1
|
Harte DSG, Lynch AM, Verma J, Rees P, Filby A, Wills JW, Johnson GE. A multi-biomarker micronucleus assay using imaging flow cytometry. Arch Toxicol 2024:10.1007/s00204-024-03801-7. [PMID: 38995349 DOI: 10.1007/s00204-024-03801-7] [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: 02/29/2024] [Accepted: 05/23/2024] [Indexed: 07/13/2024]
Abstract
Genetic toxicity testing assesses the potential of compounds to cause DNA damage. There are many genetic toxicology screening assays designed to assess the DNA damaging potential of chemicals in early drug development aiding the identification of promising drugs that have low-risk potential for causing genetic damage contributing to cancer risk in humans. Despite this, in vitro tests generate a high number of misleading positives, the consequences of which can lead to unnecessary animal testing and/or the abandonment of promising drug candidates. Understanding chemical Mode of Action (MoA) is vital to identifying the true genotoxic potential of substances and, therefore, the risk translation into the clinic. Here we demonstrate a simple, robust protocol for staining fixed, human-lymphoblast p53 proficient TK6 cells with antibodies against ɣH2AX, p53 and pH3S28 along with DRAQ5™ DNA staining that enables analysis of un-lysed cells via microscopy approaches such as imaging flow cytometry. Here, we used the Cytek® Amnis® ImageStream®X Mk II which provides a high-throughput acquisition platform with the sensitivity of flow cytometry and spatial morphological information associated with microscopy. Using the ImageStream manufacturer's software (IDEAS® 6.2), a masking strategy was developed to automatically detect and quantify micronucleus events (MN) and characterise biomarker populations. The gating strategy developed enables the generation of a template capable of automatically batch processing data files quantifying cell-cycle, MN, ɣH2AX, p53 and pH3 populations simultaneously. In this way, we demonstrate how a multiplex system enables DNA damage assessment alongside MN identification using un-lysed cells on the imaging flow cytometry platform. As a proof-of-concept, we use the tool chemicals carbendazim and methyl methanesulphonate (MMS) to demonstrate the assay's ability to correctly identify clastogenic or aneugenic MoAs using the biomarker profiles established.
Collapse
Affiliation(s)
- Danielle S G Harte
- Swansea University Medical School, Swansea University, Swansea, UK
- GSK R&D, Stevenage, UK
| | - Anthony M Lynch
- Swansea University Medical School, Swansea University, Swansea, UK
- GSK R&D, Stevenage, UK
| | - Jatin Verma
- Swansea University Medical School, Swansea University, Swansea, UK
| | - Paul Rees
- College of Engineering, Swansea University, Swansea, UK
- Imaging Platform, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Andrew Filby
- Core Flow Facility, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - John W Wills
- GSK R&D, Stevenage, UK
- Department of Veterinary Medicine, Cambridge University, Cambridge, UK
| | - George E Johnson
- Swansea University Medical School, Swansea University, Swansea, UK.
| |
Collapse
|
2
|
Carrothers E, Appleby M, Lai V, Kozbenko T, Alomar D, Smith BJ, Hamada N, Hinton P, Ainsbury EA, Hocking R, Yauk C, Wilkins RC, Chauhan V. AOP report: Development of an adverse outcome pathway for deposition of energy leading to cataracts. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2024. [PMID: 38644659 DOI: 10.1002/em.22594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/23/2024]
Abstract
Cataracts are one of the leading causes of blindness, with an estimated 95 million people affected worldwide. A hallmark of cataract development is lens opacification, typically associated not only with aging but also radiation exposure as encountered by interventional radiologists and astronauts during the long-term space mission. To better understand radiation-induced cataracts, the adverse outcome pathway (AOP) framework was used to structure and evaluate knowledge across biological levels of organization (e.g., macromolecular, cell, tissue, organ, organism and population). AOPs identify a sequence of key events (KEs) causally connected by key event relationships (KERs) beginning with a molecular initiating event to an adverse outcome (AO) of relevance to regulatory decision-making. To construct the cataract AO and retrieve evidence to support it, a scoping review methodology was used to filter, screen, and review studies based on the modified Bradford Hill criteria. Eight KEs were identified that were moderately supported by empirical evidence (e.g., dose-, time-, incidence-concordance) across the adjacent (directly linked) relationships using well-established endpoints. Over half of the evidence to justify the KER linkages was derived from the evidence stream of biological plausibility. Early KEs of oxidative stress and protein modifications had strong linkages to downstream KEs and could be the focus of countermeasure development. Several identified knowledge gaps and inconsistencies related to the quantitative understanding of KERs which could be the basis of future research, most notably directed to experiments in the range of low or moderate doses and dose-rates, relevant to radiation workers and other occupational exposures.
Collapse
Affiliation(s)
- Emma Carrothers
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Meghan Appleby
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Vita Lai
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Tatiana Kozbenko
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Dalya Alomar
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Benjamin J Smith
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Nobuyuki Hamada
- Biology and Environmental Chemistry Division, Sustainable System Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), Chiba, Japan
| | - Patricia Hinton
- Defense Research & Development Canada, Canadian Forces Environmental Medicine Establishment, Toronto, Ontario, Canada
| | - Elizabeth A Ainsbury
- Radiation, Chemical and Environmental Hazards Division, UK Health Security Agency, Birmingham, UK
- Environmental Research Group within the School of Public Health, Faculty of Medicine at Imperial College of Science, Technology and Medicine, London, UK
| | - Robyn Hocking
- Learning and Knowledge and Library Services, Health Canada, Ottawa, Ontario, Canada
| | - Carole Yauk
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Ruth C Wilkins
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| | - Vinita Chauhan
- Consumer and Clinical Radiation Protection Bureau, Environmental and Radiation Health Sciences Directorate, Health Canada, Ottawa, Ontario, Canada
| |
Collapse
|
3
|
Yin L, Hu C, Yu XJ. High-content analysis of testicular toxicity of BPA and its selected analogs in mouse spermatogonial, Sertoli cells, and Leydig cells revealed BPAF induced unique multinucleation phenotype associated with the increased DNA synthesis. Toxicol In Vitro 2023; 89:105589. [PMID: 36958674 PMCID: PMC10351343 DOI: 10.1016/j.tiv.2023.105589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 03/14/2023] [Accepted: 03/17/2023] [Indexed: 03/25/2023]
Abstract
Bisphenol A is an endocrine disruptor that has been shown to have testicular toxicity in animal models. Its structural analog, including bisphenol S (BPS), bisphenol AF (BPAF), and tetrabromobisphenol A (TBBPA) have been introduced to the market as BPA alternatives. Previously, we developed high-content analysis (HCA) assays and applied machine learning to compare the testicular toxicity of BPA and its analogs in spermatogonial cells and testicular cell co-culture models. There are diverse cell populations in the testis to support spermatogenesis, but their cell type-specific toxicities are still not clear. The purpose of this study is to examine the selective toxicity of BPA, BPS), BPAF, and TBBPA on these testicular cells, including Sertoli cells, Leydig cells, and spermatogonia cells. We developed a high-content image-based single-cell analysis and measured a broad spectrum of adverse endpoints related to the development of reproductive toxicology, including cell number, nuclear morphology, DNA synthesis, cell cycle progression, early DNA damage response, cytoskeleton structure, DNA methylation status, and autophagy. We introduced an HCA index and spectrum to reveal multiple HCA parameters and observed distinct toxicity profiling of BPA and its analogs among three testicular types. The HCA spectrum shows the dynamic, chemical-specific, dose-dependent changes of each HCA parameter. Each chemical displayed a unique dose-dependent profile within each type of cell. All three types of cells showed the highest response to BPAF at 10 μM across all endpoints measured. BPAF targeted spermatogonial cell (C18) more significantly at 5 μM. BPS more likely targeted Sertoli cell (TM4) and Leydig cell (TM3) and less at spermatogonia cells. TBBPA targeted spermatogonia, Sertoli cells, and less at TM3 cells. BPA is mainly targeted at TM4, followed by TM3 cells, and less at spermatogonial cells. Most importantly, we observed that BPAF induced a dose-dependent increase in spermatogonia cells, not in Sertoli and Leydig cells. In summary, our current HCA assays revealed the cell-type-specific toxicities of BPA and its analogs in different testicular cells. Multinucleation induced by BPAF, along with increased DNA damage and synthesis at low doses, could possibly have a profound long-term effect on reproductive systems.
Collapse
Affiliation(s)
- Lei Yin
- ReproTox Biotech LLC, 800 Bradbury Dr. SE Science & Technology Park, Albuquerque, NM 87106, United States of America
| | - Chelin Hu
- College of Nursing School, University of New Mexico, Albuquerque, NM 87106, United States of America
| | - Xiaozhong John Yu
- College of Nursing School, University of New Mexico, Albuquerque, NM 87106, United States of America.
| |
Collapse
|
4
|
Křížkovská B, Schätz M, Lipov J, Viktorová J, Jablonská E. In Vitro High-Throughput Genotoxicity Testing Using γH2AX Biomarker, Microscopy and Reproducible Automatic Image Analysis in ImageJ—A Pilot Study with Valinomycin. Toxins (Basel) 2023; 15:toxins15040263. [PMID: 37104201 PMCID: PMC10146355 DOI: 10.3390/toxins15040263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/17/2023] [Accepted: 03/28/2023] [Indexed: 04/05/2023] Open
Abstract
(1) Background: The detection of DNA double-strand breaks in vitro using the phosphorylated histone biomarker (γH2AX) is an increasingly popular method of measuring in vitro genotoxicity, as it is sensitive, specific and suitable for high-throughput analysis. The γH2AX response is either detected by flow cytometry or microscopy, the latter being more accessible. However, authors sparsely publish details, data, and workflows from overall fluorescence intensity quantification, which hinders the reproducibility. (2) Methods: We used valinomycin as a model genotoxin, two cell lines (HeLa and CHO-K1) and a commercial kit for γH2AX immunofluorescence detection. Bioimage analysis was performed using the open-source software ImageJ. Mean fluorescent values were measured using segmented nuclei from the DAPI channel and the results were expressed as the area-scaled relative fold change in γH2AX fluorescence over the control. Cytotoxicity is expressed as the relative area of the nuclei. We present the workflows, data, and scripts on GitHub. (3) Results: The outputs obtained by an introduced method are in accordance with expected results, i.e., valinomycin was genotoxic and cytotoxic to both cell lines used after 24 h of incubation. (4) Conclusions: The overall fluorescence intensity of γH2AX obtained from bioimage analysis appears to be a promising alternative to flow cytometry. Workflow, data, and script sharing are crucial for further improvement of the bioimage analysis methods.
Collapse
Affiliation(s)
- Bára Křížkovská
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Martin Schätz
- Department of Mathematics, Informatics and Cybernetics, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Jan Lipov
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Jitka Viktorová
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Eva Jablonská
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
| |
Collapse
|
5
|
Han M, Zhang Z, Liu S, Sheng Y, Waigi MG, Hu X, Qin C, Ling W. Genotoxicity of organic contaminants in the soil: A review based on bibliometric analysis and methodological progress. CHEMOSPHERE 2023; 313:137318. [PMID: 36410525 DOI: 10.1016/j.chemosphere.2022.137318] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/26/2022] [Accepted: 11/17/2022] [Indexed: 06/16/2023]
Abstract
Organic contaminants (OCs) are ubiquitous in the environment, posing severe threats to human health and ecological balance. In particular, OCs and their metabolites could interact with genetic materials to induce genotoxicity, which has attracted considerable attention. In this review, bibliometric analysis was executed to analyze the publications on the genotoxicity of OCs in soil from 1992 to 2021. The result indicated that significant contributions were made by China and the United States in this field and the research hotspots were biological risks, damage mechanisms, and testing methods. Based on this, in this review, we summarized the manifestations and influencing factors of genotoxicity of OCs to soil organisms, the main damage mechanisms, and the most commonly utilized testing methods. OCs can induce genotoxicity and the hierarchical response of soil organisms, which could be influenced by the physicochemical properties of OCs and the properties of soil. Specific mechanisms of genotoxicity can be classified into DNA damage, epigenetic toxicity, and chromosomal aberrations. OCs with different molecular weights lead to genetic material damage by inducing the generation of ROS or forming adducts with DNA, respectively. The micronucleus test and the comet test are the most commonly used testing methods. Moreover, this review also pointed out that future studies should focus on the relationships between bioaccessibilities and genotoxicities, transcriptional regulatory factors, and potential metabolites of OCs to elaborate on the biological risks and mechanisms of genotoxicity from an overall perspective.
Collapse
Affiliation(s)
- Miao Han
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Zaifeng Zhang
- Jiangsu Province Nantong Environmental Monitoring Center, Nantong 226006, PR China
| | - Si Liu
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Youying Sheng
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Michael Gatheru Waigi
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Xiaojie Hu
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Chao Qin
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Wanting Ling
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China
| |
Collapse
|
6
|
Cho E, Allemang A, Audebert M, Chauhan V, Dertinger S, Hendriks G, Luijten M, Marchetti F, Minocherhomji S, Pfuhler S, Roberts DJ, Trenz K, Yauk CL. AOP report: Development of an adverse outcome pathway for oxidative DNA damage leading to mutations and chromosomal aberrations. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2022; 63:118-134. [PMID: 35315142 PMCID: PMC9322445 DOI: 10.1002/em.22479] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 03/18/2022] [Indexed: 05/22/2023]
Abstract
The Genetic Toxicology Technical Committee (GTTC) of the Health and Environmental Sciences Institute (HESI) is developing adverse outcome pathways (AOPs) that describe modes of action leading to potentially heritable genomic damage. The goal was to enhance the use of mechanistic information in genotoxicity assessment by building empirical support for the relationships between relevant molecular initiating events (MIEs) and regulatory endpoints in genetic toxicology. Herein, we present an AOP network that links oxidative DNA damage to two adverse outcomes (AOs): mutations and chromosomal aberrations. We collected empirical evidence from the literature to evaluate the key event relationships between the MIE and the AOs, and assessed the weight of evidence using the modified Bradford-Hill criteria for causality. Oxidative DNA damage is constantly induced and repaired in cells given the ubiquitous presence of reactive oxygen species and free radicals. However, xenobiotic exposures may increase damage above baseline levels through a variety of mechanisms and overwhelm DNA repair and endogenous antioxidant capacity. Unrepaired oxidative DNA base damage can lead to base substitutions during replication and, along with repair intermediates, can also cause DNA strand breaks that can lead to mutations and chromosomal aberrations if not repaired adequately. This AOP network identifies knowledge gaps that could be filled by targeted studies designed to better define the quantitative relationships between key events, which could be leveraged for quantitative chemical safety assessment. We anticipate that this AOP network will provide the building blocks for additional genotoxicity-associated AOPs and aid in designing novel integrated testing approaches for genotoxicity.
Collapse
Affiliation(s)
- Eunnara Cho
- Environmental Health Science and Research BureauHealth CanadaOttawaOntarioCanada
- Department of BiologyCarleton UniversityOttawaOntarioCanada
| | | | | | - Vinita Chauhan
- Consumer and Clinical Radiation Protection BureauHealth CanadaOttawaOntarioCanada
| | | | | | - Mirjam Luijten
- Centre for Health ProtectionNational Institute for Public Health and the Environment (RIVM)BilthovenThe Netherlands
| | - Francesco Marchetti
- Environmental Health Science and Research BureauHealth CanadaOttawaOntarioCanada
- Department of BiologyCarleton UniversityOttawaOntarioCanada
| | - Sheroy Minocherhomji
- Amgen Research, Translational Safety and Bioanalytical SciencesAmgen Inc.Thousand OaksCaliforniaUSA
| | | | | | | | - Carole L. Yauk
- Environmental Health Science and Research BureauHealth CanadaOttawaOntarioCanada
- Department of BiologyCarleton UniversityOttawaOntarioCanada
- Department of BiologyUniversity of OttawaOttawaOntarioCanada
| |
Collapse
|
7
|
Almeida LC, Mattos AC, Dinamarco CPG, Figueiredo NG, Bila DM. Chronic toxicity and environmental risk assessment of antivirals in Ceriodaphnia dubia and Raphidocelis subcapitata. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2021; 84:1623-1634. [PMID: 34662301 DOI: 10.2166/wst.2021.347] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Antiviral drugs are a class of medications used for treating viral infections. Due to their widespread use, especially in cases of pandemics and limited human metabolism, antivirals have been detected in multiple environmental matrices. This study aims to evaluate the chronic effects of acyclovir, efavirenz, lamivudine and zidovudine using Ceriodaphnia dubia and Raphidocelis subcapitata. The results with R. subcapitata showed the following toxicities: zidovudine (IC50 = 5.442 mg L-1) < acyclovir (IC50 = 3.612 mg L-1) < lamivudine (IC50 = 3.013 mg L-1) < efavirenz (IC50 = 0.034 mg L-1). The results of the chronic bioassay with C. dubia demonstrated that zidovudine is the least toxic (EC50 = 5.671 mg L-1), followed by acyclovir (EC50 = 3.062 mg L-1), lamivudine (EC50 = 1.345 mg L-1) and efavirenz (EC50 = 0.026 mg L-1). Both species have been shown to be sensitive to efavirenz. A risk quotient (RQ) was calculated, and efavirenz had an RQ greater than 1 for both species, and lamivudine had an RQ greater than 1 for C. dubia, representing a high ecological risk for these organisms. Antivirals pose a significant environmental risk to aquatic organisms and should be taken into consideration in future monitoring of water sources.
Collapse
Affiliation(s)
- L C Almeida
- Engineering College, State University of Rio de Janeiro, São Francisco Xavier street, 524, 2029-F, Maracanã, Rio de Janeiro, 20550-900, RJ, Brazil E-mail:
| | - A C Mattos
- Engineering College, State University of Rio de Janeiro, São Francisco Xavier street, 524, 2029-F, Maracanã, Rio de Janeiro, 20550-900, RJ, Brazil E-mail:
| | - C P G Dinamarco
- Engineering College, State University of Rio de Janeiro, São Francisco Xavier street, 524, 2029-F, Maracanã, Rio de Janeiro, 20550-900, RJ, Brazil E-mail:
| | - N G Figueiredo
- National Institute of Technology, Venezuela Avenue, 82, 20081-312, RJ, Rio de Janeiro, Brazil
| | - D M Bila
- Engineering College, State University of Rio de Janeiro, São Francisco Xavier street, 524, 2029-F, Maracanã, Rio de Janeiro, 20550-900, RJ, Brazil E-mail:
| |
Collapse
|
8
|
Tian S, Cyr A, Zeise K, Bryce SM, Hall N, Bemis JC, Dertinger SD. 3Rs-friendly approach to exogenous metabolic activation that supports high-throughput genetic toxicology testing. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:408-432. [PMID: 32039521 DOI: 10.1002/em.22361] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 01/29/2020] [Accepted: 02/05/2020] [Indexed: 06/10/2023]
Abstract
MultiFlow® DNA Damage-p53, γH2AX, Phospho-Histone H3 is a miniaturized, flow cytometry-based assay that provides genotoxic mode of action information by distinguishing clastogens, aneugens, and nongenotoxicants. Work to date has focused on the p53-competent human cell line TK6. While mammalian cell genotoxicity assays typically supply exogenous metabolic activation in the form of concentrated rat liver S9, this is a less-than-ideal approach for several reasons, including 3Rs considerations. Here, we describe our experiences with low concentration S9 and saturating co-factors which were allowed to remain in contact with cells and test chemicals for 24 continuous hours. We exposed TK6 cells in 96-well plates to each of 15 reference chemicals over a range of concentrations, both in the presence and absence of 0.25% v/v phenobarbital/β-naphthoflavone-induced rat liver S9. After 4 and 24 hr of treatment cell aliquots were added to wells of a microtiter plate containing the working detergent/stain/antibody cocktail. After a brief incubation robotic sampling was employed for walk-away flow cytometric data acquisition. PROAST benchmark dose (BMD) modeling was used to characterize the resulting dose-response curves. For each of the 8 reference pro-genotoxicants studied, relative nuclei count, γH2AX, and/or p53 biomarker BMD values were order(s) of magnitude lower for 0.25% S9 conditions compared to 0% S9. Conversely, several of the direct-acting reference chemicals exhibited appreciably lower cytotoxicity and/or genotoxicity BMD values in the presence of S9 (eg, resorcinol). These results prove the efficacy of the low concentration S9 system, and indicate that an efficient and highly scalable multiplexed assay can effectively identify chemicals that require bioactivation to exert their genotoxic effects.
Collapse
Affiliation(s)
| | - Aiyana Cyr
- Litron Laboratories, Rochester, New York
| | | | | | - Nikki Hall
- Litron Laboratories, Rochester, New York
| | | | | |
Collapse
|
9
|
Ngo LP, Owiti NA, Swartz C, Winters J, Su Y, Ge J, Xiong A, Han J, Recio L, Samson LD, Engelward B. Sensitive CometChip assay for screening potentially carcinogenic DNA adducts by trapping DNA repair intermediates. Nucleic Acids Res 2020; 48:e13. [PMID: 31822921 PMCID: PMC7026589 DOI: 10.1093/nar/gkz1077] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 10/08/2019] [Accepted: 11/19/2019] [Indexed: 12/27/2022] Open
Abstract
Genotoxicity testing is critical for predicting adverse effects of pharmaceutical, industrial, and environmental chemicals. The alkaline comet assay is an established method for detecting DNA strand breaks, however, the assay does not detect potentially carcinogenic bulky adducts that can arise when metabolic enzymes convert pro-carcinogens into a highly DNA reactive products. To overcome this, we use DNA synthesis inhibitors (hydroxyurea and 1-β-d-arabinofuranosyl cytosine) to trap single strand breaks that are formed during nucleotide excision repair, which primarily removes bulky lesions. In this way, comet-undetectable bulky lesions are converted into comet-detectable single strand breaks. Moreover, we use HepaRG™ cells to recapitulate in vivo metabolic capacity, and leverage the CometChip platform (a higher throughput more sensitive comet assay) to create the 'HepaCometChip', enabling the detection of bulky genotoxic lesions that are missed by current genotoxicity screens. The HepaCometChip thus provides a broadly effective approach for detection of bulky DNA adducts.
Collapse
Affiliation(s)
- Le P Ngo
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Norah A Owiti
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Carol Swartz
- Toxicology Program, Integrated Laboratory Systems, Inc., Research Triangle Park, NC 27560, USA
| | - John Winters
- Toxicology Program, Integrated Laboratory Systems, Inc., Research Triangle Park, NC 27560, USA
| | - Yang Su
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jing Ge
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Aoli Xiong
- BioSystems and Micromechanics (BioSyM) IRG, Singapore-MIT Alliance for Research and Technology, 138602 Singapore
| | - Jongyoon Han
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- BioSystems and Micromechanics (BioSyM) IRG, Singapore-MIT Alliance for Research and Technology, 138602 Singapore
- Department of Electrical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Leslie Recio
- Toxicology Program, Integrated Laboratory Systems, Inc., Research Triangle Park, NC 27560, USA
| | - Leona D Samson
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Bevin P Engelward
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
10
|
Yin L, Siracusa JS, Measel E, Guan X, Edenfield C, Liang S, Yu X. High-Content Image-Based Single-Cell Phenotypic Analysis for the Testicular Toxicity Prediction Induced by Bisphenol A and Its Analogs Bisphenol S, Bisphenol AF, and Tetrabromobisphenol A in a Three-Dimensional Testicular Cell Co-culture Model. Toxicol Sci 2020; 173:313-335. [PMID: 31750923 PMCID: PMC6986343 DOI: 10.1093/toxsci/kfz233] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Emerging data indicate that structural analogs of bisphenol A (BPA) such as bisphenol S (BPS), tetrabromobisphenol A (TBBPA), and bisphenol AF (BPAF) have been introduced into the market as substitutes for BPA. Our previous study compared in vitro testicular toxicity using murine C18-4 spermatogonial cells and found that BPAF and TBBPA exhibited higher spermatogonial toxicities as compared with BPA and BPS. Recently, we developed a novel in vitro three-dimensional (3D) testicular cell co-culture model, enabling the classification of reproductive toxic substances. In this study, we applied the testicular cell co-culture model and employed a high-content image (HCA)-based single-cell analysis to further compare the testicular toxicities of BPA and its analogs. We also developed a machine learning (ML)-based HCA pipeline to examine the complex phenotypic changes associated with testicular toxicities. We found dose- and time-dependent changes in a wide spectrum of adverse endpoints, including nuclear morphology, DNA synthesis, DNA damage, and cytoskeletal structure in a single-cell-based analysis. The co-cultured testicular cells were more sensitive than the C18 spermatogonial cells in response to BPA and its analogs. Unlike conventional population-averaged assays, single-cell-based assays not only showed the levels of the averaged population, but also revealed changes in the sub-population. Machine learning-based phenotypic analysis revealed that treatment of BPA and its analogs resulted in the loss of spatial cytoskeletal structure, and an accumulation of M phase cells in a dose- and time-dependent manner. Furthermore, treatment of BPAF-induced multinucleated cells, which were associated with altered DNA damage response and impaired cellular F-actin filaments. Overall, we demonstrated a new and effective means to evaluate multiple toxic endpoints in the testicular co-culture model through the combination of ML and high-content image-based single-cell analysis. This approach provided an in-depth analysis of the multi-dimensional HCA data and provided an unbiased quantitative analysis of the phenotypes of interest.
Collapse
Affiliation(s)
- Lei Yin
- ReproTox Biotech LLC, Athens, Georgia 30602
| | - Jacob Steven Siracusa
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, Georgia
| | - Emily Measel
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, Georgia
| | | | - Clayton Edenfield
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, Georgia
| | - Shenxuan Liang
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, Georgia
| | - Xiaozhong Yu
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, Georgia
| |
Collapse
|
11
|
Li S, Xia M. Review of high-content screening applications in toxicology. Arch Toxicol 2019; 93:3387-3396. [PMID: 31664499 PMCID: PMC7011178 DOI: 10.1007/s00204-019-02593-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 10/08/2019] [Indexed: 12/17/2022]
Abstract
High-content screening (HCS) technology combining automated microscopy and quantitative image analysis can address biological questions in academia and the pharmaceutical industry. Various HCS experimental applications have been utilized in the research field of in vitro toxicology. In this review, we describe several HCS application approaches used for studying the mechanism of compound toxicity, highlight some challenges faced in the toxicological community, and discuss the future directions of HCS in regards to new models, new reagents, data management, and informatics. Many specialized areas of toxicology including developmental toxicity, genotoxicity, developmental neurotoxicity/neurotoxicity, hepatotoxicity, cardiotoxicity, and nephrotoxicity will be examined. In addition, several newly developed cellular assay models including induced pluripotent stem cells (iPSCs), three-dimensional (3D) cell models, and tissues-on-a-chip will be discussed. New genome-editing technologies (e.g., CRISPR/Cas9), data analyzing tools for imaging, and coupling with high-content assays will be reviewed. Finally, the applications of machine learning to image processing will be explored. These new HCS approaches offer a huge step forward in dissecting biological processes, developing drugs, and making toxicology studies easier.
Collapse
Affiliation(s)
- Shuaizhang Li
- Division for Pre-Clinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Bethesda, MD, USA
| | - Menghang Xia
- Division for Pre-Clinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, 9800 Medical Center Drive, Bethesda, MD, USA.
| |
Collapse
|
12
|
Yang B, Figueroa DM, Hou Y, Babbar M, Baringer SL, Croteau DL, Bohr VA. NEIL1 stimulates neurogenesis and suppresses neuroinflammation after stress. Free Radic Biol Med 2019; 141:47-58. [PMID: 31175982 PMCID: PMC7526462 DOI: 10.1016/j.freeradbiomed.2019.05.037] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Revised: 05/30/2019] [Accepted: 05/31/2019] [Indexed: 02/07/2023]
Abstract
Cellular exposure to ionizing radiation leads to oxidatively generated DNA damage, which has been implicated in neurodegenerative diseases. DNA damage is repaired by the evolutionarily conserved base excision repair (BER) system. Exposure of mice to ionizing radiation affects neurogenesis and neuroinflammation. However, the consequences of deficient DNA repair on adult neurogenesis and neuroinflammation are poorly understood despite their potential relevance for homeostasis. We previously reported that loss of NEIL1, an important DNA glycosylase involved in BER, is associated with deficiencies in spatial memory, olfaction, and protection against ischemic stroke in mice. Here, we show that Neil1-/- mice display an anxiety-mediated behavior in the open field test, a deficient recognitive memory in novel object recognition and increased neuroinflammatory response under basal conditions. Further, mice lacking NEIL1 have decreased neurogenesis and deficient resolution of neuroinflammation following gamma irradiation (IR)-induced stress compared to WT mice. Neil1-/- IR-exposed mice also exhibit increased DNA damage and apoptosis in the hippocampus. Interestingly, behavioral tests two weeks after IR showed impaired stress response in the Neil1-/- mice. Our data indicate that NEIL1 plays an important role in adult neurogenesis and in the resolution of neuroinflammation.
Collapse
Affiliation(s)
- Beimeng Yang
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - David M Figueroa
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Yujun Hou
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Mansi Babbar
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Stephanie L Baringer
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Deborah L Croteau
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Vilhelm A Bohr
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA; Danish Center for Healthy Aging, University of Copenhagen, 2200, Copenhagen, Denmark.
| |
Collapse
|
13
|
Geißler D, Wegmann M, Jochum T, Somma V, Sowa M, Scholz J, Fröhlich E, Hoffmann K, Niehaus J, Roggenbuck D, Resch-Genger U. An automatable platform for genotoxicity testing of nanomaterials based on the fluorometric γ-H2AX assay reveals no genotoxicity of properly surface-shielded cadmium-based quantum dots. NANOSCALE 2019; 11:13458-13468. [PMID: 31287475 DOI: 10.1039/c9nr01021a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The large number of nanomaterial-based applications emerging in the materials and life sciences and the foreseeable increasing use of these materials require methods that evaluate and characterize the toxic potential of these nanomaterials to keep safety risks to people and environment as low as possible. As nanomaterial toxicity is influenced by a variety of parameters like size, shape, chemical composition, and surface chemistry, high throughput screening (HTS) platforms are recommended for assessing cytotoxicity. Such platforms are not yet available for genotoxicity testing. Here, we present first results obtained for application-relevant nanomaterials using an automatable genotoxicity platform that relies on the quantification of the phosphorylated histone H2AX (γ-H2AX) for detecting DNA double strand breaks (DSBs) and the automated microscope system AKLIDES® for measuring integral fluorescence intensities at different excitation wavelengths. This platform is used to test the genotoxic potential of 30 nm-sized citrate-stabilized gold nanoparticles (Au-NPs) as well as micellar encapsulated iron oxide nanoparticles (FeOx-NPs) and different cadmium (Cd)-based semiconductor quantum dots (QDs), thereby also searching for positive and negative controls as reference materials. In addition, the influence of the QD shell composition on the genotoxic potential of these Cd-based QDs was studied, using CdSe cores as well as CdSe/CdS core/shell and CdSe/CdS/ZnS core/shell/shell QDs. Our results clearly revealed the genotoxicity of the Au-NPs and its absence in the FeOx-NPs. The genotoxicity of the Cd-QDs correlates with the shielding of their Cd-containing core, with the core/shell/shell architecture preventing genotoxicity risks. The fact that none of these nanomaterials showed cytotoxicity at the chosen particle concentrations in a conventional cell viability assay underlines the importance of genotoxicity studies to assess the hazardous potential of nanomaterials.
Collapse
Affiliation(s)
- D Geißler
- Bundesanstalt für Materialforschung und -prüfung (BAM), Division 1.2 Biophotonics, Richard-Willstätter-Str. 11, 12489 Berlin, Germany.
| | - M Wegmann
- Bundesanstalt für Materialforschung und -prüfung (BAM), Division 1.2 Biophotonics, Richard-Willstätter-Str. 11, 12489 Berlin, Germany. and MEDIPAN GmbH, Ludwig-Erhard-Ring 3, 15827 Dahlewitz, Germany
| | - T Jochum
- Fraunhofer-Zentrum für Angewandte Nanotechnologie CAN, Grindelallee 117, 20146 Hamburg, Germany
| | - V Somma
- MEDIPAN GmbH, Ludwig-Erhard-Ring 3, 15827 Dahlewitz, Germany
| | - M Sowa
- MEDIPAN GmbH, Ludwig-Erhard-Ring 3, 15827 Dahlewitz, Germany
| | - J Scholz
- MEDIPAN GmbH, Ludwig-Erhard-Ring 3, 15827 Dahlewitz, Germany
| | - E Fröhlich
- Medizinische Universität Graz, Zentrum für Medizinische Forschung (ZMF), Stiftingtalstrasse 24, 8010 Graz, Austria
| | - K Hoffmann
- Bundesanstalt für Materialforschung und -prüfung (BAM), Division 1.2 Biophotonics, Richard-Willstätter-Str. 11, 12489 Berlin, Germany.
| | - J Niehaus
- Medizinische Universität Graz, Zentrum für Medizinische Forschung (ZMF), Stiftingtalstrasse 24, 8010 Graz, Austria
| | - D Roggenbuck
- MEDIPAN GmbH, Ludwig-Erhard-Ring 3, 15827 Dahlewitz, Germany and Institute of Biotechnology, Faculty Environment and Natural Sciences, Brandenburg University of Technology, Germany
| | - U Resch-Genger
- Bundesanstalt für Materialforschung und -prüfung (BAM), Division 1.2 Biophotonics, Richard-Willstätter-Str. 11, 12489 Berlin, Germany.
| |
Collapse
|
14
|
Kopp B, Khoury L, Audebert M. Validation of the γH2AX biomarker for genotoxicity assessment: a review. Arch Toxicol 2019; 93:2103-2114. [DOI: 10.1007/s00204-019-02511-9] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 07/04/2019] [Indexed: 12/12/2022]
|
15
|
Takeiri A, Matsuzaki K, Motoyama S, Yano M, Harada A, Katoh C, Tanaka K, Mishima M. High-content imaging analyses of γH2AX-foci and micronuclei in TK6 cells elucidated genotoxicity of chemicals and their clastogenic/aneugenic mode of action. Genes Environ 2019; 41:4. [PMID: 30766621 PMCID: PMC6362597 DOI: 10.1186/s41021-019-0117-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 01/07/2019] [Indexed: 12/12/2022] Open
Abstract
Background The in vitro micronucleus (MN) test is an important component of a genotoxicity test battery that evaluates chemicals. Although the standard method of manually scoring micronucleated (MNed) cells by microscope is a reliable and standard method, it is laborious and time-consuming. A high-throughput assay system for detecting MN cells automatically has long been desired in the fields of pharmaceutical development or environmental risk monitoring. Although the MN test per se cannot clarify whether the mode of MN induction is aneugenic or clastogenic, this clarification may well be made possible by combining the MN test with an evaluation of γH2AX, a sensitive marker of DNA double strand breaks (DSB). In the present study, we aimed to establish a high-content (HC) imaging assay that automatically detects micronuclei (MNi) and simultaneously measures γH2AX foci in human lymphoblastoid TK6 cells. Results TK6 cells were fixed on the bottom of each well in 96-well plates hypotonically, which spreads the cells thinly to detach MNi from the primary nuclei. Then, the number of MNi and immunocytochemically-stained γH2AX foci were measured using an imaging analyzer. The system correctly judged 4 non-genotoxins and 13 genotoxins, which included 9 clastogens and 4 aneugens representing various genotoxic mechanisms, such as DNA alkylation, cross-linking, topoisomerase inhibition, and microtubule disruption. Furthermore, all the clastogens induced both γH2AX foci and MNi, while the aneugens induced only MNi, not γH2AX foci; therefore, the HC imaging assay clearly discriminated the aneugens from the clastogens. Additionally, the test system could feasibly analyze cell cycle, to add information about a chemical’s mode of action. Conclusions A HC imaging assay to detect γH2AX foci and MNi in TK6 cells was established, and the assay provided information on the aneugenic/clastogenic mode of action. Electronic supplementary material The online version of this article (10.1186/s41021-019-0117-8) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Akira Takeiri
- Fuji Gotemba Research Laboratories, Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba, Shizuoka, 412-8513 Japan
| | - Kaori Matsuzaki
- Fuji Gotemba Research Laboratories, Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba, Shizuoka, 412-8513 Japan
| | - Shigeki Motoyama
- Fuji Gotemba Research Laboratories, Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba, Shizuoka, 412-8513 Japan
| | - Mariko Yano
- Fuji Gotemba Research Laboratories, Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba, Shizuoka, 412-8513 Japan
| | - Asako Harada
- Fuji Gotemba Research Laboratories, Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba, Shizuoka, 412-8513 Japan
| | - Chiaki Katoh
- Fuji Gotemba Research Laboratories, Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba, Shizuoka, 412-8513 Japan
| | - Kenji Tanaka
- Fuji Gotemba Research Laboratories, Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba, Shizuoka, 412-8513 Japan
| | - Masayuki Mishima
- Fuji Gotemba Research Laboratories, Chugai Pharmaceutical Co., Ltd., 1-135 Komakado, Gotemba, Shizuoka, 412-8513 Japan
| |
Collapse
|
16
|
Matsuda S, Wanibuchi S, Kasahara T. Quantitative analysis of γH2AX reveals distinct responses in multiple mouse organs after administration of mitomycin C or ethyl methanesulfonate. Mutagenesis 2018; 33:371-378. [DOI: 10.1093/mutage/gey040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 11/25/2018] [Indexed: 12/18/2022] Open
Affiliation(s)
- Shun Matsuda
- Safety Evaluation Center, Ecology and Quality Management Division, CSR Division, FUJIFILM Corporation, 210 Nakanuma, Minamiashigara, Kanagawa, Japan
| | - Sayaka Wanibuchi
- Safety Evaluation Center, Ecology and Quality Management Division, CSR Division, FUJIFILM Corporation, 210 Nakanuma, Minamiashigara, Kanagawa, Japan
| | - Toshihiko Kasahara
- Safety Evaluation Center, Ecology and Quality Management Division, CSR Division, FUJIFILM Corporation, 210 Nakanuma, Minamiashigara, Kanagawa, Japan
| |
Collapse
|
17
|
Motoyama S, Takeiri A, Tanaka K, Harada A, Matsuzaki K, Taketo J, Matsuo S, Fujii E, Mishima M. Advantages of evaluating γH2AX induction in non-clinical drug development. Genes Environ 2018; 40:10. [PMID: 29785231 PMCID: PMC5950202 DOI: 10.1186/s41021-018-0098-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/26/2018] [Indexed: 01/17/2023] Open
Abstract
γH2AX, the phosphorylated form of a histone variant H2AX at Ser 139, is already widely used as a biomarker to research the fundamental biology of DNA damage and repair and to assess the risk of environmental chemicals, pollutants, radiation, and so on. It is also beginning to be used in the early non-clinical stage of pharmaceutical drug development as an in vitro tool for screening and for mechanistic studies on genotoxicity. Here, we review the available information on γH2AX-based test systems that can be used to develop drugs and present our own experience of practically applying these systems during the non-clinical phase of drug development. Furthermore, the potential application of γH2AX as a tool for in vivo non-clinical safety studies is also discussed.
Collapse
Affiliation(s)
- Shigeki Motoyama
- Research Division, Chugai Pharmaceutical Co., Ltd, Gotemba, Shizuoka Japan
| | - Akira Takeiri
- Research Division, Chugai Pharmaceutical Co., Ltd, Gotemba, Shizuoka Japan
| | - Kenji Tanaka
- Research Division, Chugai Pharmaceutical Co., Ltd, Gotemba, Shizuoka Japan
| | - Asako Harada
- Research Division, Chugai Pharmaceutical Co., Ltd, Gotemba, Shizuoka Japan
| | - Kaori Matsuzaki
- Research Division, Chugai Pharmaceutical Co., Ltd, Gotemba, Shizuoka Japan
| | - Junko Taketo
- Research Division, Chugai Pharmaceutical Co., Ltd, Gotemba, Shizuoka Japan
| | - Saori Matsuo
- Research Division, Chugai Pharmaceutical Co., Ltd, Gotemba, Shizuoka Japan
| | - Etsuko Fujii
- Research Division, Chugai Pharmaceutical Co., Ltd, Gotemba, Shizuoka Japan
| | - Masayuki Mishima
- Research Division, Chugai Pharmaceutical Co., Ltd, Gotemba, Shizuoka Japan
| |
Collapse
|
18
|
Bryce SM, Bernacki DT, Smith-Roe SL, Witt KL, Bemis JC, Dertinger SD. Investigating the Generalizability of the MultiFlow ® DNA Damage Assay and Several Companion Machine Learning Models With a Set of 103 Diverse Test Chemicals. Toxicol Sci 2018; 162:146-166. [PMID: 29106658 PMCID: PMC6059150 DOI: 10.1093/toxsci/kfx235] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The in vitro MultiFlow DNA Damage assay multiplexes p53, γH2AX, phospho-histone H3, and polyploidization biomarkers into 1 flow cytometric analysis (Bryce, S. M., Bernacki, D. T., Bemis, J. C., and Dertinger, S. D. (2016). Genotoxic mode of action predictions from a multiplexed flow cytometric assay and a machine learning approach. Environ. Mol. Mutagen. 57, 171-189). The work reported herein evaluated the generalizability of the method, as well as several data analytics strategies, to a range of chemical classes not studied previously. TK6 cells were exposed to each of 103 diverse chemicals, 86 of which were supplied by the National Toxicology Program (NTP) and selected based upon responses in genetic damage assays conducted under the Tox21 program. Exposures occurred for 24 h over a range of concentrations, and cell aliquots were removed at 4 and 24 h for analysis. Multiplexed response data were evaluated using 3 machine learning models designed to predict genotoxic mode of action based on data from a training set of 85 previously studied chemicals. Of 54 chemicals with sufficient information to make an a priori call on genotoxic potential, the prediction models' accuracies were 79.6% (random forest), 88.9% (logistic regression), and 90.7% (artificial neural network). A majority vote ensemble of the 3 models provided 92.6% accuracy. Forty-nine NTP chemicals were not adequately tested (maximum concentration did not approach assay's cytotoxicity limit) and/or had insufficient conventional genotoxicity data to allow their genotoxic potential to be defined. For these chemicals MultiFlow data will be useful in future research and hypothesis testing. Collectively, the results suggest the MultiFlow assay and associated data analysis strategies are broadly generalizable, demonstrating high predictability when applied to new chemicals and classes of compounds.
Collapse
Affiliation(s)
| | | | - Stephanie L Smith-Roe
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Kristine L Witt
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | | | | |
Collapse
|
19
|
Zhang S, Chen H, Wang A, Liu Y, Hou H, Hu Q. Genotoxicity analysis of five particle matter toxicants from cigarette smoke based on γH2AX assay combined with Hill/Two-component model. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2018; 58:131-140. [PMID: 29329021 DOI: 10.1016/j.etap.2018.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 01/04/2018] [Indexed: 06/07/2023]
Abstract
To investigate the genotoxic characteristics of typical toxicants in particle phase of cigarette smoke, including B[a]P, nicotine, tar, NNN and NNK. The in vitro γH2AX assay was used to detect the DNA double-strand breaks (DSBs) in A549 cells using high content screening (HCS). The results showed all toxicants had a dose/time-dependent effects on induction of γH2AX except for NNN and NNK. Based on dose-response of γH2AX and Hill model, the ability to induce DSBs was evaluated: NNN-acetate > B[a]P > NNK-acetate > tar > nicotine. Based on time-course of γH2AX and two-component model, the complex DNA damage was the main subtypes of DNA damage induced by these toxicants. Overall, all toxicants were genotoxic in A549 cells in a dose- or time- dependent manner except for NNN and NNK based on the γH2AX HCS assay. NNN-acetate had more potential to induce DSBs, which was followed by B[a]P, NNK-acetate, tar and nicotine.
Collapse
Affiliation(s)
- Sen Zhang
- Institute of Applied Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230088, PR China; University of Science and Technology of China, Hefei 230026, PR China; China National Tobacco Quality Supervision & Test Center, Zhengzhou 450001, PR China
| | - Huan Chen
- China National Tobacco Quality Supervision & Test Center, Zhengzhou 450001, PR China
| | - An Wang
- Institute of Applied Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230088, PR China
| | - Yong Liu
- Institute of Applied Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230088, PR China
| | - Hongwei Hou
- China National Tobacco Quality Supervision & Test Center, Zhengzhou 450001, PR China.
| | - Qingyuan Hu
- China National Tobacco Quality Supervision & Test Center, Zhengzhou 450001, PR China.
| |
Collapse
|
20
|
Ates G, Mertens B, Heymans A, Verschaeve L, Milushev D, Vanparys P, Roosens NHC, De Keersmaecker SCJ, Rogiers V, Doktorova TY. A novel genotoxin-specific qPCR array based on the metabolically competent human HepaRG™ cell line as a rapid and reliable tool for improved in vitro hazard assessment. Arch Toxicol 2018; 92:1593-1608. [DOI: 10.1007/s00204-018-2172-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 01/31/2018] [Indexed: 02/01/2023]
|
21
|
Zhang S, Chen H, Wang A, Liu Y, Hou H, Hu Q. Assessment of genotoxicity of four volatile pollutants from cigarette smoke based on the in vitro γH2AX assay using high content screening. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2017; 55:30-36. [PMID: 28818740 DOI: 10.1016/j.etap.2017.07.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 07/13/2017] [Accepted: 07/14/2017] [Indexed: 06/07/2023]
Abstract
To evaluate the genotoxic effects of formaldehyde, acetaldehyde, acrolein and benzene on A549 cells, the in vitro γH2AX assay was used in combination with high content screening (HCS) technology. All aldehydes showed a significant genotoxicity in a dose/time-dependent effect on the induction of γH2AX. Benzene failed to show a significant genotoxicity based on the γH2AX assay. However, hydroquinone (one of metabolites of benzene) showed a significant genotoxicity in vitro. Based on the dose-response of γH2AX and Hill model, the ability to induce DNA double-strand break can be evaluated as acrolein>formaldehyde>acetaldehyde>benzene. The slow DNA damage/repair mechanism may be more important than the fast one for aldehydes based on time-course of γH2AX and two-component model. Overall, all toxicants were genotoxic in a dose- or time-dependent manner based on the in vitro γH2AX HCS assay, and acrolein had a strong potential to induce DNA damage followed by formaldehyde, acetaldehyde and benzene in sequence.
Collapse
Affiliation(s)
- Sen Zhang
- Institute of Applied Technology, Hefei Institutes of physical Science, Chinese Academy of Sciences, Hefei 230088, PR China; University of Science and Technology of China, Hefei 230026, PR China; China National Tobacco Quality Supervision & Test Center, Zhengzhou 450001, PR China
| | - Huan Chen
- China National Tobacco Quality Supervision & Test Center, Zhengzhou 450001, PR China
| | - An Wang
- Institute of Applied Technology, Hefei Institutes of physical Science, Chinese Academy of Sciences, Hefei 230088, PR China
| | - Yong Liu
- Institute of Applied Technology, Hefei Institutes of physical Science, Chinese Academy of Sciences, Hefei 230088, PR China
| | - Hongwei Hou
- China National Tobacco Quality Supervision & Test Center, Zhengzhou 450001, PR China.
| | - Qingyuan Hu
- China National Tobacco Quality Supervision & Test Center, Zhengzhou 450001, PR China.
| |
Collapse
|
22
|
Bryce SM, Bernacki DT, Bemis JC, Spellman RA, Engel ME, Schuler M, Lorge E, Heikkinen PT, Hemmann U, Thybaud V, Wilde S, Queisser N, Sutter A, Zeller A, Guérard M, Kirkland D, Dertinger SD. Interlaboratory evaluation of a multiplexed high information content in vitro genotoxicity assay. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2017; 58:146-161. [PMID: 28370322 PMCID: PMC5436310 DOI: 10.1002/em.22083] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 05/18/2023]
Abstract
We previously described a multiplexed in vitro genotoxicity assay based on flow cytometric analysis of detergent-liberated nuclei that are simultaneously stained with propidium iodide and labeled with fluorescent antibodies against p53, γH2AX, and phospho-histone H3. Inclusion of a known number of microspheres provides absolute nuclei counts. The work described herein was undertaken to evaluate the interlaboratory transferability of this assay, commercially known as MultiFlow® DNA Damage Kit-p53, γH2AX, Phospho-Histone H3. For these experiments, seven laboratories studied reference chemicals from a group of 84 representing clastogens, aneugens, and nongenotoxicants. TK6 cells were exposed to chemicals in 96-well plates over a range of concentrations for 24 hr. At 4 and 24 hr, cell aliquots were added to the MultiFlow reagent mix and following a brief incubation period flow cytometric analysis occurred, in most cases directly from a 96-well plate via a robotic walk-away data acquisition system. Multiplexed response data were evaluated using two analysis approaches, one based on global evaluation factors (i.e., cutoff values derived from all interlaboratory data), and a second based on multinomial logistic regression that considers multiple biomarkers simultaneously. Both data analysis strategies were devised to categorize chemicals as predominately exhibiting a clastogenic, aneugenic, or nongenotoxic mode of action (MoA). Based on the aggregate 231 experiments that were performed, assay sensitivity, specificity, and concordance in relation to a priori MoA grouping were ≥ 92%. These results are encouraging as they suggest that two distinct data analysis strategies can rapidly and reliably predict new chemicals' predominant genotoxic MoA based on data from an efficient and transferable multiplexed in vitro assay. Environ. Mol. Mutagen. 58:146-161, 2017. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
| | | | | | | | - Maria E Engel
- Pfizer Worldwide Research and Development, Groton, Connecticut
| | - Maik Schuler
- Pfizer Worldwide Research and Development, Groton, Connecticut
| | | | | | | | | | | | | | | | - Andreas Zeller
- Roche Pharma Research and Early Development, Basel, Switzerland
| | - Melanie Guérard
- Roche Pharma Research and Early Development, Basel, Switzerland
| | | | | |
Collapse
|
23
|
Thorne D, Larard S, Baxter A, Meredith C, Gaҫa M. The comparative in vitro assessment of e-cigarette and cigarette smoke aerosols using the γH2AX assay and applied dose measurements. Toxicol Lett 2016; 265:170-178. [PMID: 27965004 DOI: 10.1016/j.toxlet.2016.12.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 12/02/2016] [Accepted: 12/07/2016] [Indexed: 11/17/2022]
Abstract
DNA damage can be caused by a variety of external and internal factors and together with cellular responses, can establish genomic instability through multiple pathways. DNA damage therefore, is considered to play an important role in the aetiology and early stages of carcinogenesis. The DNA-damage inducing potential of tobacco smoke aerosols in vitro has been extensively investigated; however, the ability of e-cigarette aerosols to induce DNA damage has not been extensively investigated. E-cigarette use has grown globally in recent years and the health implications of long term e-cigarette use are still unclear. Therefore, this study has assessed the induction of double-strand DNA damage in vitro using human lung epithelial cells to e-cigarette aerosols from two different product variants (a "cigalike" and a closed "modular" system) and cigarette smoke. A Vitrocell® VC 10 aerosol exposure system was used to generate and dilute cigarette smoke and e-cigarette aerosols, which were delivered to human bronchial epithelial cells (BEAS-2Bs) housed at the air-liquid-interface (ALI) for up to 120min exposure (diluting airflow, 0.25-1L/min). Following exposure, cells were immediately fixed, incubated with primary (0.1% γH2AX antibody in PBS) and secondary antibodies (DyLight™ 549 conjugated goat anti-mouse IgG) containing Hoechst dye DNA staining solution (0.2% secondary antibody and 0.01% Hoechst in PBS), and finally screened using the Cellomics Arrayscan VTI platform. The results from this study demonstrate a clear DNA damage-induced dose response with increasing smoke concentrations up to cytotoxic levels. In contrast, e-cigarette aerosols from two product variants did not induce DNA damage at equivalent to or greater than doses of cigarette smoke aerosol. In this study dosimetry approaches were used to contextualize exposure, define exposure conditions and facilitate comparisons between cigarette smoke and e-cigarette aerosols. Quartz crystal microbalance (QCM) technology and quantified nicotine delivery were both assessed at the exposure interface. Nicotine was eluted from the QCM surface to give a quantifiable measure of exposure to support deposited mass. Dose measured as deposited mass (μg/cm2) and nicotine (ng/mL) demonstrated that in vitro e-cigarette exposures were conducted at doses up to 12-28 fold to that of cigarette smoke and demonstrated a consistent negative finding.
Collapse
Affiliation(s)
- David Thorne
- British American Tobacco, R&D Centre, Southampton, Hampshire, SO15 8TL, UK.
| | - Sophie Larard
- British American Tobacco, R&D Centre, Southampton, Hampshire, SO15 8TL, UK
| | - Andrew Baxter
- British American Tobacco, R&D Centre, Southampton, Hampshire, SO15 8TL, UK
| | - Clive Meredith
- British American Tobacco, R&D Centre, Southampton, Hampshire, SO15 8TL, UK
| | - Marianna Gaҫa
- British American Tobacco, R&D Centre, Southampton, Hampshire, SO15 8TL, UK
| |
Collapse
|
24
|
Persson M, Hornberg JJ. Advances in Predictive Toxicology for Discovery Safety through High Content Screening. Chem Res Toxicol 2016; 29:1998-2007. [DOI: 10.1021/acs.chemrestox.6b00248] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Mikael Persson
- Drug Safety and Metabolism, Innovative Medicines and Early Development, AstraZeneca R&D Gothenburg, Pepparedsleden 1, 431 83 Mölndal, Sweden
| | - Jorrit J. Hornberg
- Drug Safety and Metabolism, Innovative Medicines and Early Development, AstraZeneca R&D Gothenburg, Pepparedsleden 1, 431 83 Mölndal, Sweden
| |
Collapse
|
25
|
Corvi R, Madia F. In vitro genotoxicity testing-Can the performance be enhanced? Food Chem Toxicol 2016; 106:600-608. [PMID: 27554597 DOI: 10.1016/j.fct.2016.08.024] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 08/18/2016] [Accepted: 08/19/2016] [Indexed: 12/16/2022]
Abstract
The assessment of genotoxicity represents an essential component of the safety assessment of all types of substances. Several in vitro tests are available at different stages of development and acceptance, yet they are not considered at present sufficient to fully replace animal tests needed to evaluate the safety of substances. For an overall improvement of the traditional genotoxicity testing paradigm, several recent activities have taken place. These include the improvement of existing tests, the development of novel tests, as well as, the establishment and exploration of approaches to optimise in vitro testing accuracy. Furthermore, useful tools, such as databases or reference chemical lists have been developed to support advances in this field.
Collapse
Affiliation(s)
- Raffaella Corvi
- European Commission, Joint Research Centre (JRC), Directorate Health, Consumers and Reference Materials, Chemicals Safety and Alternative Methods Unit, EURL ECVAM, Via E. Fermi 2749, I-21027, Ispra, Varese, Italy.
| | - Federica Madia
- European Commission, Joint Research Centre (JRC), Directorate Health, Consumers and Reference Materials, Chemicals Safety and Alternative Methods Unit, EURL ECVAM, Via E. Fermi 2749, I-21027, Ispra, Varese, Italy.
| |
Collapse
|
26
|
Bernacki DT, Bryce SM, Bemis JC, Kirkland D, Dertinger SD. γH2AX and p53 responses in TK6 cells discriminate promutagens and nongenotoxicants in the presence of rat liver S9. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2016; 57:546-558. [PMID: 27364561 PMCID: PMC4980245 DOI: 10.1002/em.22028] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 05/24/2016] [Accepted: 05/24/2016] [Indexed: 05/03/2023]
Abstract
Previous work with a diverse set of reference chemicals suggests that an in vitro multiplexed flow cytometry-based assay (MultiFlow™ DNA Damage Kit-p53, γH2AX, Phospho-Histone H3) can distinguish direct-acting clastogens and aneugens from nongenotoxicants (Bryce SM et al. []: Environ Mol Mutagen 57:171-189). This work extends this line of investigation to include compounds that require metabolic activation to form reactive electrophiles. For these experiments, TK6 cells were exposed to 11 promutagens and 37 presumed nongenotoxicants in 96 well plates. Unless precipitation or foreknowledge about cytotoxicity suggested otherwise, the highest concentration was 1 mM. Exposure occurred for 4 hr after which time cells were washed to remove S9 and test article. Immediately following the wash and again at 24 hr, cell aliquots were added to wells of a microtiter plate containing the working detergent/stain/antibody cocktail. After a brief incubation, robotic sampling was employed for walk-away flow cytometric data acquisition. Univariate logistic regression analyses indicated that γH2AX induction and p53 activation provide the greatest degree of discrimination between clastogens and nongenotoxicants. Multivariate prediction algorithms that incorporated both of these endpoints, in each combination of time points, were evaluated. The best performing models correctly predicted 9 clastogens out of 11 and 36 nongenotoxicants out of 37. These results are encouraging as they suggest that an efficient and highly scalable multiplexed assay can effectively identify clastogenic chemicals that require bioactivation. More work is planned with a broader range of chemicals, additional cell lines, and other laboratories to further evaluate the merits and limitations of this approach. Environ. Mol. Mutagen. 57:546-558, 2016. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Derek T. Bernacki
- Litron Laboratories, 3500 Winton Place, Rochester, New York, 14623, USA
| | - Steven M. Bryce
- Litron Laboratories, 3500 Winton Place, Rochester, New York, 14623, USA
| | - Jeffrey C. Bemis
- Litron Laboratories, 3500 Winton Place, Rochester, New York, 14623, USA
| | | | - Stephen D. Dertinger
- Litron Laboratories, 3500 Winton Place, Rochester, New York, 14623, USA
- corresponding author: S.D.D., 585-442-0930,
| |
Collapse
|
27
|
Progress on Molecular Mechanism of Phosphorylation/Dephosphorylation and Detection Technology of γH2AX. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2016. [DOI: 10.1016/s1872-2040(16)60952-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
28
|
Lorscheidt S, Lamprecht A. Safety assessment of nanoparticles for drug delivery by means of classic in vitro assays and beyond. Expert Opin Drug Deliv 2016; 13:1545-1558. [DOI: 10.1080/17425247.2016.1198773] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Stefan Lorscheidt
- Department of Pharmaceutics, Institute of Pharmacy, University of Bonn, Bonn, Germany
| | - Alf Lamprecht
- Department of Pharmaceutics, Institute of Pharmacy, University of Bonn, Bonn, Germany
- FDE (EA4267), University of Burgundy/Franche-Comté, Besançon, France
| |
Collapse
|
29
|
Bryce SM, Bernacki DT, Bemis JC, Dertinger SD. Genotoxic mode of action predictions from a multiplexed flow cytometric assay and a machine learning approach. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2016; 57:171-89. [PMID: 26764165 PMCID: PMC4792721 DOI: 10.1002/em.21996] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 12/15/2015] [Accepted: 12/16/2015] [Indexed: 05/19/2023]
Abstract
Several endpoints associated with cellular responses to DNA damage as well as overt cytotoxicity were multiplexed into a miniaturized, "add and read" type flow cytometric assay. Reagents included a detergent to liberate nuclei, RNase and propidium iodide to serve as a pan-DNA dye, fluorescent antibodies against γH2AX, phospho-histone H3, and p53, and fluorescent microspheres for absolute nuclei counts. The assay was applied to TK6 cells and 67 diverse reference chemicals that served as a training set. Exposure was for 24 hrs in 96-well plates, and unless precipitation or foreknowledge about cytotoxicity suggested otherwise, the highest concentration was 1 mM. At 4- and 24-hrs aliquots were removed and added to microtiter plates containing the reagent mix. Following a brief incubation period robotic sampling facilitated walk-away data acquisition. Univariate analyses identified biomarkers and time points that were valuable for classifying agents into one of three groups: clastogenic, aneugenic, or non-genotoxic. These mode of action predictions were optimized with a forward-stepping process that considered Wald test p-values, receiver operator characteristic curves, and pseudo R(2) values, among others. A particularly high performing multinomial logistic regression model was comprised of four factors: 4 hr γH2AX and phospho-histone H3 values, and 24 hr p53 and polyploidy values. For the training set chemicals, the four-factor model resulted in 94% concordance with our a priori classifications. Cross validation occurred via a leave-one-out approach, and in this case 91% concordance was observed. A test set of 17 chemicals that were not used to construct the model were evaluated, some of which utilized a short-term treatment in the presence of a metabolic activation system, and in 16 cases mode of action was correctly predicted. These initial results are encouraging as they suggest a machine learning strategy can be used to rapidly and reliably predict new chemicals' genotoxic mode of action based on data from an efficient and highly scalable multiplexed assay.
Collapse
|
30
|
Kirkland D, Kasper P, Martus HJ, Müller L, van Benthem J, Madia F, Corvi R. Updated recommended lists of genotoxic and non-genotoxic chemicals for assessment of the performance of new or improved genotoxicity tests. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2016; 795:7-30. [DOI: 10.1016/j.mrgentox.2015.10.006] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 10/27/2015] [Accepted: 10/28/2015] [Indexed: 01/09/2023]
|
31
|
Khoury L, Zalko D, Audebert M. Complementarity of phosphorylated histones H2AX and H3 quantification in different cell lines for genotoxicity screening. Arch Toxicol 2015; 90:1983-95. [PMID: 26404763 DOI: 10.1007/s00204-015-1599-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 09/10/2015] [Indexed: 12/20/2022]
Abstract
The in vitro micronucleus assay is broadly used, but is not per se able to discriminate aneugenic from clastogenic compounds, and cytotoxicity can be a confounding factor. In vitro genotoxicity assays generally rely on cell lines with limited metabolic capabilities. Recently, the use of histone H2AX and H3 phosphorylation markers (γH2AX and p-H3) was proposed to discriminate aneugenic from clastogenic chemicals. The aim of the present study was to develop a new genotoxic screening strategy based on the use of the γH2AX and p-H3 biomarkers in combination with cell lines with distinct biotransformation properties. First, we tested a training set of 20 model chemicals comprised of 10 aneugens, five clastogens and five cytotoxics on three human cell lines (HepG2, LS-174T and ACHN). Our data confirm the robustness of these two biomarkers to discriminate efficiently clastogens, aneugens and misleading cytotoxic chemicals in HepG2 cells. Aneugenic compounds induced either an increase or a decrease in p-H3 depending on their mode of action. Clastogens induced γH2AX, and cytotoxic compounds generated a marked decrease in these two biomarkers. Moreover, the use of different cell lines permits to discriminate direct from bioactivated genotoxins without the need of an exogenous metabolic activation system. Finally, we further evaluated this strategy using a test set of 13 chemicals with controversial genotoxic potential. The resulting data demonstrate that the combined analysis of γH2AX and p-H3 is an efficient strategy. Notably, we demonstrated that three compounds (fisetin, hydroquinone and okadaic acid) display both aneugenic and clastogenic properties.
Collapse
Affiliation(s)
- Laure Khoury
- INRA, UMR1331, Toxalim, Research Centre in Food Toxicology, 180 chemin de Tournefeuille, BP 93173, 31027, Toulouse Cedex 3, France.,Université de Toulouse, INPT, UPS, UMR1331, 31062, Toulouse, France
| | - Daniel Zalko
- INRA, UMR1331, Toxalim, Research Centre in Food Toxicology, 180 chemin de Tournefeuille, BP 93173, 31027, Toulouse Cedex 3, France.,Université de Toulouse, INPT, UPS, UMR1331, 31062, Toulouse, France
| | - Marc Audebert
- INRA, UMR1331, Toxalim, Research Centre in Food Toxicology, 180 chemin de Tournefeuille, BP 93173, 31027, Toulouse Cedex 3, France. .,Université de Toulouse, INPT, UPS, UMR1331, 31062, Toulouse, France.
| |
Collapse
|
32
|
Khoury L, Zalko D, Audebert M. Evaluation of four human cell lines with distinct biotransformation properties for genotoxic screening. Mutagenesis 2015; 31:83-96. [PMID: 26243742 DOI: 10.1093/mutage/gev058] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In a previous study, we validated an in vitro genotoxicity assay based on γH2AX quantification using the In-Cell Western (ICW) method in HepG2 cells. The assay demonstrated high sensitivity and specificity but failed to detect genotoxicity for few compounds that require specific metabolic bioactivation not sufficiently covered by HepG2 cells. The aim of the present study was to assess γH2AX ICW sensitivity using a broader range of genotoxic molecules with HepG2 cells and three additional human cell lines with distinct biotransformation properties: two cell lines expressing some phase I and II bioactivation capabilities (LS-174T and Hep3B), and one with poor general bioactivation properties (ACHN). We evaluated the four cell lines by testing 24 compounds recommended by European Centre for the Validation of Alternative Methods and a set of 24 additional chemicals with different mode of genotoxic action (MOA) (aneugenicity, DNA adducts formation, induction of oxidative stress), including some known to require specific cytochrome P450 metabolic bioactivation. Results for the 48 compounds tested showed that the γH2AX ICW assay was more sensitive with LS-174T and HepG2 cells than with Hep3B or ACHN cell lines. Among the 38 compounds tested with positive or equivocal carcinogenicity data, 36 (95%) showed a positive genotoxic response with the γH2AX ICW assay compared to only 27 (71%) using the Ames assay. We confirm that the γH2AX ICW assay on HepG2 cells, without an exogenous metabolic activation system, may be a suitable test to predict the in vivo genotoxicity of chemicals with different genotoxic MOA. Moreover, the use of the ACHN cell line in combination with LS-174T and HepG2 cells may permit in many cases to discriminate direct from bioactivated genotoxins. Overall, our results confirm the high sensitivity of the γH2AX ICW assay which, in turn, should reduce the number of animals used for genotoxicity assessment.
Collapse
Affiliation(s)
- Laure Khoury
- UMR1331, Toxalim, Research Centre in Food Toxicology, INRA, 180 chemin de Tournefeuille, F-31027 Toulouse, France and INPT, UPS, UMR1331, Université de Toulouse, 15 Rue des Lois, F-31062 Toulouse, France
| | - Daniel Zalko
- UMR1331, Toxalim, Research Centre in Food Toxicology, INRA, 180 chemin de Tournefeuille, F-31027 Toulouse, France and INPT, UPS, UMR1331, Université de Toulouse, 15 Rue des Lois, F-31062 Toulouse, France
| | - Marc Audebert
- UMR1331, Toxalim, Research Centre in Food Toxicology, INRA, 180 chemin de Tournefeuille, F-31027 Toulouse, France and INPT, UPS, UMR1331, Université de Toulouse, 15 Rue des Lois, F-31062 Toulouse, France
| |
Collapse
|
33
|
Garcia-Canton C, Errington G, Anadon A, Meredith C. Characterisation of an aerosol exposure system to evaluate the genotoxicity of whole mainstream cigarette smoke using the in vitro γH2AX assay by high content screening. BMC Pharmacol Toxicol 2014; 15:41. [PMID: 25056295 PMCID: PMC4122049 DOI: 10.1186/2050-6511-15-41] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 07/16/2014] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The genotoxic effect of cigarette smoke is routinely measured by treating cells with cigarette Particulate Matter (PM) at different dose levels in submerged cell cultures. However, PM exposure cannot be considered as a complete exposure as it does not contain the gas phase component of the cigarette smoke. The in vitro γH2AX assay by High Content Screening (HCS) has been suggested as a complementary tool to the standard battery of genotoxicity assays as it detects DNA double strand breaks in a high-throughput fashion. The aim of this study was to further optimise the in vitro γH2AX assay by HCS to enable aerosol exposure of human bronchial epithelial BEAS-2B cells at the air-liquid interface (ALI). METHODS Whole mainstream cigarette smoke (WMCS) from two reference cigarettes (3R4F and M4A) were assessed for their genotoxic potential. During the study, a further characterisation of the Borgwaldt RM20S® aerosol exposure system to include single dilution assessment with a reference gas was also carried out. RESULTS The results of the optimisation showed that both reference cigarettes produced a positive genotoxic response at all dilutions tested. However, the correlation between dose and response was low for both 3R4F and M4A (Pearson coefficient, r = -0.53 and -0.44 respectively). During the additional characterisation of the exposure system, it was observed that several pre-programmed dilutions did not perform as expected. CONCLUSIONS Overall, the in vitro γH2AX assay by HCS could be used to evaluate WMCS in cell cultures at the ALI. Additionally, the extended characterisation of the exposure system indicates that assessing the performance of the dilutions could improve the existing routine QC checks.
Collapse
Affiliation(s)
- Carolina Garcia-Canton
- British American Tobacco, Group Research and Development, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
- Department of Toxicology and Pharmacology, Universidad Complutense de Madrid, Madrid, Spain
| | - Graham Errington
- British American Tobacco, Group Research and Development, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| | - Arturo Anadon
- Department of Toxicology and Pharmacology, Universidad Complutense de Madrid, Madrid, Spain
| | - Clive Meredith
- British American Tobacco, Group Research and Development, Regents Park Road, Southampton, Hampshire SO15 8TL, UK
| |
Collapse
|
34
|
Gerić M, Gajski G, Garaj-Vrhovac V. γ-H2AX as a biomarker for DNA double-strand breaks in ecotoxicology. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2014; 105:13-21. [PMID: 24780228 DOI: 10.1016/j.ecoenv.2014.03.035] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 03/27/2014] [Accepted: 03/29/2014] [Indexed: 06/03/2023]
Abstract
The visualisation of DNA damage response proteins enables the indirect measurement of DNA damage. Soon after the occurrence of a DNA double-strand break (DSB), the formation of γ-H2AX histone variants is to be expected. This review is focused on the potential use of the γ-H2AX foci assay in assessing the genotoxicity of environmental contaminants including cytostatic pharmaceuticals, since standard methods may not be sensitive enough to detect the damaging effect of low environmental concentrations of such drugs. These compounds are constantly released into the environment, potentially representing a threat to water quality, aquatic organisms, and, ultimately, human health. Our review of the literature revealed that this method could be used in the biomonitoring and risk assessment of aquatic systems affected by wastewater from the production, usage, and disposal of cytostatic pharmaceuticals.
Collapse
Affiliation(s)
- Marko Gerić
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, 10000 Zagreb, Croatia
| | - Goran Gajski
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, 10000 Zagreb, Croatia
| | - Vera Garaj-Vrhovac
- Institute for Medical Research and Occupational Health, Ksaverska cesta 2, 10000 Zagreb, Croatia.
| |
Collapse
|
35
|
Garcia-Canton C, Anadon A, Meredith C. Genotoxicity evaluation of individual cigarette smoke toxicants using the in vitro γH2AX assay by high content screening. Toxicol Lett 2013; 223:81-7. [PMID: 24021168 DOI: 10.1016/j.toxlet.2013.08.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 08/29/2013] [Accepted: 08/31/2013] [Indexed: 01/01/2023]
Abstract
Cigarette smoke is a complex mixture consisting of more than 5600 identified chemical constituents of which approximately 150 have been identified so far as "tobacco smoke toxicants". Proposals made by the World Health Organisation Framework Convention on Tobacco Control mandate the lowering of nine tobacco smoke priority toxicants, including 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N-nitrosonornicotine (NNN), and benzo[a]pyrene (B[a]P) and monitoring the levels of a further nine including cadmium. Here, we evaluated the genotoxic potential in human bronchial epithelial BEAS-2B cells of four cigarette smoke toxicants; NNK, NNN, B[a]P and cadmium using the novel in vitro γH2AX assay by High Content Screening (HCS). We also examined the genotoxicity of binary mixtures of NNK and NNN reporting their relative contribution to the genotoxic end-point. The results of this preliminary assessment showed that the in vitro γH2AX assay by HCS could be used as a pre-screening tool to detect and quantify the genotoxicity effect of cigarette smoke toxicants individually and in binary mixture. Moreover, the data produced could contribute to the prioritisation of toxicant reduction research in modified tobacco products.
Collapse
Affiliation(s)
- Carolina Garcia-Canton
- British American Tobacco, Group Research and Development, Regents Park Road, Southampton, Hampshire SO15 8TL, United Kingdom; Department of Toxicology and Pharmacology, Universidad Complutense de Madrid, Madrid, Spain.
| | | | | |
Collapse
|