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Congenital Malformations in Sea Turtles: Puzzling Interplay between Genes and Environment. Animals (Basel) 2021; 11:ani11020444. [PMID: 33567785 PMCID: PMC7915190 DOI: 10.3390/ani11020444] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 12/28/2022] Open
Abstract
Simple Summary Congenital malformations can lead to embryonic mortality in many species, and sea turtles are no exception. Genetic and/or environmental alterations occur during early development in the embryo, and may produce aberrant phenotypes, many of which are incompatible with life. Causes of malformations are multifactorial; genetic factors may include mutations, chromosomal aberrations, and inbreeding effects, whereas non-genetic factors may include nutrition, hyperthermia, low moisture, radiation, and contamination. It is possible to monitor and control some of these factors (such as temperature and humidity) in nesting beaches, and toxic compounds in feeding areas, which can be transferred to the embryo through their lipophilic properties. In this review, we describe possible causes of different types of malformations observed in sea turtle embryos, as well as some actions that may help reduce embryonic mortality. Abstract The completion of embryonic development depends, in part, on the interplay between genetic factors and environmental conditions, and any alteration during development may affect embryonic genetic and epigenetic regulatory pathways leading to congenital malformations, which are mostly incompatible with life. Oviparous reptiles, such as sea turtles, that produce numerous eggs in a clutch that is buried on the beach provide an opportunity to study embryonic mortality associated with malformations that occur at different times during development, or that prevent the hatchling from emerging from the nest. In sea turtles, the presence of congenital malformations frequently leads to mortality. A few years ago, a detailed study was performed on external congenital malformations in three species of sea turtles from the Mexican Pacific and Caribbean coasts, the hawksbill turtle, Eretmochelys imbricata (n = 23,559 eggs), the green turtle, Chelonia mydas (n = 17,690 eggs), and the olive ridley, Lepidochelys olivacea (n = 20,257 eggs), finding 63 types of congenital malformations, of which 38 were new reports. Of the three species, the olive ridley showed a higher incidence of severe anomalies in the craniofacial region (49%), indicating alterations of early developmental pathways; however, several malformations were also observed in the body, including defects in the carapace (45%) and limbs (33%), as well as pigmentation disorders (20%), indicating that deviations occurred during the middle and later stages of development. Although intrinsic factors (i.e., genetic mutations or epigenetic modifications) are difficult to monitor in the field, some environmental factors (such as the incubation temperature, humidity, and probably the status of feeding areas) are, to some extent, less difficult to monitor and/or control. In this review, we describe the aetiology of different malformations observed in sea turtle embryos, and provide some actions that can reduce embryonic mortality.
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Cayir A. Environmental exposures and RNA N6-Methyladenosine modified long Non-Coding RNAs. Crit Rev Toxicol 2020; 50:641-649. [PMID: 32924714 DOI: 10.1080/10408444.2020.1812511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Recent advances in the field of RNA modifications and long non-coding RNAs (lncRNAs) have provided substantial evidence on important biological functions. LncRNAs are defined as longer than 200 nucleotides which are not translated into proteins. The term "epitranscriptome" refers to all modifications in RNA types. Adenine-6 methylation (m6A) is the most common, dynamic and prominent modifications in coding and non-coding RNAs and has critical and previously unappreciated functional roles. Accumulation evidence indicated the association between RNA m6A modification and cancer and nonmalignant diseases. Recent studies reported that several lncRNAs including MALAT1, MEG3, XIST, GAS5, and KCNK15-AS1 are subject to m6A modification. It can be suggested that lncRNAs modified by m6A modification have substantive roles in diseases. Currently limited data are available regarding how environmental exposure affects m6A-modified lncRNAs. Furthermore, we do not know the interaction of environmental exposure and m6A-modified lncRNAs in development of adverse human health outcomes. Thus, in this systematic review, we aimed to present the data of the studies that reported a significant association between environmental exposure and expression/DNA methylation of m6A-modified long non-coding RNAs.
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Affiliation(s)
- Akin Cayir
- Vocational Health College, Canakkale Onsekiz Mart University, Canakkale, Turkey
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3
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Fernández MN, Muñoz-Olivas R, Luque-Garcia JL. SILAC-based quantitative proteomics identifies size-dependent molecular mechanisms involved in silver nanoparticles-induced toxicity. Nanotoxicology 2019; 13:812-826. [DOI: 10.1080/17435390.2019.1579374] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- M. N. Fernández
- Faculty of Chemical Sciences, Department of Analytical Chemistry, Complutense University of Madrid, Madrid, Spain
| | - R. Muñoz-Olivas
- Faculty of Chemical Sciences, Department of Analytical Chemistry, Complutense University of Madrid, Madrid, Spain
| | - J. L. Luque-Garcia
- Faculty of Chemical Sciences, Department of Analytical Chemistry, Complutense University of Madrid, Madrid, Spain
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Genome-Wide Transcriptional and Functional Analysis of Human T Lymphocytes Treated with Benzo[ α]pyrene. Int J Mol Sci 2018; 19:ijms19113626. [PMID: 30453624 PMCID: PMC6274903 DOI: 10.3390/ijms19113626] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 11/16/2018] [Indexed: 12/28/2022] Open
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are widely distributed environmental contaminants, known to affect T lymphocytes. However, the molecular targets and pathways involved in their immunotoxic effects in human T lymphocytes remain unknown. Here, we analyzed the gene expression profile of primary human T lymphocytes treated with the prototypical PAH, benzo[α]pyrene (B[α]P), using a microarray-based transcriptome analysis. After a 48 h exposure to B[α]P, we identified 158 genes differentially expressed in T lymphocytes, including not only genes well-known to be affected by PAHs such as the cytochromes P450 (CYP) 1A1 and 1B1, but also others not previously shown to be targeted by B[α]P such as genes encoding the gap junction beta (GJB)-2 and 6 proteins. Functional enrichment analysis revealed that these candidates were significantly associated with the aryl hydrocarbon (AhR) and interferon (IFN) signaling pathways; a marked alteration in T lymphocyte recruitment was also observed. Using functional tests in transwell migration experiments, B[α]P was then shown to significantly decrease the chemokine (C-X-C motif) ligand 12-induced chemotaxis and transendothelial migration of T lymphocytes. In total, this study opens the way to unsuspected responsive pathway of interest, i.e., T lymphocyte migration, thus providing a more thorough understanding of the molecular basis of the immunotoxicity of PAHs.
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Biotin-mediated epigenetic modifications: Potential defense against the carcinogenicity of benzo[a]pyrene. Toxicol Lett 2016; 241:216-24. [DOI: 10.1016/j.toxlet.2015.11.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 11/03/2015] [Accepted: 11/08/2015] [Indexed: 12/16/2022]
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6
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Moffat I, Chepelev N, Labib S, Bourdon-Lacombe J, Kuo B, Buick JK, Lemieux F, Williams A, Halappanavar S, Malik A, Luijten M, Aubrecht J, Hyduke DR, Fornace AJ, Swartz CD, Recio L, Yauk CL. Comparison of toxicogenomics and traditional approaches to inform mode of action and points of departure in human health risk assessment of benzo[a]pyrene in drinking water. Crit Rev Toxicol 2015; 45:1-43. [PMID: 25605026 DOI: 10.3109/10408444.2014.973934] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Toxicogenomics is proposed to be a useful tool in human health risk assessment. However, a systematic comparison of traditional risk assessment approaches with those applying toxicogenomics has never been done. We conducted a case study to evaluate the utility of toxicogenomics in the risk assessment of benzo[a]pyrene (BaP), a well-studied carcinogen, for drinking water exposures. Our study was intended to compare methodologies, not to evaluate drinking water safety. We compared traditional (RA1), genomics-informed (RA2) and genomics-only (RA3) approaches. RA2 and RA3 applied toxicogenomics data from human cell cultures and mice exposed to BaP to determine if these data could provide insight into BaP's mode of action (MOA) and derive tissue-specific points of departure (POD). Our global gene expression analysis supported that BaP is genotoxic in mice and allowed the development of a detailed MOA. Toxicogenomics analysis in human lymphoblastoid TK6 cells demonstrated a high degree of consistency in perturbed pathways with animal tissues. Quantitatively, the PODs for traditional and transcriptional approaches were similar (liver 1.2 vs. 1.0 mg/kg-bw/day; lungs 0.8 vs. 3.7 mg/kg-bw/day; forestomach 0.5 vs. 7.4 mg/kg-bw/day). RA3, which applied toxicogenomics in the absence of apical toxicology data, demonstrates that this approach provides useful information in data-poor situations. Overall, our study supports the use of toxicogenomics as a relatively fast and cost-effective tool for hazard identification, preliminary evaluation of potential carcinogens, and carcinogenic potency, in addition to identifying current limitations and practical questions for future work.
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Affiliation(s)
- Ivy Moffat
- Water and Air Quality Bureau, Health Canada, Ottawa, ON, Canada.,Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Nikolai Chepelev
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Sarah Labib
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Julie Bourdon-Lacombe
- Water and Air Quality Bureau, Health Canada, Ottawa, ON, Canada.,Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Byron Kuo
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Julie K Buick
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - France Lemieux
- Water and Air Quality Bureau, Health Canada, Ottawa, ON, Canada
| | - Andrew Williams
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Sabina Halappanavar
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Amal Malik
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Mirjam Luijten
- National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | | | - Daniel R Hyduke
- Biological Engineering Department, Utah State University, Logan, UT, USA
| | - Albert J Fornace
- Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC, USA
| | - Carol D Swartz
- Integrated Laboratory Systems Inc., Research Triangle Park, NC, USA
| | - Leslie Recio
- Integrated Laboratory Systems Inc., Research Triangle Park, NC, USA
| | - Carole L Yauk
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
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Bausinger J, Speit G. DNA repair capacity of cultured human lymphocytes exposed to mutagens measured by the comet assay and array expression analysis. Mutagenesis 2015; 30:811-20. [DOI: 10.1093/mutage/gev040] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Wang X, Zhang J, Huang Q, Alamdar A, Tian M, Liu L, Shen H. Serum metabolomics analysis reveals impaired lipid metabolism in rats after oral exposure to benzo(a)pyrene. MOLECULAR BIOSYSTEMS 2015; 11:753-9. [DOI: 10.1039/c4mb00565a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
A metabolomics study was conducted to unveil the metabolic profiling of rats exposed to benzo(a)pyrene, and twelve differentiated metabolites were identified.
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Affiliation(s)
- Xiaoxue Wang
- Key Lab of Urban Environment and Health
- Institute of Urban Environment
- Chinese Academy of Sciences
- Xiamen
- P. R. China
| | - Jie Zhang
- Key Lab of Urban Environment and Health
- Institute of Urban Environment
- Chinese Academy of Sciences
- Xiamen
- P. R. China
| | - Qingyu Huang
- Key Lab of Urban Environment and Health
- Institute of Urban Environment
- Chinese Academy of Sciences
- Xiamen
- P. R. China
| | - Ambreen Alamdar
- Key Lab of Urban Environment and Health
- Institute of Urban Environment
- Chinese Academy of Sciences
- Xiamen
- P. R. China
| | - Meiping Tian
- Key Lab of Urban Environment and Health
- Institute of Urban Environment
- Chinese Academy of Sciences
- Xiamen
- P. R. China
| | - Liangpo Liu
- Key Lab of Urban Environment and Health
- Institute of Urban Environment
- Chinese Academy of Sciences
- Xiamen
- P. R. China
| | - Heqing Shen
- Key Lab of Urban Environment and Health
- Institute of Urban Environment
- Chinese Academy of Sciences
- Xiamen
- P. R. China
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Moreau M, Ouellet N, Ayotte P, Bouchard M. Effects of intravenous benzo[a]pyrene dose administration on levels of exposure biomarkers, DNA adducts, and gene expression in rats. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2015; 78:166-184. [PMID: 25506633 DOI: 10.1080/15287394.2014.954072] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The effects of benzo[a]pyrene (BaP) administration on biomarkers of exposure and early effects were studied in male Sprague-Dawley rats intravenously injected with doses of 0.4, 4, 10, or 40 μmol BaP/kg . Blood, tissues, and excreta were collected 8 and 24 h posttreatment. BaP and several of its metabolites were simultaneously measured in blood, tissues and excreta by ultra-high-performance liquid chromatography (UHPLC)/fluorescence. DNA adducts of BaP diol epoxide (BaPDE) in lungs were quantified using an ultrasensitive immunoassay with chemiluminescence detection. Expression of selected genes in lungs of treated rats (lung RNA) compared to control rats was also assessed by quantitative real-time polymerase chain reaction. There was a dose-dependent increase in blood, tissue, and excreted levels of BaP metabolites. At 8 and 24 h postinjection, BaP and hydroxyBaP were found in higher concentrations in blood and tissues compared to other analytes. However, diolBaP were excreted in greater amounts in urine and apparently more rapidly than hydroxyBaP. Mean percentages (± SD) of injected dose excreted in urine as 4,5-diolBaP during the 0-8 h and 0-24 h period posttreatment were 0.16 ± 0.027% and 0.14 ± 0.083%, respectively. Corresponding values for 3-OHBaP were 0.0045 ± 0.0009% and 0.026 ± 0.014%. BaP-diones were not detectable in blood, tissues, and excreta; 7,8-diolBaP and BaPtetrol were found to be minor metabolites. There was also a dose-dependent increase in DNA adduct formation in lung. Analysis of gene expression further showed a modulation of Cyp1a1, Cyp1b1, Nqo1, Nrf2, Fos, and Ahr expression at 10- and 40-μmol/kg doses, but not at the lower doses. This study provided a better assessment of the influence of absorbed BaP doses on biological levels of diolBaP and OHBaP exposure biomarkers and association of the latter with early biological alterations, such as DNA adducts and gene expression.
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Affiliation(s)
- Marjory Moreau
- a Department of Environmental and Occupational Health , Chair in Toxicological Risk Assessment and Management and Research Institute of Public Health of the University of Montreal (IRSPUM), University of Montreal , Montreal , Quebec , Canada
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Moreau M, Ayotte P, Bouchard M. Kinetics of Diol and Hydroxybenzo[a]pyrene Metabolites in Relation to DNA Adduct Formation and Gene Expression in Rats. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2015; 78:725-746. [PMID: 26090558 DOI: 10.1080/15287394.2015.1028119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Benzo[a]pyrene (BaP) is a human carcinogen, but there are no validated biomarkers of exposure and the relationship of carcinogenesis with early biological alterations is not fully documented. This study aimed at better documenting the toxicokinetics of diolBaP and hydroxyBaP metabolites as potential biomarkers of exposure to BaP in relation to DNA adduct formation and gene expression. Rats were intravenously (iv) injected with 40 μmol/kg BaP. BaP and several metabolites were measured in blood, tissues, and excreta collected at frequent intervals over 72 h posttreatment. BaP diol epoxide (BaPDE)-DNA adduct formation and gene expression were assessed in lungs. 3-HydroxyBaP (3-OHBaP) and 4,5-diolBaP were the most abundant measured metabolites, and differences in time courses were apparent between the two metabolites. Over the 0-72 h period, mean proportions of BaP dose recovered in urine as 3-OHBaP and 4,5-diolBaP (±SD) were 0.017 ± 0.003% and 0.1 ± 0.03%. Corresponding values in feces were 1.5 ± 0.5% and 0.42 ± 0.052%. BaPDE-DNA adducts were significantly increased in lungs and a correlation was observed with urinary 3-OHBaP and 4,5-diolBaP. Analysis of gene expression showed a modulation of expression of metabolic genes (Cyp1a1, Cyp1b1, Nqo1, Ahr) and oxidative stress and repair genes (Nrf2, Rad51). However, BaPDE adducts formation did not exhibit any significant correlation with expression of genes, except a negative correlation with Rad51 expression. Similarly, there was no significant correlation between urinary excretion of OHBaP and diolBaP and expression of genes, except for urinary 7-OHBaP excretion, which was negatively correlated with Rad51 expression. Results indicate that concomitant measurements of diolBaP and OHBaP may serve to better assess the extent of exposure as compared to single metabolite measurements, given kinetic differences between metabolites. Further, although some urinary metabolites were correlated with BaPDE adducts, links with gene expression need to be further investigated.
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Affiliation(s)
- Marjory Moreau
- a Department of Environmental and Occupational Health , Chair in Toxicological Risk Assessment and Management and the Research Institute of Public Health of the University of Montreal (IRSPUM), University of Montreal , Montreal , Quebec , Canada
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Fang X, Thornton C, Scheffler BE, Willett KL. Benzo[a]pyrene decreases global and gene specific DNA methylation during zebrafish development. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2013; 36:40-50. [PMID: 23542452 PMCID: PMC3654064 DOI: 10.1016/j.etap.2013.02.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 02/09/2013] [Indexed: 05/17/2023]
Abstract
DNA methylation is important for gene regulation and is vulnerable to early-life exposure to environmental contaminants. We found that direct waterborne benzo[a]pyrene (BaP) exposure at 24μg/L from 2.5 to 96hpf to zebrafish embryos significantly decreased global cytosine methylation by 44.8% and promoter methylation in vasa by 17%. Consequently, vasa expression was significantly increased by 33%. In contrast, BaP exposure at environmentally relevant concentrations did not change CpG island methylation or gene expression in cancer genes such as ras-association domain family member 1 (rassf1), telomerase reverse transcriptase (tert), c-jun, and c-myca. Similarly, BaP did not change gene expression of DNA methyltransferase 1 (dnmt1) and glycine N-methyltransferase (gnmt). While total DNMT activity was not affected, GNMT enzyme activity was moderately increased. In summary, BaP is an epigenetic modifier for global and gene specific DNA methylation status in zebrafish larvae.
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Affiliation(s)
- Xiefan Fang
- Department of Pharmacology and Environmental Toxicology Research Program, School of Pharmacy, University of Mississippi, University, MS 38677
| | - Cammi Thornton
- Department of Pharmacology and Environmental Toxicology Research Program, School of Pharmacy, University of Mississippi, University, MS 38677
| | - Brian E. Scheffler
- USDA-ARS Genomics and Bioinformatics Research Unit, Stoneville, MS 38776
| | - Kristine L. Willett
- Department of Pharmacology and Environmental Toxicology Research Program, School of Pharmacy, University of Mississippi, University, MS 38677
- Corresponding author Box 1848, 303 Faser Hall Department of Pharmacology University of Mississippi University, MS, 38677 Tel: (662) 915-6691 Fax: (662) 915-5148
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Ouedraogo M, Baudoux T, Stévigny C, Nortier J, Colet JM, Efferth T, Qu F, Zhou J, Chan K, Shaw D, Pelkonen O, Duez P. Review of current and "omics" methods for assessing the toxicity (genotoxicity, teratogenicity and nephrotoxicity) of herbal medicines and mushrooms. JOURNAL OF ETHNOPHARMACOLOGY 2012; 140:492-512. [PMID: 22386524 DOI: 10.1016/j.jep.2012.01.059] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 01/31/2012] [Accepted: 01/31/2012] [Indexed: 05/31/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The increasing use of traditional herbal medicines around the world requires more scientific evidence for their putative harmlessness. To this end, a plethora of methods exist, more or less satisfying. In this post-genome era, recent reviews are however scarce, not only on the use of new "omics" methods (transcriptomics, proteomics, metabonomics) for genotoxicity, teratogenicity, and nephrotoxicity assessment, but also on conventional ones. METHODS The present work aims (i) to review conventional methods used to assess genotoxicity, teratogenicity and nephrotoxicity of medicinal plants and mushrooms; (ii) to report recent progress in the use of "omics" technologies in this field; (iii) to underline advantages and limitations of promising methods; and lastly (iv) to suggest ways whereby the genotoxicity, teratogenicity, and nephrotoxicity assessment of traditional herbal medicines could be more predictive. RESULTS Literature and safety reports show that structural alerts, in silico and classical in vitro and in vivo predictive methods are often used. The current trend to develop "omics" technologies to assess genotoxicity, teratogenicity and nephrotoxicity is promising but most often relies on methods that are still not standardized and validated. CONCLUSION Hence, it is critical that toxicologists in industry, regulatory agencies and academic institutions develop a consensus, based on rigorous methods, about the reliability and interpretation of endpoints. It will also be important to regulate the integration of conventional methods for toxicity assessments with new "omics" technologies.
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Affiliation(s)
- Moustapha Ouedraogo
- Laboratory of Pharmacology and Toxicology, Health Sciences Faculty, University of Ouagadougou, 03 BP 7021 Ouagadougou 03, Burkina Faso. mustapha
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Zhu H, Fan Y, Shen J, Qi H, Shao J. Characterization of human DNA polymerase κ promoter in response to benzo[a]pyrene diol epoxide. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2012; 33:205-211. [PMID: 22227292 DOI: 10.1016/j.etap.2011.12.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 11/18/2011] [Accepted: 12/04/2011] [Indexed: 05/31/2023]
Abstract
DNA polymerase κ (Pol κ), a member of Y-family DNA polymerases, can synthesize DNA with moderate fidelity on undamaged DNAs and replicate accurately in vitro thymine glycol, 8-oxo-G and aromatic adducts such as benzo[a]pyrene diol epoxide (BPDE). However, few studies have been done on the transcriptional regulation of Pol κ. In this study, we predicted and cloned the promoter region of the human POLK gene. Through the analysis of deletion constructs of the POLK promoter, we demonstrated that the region -336/-141 contained repressing elements and the region -141/+226 contained positive regulatory elements for transcription of human Pol κ. Furthermore, quantitative RT-PCR showed that human POLK mRNA expression was dysregulated in FL cells treated by BPDE. The transcriptional activities of the POLK promoter regions -336/+437 and +20/+437 were significantly reduced by BPDE treatment, indicating that transcription factors in this two regions, such as HSF1, may regulate the transcription of human POLK gene in response to BPDE.
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MESH Headings
- 7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide/toxicity
- Base Sequence
- Binding Sites
- Carcinogens, Environmental/toxicity
- Cells, Cultured
- Cloning, Molecular
- Computational Biology
- DNA-Directed DNA Polymerase/genetics
- DNA-Directed DNA Polymerase/metabolism
- Epithelial Cells/enzymology
- Genes, Reporter
- Humans
- Luciferases, Firefly/genetics
- Molecular Sequence Data
- Promoter Regions, Genetic/drug effects
- RNA, Messenger/metabolism
- Real-Time Polymerase Chain Reaction
- Transcription, Genetic/drug effects
- Transfection
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Affiliation(s)
- Huifang Zhu
- Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou 310058, China
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Michaelson JJ, Trump S, Rudzok S, Gräbsch C, Madureira DJ, Dautel F, Mai J, Attinger S, Schirmer K, von Bergen M, Lehmann I, Beyer A. Transcriptional signatures of regulatory and toxic responses to benzo-[a]-pyrene exposure. BMC Genomics 2011; 12:502. [PMID: 21995607 PMCID: PMC3215681 DOI: 10.1186/1471-2164-12-502] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 10/13/2011] [Indexed: 01/01/2023] Open
Abstract
Background Small molecule ligands often have multiple effects on the transcriptional program of a cell: they trigger a receptor specific response and additional, indirect responses ("side effects"). Distinguishing those responses is important for understanding side effects of drugs and for elucidating molecular mechanisms of toxic chemicals. Results We explored this problem by exposing cells to the environmental contaminant benzo-[a]-pyrene (B[a]P). B[a]P exposure activates the aryl hydrocarbon receptor (Ahr) and causes toxic stress resulting in transcriptional changes that are not regulated through Ahr. We sought to distinguish these two types of responses based on a time course of expression changes measured after B[a]P exposure. Using Random Forest machine learning we classified 81 primary Ahr responders and 1,308 genes regulated as side effects. Subsequent weighted clustering gave further insight into the connection between expression pattern, mode of regulation, and biological function. Finally, the accuracy of the predictions was supported through extensive experimental validation. Conclusion Using a combination of machine learning followed by extensive experimental validation, we have further expanded the known catalog of genes regulated by the environmentally sensitive transcription factor Ahr. More broadly, this study presents a strategy for distinguishing receptor-dependent responses and side effects based on expression time courses.
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Affiliation(s)
- Jacob J Michaelson
- Cellular Networks and Systems Biology, Biotechnology Center, TU Dresden, Dresden, Germany
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Hendriks G, Atallah M, Raamsman M, Morolli B, van der Putten H, Jaadar H, Tijdens I, Esveldt-van Lange R, Mullenders L, van de Water B, Vrieling H. Sensitive DsRed fluorescence-based reporter cell systems for genotoxicity and oxidative stress assessment. Mutat Res 2011; 709-710:49-59. [PMID: 21382384 DOI: 10.1016/j.mrfmmm.2011.02.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 02/04/2011] [Accepted: 02/21/2011] [Indexed: 05/30/2023]
Abstract
Various in vitro test systems have been developed for genotoxic risk assessment in early drug development. However, these genotoxicity tests often show limited specificity, and provide limited insights into the mode of toxicity of the tested compounds. To identify genes that could serve as specific biomarkers for genotoxicity or oxidative stress, we exposed mouse embryonic stem (ES) cells to various genotoxic and oxidative stress-inducing compounds and performed genome-wide expression profiling. Differentially expressed genes were classified based on the fold-change of expression and their specificity for either genotoxic or oxidative stress. Promoter regions of four selected genes (Ephx1, Btg2, Cbr3 and Perp) were fused to a DsRed fluorescent reporter gene and stably integrated in mouse ES cells. Established stable reporter cell lines displayed significant induction of DsRed expression upon exposure to different classes of genotoxic and oxidative stress-inducing compounds. In contrast, exposure to non-genotoxic carcinogenic compounds did not induce DsRed expression even at cytotoxic doses. Expression of the Cbr3-DsRed reporter was more responsive to compounds that induce oxidative stress while the other three DsRed reporters reacted more specific to direct-acting genotoxic agents. Therefore, the differential response of the Btg2- and Cbr3-DsRed reporters can serve as indicator for the main action mechanism of genotoxic and oxidative stress-inducing compounds. In addition, we provide evidence that inhibition of DNA replication results in preferential activation of the Btg2-DsRed genotoxicity reporter. In conclusion, we have generated sensitive mouse ES cell reporter systems that allow detection of genotoxic and oxidative stress-inducing properties of chemical compounds and can be used in high-throughput assays.
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Affiliation(s)
- Giel Hendriks
- Department of Toxicogenetics, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
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16
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Wang Q, Jiang H, Fan Y, Huang X, Shen J, Qi H, Li Q, Lu X, Shao J. Phosphorylation of the α-subunit of the eukaryotic initiation factor-2 (eIF2α) alleviates benzo[a]pyrene-7,8-diol-9,10-epoxide induced cell cycle arrest and apoptosis in human cells. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2011; 31:18-24. [PMID: 21787665 DOI: 10.1016/j.etap.2010.08.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2010] [Accepted: 08/31/2010] [Indexed: 05/31/2023]
Abstract
Benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE) is a carcinogen causing bulky-adduct DNA damage and inducing extensive cell responses regulating cell cycle, cell survival and apoptosis. However, the mechanism of cellular responses to BPDE exposure is not fully understood. In this study, we demonstrated the involvement of the phosphorylation of the α-subunit of the eukaryotic initiation factor-2 (eIF2α) in the cellular response to BPDE exposure and addressed the role of eIF2α phosphorylation in the regulation of the cellular stress. Phosphorylation of eIF2α was induced in a normal human FL amnion epithelial cell line, and the expression of ATF4, a conserved downstream transcriptional factor of eIF2α phosphorylation, was up-regulated after BPDE exposure; however, the four known primary kinases for eIF2α phosphorylation (GCN2, HRI, PKR, and PERK) were not found activated. While BPDE induced severe cell cycle arrest and apoptosis and decreased cell viability in FL cells, salubrinal, a selective inhibitor of eIF2α dephosphorylation, maintained the eIF2α phosphorylation and attenuated cell cycle arrest and apoptosis and promoted cell survival. The findings reveal that when BPDE causes cellular damages, it induces eIF2α phosphorylation as well, which produces a pro-survival and anti-apoptotic effect to alleviate the cellular damages. Thus, the present study proposes a new cellular defensive mechanism during the environmental mutagen and carcinogen attack.
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Affiliation(s)
- Qiaoling Wang
- Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, 388 Yuhang Tang Road, Hangzhou 310058, PR China
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Lenglet G, David-Cordonnier MH. DNA-Destabilizing Agents as an Alternative Approach for Targeting DNA: Mechanisms of Action and Cellular Consequences. J Nucleic Acids 2010; 2010. [PMID: 20725618 PMCID: PMC2915751 DOI: 10.4061/2010/290935] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Revised: 05/27/2010] [Accepted: 06/03/2010] [Indexed: 01/06/2023] Open
Abstract
DNA targeting drugs represent a large proportion of the actual anticancer drug pharmacopeia, both in terms of drug brands and prescription volumes. Small DNA-interacting molecules share the ability of certain proteins to change the DNA helix's overall organization and geometrical orientation via tilt, roll, twist, slip, and flip effects. In this ocean of DNA-interacting compounds, most stabilize both DNA strands and very few display helix-destabilizing properties. These types of DNA-destabilizing effect are observed with certain mono- or bis-intercalators and DNA alkylating agents (some of which have been or are being developed as cancer drugs). The formation of locally destabilized DNA portions could interfere with protein/DNA recognition and potentially affect several crucial cellular processes, such as DNA repair, replication, and transcription. The present paper describes the molecular basis of DNA destabilization, the cellular impact on protein recognition, and DNA repair processes and the latter's relationships with antitumour efficacy.
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Affiliation(s)
- Gaëlle Lenglet
- INSERM U-837, Jean-Pierre Aubert Research Center (JPARC), Team 4 Molecular and Cellular Targeting for Cancer Treatment, Institute for Research on Cancer of Lille (IRCL), Lille F-59045, France
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18
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Dreij K, Rhrissorrakrai K, Gunsalus KC, Geacintov NE, Scicchitano DA. Benzo[a]pyrene diol epoxide stimulates an inflammatory response in normal human lung fibroblasts through a p53 and JNK mediated pathway. Carcinogenesis 2010; 31:1149-57. [PMID: 20382639 DOI: 10.1093/carcin/bgq073] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cellular responses to carcinogens are typically studied in transformed cell lines, which do not reflect the physiological status of normal tissues. To address this question, we have characterized the transcriptional program and cellular responses of human lung WI-38 fibroblasts upon exposure to the ultimate carcinogen benzo[a]pyrene diol epoxide (BPDE). In contrast to observations in cell lines, we find that BPDE treatment induces a strong inflammatory response in these normal fibroblasts. Whole-genome microarrays show induction of numerous inflammatory factors, including genes that encode interleukins (ILs), growth factors and enzymes related to prostaglandin synthesis and signaling. Real-time reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA) revealed a time- and dose-dependent-induced expression and production of cyclooxygenase 2, prostglandin E2 and IL1B, IL6 and IL8. In parallel, cell cycle progression and DNA repair processes were repressed, but DNA damage signaling was increased via p53-Ser15 phosphorylation and induced expression levels of GADD45A, CDKN1A, BTG2 and SESN1. Network analysis suggested that activator protein 1 transcription factors may link the cell cycle response and DNA damage signaling with the inflammatory stress-response in these cells. We confirmed this hypothesis by showing that p53-dependent signaling through c-jun N-terminal kinase (JNK) led to increased cJun-Ser63 phosphorylation and that inhibition of JNK-mediated cJun activation using p53- or JNK-specific inhibitors significantly reduced IL gene expression and subsequent production of IL8. This is the first demonstration that a strong inflammatory response is triggered in normal fibroblasts by BPDE and that this occurs through coordinated regulation with other cellular processes.
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Affiliation(s)
- Kristian Dreij
- Department of Biology, New York University, 1009 Silver Center, 100 Washington Square East, New York, NY 10003, USA
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19
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Lu X, Shao J, Li H, Yu Y. Temporal gene expression changes induced by a low concentration of benzo[a]pyrene diol epoxide in a normal human cell line. Mutat Res 2010; 684:74-80. [PMID: 20018196 DOI: 10.1016/j.mrfmmm.2009.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 11/30/2009] [Accepted: 12/09/2009] [Indexed: 05/28/2023]
Abstract
(+ or -)-anti-Benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE), which causes bulky-adduct DNA damage, is well-characterized as the ultimate carcinogen of benzo[a]pyrene (BaP). In this study, we have employed Affymetrix HG-U133 Plus 2.0 microarray and quantitative real-time RT-PCR methods to investigate a temporal transcriptomic response triggered by a low concentration (0.05 microM) of BPDE at 1, 10, and 22 h after exposure in normal human cells. The differential gene expression profiles at the three time points varied greatly, and generally reflected a cellular responsive process from initiation to progression and to recovery after the BPDE-caused damage. The dynamic regulation of the genes related with cell cycle progression and cell fate exhibited a tendency from inhibition to survival, which was accordant with the cell cycle arrest and cytotoxicity data induced by the low-dose BPDE exposure. In silico comparison of the genomic data revealed that BPDE and ultraviolet induced a panel of common transcriptional responses, which might be related with a series of similar molecular processes elicited by these two DNA-damaging agents. In conclusion, this whole-genome time-course study has identified a dynamically regulated transcriptional signature after low-dose BPDE exposure, which may help to understand the complex mechanisms of mutagenesis and carcinogenesis induced by BPDE.
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Affiliation(s)
- Xiangyun Lu
- Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou 310058, China
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Sparfel L, Pinel-Marie ML, Boize M, Koscielny S, Desmots S, Pery A, Fardel O. Transcriptional signature of human macrophages exposed to the environmental contaminant benzo(a)pyrene. Toxicol Sci 2010; 114:247-59. [PMID: 20064835 DOI: 10.1093/toxsci/kfq007] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are widely distributed immunotoxic and carcinogenic environmental contaminants, known to affect macrophages. In order to identify their molecular targets in such cells, we have analyzed gene expression profile of primary human macrophages treated by the prototypical PAH benzo(a)pyrene (BaP), using pangenomic oligonucleotides microarrays. Exposure of macrophages to BaP for 8 and 24 h resulted in 96 and 1100 genes, differentially expressed by at least a twofold change factor, respectively. Some of these targets, including the chemokine receptor CXCR5, the G protein-coupled receptor 35 (GPR35), and the Ras regulator RASAL1, have not been previously shown to be affected by PAHs, in contrast to others, such as interleukin-1beta and the aryl hydrocarbon receptor (AhR) repressor. These BaP-mediated gene regulations were fully validated by reverse transcription-quantitative polymerase chain reaction assays for some selected genes. Their bioinformatic analysis indicated that biological functions linked to immunity, inflammation, and cell death were among the most affected by BaP in human macrophages and that the AhR and p53 signaling pathways were the most significant canonical pathways activated by the PAH. AhR and p53 implications were moreover fully confirmed by the prevention of BaP-related upregulation of some selected target genes by AhR silencing or the use of pifithrin-alpha, an inhibitor of PAH bioactivation-related DNA damage/p53 pathways. Overall, these data, through identifying genes and signaling pathways targeted by PAHs in human macrophages, may contribute to better understand the molecular basis of the immunotoxicity of these environmental contaminants.
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Affiliation(s)
- Lydie Sparfel
- EA 4427 SeRAIC, Equipe Toxicité des hydrocarbures aromatiques polycycliques (labellisée par la Ligue Nationale contre le Cancer), Institut de Recherche en Santé, Environnement et Travail, Université de Rennes 1, 35043 Rennes, France.
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