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Klaunig JE, Bevan C, Gollapudi B. Assessment of the mode of action of perchloroethylene-induced mouse liver tumors. Toxicol Ind Health 2024; 40:272-291. [PMID: 38523547 DOI: 10.1177/07482337241240188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
Perchloroethylene (PCE) is used as a solvent and chemical intermediate. Following chronic inhalation exposure, PCE selectively induced liver tumors in mice. Understanding the mode of action (MOA) for PCE carcinogenesis in mice is important in defining its possible human cancer risk. The proposed MOA is based on the extensive examination of the peer-reviewed studies that have assessed the mouse liver effects of PCE and its major oxidative metabolite trichloroacetic acid (TCA). Similar to PCE, TCA has also been demonstrated to liver tumors selectively in mice following chronic exposure. The Key Events (KE) of the proposed PCE MOA involve oxidative metabolism of PCE to TCA [KE 1]; activation of the peroxisome proliferator-activated receptor alpha (PPARα) [KE 2]; alteration in hepatic gene expression including cell growth pathways [KE 3]; increase in cell proliferation [KE 4]; selective clonal expansion of hepatic preneoplastic foci [KE 5]; and formation of hepatic neoplasms [KE 6]. The scientific evidence supporting the PPARα MOA for PCE is strong and satisfies the requirements for a MOA analysis. The PPARα liver tumor MOA in rodents has been demonstrated not to occur in humans; thus, human liver cancer risk to PCE is not likely.
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Affiliation(s)
- James E Klaunig
- School of Public Health, Indiana University, Bloomington, IN, USA
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2
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Chen P, Li Y, Long Q, Zuo T, Zhang Z, Guo J, Xu D, Li K, Liu S, Li S, Yin J, Chang L, Kukic P, Liddell M, Tulum L, Carmichael P, Peng S, Li J, Zhang Q, Xu P. The phosphoproteome is a first responder in tiered cellular adaptation to chemical stress followed by proteomics and transcriptomics alteration. CHEMOSPHERE 2023; 344:140329. [PMID: 37783352 DOI: 10.1016/j.chemosphere.2023.140329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 09/20/2023] [Accepted: 09/28/2023] [Indexed: 10/04/2023]
Abstract
Next-generation risk assessment (NGRA) for environmental chemicals involves a weight of evidence (WoE) framework integrating a suite of new approach methodologies (NAMs) based on points of departure (PoD) obtained from in vitro assays. Among existing NAMs, the omic-based technologies are of particular importance based on the premise that any apical endpoint change indicative of impaired health must be underpinned by some alterations at the omics level, such as transcriptome, proteome, metabolome, epigenome and genome. Transcriptomic assay plays a leading role in providing relatively conservative PoDs compared with apical endpoints. However, it is unclear whether and how parameters measured with other omics techniques predict the cellular response to chemical perturbations, especially at exposure levels below the transcriptomically defined PoD. Multi-omics coverage may provide additional sensitive or confirmative biomarkers to complement and reduce the uncertainty in safety decisions made using targeted and transcriptomics assays. In the present study, we conducted multi-omics studies of transcriptomics, proteomics and phosphoproteomics on two prototype compounds, coumarin and 2,4-dichlorophenoxyacetic acid (2,4-D), with multiple chemical concentrations and time points, to understand the sensitivity of the three omics techniques in response to chemically-induced changes in HepG2. We demonstrated that, phosphoproteomics alterations occur not only earlier in time, but also more sensitive to lower concentrations than proteomics and transcriptomics when the HepG2 cells were exposed to various chemical treatments. The phosphoproteomics changes appear to approach maximum when the transcriptomics alterations begin to initiate. Therefore, it is proximal to the very early effects induced by chemical exposure. We concluded that phosphoproteomics can be utilized to provide a more complete coverage of chemical-induced cellular alteration and supplement transcriptomics-based health safety decision making.
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Affiliation(s)
- Peiru Chen
- State Key Laboratory of Proteomics, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Beijing Proteome Research Center, Institute of Lifeomics, Beijing, 102206, China; Hebei Province Key Lab of Research and Application on Microbial Diversity, College of Life Sciences, Hebei University, Baoding, 071002, China
| | - Yuan Li
- State Key Laboratory of Proteomics, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Beijing Proteome Research Center, Institute of Lifeomics, Beijing, 102206, China; Department of Biomedicine, Medical College, Guizhou University, Guiyang, 550025, China; Guizhou Provincial People's Hospital, Affiliated Hospital of Guizhou University, Guiyang, 550002, China
| | - Qi Long
- State Key Laboratory of Proteomics, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Beijing Proteome Research Center, Institute of Lifeomics, Beijing, 102206, China; School of Basic Medicine, Anhui Medical University, Hefei, 230032, China
| | - Tao Zuo
- State Key Laboratory of Proteomics, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Beijing Proteome Research Center, Institute of Lifeomics, Beijing, 102206, China
| | - Zhenpeng Zhang
- State Key Laboratory of Proteomics, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Beijing Proteome Research Center, Institute of Lifeomics, Beijing, 102206, China
| | - Jiabin Guo
- Evaluation and Research Centre for Toxicology, Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing, 100071, China
| | - Danyang Xu
- Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Kaixuan Li
- State Key Laboratory of Proteomics, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Beijing Proteome Research Center, Institute of Lifeomics, Beijing, 102206, China; Hebei Province Key Lab of Research and Application on Microbial Diversity, College of Life Sciences, Hebei University, Baoding, 071002, China
| | - Shu Liu
- State Key Laboratory of Proteomics, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Beijing Proteome Research Center, Institute of Lifeomics, Beijing, 102206, China
| | - Suzhen Li
- State Key Laboratory of Proteomics, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Beijing Proteome Research Center, Institute of Lifeomics, Beijing, 102206, China; School of Basic Medicine, Anhui Medical University, Hefei, 230032, China
| | - Jian Yin
- Evaluation and Research Centre for Toxicology, Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing, 100071, China
| | - Lei Chang
- State Key Laboratory of Proteomics, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Beijing Proteome Research Center, Institute of Lifeomics, Beijing, 102206, China
| | - Predrag Kukic
- Unilever Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire, MK44 1LQ, UK
| | - Mark Liddell
- Unilever Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire, MK44 1LQ, UK
| | - Liz Tulum
- Unilever Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire, MK44 1LQ, UK
| | - Paul Carmichael
- Unilever Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire, MK44 1LQ, UK
| | - Shuangqing Peng
- Evaluation and Research Centre for Toxicology, Institute of Disease Control and Prevention, Academy of Military Medical Sciences, Beijing, 100071, China
| | - Jin Li
- Unilever Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire, MK44 1LQ, UK.
| | - Qiang Zhang
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, USA, GA, 30322.
| | - Ping Xu
- State Key Laboratory of Proteomics, National Center for Protein Sciences (Beijing), Research Unit of Proteomics & Research and Development of New Drug of Chinese Academy of Medical Sciences, Beijing Proteome Research Center, Institute of Lifeomics, Beijing, 102206, China; Hebei Province Key Lab of Research and Application on Microbial Diversity, College of Life Sciences, Hebei University, Baoding, 071002, China; Department of Biomedicine, Medical College, Guizhou University, Guiyang, 550025, China; School of Basic Medicine, Anhui Medical University, Hefei, 230032, China; Program of Environmental Toxicology, School of Public Health, China Medical University, Shenyang, 110122, China.
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3
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Miao G, Wang Y, Wang B, Yu H, Liu J, Pan R, Zhou C, Ning J, Zheng Y, Zhang R, Jin X. Multi-omics analysis reveals hepatic lipid metabolism profiles and serum lipid biomarkers upon indoor relevant VOC exposure. ENVIRONMENT INTERNATIONAL 2023; 180:108221. [PMID: 37742460 DOI: 10.1016/j.envint.2023.108221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 08/01/2023] [Accepted: 09/18/2023] [Indexed: 09/26/2023]
Abstract
As a widespread indoor air pollutant, volatile organic compound (VOC) caused various adverse health effects, especial the damage to liver, which has become a growing public concern. However, the current toxic data are intrinsically restricted in the single or major VOC species. Limited knowledge is available regarding toxic effects, biomarkers and underlying mechanisms of real indoor VOC-caused liver damage. Herein, an indoor relevant VOC exposure model was established to evaluate the hepatic adverse outcomes. Machine learning and multi-omics approaches, including liver lipidomic, serum lipidomic and liver transcriptomic, were utilized to uncover the characteristics of liver damage, serum lipid biomarkers, and involved mechanism stimulated by VOC exposure. The result showed that indoor relevant VOC led to the abnormal hepatic lipid metabolism, mainly manifested as a decrease in triacylglycerol (TG) and its precursor substance diacylglycerol (DG), which could be contributed to the occurrence of hepatic adverse outcomes. In terms of serum lipid biomarkers, five lipid biomarkers in serum were uncovered using machine learning to reflect the hepatic lipid disorders induced by VOC. Multi-omics approaches revealed that the upregulated Dgkq disturbed the interconversion of DG and phosphatidic acid (PA), leading to a TG downregulation. The in-depth analysis revealed that VOC down-regulated FoxO transcription factor, contributing to the upregulation of Dgkq. Hence, this study can provide valuable insights into the understanding of liver damage caused by indoor relevant VOC exposure model VOC exposure, from the perspective of multi-omics analysis.
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Affiliation(s)
- Gan Miao
- Department of Occupational Health and Environmental Health, School of Public Health, Qingdao University, Qingdao, China
| | - Yu Wang
- Department of Occupational Health and Environmental Health, School of Public Health, Qingdao University, Qingdao, China
| | - Baoqiang Wang
- Department of Occupational Health and Environmental Health, School of Public Health, Qingdao University, Qingdao, China
| | - Hongyan Yu
- Department of Occupational Health and Environmental Health, School of Public Health, Qingdao University, Qingdao, China
| | - Jing Liu
- Department of Occupational Health and Environmental Health, School of Public Health, Qingdao University, Qingdao, China
| | - Ruonan Pan
- Department of Occupational Health and Environmental Health, School of Public Health, Qingdao University, Qingdao, China
| | - Chengying Zhou
- Department of Occupational Health and Environmental Health, School of Public Health, Qingdao University, Qingdao, China
| | - Jie Ning
- Department of Toxicology, School of Public Health, Hebei Medical University, Shijiazhuang, China
| | - Yuxin Zheng
- Department of Occupational Health and Environmental Health, School of Public Health, Qingdao University, Qingdao, China
| | - Rong Zhang
- Department of Toxicology, School of Public Health, Hebei Medical University, Shijiazhuang, China.
| | - Xiaoting Jin
- Department of Occupational Health and Environmental Health, School of Public Health, Qingdao University, Qingdao, China.
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Martin R, Hazemi M, Flynn K, Villeneuve D, Wehmas L. Short-Term Transcriptomic Points of Departure Are Consistent with Chronic Points of Departure for Three Organophosphate Pesticides across Mouse and Fathead Minnow. TOXICS 2023; 11:820. [PMID: 37888672 PMCID: PMC10611195 DOI: 10.3390/toxics11100820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 09/20/2023] [Accepted: 09/22/2023] [Indexed: 10/28/2023]
Abstract
New approach methods (NAMs) can reduce the need for chronic animal studies. Here, we apply benchmark dose (concentration) (BMD(C))-response modeling to transcriptomic changes in the liver of mice and in fathead minnow larvae after short-term exposures (7 days and 1 day, respectively) to several dose/concentrations of three organophosphate pesticides (OPPs): fenthion, methidathion, and parathion. The mouse liver transcriptional points of departure (TPODs) for fenthion, methidathion, and parathion were 0.009, 0.093, and 0.046 mg/Kg-bw/day, while the fathead minnow larva TPODs were 0.007, 0.115, and 0.046 mg/L, respectively. The TPODs were consistent across both species and reflected the relative potencies from traditional chronic toxicity studies with fenthion identified as the most potent. Moreover, the mouse liver TPODs were more sensitive than or within a 10-fold difference from the chronic apical points of departure (APODs) for mammals, while the fathead minnow larva TPODs were within an 18-fold difference from the chronic APODs for fish species. Short-term exposure to OPPs significantly impacted acetylcholinesterase mRNA abundance (FDR p-value <0.05, |fold change| ≥2) and canonical pathways (IPA, p-value <0.05) associated with organism death and neurological/immune dysfunctions, indicating the conservation of key events related to OPP toxicity. Together, these results build confidence in using short-term, molecular-based assays for the characterization of chemical toxicity and risk, thereby reducing reliance on chronic animal studies.
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Affiliation(s)
- Rubia Martin
- Office of Research and Development, Center for Computational Toxicology and Exposure, Chemical Characterization and Exposure Division, Oak Ridge Institute for Science and Education, U.S. Environmental Protection Agency, Durham, NC 27709, USA;
| | - Monique Hazemi
- Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Ecology Division, Oak Ridge Institute for Science and Education, U.S. Environmental Protection Agency, Duluth, MN 55804, USA;
| | - Kevin Flynn
- Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Ecology Division, U.S. Environmental Protection Agency, Duluth, MN 55804, USA; (K.F.); (D.V.)
| | - Daniel Villeneuve
- Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Ecology Division, U.S. Environmental Protection Agency, Duluth, MN 55804, USA; (K.F.); (D.V.)
| | - Leah Wehmas
- Office of Research and Development, Center for Computational Toxicology and Exposure, Chemical Characterization and Exposure Division, U.S. Environmental Protection Agency, Durham, NC 27709, USA
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Beal MA, Everett LJ. Editorial: In vitro toxicogenomics (TGx) in hazard and risk assessment. FRONTIERS IN TOXICOLOGY 2023; 5:1284932. [PMID: 37736263 PMCID: PMC10509358 DOI: 10.3389/ftox.2023.1284932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 08/30/2023] [Indexed: 09/23/2023] Open
Affiliation(s)
- Marc A. Beal
- Bureau of Chemical Safety, Health Products and Food Branch, Health Canada, Ottawa, ON, Canada
| | - Logan J. Everett
- Biomolecular and Computational Toxicology Division, Center for Computational Toxicology and Exposure, Office of Research and Development, US Environmental Protection Agency, Durham, NC, United States
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Ewald JD, Basu N, Crump D, Boulanger E, Head J. Characterizing Variability and Uncertainty Associated with Transcriptomic Dose-Response Modeling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:15960-15968. [PMID: 36268973 DOI: 10.1021/acs.est.2c04665] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Transcriptomics dose-response analysis (TDRA) has emerged as a promising approach for integrating toxicogenomics data into a risk assessment context; however, variability and uncertainty associated with experimental design are not well understood. Here, we evaluated n = 55 RNA-seq profiles derived from Japanese quail liver tissue following exposure to chlorpyrifos (0, 0.04, 0.1, 0.2, 0.4, 1, 2, 4, 10, 20, and 40 μg/g; n = 5 replicates per group) via egg injection. The full dataset was subsampled 637 times to generate smaller datasets with different dose ranges and spacing (designs A-E) and number of replicates (n = 2-5). TDRA of the 637 datasets revealed substantial variability in the gene and pathway benchmark doses, but relative stability in overall transcriptomic point-of-departure (tPOD) values when tPODs were calculated with the "pathway" and "mode" methods. Further, we found that tPOD values were more dependent on the dose range and spacing than on the number of replicates, suggesting that optimal experimental designs should use fewer replicates (n = 2 or 3) and more dose groups to reduce uncertainty in the results. Finally, tPOD values ranged by over ten times for all surveyed experimental designs and tPOD types, suggesting that tPODs should be interpreted as order-of-magnitude estimates.
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Affiliation(s)
- Jessica D Ewald
- Faculty of Agricultural and Environmental Sciences, McGill University, Ste-Anne-de-Bellevue H9X 3V9, Canada
| | - Niladri Basu
- Faculty of Agricultural and Environmental Sciences, McGill University, Ste-Anne-de-Bellevue H9X 3V9, Canada
| | - Doug Crump
- Ecotoxicology and Wildlife Health Division, National Wildlife Research Centre, Environment and Climate Change Canada, Ottawa K1A 0H3, Canada
| | - Emily Boulanger
- Faculty of Agricultural and Environmental Sciences, McGill University, Ste-Anne-de-Bellevue H9X 3V9, Canada
| | - Jessica Head
- Faculty of Agricultural and Environmental Sciences, McGill University, Ste-Anne-de-Bellevue H9X 3V9, Canada
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Zhang JX, Xu QY, Yang Y, Li N, Zhang Y, Deng LH, Zhu QX, Shen T. Kupffer cell inactivation ameliorates immune liver injury via TNF-α/TNFR1 signal pathway in trichloroethylene sensitized mice. Immunopharmacol Immunotoxicol 2020; 42:545-555. [PMID: 32811237 DOI: 10.1080/08923973.2020.1811306] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
METHODS 36 female BALB/c mice were selected and randomly divided the mice into four groups. We established a BALB/c mouse model of TCE sensitization and pretreatment with GdCl3 (40 mg/kg) by intraperitoneal injection during the during the 17th and 19th days. RESULTS We found F4/80, the marker of Kupffer cell, was increased in TCE positive group. GdCl3 treatment successfully blocked the activation of Kupffer cell. TNF-α was increased significantly in liver of TCE sensitized mice and decreased significantly when low-dose GdCl3 was used. We found TNF receptor 1 (TNFR1) was increased significantly and GdCl3 treatment resumed the expression of TNFR1 to normal level, as well as the F4/80, TNF-α and TNFR1 mRNA. We also found both caspase-8 and caspase-3 increased in TCE positive group and decreased in TCE + GdCl3 positive group. The number of apoptotic cells in TCE sensitized mice increased by TUNEL staining, and GdCl3 treatment alleviated this increase. Some cells showed edema and inflammatory cell aggregation in liver of TCE positive group, while in the TCE + GdCl3 positive group, the cytoplasm became loose and vacuole-like degeneration occurred. CONCLUSION Our study unveils cross-talk between Kupffer cell activation and TNFR1 which mediate apoptosis in liver of TCE sensitized mice.
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Affiliation(s)
- Jia-Xiang Zhang
- Department of Occupational Health and Environment Health, School of Public Health, Anhui Medical University, Hefei, Anhui, PR China.,Ministry of Education, Key Laboratory of Dermatology, Anhui Medical University, Hefei, Anhui, China
| | - Qiong-Ying Xu
- Department of Occupational Health and Environment Health, School of Public Health, Anhui Medical University, Hefei, Anhui, PR China
| | - Yi Yang
- Department of Occupational Health and Environment Health, School of Public Health, Anhui Medical University, Hefei, Anhui, PR China
| | - Na Li
- Department of Occupational Health and Environment Health, School of Public Health, Anhui Medical University, Hefei, Anhui, PR China
| | - Yan Zhang
- Department of Occupational Health and Environment Health, School of Public Health, Anhui Medical University, Hefei, Anhui, PR China
| | - Li-Hua Deng
- Shenzhen Prevention and Treatment Center for Occupational Disease, Shenzhen, Guangdong, PR China
| | - Qi-Xing Zhu
- Ministry of Education, Key Laboratory of Dermatology, Anhui Medical University, Hefei, Anhui, China.,Department of Dermatology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, PR China
| | - Tong Shen
- Department of Occupational Health and Environment Health, School of Public Health, Anhui Medical University, Hefei, Anhui, PR China.,Ministry of Education, Key Laboratory of Dermatology, Anhui Medical University, Hefei, Anhui, China
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Johnson KJ, Auerbach SS, Costa E. A Rat Liver Transcriptomic Point of Departure Predicts a Prospective Liver or Non-liver Apical Point of Departure. Toxicol Sci 2020; 176:86-102. [PMID: 32384157 PMCID: PMC7357187 DOI: 10.1093/toxsci/kfaa062] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Identifying a toxicity point of departure (POD) is a required step in human health risk characterization of crop protection molecules, and this POD has historically been derived from apical endpoints across a battery of animal-based toxicology studies. Using rat transcriptome and apical data for 79 molecules obtained from Open TG-GATES (Toxicogenomics Project-Genomics Assisted Toxicity Evaluation System) (632 datasets), the hypothesis was tested that a short-term exposure, transcriptome-based liver biological effect POD (BEPOD) could estimate a longer-term exposure "systemic" apical endpoint POD. Apical endpoints considered were body weight, clinical observation, kidney weight and histopathology and liver weight and histopathology. A BMDExpress algorithm using Gene Ontology Biological Process gene sets was optimized to derive a liver BEPOD most predictive of a systemic apical POD. Liver BEPODs were stable from 3 h to 29 days of exposure; the median fold difference of the 29-day BEPOD to BEPODs from earlier time points was approximately 1 (range: 0.7-1.1). Strong positive correlation (Pearson R = 0.86) and predictive accuracy (root mean square difference = 0.41) were observed between a concurrent (29 days) liver BEPOD and the systemic apical POD. Similar Pearson R and root mean square difference values were observed for comparisons between a 29-day systemic apical POD and liver BEPODs derived from 3 h to 15 days of exposure. These data across 79 molecules suggest that a longer-term exposure study apical POD from liver and non-liver compartments can be estimated using a liver BEPOD derived from an acute or subacute exposure study.
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Affiliation(s)
- Kamin J Johnson
- Predictive Safety Center, Corteva Agriscience, Indianapolis, Indiana
| | - Scott S Auerbach
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
| | - Eduardo Costa
- Data Science and Informatics, Corteva Agriscience, Mogi Mirim, Sao Paulo, Brazil
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9
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LaRocca J, Costa E, Sriram S, Hannas BR, Johnson KJ. Short-term toxicogenomics as an alternative approach to chronic in vivo studies for derivation of points of departure: A case study in the rat with a triazole fungicide. Regul Toxicol Pharmacol 2020; 113:104655. [PMID: 32268158 DOI: 10.1016/j.yrtph.2020.104655] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 03/30/2020] [Accepted: 04/02/2020] [Indexed: 01/17/2023]
Abstract
The derivation of an apical endpoint point of departure (POD) from animal-intensive testing programs has been the traditional cornerstone of human health risk assessment. Replacement of in vivo chronic studies with novel approaches, such as toxicogenomics, holds promise for future alternative testing paradigms that significantly reduce animal testing. We hypothesized that a toxicogenomic POD following a 14 day exposure in the rat would approximate the most sensitive apical endpoint POD derived from a battery of chronic, carcinogenicity, reproduction and endocrine guideline toxicity studies. To test this hypothesis, we utilized myclobutanil, a triazole fungicide, as a model compound. In the 14 day study, male rats were administered 0 (vehicle), 30, 150, or 400 mg/kg/day myclobutanil via oral gavage. Endpoints evaluated included traditional apical, hormone, and liver and testis transcriptomic (whole genome RNA sequencing) data. From the transcriptomic data, liver and testis biological effect POD (BEPOD) values were derived. Myclobutanil exposure for 14 days resulted in increased liver weight, altered serum hormones, liver histopathology, and differential gene expression in liver and testis. The liver and testis BEPODs from the short-term study were 22.2 and 25.4 mg/kg/day, respectively. These BEPODs were approximately an order of magnitude higher than the most sensitive apical POD identified from the two year cancer bioassay based on testis atrophy (1.4 mg/kg/day). This study demonstrates the promise of using a short-term study BEPOD to derive a POD for human health risk assessment while substantially reducing animal testing.
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10
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Nault R, Bals B, Teymouri F, Black MB, Andersen ME, McMullen PD, Krishnan S, Kuravadi N, Paul N, Kumar S, Kannan K, Jayachandra KC, Alagappan L, Patel BD, Bogen KT, Gollapudi BB, Klaunig JE, Zacharewski TR, Bringi V. A toxicogenomic approach for the risk assessment of the food contaminant acetamide. Toxicol Appl Pharmacol 2020; 388:114872. [PMID: 31881176 PMCID: PMC7014822 DOI: 10.1016/j.taap.2019.114872] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 12/10/2019] [Accepted: 12/20/2019] [Indexed: 12/26/2022]
Abstract
Acetamide (CAS 60-35-5) is detected in common foods. Chronic rodent bioassays led to its classification as a group 2B possible human carcinogen due to the induction of liver tumors in rats. We used a toxicogenomics approach in Wistar rats gavaged daily for 7 or 28 days at doses of 300 to 1500 mg/kg/day (mkd) to determine a point of departure (POD) and investigate its mode of action (MoA). Ki67 labeling was increased at doses ≥750 mkd up to 3.3-fold representing the most sensitive apical endpoint. Differential gene expression analysis by RNA-Seq identified 1110 and 1814 differentially expressed genes in male and female rats, respectively, following 28 days of treatment. Down-regulated genes were associated with lipid metabolism while up-regulated genes included cell signaling, immune response, and cell cycle functions. Benchmark dose (BMD) modeling of the Ki67 labeling index determined the BMD10 lower confidence limit (BMDL10) as 190 mkd. Transcriptional BMD modeling revealed excellent concordance between transcriptional POD and apical endpoints. Collectively, these results indicate that acetamide is most likely acting through a mitogenic MoA, though specific key initiating molecular events could not be elucidated. A POD value of 190 mkd determined for cell proliferation is suggested for risk assessment purposes.
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Affiliation(s)
- Rance Nault
- Institute for Integrative Toxicology, Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, United States of America
| | - Bryan Bals
- Michigan Biotechnology Institute, Lansing, MI, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Tim R Zacharewski
- Institute for Integrative Toxicology, Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, United States of America
| | - Venkataraman Bringi
- Chemical Engineering & Materials Science, Michigan State University, East Lansing, MI, USA.
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Wang G, Wakamiya M, Wang J, Ansari GAS, Khan MF. Cytochrome P450 2E1-deficient MRL+/+ mice are less susceptible to trichloroethene-mediated autoimmunity: Involvement of oxidative stress-responsive signaling pathways. Free Radic Biol Med 2019; 143:324-330. [PMID: 31446053 PMCID: PMC6848790 DOI: 10.1016/j.freeradbiomed.2019.08.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 08/15/2019] [Accepted: 08/21/2019] [Indexed: 01/08/2023]
Abstract
Reactive trichloroethene (TCE) metabolites and oxidative stress are involved in TCE-mediated autoimmunity, as evident from our earlier studies in MRL+/+ mice. However, molecular mechanisms underlying the autoimmunity remain largely unknown. Cytochrome P450 2E1 (CYP2E1), the major enzyme responsible for TCE metabolism, could contribute to TCE-induced toxic response through free radical generation. The current study was, therefore, aimed to further evaluate the significance of TCE metabolism leading to oxidative stress and autoimmune response by using MRL+/+ mice that lack CYP2E1. The Cyp2e1-null MRL+/+ mice were generated by backcrossing Cyp2e1-null mice (B6N; 129S4-Cyp2e1) to MRL +/+ mice. Female MRL+/+ and Cyp2e1-null MRL+/+ mice were given TCE (10 mmol/kg, i.p., every 4th day) for 6 weeks; their respective controls received corn oil only. TCE treatment in MRL+/+ mice induced oxidative stress, evident from significantly increased serum malondiadelhyde (MDA)-protein adducts, their antibodies and reduced liver GSH levels. TCE treatment also modulated Nrf2 pathway with decreased Nrf2 and HO-1, and elevated NF-κB (p65) expression in the liver. TCE exposure also led to increases in serum antinuclear antibodies (ANA) and anti-double stranded DNA antibodies (anti-dsDNA). Although TCE treatment in Cyp2e1-null MRL+/+ mice also led to increases in serum MDA-protein adducts and their antibodies, changes in liver GSH, Nrf2, HO-1 and NF-κB along with increases in serum ANA, anti-dsDNA, the alterations in the oxidative stress and autoimmunity markers in these mice were less pronounced compared to those in MRL+/+ mice. These findings support the contribution of CYP2E1-mediated TCE metabolism in autoimmune response and an important role of Nrf2 pathway in TCE-mediated autoimmunity.
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Affiliation(s)
- Gangduo Wang
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Maki Wakamiya
- Institute for Translational Sciences and Animal Resource Center, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - Jianling Wang
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - G A Shakeel Ansari
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, 77555, USA
| | - M Firoze Khan
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, 77555, USA.
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12
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The use of evidence from high-throughput screening and transcriptomic data in human health risk assessments. Toxicol Appl Pharmacol 2019; 380:114706. [DOI: 10.1016/j.taap.2019.114706] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 07/31/2019] [Accepted: 08/06/2019] [Indexed: 12/23/2022]
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13
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Wahlang B, Jin J, Beier JI, Hardesty JE, Daly EF, Schnegelberger RD, Falkner KC, Prough RA, Kirpich IA, Cave MC. Mechanisms of Environmental Contributions to Fatty Liver Disease. Curr Environ Health Rep 2019; 6:80-94. [PMID: 31134516 PMCID: PMC6698418 DOI: 10.1007/s40572-019-00232-w] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE Fatty liver disease (FLD) affects over 25% of the global population and may lead to liver-related mortality due to cirrhosis and liver cancer. FLD caused by occupational and environmental chemical exposures is termed "toxicant-associated steatohepatitis" (TASH). The current review addresses the scientific progress made in the mechanistic understanding of TASH since its initial description in 2010. RECENT FINDINGS Recently discovered modes of actions for volatile organic compounds and persistent organic pollutants include the following: (i) the endocrine-, metabolism-, and signaling-disrupting chemical hypotheses; (ii) chemical-nutrient interactions and the "two-hit" hypothesis. These key hypotheses were then reviewed in the context of the steatosis adverse outcome pathway (AOP) proposed by the US Environmental Protection Agency. The conceptual understanding of the contribution of environmental exposures to FLD has progressed significantly. However, because this is a new research area, more studies including mechanistic human data are required to address current knowledge gaps.
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Affiliation(s)
- Banrida Wahlang
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Louisville School of Medicine, Louisville, KY, 40202, USA
- University of Louisville Superfund Research Center, University of Louisville, Louisville, KY, 40202, USA
| | - Jian Jin
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Juliane I Beier
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Pittsburgh, Pittsburgh, PA, 15213, USA
- Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Josiah E Hardesty
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Erica F Daly
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Regina D Schnegelberger
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - K Cameron Falkner
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Russell A Prough
- Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, Louisville, KY, 40202, USA
| | - Irina A Kirpich
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Louisville School of Medicine, Louisville, KY, 40202, USA
- Hepatobiology & Toxicology COBRE Center, University of Louisville School of Medicine, Louisville, KY, 40202, USA
- University of Louisville Alcohol Research Center, University of Louisville, Louisville, KY, 40202, USA
| | - Matthew C Cave
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Louisville School of Medicine, Louisville, KY, 40202, USA.
- University of Louisville Superfund Research Center, University of Louisville, Louisville, KY, 40202, USA.
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, 40202, USA.
- Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, Louisville, KY, 40202, USA.
- Hepatobiology & Toxicology COBRE Center, University of Louisville School of Medicine, Louisville, KY, 40202, USA.
- University of Louisville Alcohol Research Center, University of Louisville, Louisville, KY, 40202, USA.
- The Robley Rex Veterans Affairs Medical Center, Louisville, KY, 40206, USA.
- The Jewish Hospital Liver Transplant Program, Louisville, KY, 40202, USA.
- Kosair Charities Clinical & Translational Research Building, 505 South Hancock Street, Louisville, KY, 40202, USA.
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14
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Luo YS, Furuya S, Soldatov VY, Kosyk O, Yoo HS, Fukushima H, Lewis L, Iwata Y, Rusyn I. Metabolism and Toxicity of Trichloroethylene and Tetrachloroethylene in Cytochrome P450 2E1 Knockout and Humanized Transgenic Mice. Toxicol Sci 2019; 164:489-500. [PMID: 29897530 DOI: 10.1093/toxsci/kfy099] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Trichloroethylene (TCE) and tetrachloroethylene (PCE) are structurally similar olefins that can cause liver and kidney toxicity. Adverse effects of these chemicals are associated with metabolism to oxidative and glutathione conjugation moieties. It is thought that CYP2E1 is crucial to the oxidative metabolism of TCE and PCE, and may also play a role in formation of nephrotoxic metabolites; however, inter-species and inter-individual differences in contribution of CYP2E1 to metabolism and toxicity are not well understood. Therefore, the role of CYP2E1 in metabolism and toxic effects of TCE and PCE was investigated using male and female wild-type [129S1/SvlmJ], Cyp2e1(-/-), and humanized Cyp2e1 [hCYP2E1] mice. To fill in existing gaps in our knowledge, we conducted a toxicokinetic study of TCE (600 mg/kg, single dose, i.g.) and a subacute study of PCE (500 mg/kg/day, 5 days, i.g.) in 3 strains. Liver and kidney tissues were subject to profiling of oxidative and glutathione conjugation metabolites of TCE and PCE, as well as toxicity endpoints. The amounts of trichloroacetic acid formed in the liver was hCYP2E1≈ 129S1/SvlmJ > Cyp2e1(-/-) for both TCE and PCE; levels in males were about 2-fold higher than in females. Interestingly, 2- to 3-fold higher levels of conjugation metabolites were observed in TCE-treated Cyp2e1(-/-) mice. PCE induced lipid accumulation only in liver of 129S1/SvlmJ mice. In the kidney, PCE exposure resulted in acute proximal tubule injury in both sexes in all strains (hCYP2E1 ≈ 129S1/SvlmJ > Cyp2e1(-/-)). In conclusion, our results demonstrate that CYP2E1 is an important, but not exclusive actor in the oxidative metabolism and toxicity of TCE and PCE.
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Affiliation(s)
- Yu-Syuan Luo
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843
| | - Shinji Furuya
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843
| | - Valerie Y Soldatov
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Oksana Kosyk
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Hong Sik Yoo
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Hisataka Fukushima
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843
| | - Lauren Lewis
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843
| | - Yasuhiro Iwata
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843
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15
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Lang AL, Beier JI. Interaction of volatile organic compounds and underlying liver disease: a new paradigm for risk. Biol Chem 2019; 399:1237-1248. [PMID: 29924722 DOI: 10.1515/hsz-2017-0324] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 06/14/2018] [Indexed: 01/07/2023]
Abstract
Occupational and environmental exposures to industrial chemicals are known to cause hepatotoxicity and liver injury, in humans and in animal models. Historically, research has focused on severe acute liver injury (e.g. fulminant liver failure) or endstage diseases (e.g. cirrhosis and HCC). However, it has become recently recognized that toxicants can cause more subtle changes to the liver. For example, toxicant-associated steatohepatitis, characterized by hepatic steatosis, and inflammation, was recently recognized in an occupational cohort exposed to vinyl chloride. At high occupational levels, toxicants are sufficient to cause liver damage and disease even in healthy subjects with no comorbidities for liver injury. However, it is still largely unknown how exposure to toxicants initiate and possibly more importantly exacerbate liver disease, when combined with other factors, such as underlying non-alcoholic fatty liver disease caused by poor diet and/or obesity. With better understanding of the mechanism(s) and risk factors that mediate the initiation and progression of toxicant-induced liver disease, rational targeted therapy can be developed to better predict risk, as well as to treat or prevent this disease. The purpose of this review is to summarize established and proposed mechanisms of volatile organic compound-induced liver injury and to highlight key signaling events known or hypothesized to mediate these effects.
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Affiliation(s)
- Anna L Lang
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, USA.,Hepatobiology and Toxicology Program, University of Louisville, Louisville, KY 40292, USA.,University of Louisville Alcohol Research Center, University of Louisville Health Sciences Center, Louisville, KY 40292, USA
| | - Juliane I Beier
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY 40292, USA.,Hepatobiology and Toxicology Program, University of Louisville, Louisville, KY 40292, USA.,University of Louisville Alcohol Research Center, University of Louisville Health Sciences Center, Louisville, KY 40292, USA.,Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA
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16
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Zhang J, Li N, Yang L, Xie H, Yang Y, Wang H, Wu C, Shen T, Zhu Q. Bradykinin contributes to immune liver injury via B2R receptor-mediated pathways in trichloroethylene sensitized mice: A role in Kupffer cell activation. Toxicology 2019; 415:37-48. [PMID: 30685357 DOI: 10.1016/j.tox.2019.01.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 12/18/2018] [Accepted: 01/23/2019] [Indexed: 01/20/2023]
Abstract
We have previously shown trichloroethylene (TCE) induced occupational medicamentosa-like dermatitis due to TCE (OMLDT) with immune liver injury, and kallikrein-kinin system (KKS) activation as a probably mechanism underlying the immune damage. Bradykinin (BK) is an important active component of KKS system function, but the specific role of BK in the immune liver injury has never been examined. The present study aimed to explore the important role of BK and mechanisms of action in immune liver injury induced by TCE. TCE sensitization significantly increased the expression of BK receptor (B2R) in the liver. Compared to blank and vehicle control group, TCE sensitization positive mice developed exacerbated liver injury evidenced by elevated AST, ALT levels and hepatocyte damage. TCE sensitization also stimulated MAPK and STAT3 activation in liver tissue. B2R antagonist HOE140 ameliorated these changes. Kupffer cells (KCs) of the liver were also activated following TCE sensitization; both CD68+ KCs and CD16/CD32+ M1 type KCs were increased in TCE positive group. Further experiments isolated the KCs from the liver in each group and showed that TCE sensitization resulted activation of MAPK signal pathway which in turn caused release of the pro-inflammatory cytokines, IL-1β, IL-6, TNF-α, in KCs; the antagonist HOE140 again decreased these changes in KCs. These results uncover a novel role of BK and B2R cross-talk in KCs activation in TCE sensitized mice, mediated by pro-inflammatory cytokine release via MAPK and STAT3 activation, contributing to the immune liver injury.
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Affiliation(s)
- Jiaxiang Zhang
- Institute of Dermatology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China; Department of Occupational Health and Environment Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Na Li
- Department of Occupational Health and Environment Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Ling Yang
- Institute of Dermatology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Haibo Xie
- Department of Occupational Health and Environment Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Yi Yang
- Department of Occupational Health and Environment Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China
| | - Hui Wang
- Department of Nutrition, Chaohu Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Changhao Wu
- School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - Tong Shen
- Department of Occupational Health and Environment Health, School of Public Health, Anhui Medical University, Hefei, Anhui, China.
| | - Qixing Zhu
- Institute of Dermatology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
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17
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Zamanian Z, Yousefinejad S, Khoshnoud MJ, Golbabaie F, Farhang Dehghan S, Modaresi A, Amanat S, Reza Zare M, Rahmani A. Toxic effects of subacute inhalation exposure to trichloroethylene on serum lipid profile, glucose and biochemical parameters in Sprague-Dawley rats. Inhal Toxicol 2018; 30:354-360. [PMID: 30479189 DOI: 10.1080/08958378.2018.1526233] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The current study evaluated the inhalation toxicity of trichloroethylene (TCE) at 0, 10, 100, 250 and 400 ppm in Sprague-Dawley rats for 10 day period, because the subacute inhalation toxicity of TCE on serum lipid profile, glucose and some biochemical parameters has not been previously reported. TCE vapors were generated using the dynamic generation system based on evaporation method in the exposure chamber. On the basis of the results, mean serum low-density lipoprotein (LDL) and albumin (ALB) decreased significantly in all the groups exposed to TCE compared with the control group (p < .005), but there was a significant increase for parameters: fasting blood glucose (FBG) and alkaline phosphatase (ALP) (p < .005). Rats exposed to 400 ppm TCE showed a significant decrease in serum cholesterol (CHOL) and protein (Pr) compared with the control group (p < .005). A negative relationship was found between triglycerides (TG), very low density lipoprotein (VLDL), CHOL, LDL, Pr, ALB and urea levels and the subacute exposure to concentrations of TCE (R2 = -0.26, p < .05), but there was a direct correlation for parameters FBG, ALP and alanine aminotransferase (ALT) (R2 = 0.42, p < .05). In conclusion, studies with Sprague-Dawley rats demonstrated that subacute inhalation exposure to TCE (≥ 100 PPM) is associated with biochemical and lipotoxicity in the form of decreased serum ALB and LDL and raised ALP and glucose levels. The present study also provides additional evidence relating to decreased serum CHOL and Pr after subacute inhalation exposure to 400 ppm TCE.
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Affiliation(s)
- Zahra Zamanian
- a Department of Occupational Health Engineering, School of Health , Shiraz University of Medical Sciences , Shiraz , Iran
| | - Saeed Yousefinejad
- a Department of Occupational Health Engineering, School of Health , Shiraz University of Medical Sciences , Shiraz , Iran
| | - Mohammad Javad Khoshnoud
- b Department of Pharmacology Toxicology, School of Pharmacy , Shiraz University of Medical Sciences , Shiraz , Iran
| | - Farideh Golbabaie
- c Department of Occupational Health, School of Public Health , Tehran University of Medical Sciences , Tehran , Iran
| | - Somayeh Farhang Dehghan
- d Department of Occupational Health, School of Public Health and Safety , Shahid Beheshti University of Medical Sciences , Tehran , Iran
| | - Aboutaleb Modaresi
- e Modaresi Laboratory , Larestan University of Medical Sciences, Larestan , Iran
| | - Sasan Amanat
- f Department of Nutrition, School of Public Health , Larestan University of Medical Sciences , Larestan , Iran
| | - Mohammad Reza Zare
- g Department of Environmental Health Engineering, School of Health , Larestan University of Medical Sciences , Larestan , Iran
| | - Abdolrasoul Rahmani
- a Department of Occupational Health Engineering, School of Health , Shiraz University of Medical Sciences , Shiraz , Iran
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18
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Luo YS, Hsieh NH, Soldatow VY, Chiu WA, Rusyn I. Comparative analysis of metabolism of trichloroethylene and tetrachloroethylene among mouse tissues and strains. Toxicology 2018; 409:33-43. [PMID: 30053492 PMCID: PMC6186498 DOI: 10.1016/j.tox.2018.07.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 07/22/2018] [Accepted: 07/23/2018] [Indexed: 11/21/2022]
Abstract
Trichloroethylene (TCE) and tetrachloroethylene (PCE) are structurally similar chemicals that are metabolized through oxidation and glutathione conjugation pathways. Both chemicals have been shown to elicit liver and kidney toxicity in rodents and humans; however, TCE has been studied much more extensively in terms of both metabolism and toxicity. Despite their qualitative similarities, quantitative comparison of tissue- and strain-specific metabolism of TCE and PCE has not been performed. To fill this gap, we conducted a comparative toxicokinetic study where equimolar single oral doses of TCE (800 mg/kg) or PCE (1000 mg/kg) were administered to male mice of C57BL/6J, B6C3F1/J, and NZW/LacJ strains. Samples of liver, kidney, serum, brain, and lung were obtained for up to 36 h after dosing. For each tissue, concentrations of parent compounds, as well as their oxidative and glutathione conjugation metabolites were measured and concentration-time profiles constructed. A multi-compartment toxicokinetic model was developed to quantitatively compare TCE and PCE metabolism. As expected, the flux through oxidation metabolism pathway predominated over that through conjugation across all mouse strains examined, it is 1,200-3,800 fold higher for TCE and 26-34 fold higher for PCE. However, the flux through glutathione conjugation, albeit a minor metabolic pathway, was 21-fold higher for PCE as compared to TCE. The degree of inter-strain variability was greatest for oxidative metabolites in TCE-treated and for glutathione conjugation metabolites in PCE-treated mice. This study provides critical data for quantitative comparisons of TCE and PCE metabolism, and may explain the differences in organ-specific toxicity between these structurally similar chemicals.
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Affiliation(s)
- Yu-Syuan Luo
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, USA
| | - Nan-Hung Hsieh
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, USA
| | - Valerie Y Soldatow
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA
| | - Weihsueh A Chiu
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, USA
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, USA.
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19
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Zhang Q, Li J, Middleton A, Bhattacharya S, Conolly RB. Bridging the Data Gap From in vitro Toxicity Testing to Chemical Safety Assessment Through Computational Modeling. Front Public Health 2018; 6:261. [PMID: 30255008 PMCID: PMC6141783 DOI: 10.3389/fpubh.2018.00261] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 08/21/2018] [Indexed: 12/18/2022] Open
Abstract
Chemical toxicity testing is moving steadily toward a human cell and organoid-based in vitro approach for reasons including scientific relevancy, efficiency, cost, and ethical rightfulness. Inferring human health risk from chemical exposure based on in vitro testing data is a challenging task, facing various data gaps along the way. This review identifies these gaps and makes a case for the in silico approach of computational dose-response and extrapolation modeling to address many of the challenges. Mathematical models that can mechanistically describe chemical toxicokinetics (TK) and toxicodynamics (TD), for both in vitro and in vivo conditions, are the founding pieces in this regard. Identifying toxicity pathways and in vitro point of departure (PoD) associated with adverse health outcomes requires an understanding of the molecular key events in the interacting transcriptome, proteome, and metabolome. Such an understanding will in turn help determine the sets of sensitive biomarkers to be measured in vitro and the scope of toxicity pathways to be modeled in silico. In vitro data reporting both pathway perturbation and chemical biokinetics in the culture medium serve to calibrate the toxicity pathway and virtual tissue models, which can then help predict PoDs in response to chemical dosimetry experienced by cells in vivo. Two types of in vitro to in vivo extrapolation (IVIVE) are needed. (1) For toxic effects involving systemic regulations, such as endocrine disruption, organism-level adverse outcome pathway (AOP) models are needed to extrapolate in vitro toxicity pathway perturbation to in vivo PoD. (2) Physiologically-based toxicokinetic (PBTK) modeling is needed to extrapolate in vitro PoD dose metrics into external doses for expected exposure scenarios. Linked PBTK and TD models can explore the parameter space to recapitulate human population variability in response to chemical insults. While challenges remain for applying these modeling tools to support in vitro toxicity testing, they open the door toward population-stratified and personalized risk assessment.
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Affiliation(s)
- Qiang Zhang
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Jin Li
- Unilever, Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, United Kingdom
| | - Alistair Middleton
- Unilever, Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, United Kingdom
| | - Sudin Bhattacharya
- Biomedical Engineering, Michigan State University, East Lansing, MI, United States
| | - Rory B Conolly
- Integrated Systems Toxicology Division, National Health and Environmental Effects Research Laboratory, United States Environmental Protection Agency, Durham, NC, United States
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20
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Venkatratnam A, House JS, Konganti K, McKenney C, Threadgill DW, Chiu WA, Aylor DL, Wright FA, Rusyn I. Population-based dose-response analysis of liver transcriptional response to trichloroethylene in mouse. Mamm Genome 2018; 29:168-181. [PMID: 29353386 DOI: 10.1007/s00335-018-9734-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 01/17/2018] [Indexed: 12/23/2022]
Abstract
Studies of gene expression are common in toxicology and provide important clues to mechanistic understanding of adverse effects of chemicals. Most prior studies have been performed in a single strain or cell line; however, gene expression is heavily influenced by the genetic background, and these genotype-expression differences may be key drivers of inter-individual variation in response to chemical toxicity. In this study, we hypothesized that the genetically diverse Collaborative Cross mouse population can be used to gain insight and suggest mechanistic hypotheses for the dose- and genetic background-dependent effects of chemical exposure. This hypothesis was tested using a model liver toxicant trichloroethylene (TCE). Liver transcriptional responses to TCE exposure were evaluated 24 h after dosing. Transcriptomic dose-responses were examined for both TCE and its major oxidative metabolite trichloroacetic acid (TCA). As expected, peroxisome- and fatty acid metabolism-related pathways were among the most dose-responsive enriched pathways in all strains. However, nearly half of the TCE-induced liver transcriptional perturbation was strain-dependent, with abundant evidence of strain/dose interaction, including in the peroxisomal signaling-associated pathways. These effects were highly concordant between the administered TCE dose and liver levels of TCA. Dose-response analysis of gene expression at the pathway level yielded points of departure similar to those derived from the traditional toxicology studies for both non-cancer and cancer effects. Mapping of expression-genotype-dose relationships revealed some significant associations; however, the effects of TCE on gene expression in liver appear to be highly polygenic traits that are challenging to positionally map. This study highlights the usefulness of mouse population-based studies in assessing inter-individual variation in toxicological responses, but cautions that genetic mapping may be challenging because of the complexity in gene exposure-dose relationships.
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Affiliation(s)
- Abhishek Venkatratnam
- Department of Veterinary Integrative Biosciences, Texas A&M University, 4458 TAMU, College Station, Texas, 77843, USA.,Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina, 27599, USA
| | - John S House
- Bioinformatics Research Center, North Carolina State University, Raleigh, North Carolina, 27695, USA.,Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina, 27695, USA
| | - Kranti Konganti
- Department of Veterinary Integrative Biosciences, Texas A&M University, 4458 TAMU, College Station, Texas, 77843, USA
| | - Connor McKenney
- NCSU Undergraduate program in Genetics, North Carolina State University, Raleigh, North Carolina, 27695, USA
| | - David W Threadgill
- Department of Veterinary Integrative Biosciences, Texas A&M University, 4458 TAMU, College Station, Texas, 77843, USA
| | - Weihsueh A Chiu
- Department of Veterinary Integrative Biosciences, Texas A&M University, 4458 TAMU, College Station, Texas, 77843, USA
| | - David L Aylor
- Bioinformatics Research Center, North Carolina State University, Raleigh, North Carolina, 27695, USA.,Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina, 27695, USA.,Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, 27695, USA
| | - Fred A Wright
- Bioinformatics Research Center, North Carolina State University, Raleigh, North Carolina, 27695, USA.,Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina, 27695, USA.,Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, 27695, USA.,Department of Statistics, North Carolina State University, Raleigh, North Carolina, 27695, USA
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, Texas A&M University, 4458 TAMU, College Station, Texas, 77843, USA.
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House JS, Grimm FA, Jima DD, Zhou YH, Rusyn I, Wright FA. A Pipeline for High-Throughput Concentration Response Modeling of Gene Expression for Toxicogenomics. Front Genet 2017; 8:168. [PMID: 29163636 PMCID: PMC5672545 DOI: 10.3389/fgene.2017.00168] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 10/18/2017] [Indexed: 12/21/2022] Open
Abstract
Cell-based assays are an attractive option to measure gene expression response to exposure, but the cost of whole-transcriptome RNA sequencing has been a barrier to the use of gene expression profiling for in vitro toxicity screening. In addition, standard RNA sequencing adds variability due to variable transcript length and amplification. Targeted probe-sequencing technologies such as TempO-Seq, with transcriptomic representation that can vary from hundreds of genes to the entire transcriptome, may reduce some components of variation. Analyses of high-throughput toxicogenomics data require renewed attention to read-calling algorithms and simplified dose–response modeling for datasets with relatively few samples. Using data from induced pluripotent stem cell-derived cardiomyocytes treated with chemicals at varying concentrations, we describe here and make available a pipeline for handling expression data generated by TempO-Seq to align reads, clean and normalize raw count data, identify differentially expressed genes, and calculate transcriptomic concentration–response points of departure. The methods are extensible to other forms of concentration–response gene-expression data, and we discuss the utility of the methods for assessing variation in susceptibility and the diseased cellular state.
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Affiliation(s)
- John S House
- Bioinformatics Research Center, North Carolina State University, Raleigh, NC, United States.,Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, United States
| | - Fabian A Grimm
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, United States
| | - Dereje D Jima
- Bioinformatics Research Center, North Carolina State University, Raleigh, NC, United States.,Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, United States
| | - Yi-Hui Zhou
- Bioinformatics Research Center, North Carolina State University, Raleigh, NC, United States.,Department of Biological Sciences, North Carolina State University, Raleigh, NC, United States
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, United States
| | - Fred A Wright
- Bioinformatics Research Center, North Carolina State University, Raleigh, NC, United States.,Department of Biological Sciences, North Carolina State University, Raleigh, NC, United States.,Department of Statistics, North Carolina State University, Raleigh, NC, United States
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