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Rengelshausen J, Randerath I, Schettgen T, Esser A, Kaifie A, Lang J, Kraus T, Ziegler P. Ten years after: findings from the medical surveillance program on Health Effects in High-Level Exposure to PCB (HELPcB). Arch Toxicol 2023; 97:2609-2623. [PMID: 37594590 PMCID: PMC10474999 DOI: 10.1007/s00204-023-03578-1] [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: 07/12/2023] [Accepted: 08/03/2023] [Indexed: 08/19/2023]
Abstract
After the detection of high environmental and occupational exposure to polychlorinated biphenyls (PCBs) in a German recycling company for transformers and capacitors in 2010, the multidisciplinary medical surveillance program "HELPcB" (Health Effects in High-Level Exposure to PCB) was established for former PCB-exposed workers of the company, their family members, employees of surrounding companies, and area residents to investigate potential adverse health effects by PCB exposure in a longitudinal study approach with up to seven examination time points between 2010 and 2019. More than 300 individuals were enrolled into the program. Assessments particularly included plasma and urine concentrations of PCB congeners and their metabolites, clinical laboratory parameters, Comet assay, analysis of telomere length, neuropsychological examinations, psychological screening, abdominal and thyroid ultrasound examination. This review summarizes the main results of the studies conducted in the HELPcB program yielding relevant new data on potential adverse effects of PCB exposure in humans and potential mechanisms that underlie these effects. Even larger studies in PCB-exposed individuals are warranted to confirm the results of this program and to further establish causality between PCB exposure and clinical effects in humans.
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Affiliation(s)
- Jens Rengelshausen
- Institute for Occupational, Social and Environmental Medicine, Medical Faculty, RWTH Aachen University, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Isabella Randerath
- Institute for Occupational, Social and Environmental Medicine, Medical Faculty, RWTH Aachen University, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Thomas Schettgen
- Institute for Occupational, Social and Environmental Medicine, Medical Faculty, RWTH Aachen University, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Andre Esser
- Institute for Occupational, Social and Environmental Medicine, Medical Faculty, RWTH Aachen University, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Andrea Kaifie
- Institute for Occupational, Social and Environmental Medicine, Medical Faculty, RWTH Aachen University, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Jessica Lang
- Institute for Occupational, Social and Environmental Medicine, Medical Faculty, RWTH Aachen University, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Thomas Kraus
- Institute for Occupational, Social and Environmental Medicine, Medical Faculty, RWTH Aachen University, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Patrick Ziegler
- Institute for Occupational, Social and Environmental Medicine, Medical Faculty, RWTH Aachen University, Pauwelsstraße 30, 52074, Aachen, Germany.
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2
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Behan-Bush R, Liszewski JN, Schrodt MV, Vats B, Li X, Lehmler HJ, Klingelhutz AJ, Ankrum JA. Toxicity Impacts on Human Adipose Mesenchymal Stem/Stromal Cells Acutely Exposed to Aroclor and Non-Aroclor Mixtures of Polychlorinated Biphenyl. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:1731-1742. [PMID: 36651682 PMCID: PMC9893815 DOI: 10.1021/acs.est.2c07281] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 01/06/2023] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
Polychlorinated biphenyl (PCB) accumulates in adipose where it may impact the growth and function of cells within the tissue. This is particularly concerning during adolescence when adipocytes expand rapidly. Herein, we sought to understand how exposure to PCB mixtures found in U.S. schools affects human adipose mesenchymal stem/stromal cell (MSC) health and function. We investigated how exposure to Aroclor 1016 and Aroclor 1254, as well as a newly characterized non-Aroclor mixture that resembles the PCB profile found in cabinets, Cabinet Mixture, affects adipose MSC growth, viability, and function in vitro. We found that exposure to all three mixtures resulted in two distinct types of toxicity. At PCB concentrations >20 μM, the majority of MSCs die, while at 1-10 μM, MSCs remained viable but display numerous alterations to their phenotype. At these sublethal concentrations, the MSC rate of expansion slowed and morphology changed. Further assessment revealed that PCB-exposed MSCs had impaired adipogenesis and a modest decrease in immunosuppressive capabilities. Thus, exposure to PCB mixtures found in schools negatively impacts the health and function of adipose MSCs. This work has implications for human health due to MSCs' role in supporting the growth and maintenance of adipose tissue.
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Affiliation(s)
- Riley
M. Behan-Bush
- Roy
J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa 52242, United States
- Fraternal
Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa 52242, United States
| | - Jesse N. Liszewski
- Roy
J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa 52242, United States
- Fraternal
Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa 52242, United States
| | - Michael V. Schrodt
- Roy
J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa 52242, United States
- Fraternal
Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa 52242, United States
| | - Bhavya Vats
- Roy
J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa 52242, United States
| | - Xueshu Li
- Department
of Occupational and Environmental Health, University of Iowa, Iowa City, Iowa 52242, United States
| | - Hans-Joachim Lehmler
- Department
of Occupational and Environmental Health, University of Iowa, Iowa City, Iowa 52242, United States
| | - Aloysius J. Klingelhutz
- Fraternal
Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa 52242, United States
- Department
of Microbiology and Immunology, University
of Iowa, Iowa City, Iowa 52242, United States
| | - James A. Ankrum
- Roy
J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa 52242, United States
- Fraternal
Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, Iowa 52242, United States
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Alonso-Pedrero L, Donat-Vargas C, Bes-Rastrollo M, Ojeda-Rodríguez A, Zalba G, Razquin C, Martínez-González MA, Marti A. Dietary Exposure to Polychlorinated Biphenyls and Dioxins and Its Relationship to Telomere Length in Subjects Older Than 55 Years from the SUN Project. Nutrients 2022; 14:nu14020353. [PMID: 35057533 PMCID: PMC8779661 DOI: 10.3390/nu14020353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 02/05/2023] Open
Abstract
Exposure to persistent organic pollutants (POPs) may influence telomere length (TL), which is considered as a marker of biological age associated with the risk of chronic disease. We hypothesized that dietary exposure to polychlorinated biphenyls (PCBs) and dioxins could affect TL. Our aim was to evaluate the association of dietary exposure to PCBs and dioxins with TL. In this cross-sectional study of 886 subjects older than 55 y (mean age: 67.7; standard deviation (SD): 6.1; 27% women) from the “Seguimiento Universidad de Navarra” (SUN) project. TL was determined by real-time quantitative polymerase chain reaction and dietary PCBs and dioxins exposure was collected using a validated 136-item Food Frequency Questionnaire. Multivariable linear regression models were used to control for potential confounding factors. Shorter TL was associated with dietary total PCBs (SD of T/S ratio/(ng/day) = −0.30 × 10−7; 95% CI, −0.55 × 10−7 to −0.06 × 10−7), dioxin-like PCBs (DL-PCBs) (SD of T/S ratio/(pg WHO TEQ (Toxic Equivalents)/day) = −6.17 × 10−7; 95% CI, −11.30 × 10−7 to −1.03 × 10−7), and total TEQ exposure (SD of T/S ratio/(pg WHO TEQ/day) = −5.02 × 10−7; 95% CI, −9.44 × 10−7 to −0.61 × 10−7), but not with dioxins (SD of T/S ratio/(pg WHO TEQ/day) = −13.90 × 10−7; 95% CI, −37.70 × 10−7 to 9.79 × 10−7). In this sample of middle-aged and older Spanish adults, dietary exposure to total PCBs and DL-PCBs alone and together with dioxins was associated with shorter TL. Further longitudinal studies, preferably with POPs measured in biological samples, are needed to confirm this finding.
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Affiliation(s)
- Lucia Alonso-Pedrero
- Department of Nutrition, Food Science and Physiology, University of Navarra, 31008 Pamplona, Spain; (L.A.-P.); (A.O.-R.)
- Navarra Institute for Health Research (IdiSNA), 31008 Pamplona, Spain; (M.B.-R.); (G.Z.); (M.A.M.-G.)
| | - Carolina Donat-Vargas
- Departament of Preventive Medicine and Public Health, School of Medicine, Universidad Autónoma de Madrid, CEI UAM+ CSIC, 28049 Madrid, Spain;
- Unit of Nutritional and Cardiovascular Epidemiology, Environmental Medicine Institute (IMM), Karolinska Institutet, 17177 Stockholm, Sweden
- Physiopathology of Obesity and Nutrition Networking Biomedical Research Centre (CIBERobn), Spanish National Institute of Health Carlos III, 28029 Madrid, Spain;
| | - Maira Bes-Rastrollo
- Navarra Institute for Health Research (IdiSNA), 31008 Pamplona, Spain; (M.B.-R.); (G.Z.); (M.A.M.-G.)
- Physiopathology of Obesity and Nutrition Networking Biomedical Research Centre (CIBERobn), Spanish National Institute of Health Carlos III, 28029 Madrid, Spain;
- Department of Preventive Medicine and Public Health, University of Navarra, 31008 Pamplona, Spain
| | - Ana Ojeda-Rodríguez
- Department of Nutrition, Food Science and Physiology, University of Navarra, 31008 Pamplona, Spain; (L.A.-P.); (A.O.-R.)
- Navarra Institute for Health Research (IdiSNA), 31008 Pamplona, Spain; (M.B.-R.); (G.Z.); (M.A.M.-G.)
| | - Guillermo Zalba
- Navarra Institute for Health Research (IdiSNA), 31008 Pamplona, Spain; (M.B.-R.); (G.Z.); (M.A.M.-G.)
- Department of Biochemistry and Genetics, University of Navarra, 31008 Pamplona, Spain
| | - Cristina Razquin
- Physiopathology of Obesity and Nutrition Networking Biomedical Research Centre (CIBERobn), Spanish National Institute of Health Carlos III, 28029 Madrid, Spain;
- Department of Preventive Medicine and Public Health, University of Navarra, 31008 Pamplona, Spain
| | - Miguel A. Martínez-González
- Navarra Institute for Health Research (IdiSNA), 31008 Pamplona, Spain; (M.B.-R.); (G.Z.); (M.A.M.-G.)
- Physiopathology of Obesity and Nutrition Networking Biomedical Research Centre (CIBERobn), Spanish National Institute of Health Carlos III, 28029 Madrid, Spain;
- Department of Preventive Medicine and Public Health, University of Navarra, 31008 Pamplona, Spain
- Department of Nutrition, Harvard TH Chan School of Public Health, Boston, MA 02115, USA
| | - Amelia Marti
- Department of Nutrition, Food Science and Physiology, University of Navarra, 31008 Pamplona, Spain; (L.A.-P.); (A.O.-R.)
- Navarra Institute for Health Research (IdiSNA), 31008 Pamplona, Spain; (M.B.-R.); (G.Z.); (M.A.M.-G.)
- Physiopathology of Obesity and Nutrition Networking Biomedical Research Centre (CIBERobn), Spanish National Institute of Health Carlos III, 28029 Madrid, Spain;
- Correspondence: ; Tel.: +34-948-425600 (ext. 806244)
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Zhang CY, Flor S, Ruiz P, Dhakal R, Hu X, Teesch LM, Ludewig G, Lehmler HJ. 3,3'-Dichlorobiphenyl Is Metabolized to a Complex Mixture of Oxidative Metabolites, Including Novel Methoxylated Metabolites, by HepG2 Cells. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:12345-12357. [PMID: 32910851 PMCID: PMC7544623 DOI: 10.1021/acs.est.0c03476] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
3,3'-Dichlorobiphenyl (PCB 11) is a byproduct of industrial processes and detected in environmental samples. PCB 11 and its metabolites are present in human serum, and emerging evidence demonstrates that PCB 11 is a developmental neurotoxicant. However, little is known about the metabolism of PCB 11 in humans. Here, we investigated the metabolism of PCB 11 and the associated metabolomics changes in HepG2 cells using untargeted high-resolution mass spectrometry. HepG2 cells were exposed for 24 h to PCB 11 in DMSO or DMSO alone. Cell culture media were analyzed with ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry. Thirty different metabolites were formed by HepG2 cells exposed to 10 μM PCB 11, including monohydroxylated, dihydroxylated, methoxylated-hydroxylated, and methoxylated-dihydroxylated metabolites and the corresponding sulfo and glucuronide conjugates. The methoxylated PCB metabolites were observed for the first time in a human-relevant model. 4-OH-PCB 11 (3,3'-dichlorobiphenyl-4-ol) and the corresponding catechol metabolite, 4,5-di-OH-PCB 11 (3',5-dichloro-3,4-dihydroxybiphenyl), were unambiguously identified based on liquid and gas chromatographic analyses. PCB 11 also altered several metabolic pathways, in particular vitamin B6 metabolism. These results demonstrate that complex PCB 11 metabolite profiles are formed in HepG2 cells that warrant further toxicological investigation, particularly since catechol metabolites are likely reactive and toxic.
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Affiliation(s)
- Chun-Yun Zhang
- Department of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Susanne Flor
- Department of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Patricia Ruiz
- Divison of Toxicology and Human Health Sciences, Computational Toxicology and Methods Development Lab, Agency for Toxic Substances and Disease Registry, Atlanta, Georgia 30333, United States
| | - Ram Dhakal
- Department of Occupational and Environmental Health, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Xin Hu
- Department of Medicine, School of Medicine, Emory University, Atlanta, GA 30303, United States
| | - Lynn M. Teesch
- High Resolution Mass Spectrometry Facility, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Gabriele Ludewig
- Department of Occupational and Environmental Health, 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
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5
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Yuan J, Liu Y, Wang J, Zhao Y, Li K, Jing Y, Zhang X, Liu Q, Geng X, Li G, Wang F. Long-term Persistent Organic Pollutants Exposure Induced Telomere Dysfunction and Senescence-Associated Secretary Phenotype. J Gerontol A Biol Sci Med Sci 2019; 73:1027-1035. [PMID: 29360938 PMCID: PMC6037063 DOI: 10.1093/gerona/gly002] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 01/16/2018] [Indexed: 12/21/2022] Open
Abstract
Environmentally persistent organic pollutant (POP) is the general term for refractory organic compounds that show long-range atmospheric transport, environmental persistence, and bioaccumulation. It has been reported that the accumulation of POPs could lead to cellular DNA damage and adverse effects of on metabolic health. To better understand the mechanism of the health risks associated with POPs, we conducted an evidence-based cohort investigation (n = 5,955) at the Jinghai e-waste disposal center in China from 2009 to 2016, where people endure serious POP exposure. And high levels of aging-related diseases, including hypertension, diabetes, autoimmune diseases, and reproductive disorders were identified associated with the POP exposure. In the subsequent molecular level study, an increased telomere dysfunction including telomere multiple telomere signals, telomere signal-free ends, telomere shortening and activation of alternative lengthening of telomeres were observed, which might result from the hypomethylated DNA modification induced telomeric repeat-containing RNA overexpression. Moreover, dysfunctional telomere-leaded senescence-associated secretory phenotype was confirmed, as the proinflammatory cytokines and immunosenescence hallmarks including interleukin-6, P16INK4a, and P14ARF were stimulated. Thus, we proposed that the dysfunctional telomere and elevated systemic chronic inflammation contribute to the aging-associated diseases, which were highly developed among the POP exposure individuals.
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Affiliation(s)
- Jinghua Yuan
- Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, China
| | - Yang Liu
- Department of Radiobiology, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Juan Wang
- Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, China
| | - Yuxia Zhao
- Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, China
| | - Keqiu Li
- Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, China
| | - Yaqing Jing
- Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, China
| | - Xiaoning Zhang
- Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, China
| | - Qiang Liu
- Department of Radiobiology, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Xin Geng
- Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, China
| | - Guang Li
- Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, China
| | - Feng Wang
- Department of Genetics, School of Basic Medical Sciences, Tianjin Medical University, China
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Vriens A, Nawrot TS, Janssen BG, Baeyens W, Bruckers L, Covaci A, De Craemer S, De Henauw S, Den Hond E, Loots I, Nelen V, Schettgen T, Schoeters G, Martens DS, Plusquin M. Exposure to Environmental Pollutants and Their Association with Biomarkers of Aging: A Multipollutant Approach. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:5966-5976. [PMID: 31041867 DOI: 10.1021/acs.est.8b07141] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Mitochondrial DNA (mtDNA) content and telomere length are putative aging biomarkers and are sensitive to environmental stressors, including pollutants. Our objective was to identify, from a set of environmental exposures, which exposure is associated with leukocyte mtDNA content and telomere length in adults. This study includes 175 adults from 50 to 65 years old from the cross-sectional Flemish Environment and Health study, of whom leukocyte telomere length and mtDNA content were determined using qPCR. The levels of exposure of seven metals, 11 organohalogens, and four perfluorinated compounds (PFHxS, PFNA, PFOA, PFOS) were measured. We performed sparse partial least-squares regression analyses followed by ordinary least-squares regression to assess the multipollutant associations. While accounting for possible confounders and coexposures, we identified that urinary cadmium (6.52%, 95% confidence interval, 1.06, 12.28), serum hexachlorobenzene (2.89%, 018, 5.68), and perfluorooctanesulfonic acid (11.38%, 5.97, 17.08) exposure were positively associated ( p < 0.05) with mtDNA content, while urinary copper (-9.88%, -14.82, -4.66) and serum perfluorohexanesulfonic acid (-4.75%, -8.79, -0.54) exposure were inversely associated with mtDNA content. Urinary antimony (2.69%, 0.45, 4.99) and mercury (1.91%, 0.42, 3.43) exposure were positively associated with leukocyte telomere length, while urinary copper (-3.52%, -6.60, -0.34) and serum perfluorooctanesulfonic acid (-3.64%, -6.60, -0.60) showed an inverse association. Our findings support the hypothesis that environmental pollutants interact with molecular hallmarks of aging.
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Affiliation(s)
- Annette Vriens
- Centre for Environmental Sciences , Hasselt University , Hasselt 3500 , Belgium
| | - Tim S Nawrot
- Centre for Environmental Sciences , Hasselt University , Hasselt 3500 , Belgium
- Department of Public Health & Primary Care , Leuven University , Leuven 3000 , Belgium
| | - Bram G Janssen
- Centre for Environmental Sciences , Hasselt University , Hasselt 3500 , Belgium
| | - Willy Baeyens
- Department of Analytical and Environmental Chemistry , Vrije Universiteit Brussel , Brussels 1050 , Belgium
| | - Liesbeth Bruckers
- Interuniversity Institute for Biostatistics and Statistical Bioinformatics , Hasselt University , Diepenbeek 3590 , Belgium
| | | | - Sam De Craemer
- Department of Analytical and Environmental Chemistry , Vrije Universiteit Brussel , Brussels 1050 , Belgium
| | - Stefaan De Henauw
- Department of Public Health , Ghent University , Ghent 9000 , Belgium
| | - Elly Den Hond
- Provincial Institute for Hygiene , Antwerp 2000 , Belgium
| | | | - Vera Nelen
- Provincial Institute for Hygiene , Antwerp 2000 , Belgium
| | - Thomas Schettgen
- Institute for Occupational, Social and Environmental Medicine, Medical Faculty , RWTH Aachen University , Aachen 52062 , Germany
| | - Greet Schoeters
- Environmental Risk and Health , Flemish Institute for Technological Research (VITO) , Mol 2400 , Belgium
| | - Dries S Martens
- Centre for Environmental Sciences , Hasselt University , Hasselt 3500 , Belgium
| | - Michelle Plusquin
- Centre for Environmental Sciences , Hasselt University , Hasselt 3500 , Belgium
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de Souza MR, Kahl VFS, Rohr P, Kvitko K, Cappetta M, Lopes WM, da Silva J. Shorter telomere length and DNA hypermethylation in peripheral blood cells of coal workers. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2018; 836:36-41. [DOI: 10.1016/j.mrgentox.2018.03.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 10/31/2017] [Accepted: 03/27/2018] [Indexed: 12/31/2022]
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Vasko T, Hoffmann J, Gostek S, Schettgen T, Quinete N, Preisinger C, Kraus T, Ziegler P. Telomerase gene expression bioassays indicate metabolic activation of genotoxic lower chlorinated polychlorinated biphenyls. Sci Rep 2018; 8:16903. [PMID: 30443001 PMCID: PMC6237825 DOI: 10.1038/s41598-018-35043-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 10/29/2018] [Indexed: 12/18/2022] Open
Abstract
Polychlorinated biphenyls (PCBs) are ubiquitously occurring pollutants with different chemical and toxicological properties. In this study we evaluated blood plasma samples of two PCB-exposed cohorts for their ability to alter telomerase (hTERT) gene expression. Blood plasma from PCB-exposed individuals inhibited hTERT expression depending solely on the concentration of lower chlorinated PCBs, with the lowest observed adverse effect level (LOAEL) at a plasma concentration between 0.5 and 2 µg/L of LC PCBs. Individual OH-metabolites derived from the WHO indicator congeners PCB 28 and PCB 101 mimicked these effects on hTERT expression in vitro with high toxicity, including DNA damage. However, by the combination of different OH-metabolites, the bio effective PCB concentration was reduced and the respective effects on hTERT expression could be increased. At a concentration which showed no toxic activity in MTT assay, hTERT inhibition reflected the interference of OH-PCBs with the mitochondrial respiratory chain, which could lead to the production of reactive oxygen species (ROS). As individual OH-metabolites already showed a much stronger inhibition of hTERT gene expression at a lower concentration than their parental compounds, the hTERT gene expression bioassay described in this study seems to indicate metabolic activation of LC PCBs rather than the mere effect of LC PCBs on their own. In summary, this study provides dose-response linkages between effects of lower chlorinated PCBs and their concentrations in human plasma.
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Affiliation(s)
- Theresa Vasko
- Institute for Occupational, Social and Environmental Medicine, RWTH Aachen University, Aachen, Germany
| | - Jenny Hoffmann
- Institute for Occupational, Social and Environmental Medicine, RWTH Aachen University, Aachen, Germany
| | - Sonja Gostek
- Institute for Occupational, Social and Environmental Medicine, RWTH Aachen University, Aachen, Germany
| | - Thomas Schettgen
- Institute for Occupational, Social and Environmental Medicine, RWTH Aachen University, Aachen, Germany
| | - Natalia Quinete
- Institute for Occupational, Social and Environmental Medicine, RWTH Aachen University, Aachen, Germany.,Southeast Environmental Research Center, Florida International University Florida, Florida, USA
| | | | - Thomas Kraus
- Institute for Occupational, Social and Environmental Medicine, RWTH Aachen University, Aachen, Germany
| | - Patrick Ziegler
- Institute for Occupational, Social and Environmental Medicine, RWTH Aachen University, Aachen, Germany.
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9
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Callahan CL, Pavuk M, Birnbaum LS, Ren X, Olson JR, Bonner MR. Serum polychlorinated biphenyls and leukocyte telomere length in a highly-exposed population: The Anniston Community Health Survey. ENVIRONMENT INTERNATIONAL 2017; 108:212-220. [PMID: 28886414 PMCID: PMC5623110 DOI: 10.1016/j.envint.2017.08.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 08/26/2017] [Accepted: 08/27/2017] [Indexed: 05/05/2023]
Abstract
BACKGROUND Serum polychlorinated biphenyls (PCBs) have previously been associated with longer leukocyte telomere length (LTL) in most, but not all, of the few previous studies. PCBs were produced in Anniston, Alabama from 1929 to 1971 and participants of the Anniston Community Health Survey (ACHS) were highly exposed. OBJECTIVES We evaluated serum levels of 35 PCBs and relative telomere length in 559 ACHS participants. METHODS Relative LTL was measured in DNA extracted from blood clots. We assessed PCBs individually, grouped by chlorination, and summed PCBs. We used linear regression to assess the association between each PCB metric while adjusting for pertinent covariates. RESULTS Serum PCBs were associated with longer LTL among white participants and the oldest age group of black participants. Among white participants, compared with those in the first quartile of sum PCBs those in the third quartile of sum PCBs had 8.09% longer relative LTL (95% CI: 1.99; 14.55) and those in the fourth had 7.58% longer relative LTL (95%CI: -0.01; 15.76) (p-quadratic=0.05). Among African American participants, serum PCBs were associated with longer relative LTL among those over age 64 only. Tests for interaction were not statistically significant. CONCLUSIONS We observed a non-linear positive association between serum PCBs and LTL among white participants. Serum PCBs were associated with longer LTL in the oldest age group of African Americans. This association may provide insight into the cancers previously associated with exposure to PCBs, melanoma and non-Hodgkin lymphoma, which have been associated with long LTL in previous studies.
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Affiliation(s)
- Catherine L Callahan
- Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA.
| | - Marian Pavuk
- Division of Toxicology and Human Health Sciences, Agency for Toxic Substances and Disease Registry, Centers for Disease Control, Atlanta, GA, USA
| | - Linda S Birnbaum
- National Cancer Institute at NIEHS, Research Triangle Park, NC, USA
| | - Xuefeng Ren
- Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA
| | - James R Olson
- Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA
| | - Matthew R Bonner
- Department of Epidemiology and Environmental Health, School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA
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Ledda C, Loreto C, Zammit C, Marconi A, Fago L, Matera S, Costanzo V, Sanzà GF, Palmucci S, Ferrante M, Costa C, Fenga C, Biondi A, Pomara C, Rapisarda V. Non‑infective occupational risk factors for hepatocellular carcinoma: A review (Review). Mol Med Rep 2017; 15:511-533. [PMID: 28000892 PMCID: PMC5364850 DOI: 10.3892/mmr.2016.6046] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 07/01/2016] [Indexed: 02/07/2023] Open
Abstract
Liver cancer is the second leading worldwide cause of cancer‑associated mortalities. Hepatocellular carcinoma, which accounts for the majority of liver tumors, ranks fifth among types of human cancer. Well‑established risk factors for liver cancer include the hepatitis B and C viruses, aflatoxins, alcohol consumption, and oral contraceptives. Tobacco smoking, androgenic steroids, and diabetes mellitus are suspected risk factors. Current knowledge regarding non‑infective occupational risk factors for liver cancer is inconclusive. The relevance of liver disorders to occupational medicine lies in the fact that the majority of chemicals are metabolized in the liver, and toxic metabolites generated via metabolism are the predominant cause of liver damage. However, their non‑specific clinical manifestations that are similar in a number of liver diseases make diagnosis difficult. Furthermore, concomitant conditions, such as viral hepatitis and alcohol or drug abuse, may mask liver disorders that result from occupational hepatotoxic agents and block the demonstration of an occupational cause. The identification of environmental agents that result in human cancer is a long and often difficult process. The purpose of the present review is to summarize current knowledge regarding the association of non‑infective occupational risk exposure and HCC, to encourage further research and draw attention to this global occupational public health problem.
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Affiliation(s)
- Caterina Ledda
- Occupational Medicine, Department of Clinical and Experimental Medicine, University of Catania, I-95123 Catania, Italy
- Hygiene and Public Health, Department of Medical Sciences, Surgical and Advanced Technologies ‘GF Ingrassia’, University of Catania, I-95123 Catania, Italy
| | - Carla Loreto
- Human Anatomy and Histology, Department of Biomedical and Biotechnology Sciences, University of Catania, I-95123 Catania, Italy
| | - Christian Zammit
- Anatomy Department, Faculty of Medicine and Surgery, University of Malta, MSD-2080 Msida, Malta
| | - Andrea Marconi
- Occupational Medicine, Department of Clinical and Experimental Medicine, University of Catania, I-95123 Catania, Italy
| | - Lucrezia Fago
- Occupational Medicine, Department of Clinical and Experimental Medicine, University of Catania, I-95123 Catania, Italy
| | - Serena Matera
- Occupational Medicine, Department of Clinical and Experimental Medicine, University of Catania, I-95123 Catania, Italy
| | - Valentina Costanzo
- Occupational Medicine, Department of Clinical and Experimental Medicine, University of Catania, I-95123 Catania, Italy
| | - Giovanni Fuccio Sanzà
- Division of Radiology, ‘Policlinico-Vittorio Emanuele’ University Hospital, University of Catania, I-95123 Catania, Italy
| | - Stefano Palmucci
- Division of Radiology, ‘Policlinico-Vittorio Emanuele’ University Hospital, University of Catania, I-95123 Catania, Italy
| | - Margherita Ferrante
- Hygiene and Public Health, Department of Medical Sciences, Surgical and Advanced Technologies ‘GF Ingrassia’, University of Catania, I-95123 Catania, Italy
| | - Chiara Costa
- Occupational Medicine, Department of the Environment, Safety, Territory, Food and Health Sciences, University of Messina, I-98125 Messina, Italy
| | - Concettina Fenga
- Occupational Medicine, Department of the Environment, Safety, Territory, Food and Health Sciences, University of Messina, I-98125 Messina, Italy
| | - Antonio Biondi
- General Surgery, Department of General Surgery and Medical-Surgical Specialties, University of Catania, I-95123 Catania, Italy
| | - Cristoforo Pomara
- Anatomy Department, Faculty of Medicine and Surgery, University of Malta, MSD-2080 Msida, Malta
- Forensic Pathology, Department of Clinical and Experimental Medicine, University of Foggia, I-71122 Foggia, Italy
| | - Venerando Rapisarda
- Occupational Medicine, Department of Clinical and Experimental Medicine, University of Catania, I-95123 Catania, Italy
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Ziegler S, Schettgen T, Beier F, Wilop S, Quinete N, Esser A, Masouleh BK, Ferreira MSV, Vankann L, Uciechowski P, Rink L, Kraus T, Brümmendorf TH, Ziegler P. Accelerated telomere shortening in peripheral blood lymphocytes after occupational polychlorinated biphenyls exposure. Arch Toxicol 2017; 91:289-300. [PMID: 27146145 PMCID: PMC5225163 DOI: 10.1007/s00204-016-1725-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 04/21/2016] [Indexed: 12/30/2022]
Abstract
Polychlorinated biphenyls (PCBs) are organochlorine pollutants with a worldwide dissemination. We examined telomere length (TL) in peripheral blood cells of 207 individuals with a high body burden of PCBs due to occupational exposure in a transformer recycling company. Whereas TL in granulocytes was not affected, the age-adjusted TL in lymphocytes (∆TLLymph) of exposed individuals was significantly shorter than expected [-0.77 kb; 95 % confidence interval (CI) -0.9316; -0.6052; p = 0.0001]. PCB exposure did not affect lymphocyte numbers or T cell receptor excision circle (TREC) levels in T cells, suggesting that PCBs cause loss of telomeric DNA in T cells due to their metabolic activation and antigen-stimulated proliferation. In support of this hypothesis, blood plasma levels of PCB-exposed individuals inhibited expression of telomerase, the telomere elongating enzyme in vitro in antigen-specific T cell proliferation assays. 3-OH-CB28, a downstream metabolite of the lower chlorinated PCB-28 in PCB-exposed individuals (mean blood plasma concentration: 0.185 ± 0.68 ng/mL), inhibited telomerase gene expression within 48 h of incubation in lymphoproliferative assays starting at a concentration of 0.27-6.75 µg/mL and accelerated telomere shortening in long-term cell culture experiments. Accelerated telomere shortening due to PCB exposure may lead to limitations of cell renewal and clonal expansion of lymphocyte populations. As PCB-related immune dysfunctions have been linked to increased susceptibility to infectious diseases and increased risk of cancer, our data provide a possible explanation, for how PCBs could promote infections and cancer through limiting immune surveillance.
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Affiliation(s)
- Susanne Ziegler
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Thomas Schettgen
- Institute for Occupational and Social Medicine, University Hospital of the RWTH Aachen, RWTH Aachen University, Aachen, Germany
| | - Fabian Beier
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Stefan Wilop
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Natalia Quinete
- Institute for Occupational and Social Medicine, University Hospital of the RWTH Aachen, RWTH Aachen University, Aachen, Germany
| | - Andre Esser
- Institute for Occupational and Social Medicine, University Hospital of the RWTH Aachen, RWTH Aachen University, Aachen, Germany
| | - Behzad Kharabi Masouleh
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Monica S V Ferreira
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Lucia Vankann
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | | | - Lothar Rink
- Institute of Immunology, RWTH Aachen University, Aachen, Germany
| | - Thomas Kraus
- Institute for Occupational and Social Medicine, University Hospital of the RWTH Aachen, RWTH Aachen University, Aachen, Germany
| | - Tim H Brümmendorf
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Patrick Ziegler
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Medical Faculty, RWTH Aachen University, Aachen, Germany.
- Institute for Occupational and Social Medicine, University Hospital of the RWTH Aachen, RWTH Aachen University, Aachen, Germany.
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12
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Xin X, Senthilkumar PK, Schnoor JL, Ludewig G. Effects of PCB126 and PCB153 on telomerase activity and telomere length in undifferentiated and differentiated HL-60 cells. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:2173-85. [PMID: 26330309 PMCID: PMC4718801 DOI: 10.1007/s11356-015-5187-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Accepted: 08/10/2015] [Indexed: 05/08/2023]
Abstract
PCBs are persistent organic pollutants that are carcinogenic and immunotoxic and have developmental toxicity. This suggests that they may interfere with normal cell maturation. Cancer and stem/progenitor cells have telomerase activity to maintain and protect the chromosome ends, but lose this activity during differentiation. We hypothesized that PCBs interfere with telomerase activity and the telomere complex, thereby disturbing cell differentiation and stem/progenitor cell function. HL-60 cells are cancer cells that can differentiated into granulocytes and monocytes. We exposed HL-60 cells to PCB126 (dioxin-like) and PCB153 (nondioxin-like) 6 days before and during 3 days of differentiation. The differentiated cells showed G0/G1 phase arrest and very low telomerase activity. hTERT and hTR, two telomerase-related genes, were downregulated. The telomere shelterins TRF1, TRF2, and POT1 were upregulated in granulocytes, and TRF2 was upregulated and POT1 downregulated in monocytes. Both PCBs further reduced telomerase activity in differentiated cells, but had only small effects on the differentiation and telomere-related genes. Treatment of undifferentiated HL-60 cells for 30 days with PCB126 produced a downregulation of telomerase activity and a decrease of hTERT, hTR, TRF1, and POT1 gene expression. With PCB153, the effects were less pronounced and some shelterin genes were increased after 30 days of exposure. With each PCB, no differentiation of cells was observed and cells continued to proliferate despite reduced telomerase activity, resulting in shortened telomeres after 30 days of exposure. These results indicate cell-type and PCB congener-specific effects on telomere/telomerase-related genes. Although PCBs do not seem to strongly affect differentiation, they may influence stem or progenitor cells through telomere attrition with potential long-term consequences for health.
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Affiliation(s)
- Xing Xin
- Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA, 52242, USA
| | - P K Senthilkumar
- Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA, 52242, USA
- Risk Evaluation Branch, Center for Disease Control and Prevention, Cincinnati, OH, 45226, USA
| | - Jerald L Schnoor
- Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA, 52242, USA
- Department of Civil and Environmental Engineering, The University of Iowa, Iowa City, IA, 52242, USA
- Department of Occupational and Environmental Health, The University of Iowa, 100 Oakdale Campus, IREH, Iowa City, IA, 52242-5000, USA
| | - Gabriele Ludewig
- Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA, 52242, USA.
- Department of Occupational and Environmental Health, The University of Iowa, 100 Oakdale Campus, IREH, Iowa City, IA, 52242-5000, USA.
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13
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Grimm FA, Hu D, Kania-Korwel I, Lehmler HJ, Ludewig G, Hornbuckle KC, Duffel MW, Bergman A, Robertson LW. Metabolism and metabolites of polychlorinated biphenyls. Crit Rev Toxicol 2015; 45:245-72. [PMID: 25629923 PMCID: PMC4383295 DOI: 10.3109/10408444.2014.999365] [Citation(s) in RCA: 276] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Accepted: 12/11/2014] [Indexed: 11/13/2022]
Abstract
Abstract The metabolism of polychlorinated biphenyls (PCBs) is complex and has an impact on toxicity, and thereby on the assessment of PCB risks. A large number of reactive and stable metabolites are formed in the processes of biotransformation in biota in general, and in humans in particular. The aim of this document is to provide an overview of PCB metabolism, and to identify the metabolites of concern and their occurrence. Emphasis is given to mammalian metabolism of PCBs and their hydroxyl, methylsulfonyl, and sulfated metabolites, especially those that persist in human blood. Potential intracellular targets and health risks are also discussed.
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Affiliation(s)
- FA Grimm
- Interdisciplinary Graduate Program in Human Toxicology, Department of Pharmaceutical Sciences & Experimental Therapeutics, University of Iowa
| | - D Hu
- Department of Civil and Environmental Engineering, University of Iowa
| | - I Kania-Korwel
- Department of Occupational & Environmental Health, University of Iowa
| | - HJ Lehmler
- Interdisciplinary Graduate Program in Human Toxicology, Department of Occupational & Environmental Health, University of Iowa
| | - G Ludewig
- Interdisciplinary Graduate Program in Human Toxicology, Department of Occupational & Environmental Health, University of Iowa
| | - KC Hornbuckle
- Interdisciplinary Graduate Program in Human Toxicology, Department of Civil and Environmental Engineering, University of Iowa
| | - MW Duffel
- Interdisciplinary Graduate Program in Human Toxicology, Department of Pharmaceutical Sciences & Experimental Therapeutics, University of Iowa
| | - A Bergman
- Swedish Toxicology Sciences Research Center (SWETOX), Forskargatan 20, SE-151 36 Södertälje, SWEDEN
| | - LW Robertson
- Interdisciplinary Graduate Program in Human Toxicology, Department of Occupational & Environmental Health, University of Iowa
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14
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Intercalation binding of food antioxidant butylated hydroxyanisole to calf thymus DNA. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2014; 141:253-61. [PMID: 25463675 DOI: 10.1016/j.jphotobiol.2014.10.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 09/26/2014] [Accepted: 10/22/2014] [Indexed: 12/28/2022]
Abstract
The binding properties of food antioxidant butylated hydroxyanisole (BHA) associated with calf thymus DNA (ctDNA) in physiological buffer (pH 7.4) were investigated. Experimental results based on fluorescence, UV-vis absorption, circular dichroism (CD), viscosity measurements and autodocking techniques confirmed the intercalation binding between BHA and ctDNA. The changes in Fourier transform infrared spectra of ctDNA induced by BHA suggested that BHA was more prone to bind to G-C rich region of ctDNA, which was further ascertained with the molecular docking studies. Analysis of the CD spectra indicated that this binding interaction led to a transformation from B-like DNA structure toward A-like conformation. The complexation of BHA with ctDNA was driven mainly by hydrogen bonds and hydrophobic forces. The binding constants of the BHA-ctDNA complex were calculated to be 2.03 × 10(4), 1.92 × 10(4) and 1.59 × 10(4)L mol(-1) at 298, 304 and 310 K, respectively. Gel electrophoresis results suggested that intercalated BHA molecules did not significantly affect plasmid DNA. Moreover, the concentration profiles and the spectra for the three reaction components (BHA, ctDNA, and BHA-ctDNA complex) of the system by resolving the augmented UV-vis spectral data matrix with the use of multivariate curve resolution-alternating least squares approach provided quantitative data to estimate the progress of BHA-ctDNA interaction. This study is expected to provide new insights into the mechanism of interaction between BHA and ctDNA.
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15
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Zhu Y, Mapuskar KA, Marek RF, Xu W, Lehmler HJ, Robertson LW, Hornbuckle KC, Spitz DR, Aykin-Burns N. A new player in environmentally induced oxidative stress: polychlorinated biphenyl congener, 3,3'-dichlorobiphenyl (PCB11). Toxicol Sci 2013; 136:39-50. [PMID: 23997111 DOI: 10.1093/toxsci/kft186] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recent analysis of air samples from Chicago and Lake Michigan areas observed a ubiquitous airborne polychlorinated biphenyl (PCB) congener, 3,3'-dichlorobiphenyl (PCB11). Our analysis of serum samples also revealed the existence of hydroxylated metabolites of PCB11 in human blood. Because PCBs and PCB metabolites have been suggested to induce oxidative stress, this study sought to determine whether environmental exposure to PCB11 and its 4-hydroxyl metabolite could induce alterations in steady-state levels of reactive oxygen species (ROS) and cytotoxicity in immortalized human prostate epithelial cells (RWPE-1). This study also examines if antioxidants could protect the cells from PCB11-induced cytotoxicity. Exponentially growing RWPE-1 cells were exposed to PCB11 and its metabolite, 3,3'-dichlorobiphenyl-4-ol (4-OH-PCB11), as well as an airborne PCB mixture resembling the Chicago ambient air congener profile, every day for 5 days. Results showed that 4-OH-PCB11 could significantly induce cell growth suppression and decrease the viability and plating efficiency of RWPE-1 cells. 4-OH-PCB11 also significantly increased steady-state levels of intracellular superoxide, O₂•⁻), as well as hydroperoxides. Finally, treatment with the combination of polyethylene glycol-conjugated CuZn superoxide dismutase and catalase added 1h after 4-OH-PCB11 exposures, significantly protected RWPE-1 cells from PCB toxicity. The results strongly support the hypothesis that exposure to a hydroxylated metabolite of PCB11 can inhibit cell proliferation and cause cytotoxicity by increasing steady-state levels of ROS. Furthermore, antioxidant treatments following PCBs exposure could significantly mitigate the PCB-induced cytotoxicity in exponentially growing human prostate epithelial cells.
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Affiliation(s)
- Yueming Zhu
- * Free Radical and Radiation Biology Program, B180 Medical Laboratories, Department of Radiation Oncology, Holden Comprehensive Cancer Center
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16
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Ludewig G, Robertson LW. Polychlorinated biphenyls (PCBs) as initiating agents in hepatocellular carcinoma. Cancer Lett 2013; 334:46-55. [PMID: 23211541 PMCID: PMC3648605 DOI: 10.1016/j.canlet.2012.11.041] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 11/20/2012] [Accepted: 11/25/2012] [Indexed: 12/11/2022]
Abstract
PCBs are carcinogens, but for many decades it was assumed that PCBs may not possess initiating activity. Initiation is a process that involves changes in the DNA sequence, often, but not exclusively produced through DNA adduction by a reactive compound or reactive oxygen species (ROS). DNA adducts can be detected by (32)P-postlabeling, a method that Dr. Ramesh Gupta co-developed and refined. Today these types of assays together with other mechanistic studies provide convincing evidence that specific PCB congeners can be biotransformed to genotoxic and therefore potentially initiating metabolites. This review will provide an overview of our current knowledge of PCBs' genotoxic potential and mechanism of action, emphasizing the contributions of Dr. Ramesh Gupta during his tenures at the Universities of Kentucky and Louisville.
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Affiliation(s)
- Gabriele Ludewig
- The University of Iowa, 100 Oakdale Campus, IREH, Iowa City, IA 52242-5000, United States.
| | - Larry W Robertson
- The University of Iowa, 100 Oakdale Campus, IREH, Iowa City, IA 52242-5000, United States
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Dhakal K, He X, Lehmler HJ, Teesch LM, Duffel MW, Robertson LW. Identification of sulfated metabolites of 4-chlorobiphenyl (PCB3) in the serum and urine of male rats. Chem Res Toxicol 2012; 25:2796-804. [PMID: 23137097 DOI: 10.1021/tx300416v] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polychlorinated biphenyls (PCBs) are legacy pollutants that exert toxicities through various mechanisms. In recent years exposure to PCBs via inhalation has been recognized as a hazard. Those PCBs with lower numbers of chlorine atoms (LC-PCBs) are semivolatile and have been reported in urban air, as well as in the indoor air of older buildings. LC-PCBs are bioactivated to phenols and further to quinone electrophiles with genotoxic/carcinogenic potential. We hypothesized that phenolic LC-PCBs are subject to conjugation and excretion in the urine. PCB3, often present in high concentrations in air, is a prototypical congener for the study of the metabolism and toxicity of LC-PCBs. Our objective was to identify metabolites of PCB3 in urine that could be potentially employed in the estimation of exposure to LC-PCBs. Male Sprague-Dawley rats (150-175 g) were housed in metabolism cages and received a single intraperitoneal injection of 600 μmol/kg body weight of PCB3. Urine was collected every 4 h; rats were euthanized at 36 h; and serum was collected. LC/MS analysis of urine before and after incubation with β-glucuronidase and sulfatase showed that sulfate conjugates were in higher concentrations than glucuronide conjugates and free phenolic forms. At least two major metabolites and two minor metabolites were identified in urine that could be attributed to mercapturic acid metabolites of PCB3. Quantitation by authentic standards confirmed that approximately 3% of the dose was excreted in the urine as sulfates over 36 h, with peak excretion occurring at 10-20 h after exposure. The major metabolites were 4'PCB3sulfate, 3'PCB3 sulfate, 2'PCB3 sulfate, and presumably a catechol sulfate. The serum concentration of 4'PCB3 sulfate was 6.18 ± 2.16 μg/mL. This is the first report that sulfated metabolites of PCBs are formed in vivo. These findings suggest a prospective approach for exposure assessment of LC-PCBs by analysis of phase II metabolites in urine.
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Affiliation(s)
- Kiran Dhakal
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, Iowa 52242, United States
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Abstract
Association Between Telomere Shortening and Ageing During Occupational ExposureTelomere length is considered as a biomarker of ageing, resulting in shortening during the process. The present investigation was an attempt to determine the relative telomere length in mechanical workshop workers. Telomere length shortening in cells during occupational exposure causes accelerated ageing. Genomic DNA was isolated from buccal epithelial cells collected from 240 individuals, comprising two groups of 120 exposed workers and 120 unexposed controls. Telomere length was measured by using real time PCR. Both telomere (T) and single copy gene (S) specific primers were used to compute the relative T/S ratio and expressed as the relative telomere length. Telomere length differed significantly between the workers and controls (p<0.05). The results showed an indirect and significant association (r=-0.356, p=0.001) between age and telomere length in the workers. This study showed that the difference in telomere length shortening was statistically significant (p<0.05) between the workers and controls. It was concluded that occupational exposure acts as a risk factor to enhance telomere length shortening and accelerate ageing.
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Senthilkumar PK, Robertson LW, Ludewig G. PCB153 reduces telomerase activity and telomere length in immortalized human skin keratinocytes (HaCaT) but not in human foreskin keratinocytes (NFK). Toxicol Appl Pharmacol 2011; 259:115-23. [PMID: 22210444 DOI: 10.1016/j.taap.2011.12.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 12/09/2011] [Accepted: 12/14/2011] [Indexed: 02/07/2023]
Abstract
Polychlorinated biphenyls (PCBs), ubiquitous environmental pollutants, are characterized by long term-persistence in the environment, bioaccumulation, and biomagnification in the food chain. Exposure to PCBs may cause various diseases, affecting many cellular processes. Deregulation of the telomerase and the telomere complex leads to several biological disorders. We investigated the hypothesis that PCB153 modulates telomerase activity, telomeres and reactive oxygen species resulting in the deregulation of cell growth. Exponentially growing immortal human skin keratinocytes (HaCaT) and normal human foreskin keratinocytes (NFK) were incubated with PCB153 for 48 and 24days, respectively, and telomerase activity, telomere length, superoxide level, cell growth, and cell cycle distribution were determined. In HaCaT cells exposure to PCB153 significantly reduced telomerase activity, telomere length, cell growth and increased intracellular superoxide levels from day 6 to day 48, suggesting that superoxide may be one of the factors regulating telomerase activity, telomere length and cell growth compared to untreated control cells. Results with NFK cells showed no shortening of telomere length but reduced cell growth and increased superoxide levels in PCB153-treated cells compared to untreated controls. As expected, basal levels of telomerase activity were almost undetectable, which made a quantitative comparison of treated and control groups impossible. The significant down regulation of telomerase activity and reduction of telomere length by PCB153 in HaCaT cells suggest that any cell type with significant telomerase activity, like stem cells, may be at risk of premature telomere shortening with potential adverse health effects for the affected organism.
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Affiliation(s)
- P K Senthilkumar
- Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA 52242-5000, USA
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20
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Senthilkumar PK, Klingelhutz AJ, Jacobus JA, Lehmler H, Robertson LW, Ludewig G. Airborne polychlorinated biphenyls (PCBs) reduce telomerase activity and shorten telomere length in immortal human skin keratinocytes (HaCat). Toxicol Lett 2011; 204:64-70. [PMID: 21530622 DOI: 10.1016/j.toxlet.2011.04.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 04/12/2011] [Accepted: 04/14/2011] [Indexed: 12/17/2022]
Abstract
PCBs, a group of 209 individual congeners, are ubiquitous environmental pollutants and classified as probable human carcinogens. One major route of exposure is by inhalation of these industrial compounds, possibly daily from inner city air and/or indoor air in contaminated buildings. Hallmarks of aging and carcinogenesis are changes in telomere length and telomerase activity. We hypothesize that semi-volatile PCBs, like those found in inner city air, are capable of disrupting telomerase activity and altering telomere length. To explore this possibility, we exposed human skin keratinocytes to a synthetic Chicago Airborne Mixture (CAM) of PCBs, or the prominent airborne PCB congeners, PCB28 or PCB52 for up to 48 days and determined telomerase activity, telomere length, cell proliferation, and cell cycle distribution. PCBs 28, 52 and CAM significantly reduced telomerase activity from days 18-48. Telomere length was shortened by PCB 52 from day 18 and PCB 28 and CAM from days 30 on. All PCBs decreased cell proliferation from day 18; only PCB 52 produced a small increase of cells in G0/G1 of the cell cycle. This significant inhibition of telomerase activity and reduction of telomere length by PCB congeners suggest a potential mechanism by which these compounds could lead to accelerated aging and cancer.
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Affiliation(s)
- P K Senthilkumar
- Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA, United States
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21
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Robertson LW, Ludewig G. Polychlorinated Biphenyl (PCB) carcinogenicity with special emphasis on airborne PCBs. GEFAHRSTOFFE, REINHALTUNG DER LUFT = AIR QUALITY CONTROL 2011; 71:25-32. [PMID: 21686028 PMCID: PMC3113507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Polychlorinated biphenyls (PCBs) are industrial chemicals used in various applications requiring chemical stabilityand have now become widely dispersed. Their characteristics of persistence, low water/higher lipid solubility, contribute to their ability to bioconcentrate and bioaccumulate. Traditionally PCBs have been regulated as food contaminants and the general population is primarily exposed by that route. PCBs in foodstuffs are generally higher chlorinated, resistant to metabolic breakdown, and elicit toxic changes that are thought to be predominantly receptor/parent PCB-driven. But for certain occupational exposures, and for those persons residing or working in contaminated buildings, and in large cities, an inhalation route of exposure may predominate. Airborne PCBs are, in contrast to foodborne PCBs, lower chlorinated, more volatile, and subject to metabolic attack. In this review, we have explored (geno-) toxic manifestations of PCBs typical of those found in air. Here metabolic conversion of the parent PCB to hydroxylated and other metabolic progeny appear to play a dominant role, especially in genotoxicity. We should be cognizant of the impact of exposures to airborne PCBs for those individuals who are occupationally exposed, for persons living near contaminated sites, for those who work or go to school in contaminated buildings, and especially cognizant of the young, the socio-economically disadvantaged and medically-underserved or nutritionally-deficient populations.
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Affiliation(s)
- Larry W Robertson
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa
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Xie W, Wang K, Robertson LW, Ludewig G. Investigation of mechanism(s) of DNA damage induced by 4-monochlorobiphenyl (PCB3) metabolites. ENVIRONMENT INTERNATIONAL 2010; 36:950-61. [PMID: 20129669 PMCID: PMC2888624 DOI: 10.1016/j.envint.2009.12.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 12/01/2009] [Accepted: 12/20/2009] [Indexed: 05/21/2023]
Abstract
4-Monochlorobiphenyl (PCB3) is readily converted by xenobiotic-metabolizing enzymes to dihydroxy-metabolites and quinones. The PCB3 hydroquinone (PCB3-HQ; 2-(4'-chlorophenyl)-1,4-hydroquinone) induces chromosome loss in Chinese Hamster V79 cells, whereas the para-quinone (PCB3-pQ; 2-(4'-chlorophenyl)-1,4-benzoquinone) very efficiently induces gene mutations and chromosome breaks. Apparently, each of these two metabolites, which are a redox pair, has a different spectrum of genotoxic effects due to different, metabolite-specific mechanisms. We hypothesized that the HQ requires enzymatic activation by peroxidases with the formation of reactive oxygen species (ROS) as the ultimate genotoxin, whereas the pQ reacts directly with nucleophilic sites in DNA and/or proteins. To examine this hypothesis, we employed two cell lines with different myeloperoxidase (MPO) activities, MPO-rich HL-60 and MPO-deficient Jurkat cells, and measured cytotoxicity, DNA damage (COMET assay), MPO activity, intracellular levels of reactive oxygen species (ROS) and intracellular free -SH groups (monochlorobimane assay, MCB) and free GSH contents (enzyme recycling method) after treatment with PCB3-HQ and PCB3-pQ. We also examined the modulation of these effects by normal/low temperature, pre-treatment with an MPO inhibitor (succinylacetone, SA), or GSH depletion. PCB3-p-Q increased intracellular ROS levels and induced DNA damage in both HL-60 and Jurkat cells at 37°C and 6°C, indicating a direct, MPO-independent mode of activity. It also strongly reduced intracellular free -SH groups and GSH levels in normal and GSH-depleted cells. Thus the ROS increase could be caused by reduced protection by GSH or non-enzymatic autoxidation of the resulting PCB3-HQ-GSH adduct. PCB3-HQ did not produce a significant reduction of intracellular GSH in HL-60 cells and reduced intracellular free -SH groups only at the highest concentration tested in GSH depleted cells. Moreover, PCB3-HQ induced DNA damage and ROS production only at 37 °C in HL-60 cells, not at 6 °C or in Jurkat cells at either temperature; no significant DNA damage and ROS production was observed in HL-60 cells at 37 °C if MPO activity was inhibited by SA. These studies show that the effects of PCB3-HQ are enzyme dependent, i.e. PCB3-HQ is oxidized by MPO in HL-60 cells with the generation of ROS and induction of DNA damage. However, this is not the case with the PCB3-pQ, which may produce DNA damage by the reactivity of the quinone with the DNA or nuclear proteins, or possibly by indirectly increasing intracellular ROS levels by GSH depletion. These different modes of action explain not only the different types of genotoxicity observed previously, but also suggest different organ specificity of these genotoxins.
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Affiliation(s)
- Wei Xie
- Department of Occupational and Environmental Health, College of Public Health, Iowa City, Iowa 52242, USA
| | - Kai Wang
- Department of Biostatistics University of Iowa, College of Public Health, Iowa City, Iowa 52242, USA
| | - Larry W. Robertson
- Department of Occupational and Environmental Health, College of Public Health, Iowa City, Iowa 52242, USA
| | - Gabriele Ludewig
- Department of Occupational and Environmental Health, College of Public Health, Iowa City, Iowa 52242, USA
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