV and host cell components or pathways, with the aim of developing more BKPyV-specific antiviral treatment options. In this study we characterized the relationship between BKPyV infection and the cellular DNA damage response (DDR), a signaling cascade that is initiated by cells to repair damaged DNA molecules. Our study indicated that BKPyV activates and hijacks the DDR to facilitate its infection and that various components of the DDR may play distinct roles during this process. These data suggest that the DDR may provide a potential host target to control BKPyV reactivation in transplant recipients.
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Affiliation(s)
- Mengxi Jiang
- Department of Microbiology and Immunology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Linbo Zhao
- Graduate Program in Cancer Biology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Monica Gamez
- Department of Microbiology and Immunology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Michael J. Imperiale
- Department of Microbiology and Immunology and Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Graduate Program in Cancer Biology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- * E-mail:
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20
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Mercado-Feliciano M, Cora MC, Witt KL, Granville CA, Hejtmancik MR, Fomby L, Knostman KA, Ryan MJ, Newbold R, Smith C, Foster PM, Vallant MK, Stout MD. An ethanolic extract of black cohosh causes hematological changes but not estrogenic effects in female rodents. Toxicol Appl Pharmacol 2012; 263:138-47. [PMID: 22687605 DOI: 10.1016/j.taap.2012.05.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 05/30/2012] [Accepted: 05/31/2012] [Indexed: 10/28/2022]
Abstract
Black cohosh rhizome (Actaea racemosa) is used as a remedy for pain and gynecological ailments; modern preparations are commonly sold as ethanolic extracts available as dietary supplements. Black cohosh was nominated to the National Toxicology Program (NTP) for toxicity testing due to its widespread use and lack of safety data. Several commercially available black cohosh extracts (BCE) were characterized by the NTP, and one with chemical composition closest to formulations available to consumers was used for all studies. Female B6C3F1/N mice and Wistar Han rats were given 0, 15 (rats only), 62.5 (mice only), 125, 250, 500, or 1000 mg/kg/day BCE by gavage for 90 days starting at weaning. BCE induced dose-dependent hematological changes consistent with a non-regenerative macrocytic anemia and increased frequencies of peripheral micronucleated red blood cells (RBC) in both species. Effects were more severe in mice, which had decreased RBC counts in all treatment groups and increased micronucleated RBC at doses above 125 mg/kg. Dose-dependent thymus and liver toxicity was observed in rats but not mice. No biologically significant effects were observed in other organs. Puberty was delayed 2.9 days at the highest treatment dose in rats; a similar magnitude delay in mice occurred in the 125 and 250 mg/kg groups but not at the higher doses. An additional uterotrophic assay conducted in mice exposed for 3 days to 0.001, 0.01, 0.1, 1, 10, 100 and 500 mg/kg found no estrogenic or anti-estrogenic activity. These are the first studies to observe adverse effects of BCE in rodents.
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Affiliation(s)
- Minerva Mercado-Feliciano
- National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, 111 Alexander Drive, Research Triangle Park, NC, USA
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21
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Hobbs CA, Chhabra RS, Recio L, Streicker M, Witt KL. Genotoxicity of styrene-acrylonitrile trimer in brain, liver, and blood cells of weanling F344 rats. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2012; 53:227-38. [PMID: 22351108 PMCID: PMC3520608 DOI: 10.1002/em.21680] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 12/15/2011] [Accepted: 12/18/2011] [Indexed: 05/05/2023]
Abstract
Styrene-acrylonitrile Trimer (SAN Trimer), a by-product in production of acrylonitrile styrene plastics, was identified at a Superfund site in Dover Township, NJ, where childhood cancer incidence rates were elevated for a period of several years. SAN Trimer was therefore tested by the National Toxicology Program in a 2-year perinatal carcinogenicity study in F344/N rats and a bacterial mutagenicity assay; both studies gave negative results. To further characterize its genotoxicity, SAN Trimer was subsequently evaluated in a combined micronucleus (MN)/Comet assay in juvenile male and female F344 rats. SAN Trimer (37.5, 75, 150, or 300 mg/kg/day) was administered by gavage once daily for 4 days. Micronucleated reticulocyte (MN-RET) frequencies in blood were determined by flow cytometry, and DNA damage in blood, liver, and brain cells was assessed using the Comet assay. Highly significant dose-related increases (P < 0.0001) in MN-RET were measured in both male and female rats administered SAN Trimer. The RET population was reduced in high dose male rats, suggesting chemical-related bone marrow toxicity. Results of the Comet assay showed significant, dose-related increases in DNA damage in brain cells of male (P < 0.0074) and female (P < 0.0001) rats; increased levels of DNA damage were also measured in liver cells and leukocytes of treated rats. Chemical-related cytotoxicity was not indicated in any of the tissues examined for DNA damage. The results of this subacute MN/Comet assay indicate induction of significant genetic damage in multiple tissues of weanling F344 male and female rats after oral exposure to SAN Trimer.
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Affiliation(s)
- Cheryl A Hobbs
- Department of Genetic and Molecular Toxicology, Research Triangle Park, North Carolina 27709, USA.
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Hobbs CA, Swartz C, Maronpot R, Davis J, Recio L, Hayashi SM. Evaluation of the genotoxicity of the food additive, gum ghatti. Food Chem Toxicol 2012; 50:854-60. [DOI: 10.1016/j.fct.2011.11.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 11/14/2011] [Accepted: 11/16/2011] [Indexed: 11/25/2022]
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Lent EM, Crouse LC, Quinn MJ, Wallace SM. Assessment of the in vivo genotoxicity of isomers of dinitrotoluene using the alkaline Comet and peripheral blood micronucleus assays. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2012; 742:54-60. [DOI: 10.1016/j.mrgentox.2011.11.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Revised: 11/23/2011] [Accepted: 11/24/2011] [Indexed: 11/17/2022]
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McKeon M, Xu Y, Kirkland D, Schmuck G, Krebsfänger N, Avlasevich SL, Dertinger SD. Cyclophosphamide and etoposide canine studies demonstrate the cross-species potential of the flow cytometric peripheral blood micronucleated reticulocyte endpoint. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2012; 742:79-83. [DOI: 10.1016/j.mrgentox.2011.12.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 12/12/2011] [Accepted: 12/14/2011] [Indexed: 12/01/2022]
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Abstract
Chromosome aberration assays are employed to detect the induction of chromosome breakage (clastogenesis) in somatic and germ cells by direct observation of the chromosomal damage during metaphase analysis, or by indirect observation of chromosomal fragments. Thus, various types of cytogenetic change can be detected such as structural chromosome aberrations (CA), sister chromatid exchanges (SCE), ploidy changes, and micronuclei. Following the induction of the chromosomal damage, most of the aberrations and abnormalities detected by these assays can be detrimental or even lethal to the cell. Their presence, however, indicates a potential to also induce more subtle and therefore transmissible chromosomal damage which survives cell division to produce heritable cytogenetic changes. Usually, induced cytogenetic damage is accompanied by other genotoxic damage such as gene mutations.
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Dertinger SD, Phonethepswath S, Weller P, Nicolette J, Murray J, Sonders P, Vohr HW, Shi J, Krsmanovic L, Gleason C, Custer L, Henwood A, Sweder K, Stankowski LF, Roberts DJ, Giddings A, Kenny J, Lynch AM, Defrain C, Nesslany F, van der Leede BJM, Van Doninck T, Schuermans A, Tanaka K, Hiwata Y, Tajima O, Wilde E, Elhajouji A, Gunther WC, Thiffeault CJ, Shutsky TJ, Fiedler RD, Kimoto T, Bhalli JA, Heflich RH, MacGregor JT. International Pig-a gene mutation assay trial: evaluation of transferability across 14 laboratories. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2011; 52:690-698. [PMID: 21910140 DOI: 10.1002/em.20672] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 07/11/2011] [Indexed: 05/31/2023]
Abstract
A collaborative international trial was conducted to evaluate the reproducibility and transferability of an in vivo mutation assay based on the enumeration of CD59-negative rat erythrocytes, a phenotype that is indicative of Pig-a gene mutation. Fourteen laboratories participated in this study, where anti-CD59-PE, SYTO 13 dye, and flow cytometry were used to determine the frequency of CD59-negative erythrocytes (RBC(CD59-)) and CD59-negative reticulocytes (RET(CD59-)). To provide samples with a range of mutant phenotype cell frequencies, male rats were exposed to N-ethyl-N-nitrosourea (ENU) via oral gavage for three consecutive days (Days 1-3). Each laboratory studied 0, 20, and 40 mg ENU/kg/day (n = 5 per group). Three sites also evaluated 4 mg/kg/day. At a minimum, blood samples were collected three times: predosing and on Days 15 and 30. Blood samples were processed according to a standardized sample processing and data acquisition protocol, and three endpoints were measured: %reticulocytes, frequency of RET(CD59-) , and frequency of RBC(CD59-) . The methodology was found to be reproducible, as the analysis of technical replicates resulted in experimental coefficients of variation that approached theoretical values. Good transferability was evident from the similar kinetics and magnitude of the dose-related responses that were observed among different laboratories. Concordance correlation coefficients showed a high level of agreement between the reference site and the test sites (range: 0.87-0.99). Collectively, these data demonstrate that with adequate training of personnel, flow cytometric analysis is capable of reliably enumerating mutant phenotype erythrocytes, thereby providing a robust in vivo mutation assay that is readily transferable across laboratories.
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Stankowski LF, Roberts DJ, Chen H, Lawlor T, McKeon M, Murli H, Thakur A, Xu Y. Integration of Pig-a, micronucleus, chromosome aberration, and Comet assay endpoints in a 28-day rodent toxicity study with 4-nitroquinoline-1-oxide. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2011; 52:738-747. [PMID: 22020836 DOI: 10.1002/em.20692] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2011] [Revised: 09/08/2011] [Accepted: 09/08/2011] [Indexed: 05/31/2023]
Abstract
As part of the Stage III Pig-a multilaboratory validation trial, we examined the induction of CD59-negative reticulocytes and total red blood cells (RET(CD59-) and RBC(CD59-) , respectively) in male Sprague Dawley(®) rats treated with 4-nitroquinoline-1-oxide (4NQO), for 28 consecutive days by oral gavage, at doses of 1.25, 2.50, 3.75, 5.00, and 7.50 mg kg(-1) day(-1) (the high dose group was sacrificed on Day 15 due to excessive morbidity/mortality). Animals also were evaluated for: micronucleated reticulocytes (mnRET) by flow cytometry; DNA damage in peripheral blood, liver, and stomach using the Comet assay; and chromosome aberrations (CAb) in peripheral blood lymphocytes (PBL). All endpoints were analyzed at two or more timepoints where possible. Mortality, body and organ weights, food consumption, and clinical pathology also were evaluated, and demonstrated that the maximum tolerated dose was achieved at 5.00 mg kg(-1) day(-1) . The largest increases observed for the genetic toxicology endpoints (fold-increase compared to control, where significant; all at 5.00 mg kg(-1) day(-1) on Day 29) were: RET(CD59-) (21X), RBC(CD59-) (9.0X), and mnRET (2.0X). In contrast, no significant increases were observed for the CAb or Comet response, in any tissue analyzed, at any timepoint. Because 4NQO is a well known mutagen, clastogen, and carcinogen, the lack of response for these latter endpoints was unexpected. These results emphasize the extreme care that must betaken in dose and endpoint selection when incorporating genotoxicity endpoints into routine toxicity studies as has been recommended or is under consideration by various regulatory and industrial bodies.
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Improvement of in vivo genotoxicity assessment: Combination of acute tests and integration into standard toxicity testing. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2011; 723:108-20. [DOI: 10.1016/j.mrgentox.2010.12.005] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 12/10/2010] [Indexed: 01/15/2023]
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Lynch AM, Sasaki JC, Elespuru R, Jacobson-Kram D, Thybaud V, De Boeck M, Aardema MJ, Aubrecht J, Benz RD, Dertinger SD, Douglas GR, White PA, Escobar PA, Fornace A, Honma M, Naven RT, Rusling JF, Schiestl RH, Walmsley RM, Yamamura E, van Benthem J, Kim JH. New and emerging technologies for genetic toxicity testing. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2011; 52:205-223. [PMID: 20740635 DOI: 10.1002/em.20614] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 06/02/2010] [Accepted: 06/07/2010] [Indexed: 05/29/2023]
Abstract
The International Life Sciences Institute (ILSI) Health and Environmental Sciences Institute (HESI) Project Committee on the Relevance and Follow-up of Positive Results in In Vitro Genetic Toxicity (IVGT) Testing established an Emerging Technologies and New Strategies Workgroup to review the current State of the Art in genetic toxicology testing. The aim of the workgroup was to identify promising technologies that will improve genotoxicity testing and assessment of in vivo hazard and risk, and that have the potential to help meet the objectives of the IVGT. As part of this initiative, HESI convened a workshop in Washington, DC in May 2008 to discuss mature, maturing, and emerging technologies in genetic toxicology. This article collates the abstracts of the New and Emerging Technologies Workshop together with some additional technologies subsequently considered by the workgroup. Each abstract (available in the online version of the article) includes a section addressed specifically to the strengths, weaknesses, opportunities, and threats associated with the respective technology. Importantly, an overview of the technologies and an indication of how their use might be aligned with the objectives of IVGT are presented. In particular, consideration was given with regard to follow-up testing of positive results in the standard IVGT tests (i.e., Salmonella Ames test, chromosome aberration assay, and mouse lymphoma assay) to add weight of evidence and/or provide mechanism of action for improved genetic toxicity risk assessments in humans.
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Costa C, Silva S, Neves J, Coelho P, Costa S, Laffon B, Snawder J, Teixeira JP. Micronucleus frequencies in lymphocytes and reticulocytes in a pesticide-exposed population in Portugal. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2011; 74:960-970. [PMID: 21707421 DOI: 10.1080/15287394.2011.582024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A wide range of chemical products known to be acutely toxic is currently used in the agricultural sector, including numerous pesticides with different compositions. Nevertheless, the effects in human health as result of chronic exposure to low levels are not yet completely understood. The methodology for determination of micronuclei (MN) in lymphocytes (CBMN) is well established, and accumulating data demonstrated a correlation to enhanced risk of cancer development. However, analysis of MN in reticulocytes (MN-RET) in humans is a recent tool on human biomonitoring. The aim of this study was to examine the influence of pesticide exposure on MN-RET and CBMN frequencies. In total, 177 individuals were studied (93 controls and 84 exposed). All individuals included in the exposed group were exposed regularly to various chemicals. Both MN-RET and CBMN were significantly higher in the exposed subjects compared to controls. The CBMN frequencies were quantitatively higher in females than males, especially within the exposed group. Smoking habits exerted no marked influence on the frequency of the biomarkers studied. A significant and positive correlation was found between both indicators. Within the exposed group, data showed that there was a significant correlation between MN-RET and recent exposure (exposure in the previous 10 d) that is not found when considering CBMN. It is conceivable that due to the short life span of reticulocytes, MN-RET were found to be more reliable to characterize recent genetic damage as opposed to CBMN.
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Affiliation(s)
- Carla Costa
- National Institute of Health, Environmental Health Department, Porto, Portugal.
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Dertinger SD, Torous DK, Hayashi M, MacGregor JT. Flow cytometric scoring of micronucleated erythrocytes: an efficient platform for assessing in vivo cytogenetic damage. Mutagenesis 2010; 26:139-45. [DOI: 10.1093/mutage/geq055] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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Vasquez MZ. Combining the in vivo comet and micronucleus assays: a practical approach to genotoxicity testing and data interpretation. Mutagenesis 2009; 25:187-99. [PMID: 19969526 PMCID: PMC2825345 DOI: 10.1093/mutage/gep060] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Despite regulatory directives requiring the reduction of animal use in safety testing, recent modifications to genotoxicity testing guidelines now propose the use of two in vivo genotoxicity assays as a follow-up to an in vitro positive (International Conference on Harmonization Consensus Draft Guidance S2[R1] released March, 2008). To address both goals, the in vivo comet and micronucleus (MN) assays can be successfully combined into one informative study. Combining these two assays with such differences in sensitivity, endpoints measured and the type of data generated significantly improves upon the current standard capabilities for detecting genotoxicity without requiring additional animals. But to take full advantage of the benefits of incorporating the comet assay in safety testing, these same differences must be recognized and considered. Developed from over 15 years experience using the in vivo comet and MN assays in genotoxicity testing of chemicals and pharmaceuticals, this paper presents guidelines for the appropriate experimental design, dose selection and data interpretation for combined in vivo comet/MN assay studies. To illustrate the approach, data from combined assay studies are presented and discussed.
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Hayes J, Doherty AT, Adkins DJ, Oldman K, O'Donovan MR. The rat bone marrow micronucleus test--study design and statistical power. Mutagenesis 2009; 24:419-24. [DOI: 10.1093/mutage/gep024] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Vikram A, Tripathi D, Pawar A, Ramarao P, Jena G. Pre-bled-young-rats in genotoxicity testing: A model for peripheral blood micronucleus assay. Regul Toxicol Pharmacol 2008; 52:147-57. [DOI: 10.1016/j.yrtph.2008.07.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2008] [Revised: 07/09/2008] [Accepted: 07/23/2008] [Indexed: 11/25/2022]
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