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Bullert A, Li X, Gautam B, Wang H, Adamcakova-Dodd A, Wang K, Thorne PS, Lehmler HJ. Distribution of 2,2',5,5'-Tetrachlorobiphenyl (PCB52) Metabolites in Adolescent Rats after Acute Nose-Only Inhalation Exposure. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:6105-6116. [PMID: 38547313 PMCID: PMC11008251 DOI: 10.1021/acs.est.3c09527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 02/02/2024] [Accepted: 03/09/2024] [Indexed: 04/10/2024]
Abstract
Inhalation of PCB-contaminated air is increasingly recognized as a route for PCB exposure. Because limited information about the disposition of PCBs following inhalation exposure is available, this study investigated the disposition of 2,2',5,5'-tetrachlorobiphenyl (PCB52) and its metabolites in rats following acute, nose-only inhalation of PCB52. Male and female Sprague-Dawley rats (50-58 days of age, 210 ± 27 g; n = 6) were exposed for 4 h by inhalation to approximately 14 or 23 μg/kg body weight of PCB52 using a nose-only exposure system. Sham animals (n = 6) were exposed to filtered lab air. Based on gas chromatography-tandem mass spectrometry (GC-MS/MS), PCB52 was present in adipose, brain, intestinal content, lung, liver, and serum. 2,2',5,5'-Tetrachlorobiphenyl-4-ol (4-OH-PCB52) and one unknown monohydroxylated metabolite were detected in these compartments except for the brain. Liquid chromatography-high resolution mass spectrometry (LC-HRMS) analysis identified several metabolites, including sulfated, methoxylated, and dechlorinated PCB52 metabolites. These metabolites were primarily found in the liver (7 metabolites), lung (9 metabolites), and serum (9 metabolites) due to the short exposure time. These results demonstrate for the first time that complex mixtures of sulfated, methoxylated, and dechlorinated PCB52 metabolites are formed in adolescent rats following PCB52 inhalation, laying the groundwork for future animal studies of the adverse effects of inhaled PCB52.
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Affiliation(s)
- Amanda
J. Bullert
- Department
of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary
Graduate Program in Neuroscience, The University
of Iowa, Iowa City, Iowa 52242, United States
| | - Xueshu Li
- Department
of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Binita Gautam
- Department
of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Hui Wang
- Department
of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Andrea Adamcakova-Dodd
- Department
of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Kai Wang
- Department
of Biostatistics, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Peter S. Thorne
- Department
of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary
Graduate Program in Neuroscience, The University
of Iowa, Iowa City, Iowa 52242, United States
| | - Hans-Joachim Lehmler
- Department
of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary
Graduate Program in Neuroscience, The University
of Iowa, Iowa City, Iowa 52242, United States
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2
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Wang H, Bullert AJ, Li X, Stevens H, Klingelhutz AJ, Ankrum JA, Adamcakova-Dodd A, Thorne PS, Lehmler HJ. Use of a polymeric implant system to assess the neurotoxicity of subacute exposure to 2,2',5,5'-tetrachlorobiphenyl-4-ol, a human metabolite of PCB 52, in male adolescent rats. Toxicology 2023; 500:153677. [PMID: 37995827 PMCID: PMC10757425 DOI: 10.1016/j.tox.2023.153677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/06/2023] [Accepted: 11/18/2023] [Indexed: 11/25/2023]
Abstract
Polychlorinated biphenyls (PCBs) are persistent organic pollutants (POPs) that ubiquitously exist in the environment. PCB exposure has been linked to cancer and multi-system toxicity, including endocrine disruption, immune inhibition, and reproductive and neurotoxicity. 2,2',5,5'-Tetrachlorobiphenyl (PCB 52) is one of the most frequently detected congeners in the environment and human blood. The hydroxylated metabolites of PCB 52 may also be neurotoxic, especially for children whose brains are still developing. However, it is challenging to discern the contribution of these metabolites to PCB neurotoxicity because the metabolism of PCB is species-dependent. In this study, we evaluated the subacute neurotoxicity of a human-relevant metabolite, 2,2',5,5'-tetrachlorobiphenyl-4-ol (4-52), on male adolescent Sprague Dawley rats, via a novel polymeric implant drug delivery system grafted subcutaneously, at total loading concentrations ranging from 0%, 1%, 5%, and 10% of the implant (w/w) for 28 days. Y-maze, hole board test, open field test, and elevated plus maze were performed on exposure days 24-28 to assess their locomotor activity, and exploratory and anxiety-like behavior. 4-52 and other possible hydroxylated metabolites in serum and vital tissues were quantified using gas chromatography with tandem mass spectrometry (GC-MS/MS). Our results demonstrate the sustained release of 4-52 from the polymeric implants into the systemic circulation in serum and tissues. Dihydroxylated and dechlorinated metabolites were detected in serum and tissues, depending on the dose and tissue type. No statistically significant changes were observed in the neurobehavioral tasks across all exposure groups. The results demonstrate that subcutaneous polymeric implants provide a straightforward method to expose rats to phenolic PCB metabolites to study neurotoxic outcomes, e.g., in memory, anxiety, and exploratory behaviors.
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Affiliation(s)
- Hui Wang
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, IA, USA
| | - Amanda J Bullert
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, IA, USA; Interdisciplinary Graduate Program in Neuroscience, the University of Iowa, Iowa City, IA, USA
| | - Xueshu Li
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, IA, USA
| | - Hanna Stevens
- Interdisciplinary Graduate Program in Neuroscience, the University of Iowa, Iowa City, IA, USA; Department of Psychiatry, the University of Iowa, Iowa City, IA, USA; Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, IA, USA
| | | | - James A Ankrum
- Roy J. Carver Department of Biomedical Engineering, the University of Iowa, Iowa City, IA, USA
| | - Andrea Adamcakova-Dodd
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, IA, USA
| | - Peter S Thorne
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, IA, USA; Interdisciplinary Graduate Program in Neuroscience, the University of Iowa, Iowa City, IA, USA; Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, IA, USA
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, IA, USA; Interdisciplinary Graduate Program in Neuroscience, the University of Iowa, Iowa City, IA, USA; Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, IA, USA.
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3
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Bullert A, Li X, Chunyun Z, Lee K, Pulliam CF, Cagle BS, Doorn JA, Klingelhutz AJ, Robertson LW, Lehmler HJ. Disposition and metabolomic effects of 2,2',5,5'-tetrachlorobiphenyl in female rats following intraperitoneal exposure. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2023; 102:104245. [PMID: 37572994 PMCID: PMC10562985 DOI: 10.1016/j.etap.2023.104245] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/14/2023]
Abstract
The disposition and toxicity of lower chlorinated PCBs (LC-PCBs) with less than five chlorine substituents have received little attention. This study characterizes the distribution and metabolomic effects of PCB 52, an LC-PCB found in indoor and outdoor air, three weeks after intraperitoneal exposure of female Sprague Dawley rats to 0, 1, 10, or 100 mg/kg BW. PCB 52 exposure did not affect overall body weight. Gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis identified PCB 52 in all tissues investigated. Hydroxylated, sulfated, and methylated PCB metabolites, identified using GC-MS/MS and nontarget liquid chromatography-high resolution mass spectrometry (Nt-LCMS), were primarily found in the serum and liver of rats exposed to 100 mg/kg BW. Metabolomic analysis revealed minor effects on L-cysteine, glycine, cytosine, sphingosine, thymine, linoleic acid, orotic acid, L-histidine, and erythrose serum levels. Thus, the metabolism of PCB 52 and its effects on the metabolome must be considered in toxicity studies.
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Affiliation(s)
- Amanda Bullert
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA; Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
| | - Xueshu Li
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
| | - Zhang Chunyun
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
| | - Kendra Lee
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
| | - Casey F Pulliam
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA
| | - Brianna S Cagle
- Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa, Iowa City, IA 52242, USA
| | - Jonathan A Doorn
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA; Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA; Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa, Iowa City, IA 52242, USA
| | - Aloysius J Klingelhutz
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Larry W Robertson
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA; Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA; Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA; Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA.
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Li X, Bullert AJ, Han W, Yang W, Zhang QY, Ding X, Lehmler HJ. Enantiomeric Fractions Reveal Differences in the Atropselective Disposition of 2,2',3,5',6-Pentachlorobiphenyl (PCB 95) in Wildtype, Cyp2abfgs-Null, and CYP2A6-Humanized Mice. Chem Res Toxicol 2023; 36:1386-1397. [PMID: 37467352 PMCID: PMC10445290 DOI: 10.1021/acs.chemrestox.3c00128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Indexed: 07/21/2023]
Abstract
Polychlorinated biphenyls (PCBs) are environmental contaminants that can cause neurotoxicity. PCBs, such as PCB 95 (2,2',3,5',6-pentachlorobiphenyl), can be metabolized by cytochrome P450 enzymes into neurotoxic metabolites. To better understand how the metabolism of PCB 95 affects neurotoxic outcomes, we conducted a study on the disposition of PCB 95 in transgenic mouse models. The mice were given a single oral dose of PCB 95 (1.0 mg/kg) and were euthanized 24 h later for analysis. PCB 95 levels were highest in adipose tissue, followed by the liver, brain, and blood. Adipose tissue levels were significantly higher in wild-type (WT) mice than in Cyp2abfgs-null (KO) or CYP2A6-transgenic (KI) mice. We also observed genotype-dependent differences in the enrichment of aS-PCB 95 in female mice, with a less pronounced enrichment in KO than WT and KI mice. Ten hydroxylated PCB 95 metabolites were detected in blood and tissue across all exposure groups. The metabolite profiles differed across tissues, while sex and genotype-dependent differences were less pronounced. Total OH-PCB levels were highest in the blood, followed by the liver, adipose tissue, and brain. Total OH-PCB blood levels were lower in KO than in WT mice, while the opposite trend was observed in the liver. In male mice, total OH-PCB metabolite levels were significantly lower in KI than in WT mice in blood and the liver, while the opposite trend was observed in female mice. In conclusion, the study highlights the differences in the atropselective disposition of PCB 95 and its metabolites in different types of mice, demonstrating the usefulness of these transgenic mouse models for characterizing the role of PCB metabolism in PCB neurotoxicity.
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Affiliation(s)
- Xueshu Li
- Department
of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, Iowa 52242, United States
| | - Amanda J. Bullert
- Department
of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary
Graduate Program in Neuroscience, University
of Iowa, Iowa City, Iowa 52242, United States
| | - Weiguo Han
- Department
of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721, United States
| | - Weizhu Yang
- Department
of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721, United States
| | - Qing-Yu Zhang
- Department
of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721, United States
| | - Xinxin Ding
- Department
of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona 85721, United States
| | - Hans-Joachim Lehmler
- Department
of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary
Graduate Program in Neuroscience, University
of Iowa, Iowa City, Iowa 52242, United States
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5
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Bullert A, Li X, Zhang C, Lee K, Pulliam CF, Cagle BS, Doorn JA, Klingelhutz AJ, Robertson LW, Lehmler HJ. Disposition and Metabolomic Effects of 2,2',5,5'-Tetrachlorobiphenyl in Female Rats Following Intraperitoneal Exposure. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.19.544952. [PMID: 37609242 PMCID: PMC10441371 DOI: 10.1101/2023.06.19.544952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
The disposition and toxicity of lower chlorinated PCBs (LC-PCBs) with less than five chlorine substituents have received little attention. This study characterizes the distribution and metabolomic effects of PCB 52, an LC-PCB found in indoor and outdoor air, three weeks after intraperitoneal exposure of female Sprague Dawley rats to 0, 1, 10, or 100 mg/kg BW. PCB 52 exposure did not affect overall body weight. Gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis identified PCB 52 in all tissues investigated. Hydroxylated, sulfated, and methylated PCB metabolites, identified using GC-MS/MS and nontarget liquid chromatography-high resolution mass spectrometry (Nt-LCMS), were primarily found in the serum and liver of rats exposed to 100 mg/kg BW. Metabolomic analysis revealed minor effects on L-cysteine, glycine, cytosine, sphingosine, thymine, linoleic acid, orotic acid, L-histidine, and erythrose serum levels. Thus, the metabolism of PCB 52 and its effects on the metabolome must be considered in toxicity studies. Highlights PCB 52 was present in adipose, brain, liver, and serum 3 weeks after PCB exposureLiver and serum contained hydroxylated, sulfated, and methylated PCB 52 metabolitesMetabolomics analysis revealed minor changes in endogenous serum metabolitesLevels of dopamine and its metabolites in the brain were not affected by PCB 52.
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Affiliation(s)
- Amanda Bullert
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
| | - Xueshu Li
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
| | - Chunyun Zhang
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
| | - Kendra Lee
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
| | - Casey F. Pulliam
- Interdisciplinary Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA
| | - Brianna S. Cagle
- Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa, Iowa City, IA 52242, USA
| | - Jonathan A. Doorn
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
- Interdisciplinary Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA
- Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa, Iowa City, IA 52242, USA
| | - Aloysius J. Klingelhutz
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Larry W. Robertson
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
- Interdisciplinary Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA 52242, USA
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
- Interdisciplinary Program in Human Toxicology, University of Iowa, Iowa City, IA 52242, USA
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Lehmler HJ, Uwimana E, Dean LE, Kovalchuk N, Zhang QY, Ding X. Probing the Role of CYP2 Enzymes in the Atropselective Metabolism of Polychlorinated Biphenyls Using Liver Microsomes from Transgenic Mouse Models. Chem Res Toxicol 2022; 35:2310-2323. [PMID: 36473170 PMCID: PMC9957597 DOI: 10.1021/acs.chemrestox.2c00276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Chiral polychlorinated biphenyls (PCB) are environmentally relevant developmental neurotoxicants. Because their hydroxylated metabolites (OH-PCBs) are also neurotoxic, it is necessary to determine how PCB metabolism affects the developing brain, for example, in mouse models. Because the cytochrome P450 isoforms involved in the metabolism of chiral PCBs remain unexplored, we investigated the metabolism of PCB 91 (2,2',3,4',6-pentachlorobiphenyl), PCB 95 (2,2',3,5',6-pentachlorobiphenyl), PCB 132 (2,2',3,3',4,6'-hexachlorobiphenyl), and PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl) using liver microsomes from male and female Cyp2a(4/5)bgs-null, Cyp2f2-null, and wild-type mice. Microsomes, pooled by sex, were incubated with 50 μM PCB for 30 min, and the levels and enantiomeric fractions of the OH-PCBs were determined gas chromatographically. All four PCB congeners appear to be atropselectively metabolized by CYP2A(4/5)BGS and CYP2F2 enzymes in a congener- and sex-dependent manner. The OH-PCB metabolite profiles of PCB 91 and PCB 132, PCB congeners with one para-chlorine substituent, differed between null and wild-type mice. No differences in the metabolite profiles were observed for PCB 95 and PCB 136, PCB congeners without a para-chlorine group. These findings suggest that Cyp2a(4/5)bgs-null and Cyp2f2-null mice can be used to study how a loss of a specific metabolic function (e.g., deletion of Cyp2a(4/5)bgs or Cyp2f2) affects the toxicity of chiral PCB congeners.
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Affiliation(s)
- Hans-Joachim Lehmler
- Interdisciplinary Graduate Program in Human Toxicology and Department of Occupational and Environmental Health, University of Iowa, Iowa City, IA 52242, United States
| | - Eric Uwimana
- Interdisciplinary Graduate Program in Human Toxicology and Department of Occupational and Environmental Health, University of Iowa, Iowa City, IA 52242, United States
| | - Laura E. Dean
- Interdisciplinary Graduate Program in Human Toxicology and Department of Occupational and Environmental Health, University of Iowa, Iowa City, IA 52242, United States
| | - Nataliia Kovalchuk
- Department of Pharmacology & Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ 85721, United States
| | - Qing-Yu Zhang
- Department of Pharmacology & Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ 85721, United States
| | - Xinxin Ding
- Department of Pharmacology & Toxicology, College of Pharmacy, University of Arizona, Tucson, AZ 85721, United States
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Zhu L, Huo X, Zhou J, Zhang Q, Wang W. Metabolic activation mechanism of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB136) by cytochrome P450 2B6: A QM/MM approach. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 776:145579. [PMID: 33652317 DOI: 10.1016/j.scitotenv.2021.145579] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 01/28/2021] [Accepted: 01/28/2021] [Indexed: 06/12/2023]
Abstract
Cytochrome P450 enzymes (CYPs) play an essential role in the bio-transformation of polychlorinated biphenyls (PCBs). The present work implemented quantum mechanic/molecular mechanic methods (QM/MM) and density functional theory (DFT) to study the metabolic activation of 2,2',3,3',6,6'-hexachlorobiphenyl (PCB136) catalyzed by CYP2B6. Electrophilic additions at the Cα and Cβ positions generate different active intermediates. The electrophilic addition energy barrier of Cβ is 10.9 kcal/mol higher than that of Cα, and Cα is the preferred site for the electrophilic addition reaction. Based on the previous experimental studies, this work investigated the mechanism of converting active intermediates into OH-PCB136, which has high toxicity in a non-enzymatic environment. Structural analysis via the electrostatic and noncovalent interactions indicates that Phe108, Ile114, Phe115, Phe206, Phe297, Ala298, Leu363, Val367, TIP32475 and TIP32667 play crucial roles in substrate recognition and metabolism. The analysis suggests that the halogen-π interactions are important factors for the metabolism of CYP2B6 to halogenated environmental pollutants. This work improved the understanding of the metabolism and activation process of chiral PCBs, and can be used as a guide to improve the microbial degradation efficiency of PCB136.
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Affiliation(s)
- Ledong Zhu
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
| | - Xinxi Huo
- Environment Research Institute, Shandong University, Qingdao 266237, PR China; Office of Supervisory and Audit, Shandong University, Qingdao 266237, PR China
| | - Jie Zhou
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
| | - Qingzhu Zhang
- Environment Research Institute, Shandong University, Qingdao 266237, PR China.
| | - Wenxing Wang
- Environment Research Institute, Shandong University, Qingdao 266237, PR China
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Dai S, Qiu J, Wang M. Concentration-dependent enantioselective accumulation of chiral polychlorinated biphenyls in Nelumbo nucifera Gaertn. root from contaminative sediment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:27878-27884. [PMID: 33517550 DOI: 10.1007/s11356-021-12530-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 01/13/2021] [Indexed: 06/12/2023]
Abstract
Nelumbo nucifera Gaertn. (lotus) roots were collected from contaminated sediments which were artificially adding different concentrations of chiral polychlorinated biphenyls (PCBs) to investigate the effect of concentration on the accumulation characteristics and chiral signatures of PCBs in lotus root during its growth period of 150 days. Under high PCB exposure concentration, the biota-sediment accumulation factors (BSAFs) of PCBs 91, 95, and 136 in the lotus root were up to 0.25-0.46 and 8.10-10.5 times higher than those under low-exposure concentration (0.024-0.052). The BSAFs of PCBs 149, 176, and 183 under high-exposure concentration were up to 0.24-0.44, while they were undetected at low concentration. The significant difference observed in the BSAFs based on different concentrations indicates that the lotus root accumulation efficiency toward chiral PCBs increases with the contaminate concentration. Although the (-)-enantiomers of PCBs 91, 95, and 136 were all preferentially accumulated in lotus root under two exposure concentrations, the extent of the preferential accumulation of (-)-PCB 95 decreased with increasing exposure concentration throughout the whole growth period (30-150 days). In addition, the (-)-enantiomers of PCBs 91 and 136 also showed the same tendency during most of the growth period. Conclusively, the exposure concentrations are an important influence factor on the enantioselective accumulation of chiral PCBs in lotus root.
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Affiliation(s)
- Shouhui Dai
- Equipment Public Service Center, Key Laboratory of Tropical Marine Bio-Resources and Ecology South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, People's Republic of China.
| | - Jing Qiu
- Institute of Quality Standard & Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Min Wang
- Institute of Quality Standard & Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
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9
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Li X, Zhang C, Wang K, Lehmler HJ. Fatty liver and impaired hepatic metabolism alter the congener-specific distribution of polychlorinated biphenyls (PCBs) in mice with a liver-specific deletion of cytochrome P450 reductase. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 266:115233. [PMID: 32712482 PMCID: PMC7492420 DOI: 10.1016/j.envpol.2020.115233] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/22/2020] [Accepted: 07/10/2020] [Indexed: 05/09/2023]
Abstract
Polychlorinated biphenyls (PCBs) are persistent organic pollutants that are linked to adverse health outcomes. PCB tissue levels are determinants of PCB toxicity; however, it is unclear how factors, such as an altered metabolism and/or a fatty liver, affect PCB distribution in vivo. We determined the congener-specific disposition of PCBs in mice with a liver-specific deletion of cytochrome P450 reductase (KO), a model of fatty liver with impaired hepatic metabolism, and wild-type (WT) mice. Eight-week-old male WT (MWT, n = 3), male KO (MKO, n = 5), female WT (FWT, n = 4), and female KO mice (FKO, n = 4) were exposed orally to Aroclor 1254. PCBs were quantified in adipose, blood, brain, and liver tissues by gas chromatography-mass spectrometry. The ΣPCB levels followed the rank order adipose > liver ∼ brain > blood in WT and adipose ∼ liver > brain > blood in KO mice. PCB levels were much higher in the liver of KO than WT mice, irrespective of the sex. A comparison across exposure groups revealed minor genotype and sex-dependent differences in the PCB congener profiles (cos Θ > 0.92). Within each exposure group, tissue profiles showed small differences between tissues (cos Θ = 0.85 to 0.98). These differences were due to a decrease in metabolically more labile PCB congeners and an increase in congeners resistant to metabolism. The tissue-to-blood ratio of PCBs decreased for adipose, increased for the brain, and remained constant for the liver with an increase in chlorination. While these ratios did not follow the trends predicted using a composition-based model, the agreement between experimental and calculated partition coefficients was reasonable. Although the distribution of PCBs differs between KO and WT mice, the magnitude of the partitioning of PCBs from the blood into tissues can be approximated using composition-based models.
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Affiliation(s)
- Xueshu Li
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA
| | - Chunyun Zhang
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA
| | - Kai Wang
- Department of Biostatistics, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA.
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Li X, Zhang C, Wang K, Lehmler HJ. Fatty liver and impaired hepatic metabolism alter the congener-specific distribution of polychlorinated biphenyls (PCBs) in mice with a liver-specific deletion of cytochrome P450 reductase. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020. [PMID: 32712482 DOI: 10.25820/data.006117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Polychlorinated biphenyls (PCBs) are persistent organic pollutants that are linked to adverse health outcomes. PCB tissue levels are determinants of PCB toxicity; however, it is unclear how factors, such as an altered metabolism and/or a fatty liver, affect PCB distribution in vivo. We determined the congener-specific disposition of PCBs in mice with a liver-specific deletion of cytochrome P450 reductase (KO), a model of fatty liver with impaired hepatic metabolism, and wild-type (WT) mice. Eight-week-old male WT (MWT, n = 3), male KO (MKO, n = 5), female WT (FWT, n = 4), and female KO mice (FKO, n = 4) were exposed orally to Aroclor 1254. PCBs were quantified in adipose, blood, brain, and liver tissues by gas chromatography-mass spectrometry. The ΣPCB levels followed the rank order adipose > liver ∼ brain > blood in WT and adipose ∼ liver > brain > blood in KO mice. PCB levels were much higher in the liver of KO than WT mice, irrespective of the sex. A comparison across exposure groups revealed minor genotype and sex-dependent differences in the PCB congener profiles (cos Θ > 0.92). Within each exposure group, tissue profiles showed small differences between tissues (cos Θ = 0.85 to 0.98). These differences were due to a decrease in metabolically more labile PCB congeners and an increase in congeners resistant to metabolism. The tissue-to-blood ratio of PCBs decreased for adipose, increased for the brain, and remained constant for the liver with an increase in chlorination. While these ratios did not follow the trends predicted using a composition-based model, the agreement between experimental and calculated partition coefficients was reasonable. Although the distribution of PCBs differs between KO and WT mice, the magnitude of the partitioning of PCBs from the blood into tissues can be approximated using composition-based models.
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Affiliation(s)
- Xueshu Li
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA
| | - Chunyun Zhang
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA
| | - Kai Wang
- Department of Biostatistics, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA.
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Liu J, Tan Y, Song E, Song Y. A Critical Review of Polychlorinated Biphenyls Metabolism, Metabolites, and Their Correlation with Oxidative Stress. Chem Res Toxicol 2020; 33:2022-2042. [DOI: 10.1021/acs.chemrestox.0c00078] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Jing Liu
- College of Eco-Environmental Engineering, Guizhou Minzu University, Guiyang 550025, People’s Republic of China
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, People’s Republic of China
| | - Ya Tan
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, People’s Republic of China
| | - Erqun Song
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, People’s Republic of China
| | - Yang Song
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, People’s Republic of China
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Chen N, Shan Q, Qi Y, Liu W, Tan X, Gu J. Transcriptome analysis in normal human liver cells exposed to 2, 3, 3', 4, 4', 5 - Hexachlorobiphenyl (PCB 156). CHEMOSPHERE 2020; 239:124747. [PMID: 31514003 DOI: 10.1016/j.chemosphere.2019.124747] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/31/2019] [Accepted: 09/03/2019] [Indexed: 05/20/2023]
Abstract
BACKGROUNDS Polychlorinated biphenyls are persistent environmental pollutants associated with the onset of non-alcoholic fatty liver disease in humans, but there is limited information on the underlying mechanism. In the present study, we investigated the alterations in gene expression profiles in normal human liver cells L-02 following exposure to 2, 3, 3', 4, 4', 5 - hexachlorobiphenyl (PCB 156), a potent compound that may induce non-alcoholic fatty liver disease. METHODS The L-02 cells were exposed to PCB 156 for 72 h and the contents of intracellular triacylglyceride and total cholesterol were subsequently measured. Microarray analysis of mRNAs and long non-coding RNAs (lncRNAs) in the cells was also performed after 3.4 μM PCB 156 treatment. RESULTS Exposure to PCB 156 (3.4 μM, 72 h) resulted in significant increases of triacylglyceride and total cholesterol concentrations in L-02 cells. Microarray analysis identified 222 differentially expressed mRNAs and 628 differentially expressed lncRNAs. Gene Ontology and pathway analyses associated the differentially expressed mRNAs with metabolic and inflammatory processes. Moreover, lncRNA-mRNA co-expression network revealed 36 network pairs comprising 10 differentially expressed mRNAs and 34 dysregulated lncRNAs. The results of bioinformatics analysis further indicated that dysregulated lncRNA NONHSAT174696, lncRNA NONHSAT179219, and lncRNA NONHSAT161887, as the regulators of EDAR, CYP1B1, and ALDH3A1 respectively, played an important role in the PCB 156-induced lipid metabolism disorder. CONCLUSION Our findings provide an overview of differentially expressed mRNAs and lncRNAs in L-02 cells exposed to PCB 156, and contribute to the field of polychlorinated biphenyl-induced non-alcoholic fatty liver disease.
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Affiliation(s)
- Ningning Chen
- College of Biological Science and Technology, University of Jinan, Jinan, 250022, China
| | - Qiuli Shan
- College of Biological Science and Technology, University of Jinan, Jinan, 250022, China; State Key Laboratory of Environmental Chemistry and Eco-Toxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Yu Qi
- State Key Laboratory of Environmental Chemistry and Eco-Toxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Wei Liu
- State Key Laboratory of Environmental Chemistry and Eco-Toxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Xiaojun Tan
- College of Biological Science and Technology, University of Jinan, Jinan, 250022, China
| | - Jinsong Gu
- College of Biological Science and Technology, University of Jinan, Jinan, 250022, China
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Wu X, Zhai G, Schnoor JL, Lehmler HJ. Atropselective Disposition of 2,2',3,4',6-Pentachlorobiphenyl (PCB 91) and Identification of Its Metabolites in Mice with Liver-Specific Deletion of Cytochrome P450 Reductase. Chem Res Toxicol 2019; 33:1328-1338. [PMID: 31403789 DOI: 10.1021/acs.chemrestox.9b00255] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hepatic cytochrome P450 enzymes metabolize chiral polychlorinated biphenyls (PCBs) to hydroxylated metabolites (OH-PCBs). Animal models with impaired metabolism of PCBs are one approach to study how the atropselective oxidation of PCBs to OH-PCBs contributes to toxic outcomes, such as neurodevelopmental disorders, following PCB exposure. We investigated the disposition of PCB 91, a para-substituted PCB congener, in mice with a liver-specific deletion of the cytochrome P450 reductase (cpr) gene (KO mice). KO mice and wild-type (WT) mice were exposed orally to racemic PCB 91 (30 mg/kg b.w.). Levels and enantiomeric fractions of PCB 91 and its hydroxylated metabolites were determined in tissues 3 days after PCB exposure and in excreta on days 1-3 after PCB exposure. PCB 91, but not OH-PCB levels were higher in KO compared to WT mice. The elevated fat and protein content in the liver of KO mice resulted in the hepatic accumulation of PCB 91. OH-PCBs were detected in blood, liver, and excreta samples of KO and WT mice. 2,2',3,4',6-Pentachlorobiphenyl-5-ol (5-91) was the major metabolite. A considerable percent of the total PCB 91 dose (%TD) was excreted with the feces as 5-91 (23%TD and 31%TD in KO and WT mice, respectively). We tentatively identified glucuronide and sulfate metabolites present in urine samples. The PCB 91 atropisomer eluting first on the chiral column (E1-PCB 91) displayed genotype-dependent atropisomeric enrichment, with a more pronounced atropisomeric enrichment observed in WT compared to KO mice. E1-atropisomers of 5-91 and 2,2',3,4',6-pentachlorobiphenyl-4-ol (4-91) were enriched in blood and liver, irrespective of the genotype; however, the extent of the enrichment of E1-5-91 was genotype dependent. These differences in atropselective disposition are consistent with slower metabolism of PCB 91 in KO compared to WT mice and the accumulation of the parent PCB in the fatty liver of KO mice.
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