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Clarkson TC, Iguchi N, Xie AX, Malykhina AP. Differential transcriptomic changes in the central nervous system and urinary bladders of mice infected with a coronavirus. PLoS One 2022; 17:e0278918. [PMID: 36490282 PMCID: PMC9733897 DOI: 10.1371/journal.pone.0278918] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 11/28/2022] [Indexed: 12/13/2022] Open
Abstract
Multiple sclerosis (MS) often leads to the development of neurogenic lower urinary tract symptoms (LUTS). We previously characterized neurogenic bladder dysfunction in a mouse model of MS induced by a coronavirus, mouse hepatitis virus (MHV). The aim of the study was to identify genes and pathways linking neuroinflammation in the central nervous system with urinary bladder (UB) dysfunction to enhance our understanding of the mechanisms underlying LUTS in demyelinating diseases. Adult C57BL/6 male mice (N = 12) received either an intracranial injection of MHV (coronavirus-induced encephalomyelitis, CIE group), or sterile saline (control group). Spinal cord (SC) and urinary bladders (UB) were collected from CIE mice at 1 wk and 4 wks, followed by RNA isolation and NanoString nCounter Neuroinflammation assay. Transcriptome analysis of SC identified a significantly changed expression of >150 genes in CIE mice known to regulate astrocyte, microglia and oligodendrocyte functions, neuroinflammation and immune responses. Two genes were significantly upregulated (Ttr and Ms4a4a), and two were downregulated (Asb2 and Myct1) only in the UB of CIE mice. Siglec1 and Zbp1 were the only genes significantly upregulated in both tissues, suggesting a common transcriptomic link between neuroinflammation in the CNS and neurogenic changes in the UB of CIE mice.
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Affiliation(s)
- Taylor C. Clarkson
- Division of Urology, Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Nao Iguchi
- Division of Urology, Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Alison Xiaoqiao Xie
- Division of Urology, Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Anna P. Malykhina
- Division of Urology, Department of Surgery, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
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Zhuo H, Huang H, Sjodin A, Jin L, Ma S, Denic-Roberts H, Warren JL, Jones R, Davis M, Sun P, Yu H, Ward MH, Udelsman R, Zhang Y, Rusiecki JA. A nested case-control study of serum polychlorinated biphenyls and papillary thyroid cancer risk among U.S. military service members. ENVIRONMENTAL RESEARCH 2022; 212:113367. [PMID: 35504340 PMCID: PMC9238631 DOI: 10.1016/j.envres.2022.113367] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 04/19/2022] [Accepted: 04/21/2022] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND OBJECTIVES Although polychlorinated biphenyls (PCBs) were banned decades ago, populations are continuously exposed to PCBs due to their persistence and bioaccumulation/biomagnification in the environment. Results from limited epidemiologic studies linking PCBs to thyroid cancer have been inconclusive. This study aimed to investigate the association between individual PCBs and PCB mixture and papillary thyroid cancer (PTC), the most common thyroid cancer histologic subtype. METHODS We carried out a nested case-control study including 742 histologically confirmed PTC cases diagnosed in 2000-2013 and 742 individually matched controls among U.S. military service members. Pre-diagnostic serum samples that were collected on average nine years before PTC diagnosis were used to measure PCB congeners by gas chromatography isotope dilution high resolution mass spectrometry (GC/ID-HRMS). Conditional logistic regression, Bayesian kernel machine regression (BKMR), and weighted quantile sum (WQS) regression were employed to estimate the association between single PCB congeners as well as their mixture and PTC. RESULTS Four PCB congeners (PCB-74, PCB-99, PCB-105, PCB-118) had significant associations and dose-response relationships with increased risk of PTC in single congener models. When considering the effects from all measured PCBs and their potential interactions in the BKMR model, PCB-118 showed positive trends of association with PTC. Increased exposure to the PCB congeners as a mixturewas also associated with an increased risk of PTC in the WQS model, with the mixture dominated by PCB-118, followed by PCB-74 and PCB-99. One PCB congener, PCB-187, showed an inverse trend of association with PTC in the mixture analysis. DISCUSSION This study suggests that exposure to certain PCBs as well as a mixture of PCBs were associated with an increased risk of PTC. The observed association was mainly driven by PCB-118, and to a lesser extent by PCB-74 and PCB-99. The findings warrant further investigation.
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Affiliation(s)
- Haoran Zhuo
- Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, USA
| | - Huang Huang
- Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, USA
| | - Andreas Sjodin
- Persistent Pollutants Biomonitoring Laboratory, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Lan Jin
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT, USA
| | - Shuangge Ma
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA
| | - Hristina Denic-Roberts
- Oak Ridge Institute for Science and Education (ORISE), MD, USA; Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Department of Preventive Medicine & Biostatistics, Bethesda, MD, USA
| | - Joshua L Warren
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA
| | - Richard Jones
- Persistent Pollutants Biomonitoring Laboratory, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Mark Davis
- Persistent Pollutants Biomonitoring Laboratory, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Peiyuan Sun
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA
| | - Herbert Yu
- Epidemiology Program, University of Hawaii Cancer Center, Hawaii, USA
| | - Mary H Ward
- Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA
| | - Robert Udelsman
- Endocrine Neoplasia Institute, Miami Cancer Institute, Miami, FL, USA
| | - Yawei Zhang
- Department of Environmental Health Sciences, Yale School of Public Health, New Haven, CT, USA
| | - Jennifer A Rusiecki
- Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Department of Preventive Medicine & Biostatistics, Bethesda, MD, USA.
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Wang H, Adamcakova-Dodd A, Lehmler HJ, Hornbuckle KC, Thorne PS. Toxicity Assessment of 91-Day Repeated Inhalation Exposure to an Indoor School Air Mixture of PCBs. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:1780-1790. [PMID: 34994547 PMCID: PMC9122270 DOI: 10.1021/acs.est.1c05084] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
School indoor air contaminated with polychlorinated biphenyls (PCBs) released from older building materials and paint pigments may pose health risks to children, as well as teachers and staff, by inhalation of PCBs. The health effects of long-term inhalation exposure to PCBs are poorly understood. We conducted a comprehensive toxicity assessment of 91-day repeated inhalation exposure to a lab-generated mixture of PCBs designed to emulate indoor school air, combining transcriptomics, metabolomics, and neurobehavioral outcomes. Female Sprague-Dawley rats were exposed to school air mixture (SAM+) at a concentration of 45.5 ± 5.9 μg/m3 ∑209PCB or filtered air 4 h/day, 6 days/week for 13 weeks using nose-only exposure systems. The congener-specific PCB body burden was quantified in major tissues using GC-MS/MS. The generated SAM+ vapor recapitulated the target school air profile with a similarity coefficient, cos θ of 0.91. PCB inhalation yielded 875-9930 ng/g ∑209PCBlipid weight levels in tissues in the following ascending order: brain < liver < lung < serum < adipose tissue. We observed that PCB exposure impaired memory, induced anxiety-like behavior, significantly reduced white blood cell counts, mildly disrupted metabolomics in plasma, and influenced transcription processes in the brain with 274 upregulated and 58 downregulated genes. With relatively high exposure and tissue loading, evidence of toxicity from half the end points tested was seen in the rats.
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Affiliation(s)
- Hui Wang
- Department of Occupational and Environmental Health, University of Iowa, Iowa City, Iowa 52242, United States
| | - Andrea Adamcakova-Dodd
- 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
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, Iowa 52242, United States
| | - Keri C. Hornbuckle
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, Iowa 52242, United States
- Department of Civil and Environmental Engineering, University of Iowa, Iowa City, Iowa 52242, United States
| | - Peter S. Thorne
- Department of Occupational and Environmental Health, University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, Iowa 52242, United States
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Geng N, Luo Y, Cao R, Song X, Li F, Wang F, Gong Y, Xing L, Zhang H, Chen J. Effect of short-chain chlorinated paraffins on metabolic profiling of male SD rats. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 750:141404. [PMID: 33182165 DOI: 10.1016/j.scitotenv.2020.141404] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 06/11/2023]
Abstract
The toxic effect of high-dose of short-chain chlorinated paraffins (SCCPs) has been extensively studied, however the possible health risks induced by SCCPs at low-dose remain largely unknown. In this study, a comprehensive toxicology analysis of SCCPs was conducted with the exposure levels from the environmental dose to the Lowest Observed Adverse Effect Level (LOAEL) of 100 mg/kg/day. General toxicology analysis revealed inconspicuous toxicity of the environmental dose of SCCPs, high dose SCCP exposure inhibited the growth rate and increased the liver weight of rat. Metabolomics analysis indicated that SCCP-induced toxicity was triggered at environmentally relevant doses. First, inhibition of energy metabolism was observed with the decrease in blood glucose and the dysfunction of TCA cycle, which may have contributed to lower body weight gain in rats exposed to a high dose of SCCPs. Second, the increase of free fatty acids indicated the acceleration of lipid metabolism to compensate for the energy deficiency caused by hypoglycemia. Lipid oxidative metabolism inevitably leads to oxidative stress and stimulates the up-regulation of antioxidant metabolites such as GSH and GSSH. The up-regulation of polyunsaturated fatty acids (PUFAs) and phospholipids composed of arachidonic acid indicates the occurrence of inflammation. Dysfunction of lipid metabolism can be an indicator of SCCP-induced liver injury.
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Affiliation(s)
- Ningbo Geng
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Yun Luo
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rong Cao
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Xiaoyao Song
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Fang Li
- Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Feidi Wang
- Institute of Quality and Standard for Agro-Products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Yufeng Gong
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Liguo Xing
- Safety Evaluation Center of Shenyang Research Institute of Chemical Industry Ltd, Shenyang 110021, China
| | - Haijun Zhang
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Jiping Chen
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
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Wang H, Adamcakova-Dodd A, Flor S, Gosse L, Klenov VE, Stolwijk JM, Lehmler HJ, Hornbuckle KC, Ludewig G, Robertson LW, Thorne PS. Comprehensive Subchronic Inhalation Toxicity Assessment of an Indoor School Air Mixture of PCBs. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:15976-15985. [PMID: 33256405 PMCID: PMC7879961 DOI: 10.1021/acs.est.0c04470] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Few in vivo inhalation studies have explored the toxicity of environmentally relevant mixtures of polychlorinated biphenyls (PCBs). The manufacture of industrial PCBs was banned in 1978, but PCBs continue to be formed in industrial and consumer products. Schools represent a significant source of airborne exposures to legacy and nonlegacy PCBs, placing children at risk. To evaluate the impact of these exposures, we generated an airborne mixture of PCBs, called the School Air Mixture (SAM), to match the profile of an older school from our adolescent cohort study. Female Sprague-Dawley rats were exposed either to SAM or filtered air in nose-only exposure systems, 4 h/day for 4 weeks. Congener-specific air and tissue PCB profiles were assessed using gas chromatography with tandem mass spectrometry (GC-MS/MS). PCB exposures recapitulated the target school air profile with a similarity coefficient, cos θ of 0.83. PCB inhalation yielded μg/g ∑209 PCB levels in tissues. Neurobehavioral testing demonstrated a modest effect on spatial learning and memory in SAM-exposed rats. PCB exposure induced oxidative stress in the liver and lungs, affected the maturational stages of hematopoietic stem cells, reduced telomerase activity in bone marrow cells, and altered the gut microbiota. This is the first study to emulate PCB exposures in a school and comprehensively evaluate toxicity.
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Affiliation(s)
- 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
| | - Susanne Flor
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Laura Gosse
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Violet E. Klenov
- Department of Obstetrics and Gynecology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Jeffrey M. Stolwijk
- Interdisciplinary Graduate Program in Human Toxicology, 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 Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Keri C. Hornbuckle
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
- Department of Civil and Environmental Engineering, 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
- Interdisciplinary Graduate Program in Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
| | - Larry W. Robertson
- Department of Occupational and Environmental Health, the University of Iowa, Iowa City, Iowa 52242, United States
- Interdisciplinary Graduate Program in Human Toxicology, 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 Human Toxicology, the University of Iowa, Iowa City, Iowa 52242, United States
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Egusquiza RJ, Ambrosio ME, Wang SG, Kay KM, Zhang C, Lehmler HJ, Blumberg B. Evaluating the Role of the Steroid and Xenobiotic Receptor (SXR/PXR) in PCB-153 Metabolism and Protection against Associated Adverse Effects during Perinatal and Chronic Exposure in Mice. ENVIRONMENTAL HEALTH PERSPECTIVES 2020; 128:47011. [PMID: 32352317 PMCID: PMC7228131 DOI: 10.1289/ehp6262] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 03/20/2020] [Accepted: 03/24/2020] [Indexed: 06/02/2023]
Abstract
BACKGROUND Polychlorinated biphenyls (PCBs) are environmental toxicants; PCB exposure has been associated with adverse effects on wildlife and humans. However, the mechanisms underlying these adverse effects are not fully understood. The steroid and xenobiotic receptor [SXR; also known as the pregnane X receptor (PXR) and formally known as NR1I2] is a nuclear hormone receptor that regulates inducible metabolism of drugs and xenobiotics and is activated or inhibited by various PCB congeners. OBJECTIVES The aim of this study was to investigate the effects of exposure to PCB-153, the most prevalent PCB congener in human tissues, on SXR knockout mice (SXRKO) and to elucidate the role of SXR in PCB-153 metabolism and promotion of its harmful effects. METHODS Wild-type (WT) and SXRKO mice were chronically or perinatally exposed to a low dose (54μg/kg/d) of PCB-153. Blood, livers, and spleens were analyzed using transcriptome sequencing (RNA-seq) and molecular techniques to investigate the impacts of exposure on metabolism, oxidative stress, and hematological parameters. RESULTS SXRKO mice perinatally exposed to PCB-153 displayed elevated oxidative stress, symptoms of hemolytic anemia, and premature death. Transcriptomal analysis revealed that expression of genes involved in metabolic processes was altered in SXRKO mice. Elevated levels of the PCB-153 metabolite, 3-OH-PCB-153, were found in exposed SXRKO mice compared to exposed WT mice. Blood hemoglobin (HGB) levels were lower throughout the lifespan, and the occurrence of intestinal tumors was larger in SXRKO mice chronically exposed to PCB-153 compared to vehicle and WT controls. DISCUSSION Our results suggest that altered metabolism induced by SXR loss of function resulted in the accumulation of hydroxylated metabolites upon exposure to PCB-153, leading to oxidative stress, hemolytic anemia, and tumor development in a mouse model. These results support a major role for SXR/PXR in protection against xenobiotic-induced oxidative stress by maintaining proper metabolism in response to PCB-153 exposure. This role of SXR could be generally applicable to other environmental toxicants as well as pharmaceutical drugs. https://doi.org/10.1289/EHP6262.
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Affiliation(s)
- Riann Jenay Egusquiza
- Department of Pharmaceutical Sciences, University of California, Irvine, California, USA
| | - Maria Elena Ambrosio
- Department of Developmental and Cell Biology, University of California, Irvine, California, USA
| | - Shuyi Gin Wang
- Department of Developmental and Cell Biology, University of California, Irvine, California, USA
| | - Kaelen Marie Kay
- Department of Developmental and Cell Biology, University of California, Irvine, California, USA
| | - Chunyun Zhang
- Department of Occupational and Environmental Health, University of Iowa, Iowa City, Iowa, USA
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, University of Iowa, Iowa City, Iowa, USA
| | - Bruce Blumberg
- Department of Pharmaceutical Sciences, University of California, Irvine, California, USA
- Department of Developmental and Cell Biology, University of California, Irvine, California, USA
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7
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Klocke C, Lein PJ. Evidence Implicating Non-Dioxin-Like Congeners as the Key Mediators of Polychlorinated Biphenyl (PCB) Developmental Neurotoxicity. Int J Mol Sci 2020; 21:E1013. [PMID: 32033061 PMCID: PMC7037228 DOI: 10.3390/ijms21031013] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 01/31/2020] [Accepted: 02/02/2020] [Indexed: 12/15/2022] Open
Abstract
Despite being banned from production for decades, polychlorinated biphenyls (PCBs) continue to pose a significant risk to human health. This is due to not only the continued release of legacy PCBs from PCB-containing equipment and materials manufactured prior to the ban on PCB production, but also the inadvertent production of PCBs as byproducts of contemporary pigment and dye production. Evidence from human and animal studies clearly identifies developmental neurotoxicity as a primary endpoint of concern associated with PCB exposures. However, the relative role(s) of specific PCB congeners in mediating the adverse effects of PCBs on the developing nervous system, and the mechanism(s) by which PCBs disrupt typical neurodevelopment remain outstanding questions. New questions are also emerging regarding the potential developmental neurotoxicity of lower chlorinated PCBs that were not present in the legacy commercial PCB mixtures, but constitute a significant proportion of contemporary human PCB exposures. Here, we review behavioral and mechanistic data obtained from experimental models as well as recent epidemiological studies that suggest the non-dioxin-like (NDL) PCBs are primarily responsible for the developmental neurotoxicity associated with PCBs. We also discuss emerging data demonstrating the potential for non-legacy, lower chlorinated PCBs to cause adverse neurodevelopmental outcomes. Molecular targets, the relevance of PCB interactions with these targets to neurodevelopmental disorders, and critical data gaps are addressed as well.
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Affiliation(s)
| | - Pamela J. Lein
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA 95616, USA;
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Nesan D, Kurrasch DM. Gestational Exposure to Common Endocrine Disrupting Chemicals and Their Impact on Neurodevelopment and Behavior. Annu Rev Physiol 2019; 82:177-202. [PMID: 31738670 DOI: 10.1146/annurev-physiol-021119-034555] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Endocrine disrupting chemicals are common in our environment and act on hormone systems and signaling pathways to alter physiological homeostasis. Gestational exposure can disrupt developmental programs, permanently altering tissues with impacts lasting into adulthood. The brain is a critical target for developmental endocrine disruption, resulting in altered neuroendocrine control of hormonal signaling, altered neurotransmitter control of nervous system function, and fundamental changes in behaviors such as learning, memory, and social interactions. Human cohort studies reveal correlations between maternal/fetal exposure to endocrine disruptors and incidence of neurodevelopmental disorders. Here, we summarize the major literature findings of endocrine disruption of neurodevelopment and concomitant changes in behavior by four major endocrine disruptor classes:bisphenol A, polychlorinated biphenyls, organophosphates, and polybrominated diphenyl ethers. We specifically review studies of gestational and/or lactational exposure to understand the effects of early life exposure to these compounds and summarize animal studies that help explain human correlative data.
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Affiliation(s)
- Dinushan Nesan
- Department of Medical Genetics, University of Calgary, Calgary, Alberta T2N 4N1, Canada; , .,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
| | - Deborah M Kurrasch
- Department of Medical Genetics, University of Calgary, Calgary, Alberta T2N 4N1, Canada; , .,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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9
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Pessah IN, Lein PJ, Seegal RF, Sagiv SK. Neurotoxicity of polychlorinated biphenyls and related organohalogens. Acta Neuropathol 2019; 138:363-387. [PMID: 30976975 PMCID: PMC6708608 DOI: 10.1007/s00401-019-01978-1] [Citation(s) in RCA: 106] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 02/12/2019] [Accepted: 02/19/2019] [Indexed: 01/28/2023]
Abstract
Halogenated organic compounds are pervasive in natural and built environments. Despite restrictions on the production of many of these compounds in most parts of the world through the Stockholm Convention on Persistent Organic Pollutants (POPs), many "legacy" compounds, including polychlorinated biphenyls (PCBs), are routinely detected in human tissues where they continue to pose significant health risks to highly exposed and susceptible populations. A major concern is developmental neurotoxicity, although impacts on neurodegenerative outcomes have also been noted. Here, we review human studies of prenatal and adult exposures to PCBs and describe the state of knowledge regarding outcomes across domains related to cognition (e.g., IQ, language, memory, learning), attention, behavioral regulation and executive function, and social behavior, including traits related to attention-deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD). We also review current understanding of molecular mechanisms underpinning these associations, with a focus on dopaminergic neurotransmission, thyroid hormone disruption, calcium dyshomeostasis, and oxidative stress. Finally, we briefly consider contemporary sources of organohalogens that may pose human health risks via mechanisms of neurotoxicity common to those ascribed to PCBs.
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Affiliation(s)
- Isaac N Pessah
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, 1089 VM3B, Davis, CA, 95616, USA.
| | - Pamela J Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, 1089 VM3B, Davis, CA, 95616, USA
| | - Richard F Seegal
- Professor Emeritus, School of Public Health, University at Albany, Rensselaer, NY, USA
| | - Sharon K Sagiv
- Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California, Berkeley, CA, USA
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10
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Meroni SB, Galardo MN, Rindone G, Gorga A, Riera MF, Cigorraga SB. Molecular Mechanisms and Signaling Pathways Involved in Sertoli Cell Proliferation. Front Endocrinol (Lausanne) 2019; 10:224. [PMID: 31040821 PMCID: PMC6476933 DOI: 10.3389/fendo.2019.00224] [Citation(s) in RCA: 138] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 03/21/2019] [Indexed: 12/16/2022] Open
Abstract
Sertoli cells are somatic cells present in seminiferous tubules which have essential roles in regulating spermatogenesis. Considering that each Sertoli cell is able to support a limited number of germ cells, the final number of Sertoli cells reached during the proliferative period determines sperm production capacity. Only immature Sertoli cells, which have not established the blood-testis barrier, proliferate. A number of hormonal cues regulate Sertoli cell proliferation. Among them, FSH, the insulin family of growth factors, activin, and cytokines action must be highlighted. It has been demonstrated that cAMP/PKA, ERK1/2, PI3K/Akt, and mTORC1/p70SK6 pathways are the main signal transduction pathways involved in Sertoli cell proliferation. Additionally, c-Myc and hypoxia inducible factor are transcription factors which participate in the induction by FSH of various genes of relevance in cell cycle progression. Cessation of proliferation is a pre-requisite to Sertoli cell maturation accompanied by the establishment of the blood-testis barrier. With respect to this barrier, the participation of androgens, estrogens, thyroid hormones, retinoic acid and opioids has been reported. Additionally, two central enzymes that are involved in sensing cell energy status have been associated with the suppression of Sertoli cell proliferation, namely AMPK and Sirtuin 1 (SIRT1). Among the molecular mechanisms involved in the cessation of proliferation and in the maturation of Sertoli cells, it is worth mentioning the up-regulation of the cell cycle inhibitors p21Cip1, p27Kip, and p19INK4, and of the gap junction protein connexin 43. A decrease in Sertoli cell proliferation due to administration of certain therapeutic drugs and exposure to xenobiotic agents before puberty has been experimentally demonstrated. This review focuses on the hormones, locally produced factors, signal transduction pathways, and molecular mechanisms controlling Sertoli cell proliferation and maturation. The comprehension of how the final number of Sertoli cells in adulthood is established constitutes a pre-requisite to understand the underlying causes responsible for the progressive decrease in sperm production that has been observed during the last 50 years in humans.
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Patel JF, Hartman TJ, Sjodin A, Northstone K, Taylor EV. Prenatal exposure to polychlorinated biphenyls and fetal growth in British girls. ENVIRONMENT INTERNATIONAL 2018; 116:116-121. [PMID: 29677556 PMCID: PMC6392071 DOI: 10.1016/j.envint.2018.04.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 04/04/2018] [Accepted: 04/05/2018] [Indexed: 05/06/2023]
Abstract
Polychlorinated biphenyls (PCBs) are synthetic chemicals that bioaccumulate in the food chain. PCBs were used primarily for industrial applications due to their insulating and fire retardant properties, but were banned in the 1970s in the United States and in the 1980s in the United Kingdom, as adverse health effects following exposure were identified. Previous studies of populations with high PCB exposure have reported inverse associations with birth weight and gestational length. Birth weight is a powerful predictor of infant survival, and low birth weight can predispose infants to chronic conditions in adult life such as diabetes and cardiovascular diseases. Using data from the Avon Longitudinal Study of Parents and Children, we investigated the association between prenatal exposure to PCBs and fetal growth in a sample of 448 mother-daughter dyads. Concentrations of three common PCB analytes, PCB-118, PCB-153 and PCB-187, were measured in maternal serum collected during pregnancy, and fetal growth was measured by birth weight and birth length. Multivariable linear regression was used to examine the associations between PCB analytes and measures of fetal growth, after adjusting for parity, maternal age, pre-pregnancy BMI, educational status, tobacco use and gestational age of infant at sample collection. Birth length, ponderal index and gestational age were not associated with any of the PCB analytes. Mothers' educational status modified associations for PCB analytes with birthweight. We observed significant inverse associations with birth weight only among daughters of mothers with less education. Daughter's birth weight was -138.4 g lower (95% CI: -218.0, -58.9) for each 10 ng/g lipid increase in maternal serum PCB-118. Similarly, every 10 ng/g lipid increase in maternal serum PCB-153 was associated with a -41.9 g (95% CI: -71.6, -12.2) lower birth weight. Every 10 ng/g lipids increase in maternal serum PCB-187, was associated with a -170.4 g (95% CI: -306.1, -34.7) lower birth weight, among girls with mothers in the lowest education group. Our findings suggest that prenatal exposure to PCBs is inversely associated with daughters' birth weight and that mothers' education, which is a possible marker for socioeconomic status, significantly modified the association between maternal PCB concentrations and birth weight in female newborns.
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Affiliation(s)
- Jill F Patel
- Centers for Disease Control and Prevention, Atlanta, GA 30341, United States; Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA 30322, United States
| | - Terryl J Hartman
- Centers for Disease Control and Prevention, Atlanta, GA 30341, United States; Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA 30322, United States; Winship Cancer Institute, Emory University, Atlanta, GA 30322, United States.
| | - Andreas Sjodin
- Centers for Disease Control and Prevention, Atlanta, GA 30341, United States
| | - Kate Northstone
- The National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care West (NIHR CLAHRC West) at University Hospitals Bristol NHS Foundation Trust, UK; School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - Ethel V Taylor
- Centers for Disease Control and Prevention, Atlanta, GA 30341, United States
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12
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Dingemans MML, Kock M, van den Berg M. Mechanisms of Action Point Towards Combined PBDE/NDL-PCB Risk Assessment. Toxicol Sci 2018; 153:215-24. [PMID: 27672163 DOI: 10.1093/toxsci/kfw129] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
At present, human risk assessment of the structurally similar non-dioxin-like (NDL) PCBs and polybrominated diphenylethers (PBDEs) is done independently for both groups of compounds. There are however obvious similarities between NDL-PCBs and PBDEs with regard to modulation of the intracellular calcium homeostasis (basal calcium levels, voltage-gated calcium channels, calcium uptake, ryanodine receptor) and thyroid hormone (TH) homeostasis (TH levels and transport). which are mechanisms of action related to neurobehavioral effects (spontaneous activity, habituation and learning ability). There also similarities in agonistic interactions with the hepatic nuclear receptors PXR and CAR. Several effects on developmental (reproductive) processes have also been observed, but results were more dispersed and insufficient to compare both groups of compounds. The available mechanistic information is sufficient to warrant a dose addition model for NDL-PCBs and PBDEs, including their hydroxylated metabolites.Although many of the observed effects are similar from a qualitative point of view for both groups, congener or tissue specific differences have also been found. As this is a source of uncertainty in the combined hazard and risk assessment of these compounds, molecular entities involved in the observed mechanisms and adverse outcomes associated with these compounds need to be identified. The systematical generation of (quantitative) structure-activity information for NDL-PCBs and PBDEs on these targets (including potential non-additive effects) will allow a more realistic risk estimation associated with combined exposure to both groups of compounds during early life. Additional validation studies are needed to quantify these uncertainties for risk assessment of NDL-PCBs and PBDEs.
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Affiliation(s)
- Milou M L Dingemans
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Marjolijn Kock
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Martin van den Berg
- Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
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13
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Benson K, Yang E, Dutton N, Sjodin A, Rosenbaum PF, Pavuk M. Polychlorinated biphenyls, indicators of thyroid function and thyroid autoantibodies in the Anniston Community Health Survey I (ACHS-I). CHEMOSPHERE 2018; 195:156-165. [PMID: 29268174 DOI: 10.1016/j.chemosphere.2017.12.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 11/02/2017] [Accepted: 12/08/2017] [Indexed: 06/07/2023]
Abstract
In this study, we examined associations between serum concentrations of 35 polychlorinated biphenyl (PCB) congeners, pesticides, and indicators of thyroid function in participants of the Anniston Community Health Survey (ACHS). Study subjects lived in the vicinity of a former PCB production facility and had PCB concentrations 2 to 3 times higher than similar age and race groups from the general population. We investigated associations among serum levels of thyroid hormones (thyroxin [T4], free thyroxin [fT4], triiodothyronine [T3], thyroid stimulation hormone [TSH]) and auto-antibodies (thyroglobulin antibody [TgAb] or thyroperoxidase antibody [TPOAb]) and combined indicators of thyroid function with the sum of PCBs, varying PCB groups, individual PCB congeners, and 8 pesticides. Logistic and linear regression models were adjusted for log10 transformed total lipids, age, sex, ethnicity, BMI, smoking, and family history of thyroid disease. We also performed analyses stratified by ethnicity and sex. Linear regression showed inverse associations between TT3 and thyroid-like PCBs (sum of PCBs 28, 52, 74, 101, 105, and 118; p = .0004), two pesticides (hexachlorobenzene, and pp'-DDE), and individual congeners (PCBs 74, 105). Null associations were observed between PCBs, pesticides, TSH, TT4, and fT4. Logistic regression analyses did not provide support for TT3 findings and found no association with other thyroid hormones, antibodies, or combined indicator of thyroid function. These results suggest there is little evidence that these chemicals have any major clinical effect on thyroid function in this highly PCB exposed population.
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Affiliation(s)
- Kelsey Benson
- Agency for Toxic Substances and Disease Registry (ATSDR), Atlanta, GA, USA.
| | - Eric Yang
- Oak Ridge Institute for Science and Education (ORISE), USA
| | - Nina Dutton
- Oak Ridge Institute for Science and Education (ORISE), USA
| | - Andreas Sjodin
- Division of Laboratory Sciences, National Center for Environmental Health (NCEH), Atlanta, GA, USA
| | - Paula F Rosenbaum
- Department of Public Health & Preventive Medicine, State University of New York (SUNY) Upstate Medical University, Syracuse, NY, USA
| | - Marian Pavuk
- Agency for Toxic Substances and Disease Registry (ATSDR), Atlanta, GA, USA
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14
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Mucio-Ramírez S, Sánchez-Islas E, Sánchez-Jaramillo E, Currás-Collazo M, Juárez-González VR, Álvarez-González MY, Orser LE, Hou B, Pellicer F, Kodavanti PRS, León-Olea M. Perinatal exposure to organohalogen pollutants decreases vasopressin content and its mRNA expression in magnocellular neuroendocrine cells activated by osmotic stress in adult rats. Toxicol Appl Pharmacol 2017; 329:173-189. [PMID: 28579251 PMCID: PMC5996972 DOI: 10.1016/j.taap.2017.05.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 05/29/2017] [Accepted: 05/31/2017] [Indexed: 11/17/2022]
Abstract
Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are environmental pollutants that produce neurotoxicity and neuroendocrine disruption. They affect the vasopressinergic system but their disruptive mechanisms are not well understood. Our group reported that rats perinatally exposed to Aroclor-1254 (A1254) and DE-71 (commercial mixtures of PCBs and PBDEs) decrease somatodendritic vasopressin (AVP) release while increasing plasma AVP responses to osmotic activation, potentially emptying AVP reserves required for body-water balance. The aim of this research was to evaluate the effects of perinatal exposure to A1254 or DE-71 (30mgkg/day) on AVP transcription and protein content in the paraventricular and supraoptic hypothalamic nuclei, of male and female rats, by in situ hybridization and immunohistochemistry. cFOS mRNA expression was evaluated in order to determine neuroendocrine cells activation due to osmotic stimulation. Animal groups were: vehicle (control); exposed to either A1254 or DE-71; both, control and exposed, subjected to osmotic challenge. The results confirmed a physiological increase in AVP-immunoreactivity (AVP-IR) and gene expression in response to osmotic challenge as reported elsewhere. In contrast, the exposed groups did not show this response to osmotic activation, they showed significant reduction in AVP-IR neurons, and AVP mRNA expression as compared to the hyperosmotic controls. cFOS mRNA expression increased in A1254 dehydrated groups, suggesting that the AVP-IR decrease was not due to a lack of the response to the osmotic activation. Therefore, A1254 may interfere with the activation of AVP mRNA transcript levels and protein, causing a central dysfunction of vasopressinergic system.
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Affiliation(s)
- Samuel Mucio-Ramírez
- Departamento de Neuromorfología Funcional, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Calz. México Xochimilco No. 101, Col. San Lorenzo Huipulco, México D.F. C.P. 14370, México.
| | - Eduardo Sánchez-Islas
- Departamento de Neuromorfología Funcional, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Calz. México Xochimilco No. 101, Col. San Lorenzo Huipulco, México D.F. C.P. 14370, México.
| | - Edith Sánchez-Jaramillo
- Laboratorio de Neuroendocrinología Molecular, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Calz. México Xochimilco No. 101, Col. San Lorenzo Huipulco. México D.F. C.P. 14370, México.
| | - Margarita Currás-Collazo
- Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92521, USA.
| | - Victor R Juárez-González
- Medicina Molecular y Bioprocesos, Instituto de Biotecnología, UNAM, Av. Universidad #2001, Col. Chamilpa, C.P. 62210 Cuernavaca, Morelos, México.
| | - Mhar Y Álvarez-González
- Departamento de Neuromorfología Funcional, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Calz. México Xochimilco No. 101, Col. San Lorenzo Huipulco, México D.F. C.P. 14370, México.
| | - L E Orser
- Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92521, USA
| | - Borin Hou
- Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92521, USA
| | - Francisco Pellicer
- Laboratorio de Fisiología Integrativa, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz. Calz. México Xochimilco No. 101, Col. San Lorenzo Huipulco, México D.F. C.P. 14370, México.
| | - Prasada Rao S Kodavanti
- Neurotoxicology Branch, Toxicity Assessment Division, NHEERL/ORD, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
| | - Martha León-Olea
- Departamento de Neuromorfología Funcional, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Calz. México Xochimilco No. 101, Col. San Lorenzo Huipulco, México D.F. C.P. 14370, México.
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15
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Khan MA, Fenton SE, Swank AE, Hester SD, Williams A, Wolf DC. A Mixture of Ammonium Perchlorate and Sodium Chlorate Enhances Alterations of the Pitutary-Thyroid Axis Caused by the Individual Chemicals in Adult Male F344 Rats. Toxicol Pathol 2016; 33:776-83. [PMID: 16392172 DOI: 10.1080/01926230500449832] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Ammonium perchlorate (AP) and sodium chlorate (SC) have been detected in public drinking water supplies in many parts of the United States. These chemicals cause perturbations in pituitary-thyroid homeostasis in animals by competitively inhibiting iodide uptake, thus hindering the synthesis of thyroglobulin and reducing circulating T4 (thyroxine). Little is known about the short-term exposure effects of mixtures of perchlorate and chlorate. The present study investigated the potential for the response to a mixture of these chemicals on the pituitary-thyroid axis in rats to be greater than that induced by the individual chemicals. Adult male F-344 rats were exposed, via their drinking water, to the nominal concentrations of 0.1, 1.0, 10 mg/L AP or 10, 100, 1000 mg/L SC and their mixtures for 7 days. Serum T4 levels were significantly ( p < 0.05) reduced in rats following exposure to the mixtures, but not after exposure to the individual chemicals. Serum T3 (triiodothyronine) was not altered by treatment and TSH (thyroid stimulating hormone) was only increased after the high-dose chlorate treatment. Histological examination of the thyroid gland showed colloid depletion and hypertrophy of follicular epithelial cells in high-dose single chemical and all mixture-treated rats, while hyperplasia was observed only in some of the rats treated with mixtures (AP 10 + SC 100, AP 0.1 + SC 1000, and AP 10 + SC 1000 mg/L). These data suggest that short-term exposure to the mixture of AP and SC enhances the effect of either chemical alone on the pituitary-thyroid axis in rats.
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Affiliation(s)
- Moazzam A Khan
- National Research Council, Environmental Carcinogenesis Divisions, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
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16
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van Esterik JCJ, Verharen HW, Hodemaekers HM, Gremmer ER, Nagarajah B, Kamstra JH, Dollé MET, Legler J, van der Ven LTM. Compound- and sex-specific effects on programming of energy and immune homeostasis in adult C57BL/6JxFVB mice after perinatal TCDD and PCB 153. Toxicol Appl Pharmacol 2015; 289:262-75. [PMID: 26415833 DOI: 10.1016/j.taap.2015.09.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Revised: 09/22/2015] [Accepted: 09/24/2015] [Indexed: 01/01/2023]
Abstract
Early life exposure to endocrine disrupting compounds has been linked to chronic diseases later in life, like obesity and related metabolic disorders. We exposed C57BL/6JxFVB hybrid mice to the aryl hydrocarbon receptor agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and the constitutive androstane receptor/pregnane X receptor agonist polychlorinated biphenyl 153 (PCB 153) in an experimental design relevant for human exposure. Exposure occurred during gestation and lactation via maternal feed to a wide dose range (TCDD: 10-10,000 pg/kg body weight/day; PCB 153: 0.09-1406 μg/kg body weight/d). Then exposure was ceased and offspring were followed up to 1 year of age. Metabolic parameters like body weight, fat pad weights, glucose tolerance, endocrine serum profile, and neurobehavioral and immunological parameters were determined. Body weight was transiently affected by both compounds throughout the follow-up. TCDD-exposed males showed decreased fat pad and spleen weights and an increase in IL-4 production of splenic immune cells. In contrast, females showed increased fat pad weights and production of IFNγ. PCB 153-exposed males showed an increase in glucose, whereas females showed an increase in glucagon, a decrease in pancreas weight, and an increase in thymus weight. In conclusion, early life exposure to TCDD appears to affect programming of energy and immune homeostasis in offspring, whereas the effects of perinatal PCB 153 were mainly on programming of glucose homeostasis. Both compounds act sex-specifically. Lowest derived BMDLs (lower bounds of the (two sided) 90%-confidence interval for the benchmark dose) for both compounds are not lower than current tolerable daily intakes.
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Affiliation(s)
- J C J van Esterik
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands; Department of Chemistry and Biology, Institute for Environmental Studies (IVM), VU University, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
| | - H W Verharen
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands.
| | - H M Hodemaekers
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands.
| | - E R Gremmer
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands.
| | - B Nagarajah
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands.
| | - J H Kamstra
- Department of Chemistry and Biology, Institute for Environmental Studies (IVM), VU University, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
| | - M E T Dollé
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands.
| | - J Legler
- Department of Chemistry and Biology, Institute for Environmental Studies (IVM), VU University, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
| | - L T M van der Ven
- Center for Health Protection, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands.
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17
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Hayashi L, Sheth M, Young A, Kruger M, Wayman GA, Coffin AB. The effect of the aquatic contaminants bisphenol-A and PCB-95 on the zebrafish lateral line. Neurotoxicology 2014; 46:125-36. [PMID: 25556122 DOI: 10.1016/j.neuro.2014.12.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Revised: 12/18/2014] [Accepted: 12/22/2014] [Indexed: 01/18/2023]
Abstract
Environmental toxicants such as bisphenol-A (BPA) and polychlorinated biphenyls (PCBs) are prevalent in our water supply, soil, and many food products and can profoundly affect the central nervous system. Both BPA and PCBs can disrupt endocrine signaling, which is important for auditory development and function, but the effect of these toxicants on the auditory periphery is not understood. In this study we investigated the effect of PCB-95 and BPA on lateral line development, function, and regeneration in larval zebrafish. The lateral line is a system of mechanosensory hair cells on the exterior of the fish that are homologous to the hair cells located in the mammalian inner ear. We found that PCB-95 had no effect on lateral line development or hair cell survival. BPA also did not affect lateral line development, but instead had a significant effect on both hair cell survival and regeneration. BPA-induced hair cell loss is both dose- and time-dependent, with concentrations of 1 μM or higher killing lateral line hair cells during a 24h exposure period. Pharmacologic manipulation experiments suggest that BPA kills hair cells via activation of oxidative stress pathways, similar to prior reports of BPA toxicity in other tissues. We also observed that hair cells killed with neomycin, a known ototoxin, failed to regenerate normally when BPA was present, suggesting that BPA in aquatic environments could impede innate regenerative responses in fishes. Collectively, these data demonstrate that BPA can have detrimental effects on sensory systems, both in aquatic life and perhaps in terrestrial organisms, including humans.
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Affiliation(s)
- Lauren Hayashi
- College of Arts and Sciences, Washington State University, Vancouver, WA, USA.
| | - Meghal Sheth
- College of Arts and Sciences, Washington State University, Vancouver, WA, USA.
| | - Alexander Young
- College of Arts and Sciences, Washington State University, Vancouver, WA, USA.
| | - Matthew Kruger
- College of Arts and Sciences, Washington State University, Vancouver, WA, USA.
| | - Gary A Wayman
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, USA.
| | - Allison B Coffin
- College of Arts and Sciences, Washington State University, Vancouver, WA, USA; Department of Integrative Physiology and Neuroscience, Washington State University, Vancouver, WA, USA.
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18
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León-Olea M, Martyniuk CJ, Orlando EF, Ottinger MA, Rosenfeld C, Wolstenholme J, Trudeau VL. Current concepts in neuroendocrine disruption. Gen Comp Endocrinol 2014; 203:158-173. [PMID: 24530523 PMCID: PMC4133337 DOI: 10.1016/j.ygcen.2014.02.005] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Revised: 02/01/2014] [Accepted: 02/04/2014] [Indexed: 11/17/2022]
Abstract
In the last few years, it has become clear that a wide variety of environmental contaminants have specific effects on neuroendocrine systems in fish, amphibians, birds and mammals. While it is beyond the scope of this review to provide a comprehensive examination of all of these neuroendocrine disruptors, we will focus on select representative examples. Organochlorine pesticides bioaccumulate in neuroendocrine areas of the brain that directly regulate GnRH neurons, thereby altering the expression of genes downstream of GnRH signaling. Organochlorine pesticides can also agonize or antagonize hormone receptors, adversely affecting crosstalk between neurotransmitter systems. The impacts of polychlorinated biphenyls are varied and in many cases subtle. This is particularly true for neuroedocrine and behavioral effects of exposure. These effects impact sexual differentiation of the hypothalamic-pituitary-gonadal axis, and other neuroendocrine systems regulating the thyroid, metabolic, and stress axes and their physiological responses. Weakly estrogenic and anti-androgenic pollutants such as bisphenol A, phthalates, phytochemicals, and the fungicide vinclozolin can lead to severe and widespread neuroendocrine disruptions in discrete brain regions, including the hippocampus, amygdala, and hypothalamus, resulting in behavioral changes in a wide range of species. Behavioral features that have been shown to be affected by one or more these chemicals include cognitive deficits, heightened anxiety or anxiety-like, sociosexual, locomotor, and appetitive behaviors. Neuroactive pharmaceuticals are now widely detected in aquatic environments and water supplies through the release of wastewater treatment plant effluents. The antidepressant fluoxetine is one such pharmaceutical neuroendocrine disruptor. Fluoxetine is a selective serotonin reuptake inhibitor that can affect multiple neuroendocrine pathways and behavioral circuits, including disruptive effects on reproduction and feeding in fish. There is growing evidence for the association between environmental contaminant exposures and diseases with strong neuroendocrine components, for example decreased fecundity, neurodegeneration, and cardiac disease. It is critical to consider the timing of exposures of neuroendocrine disruptors because embryonic stages of central nervous system development are exquisitely sensitive to adverse effects. There is also evidence for epigenetic and transgenerational neuroendocrine disrupting effects of some pollutants. We must now consider the impacts of neuroendocrine disruptors on reproduction, development, growth and behaviors, and the population consequences for evolutionary change in an increasingly contaminated world. This review examines the evidence to date that various so-called neuroendocrine disruptors can induce such effects often at environmentally-relevant concentrations.
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Affiliation(s)
- Martha León-Olea
- Departamento de Neuromorfología Funcional, Dirección de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría, R.F.M., México D.F., México
| | - Christopher J. Martyniuk
- Canadian Rivers Institute and Department of Biology, University of New Brunswick, Saint John, New Brunswick, E2L 4L5, Canada
| | - Edward F. Orlando
- University of Maryland, Department of Animal and Avian Sciences, College Park, MD 20742, USA
| | - Mary Ann Ottinger
- University of Maryland, Department of Animal and Avian Sciences, College Park, MD 20742, USA
- Department of Biology and Biochemistry, University of Houston, Houston, TX 77204, USA
| | - Cheryl Rosenfeld
- Departments of Biomedical Sciences and Bond Life Sciences Center, Genetics Area Program, University of Missouri, Columbia, MO 65211, USA
| | - Jennifer Wolstenholme
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 23112, USA
| | - Vance L. Trudeau
- Department of Biology, University of Ottawa, 30 Marie Curie Private, Ottawa, ON, Canada, K1N 6N5
- Corresponding author:
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19
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Morphological and functional deterioration of the rat thyroid following chronic exposure to low-dose PCB118. ACTA ACUST UNITED AC 2013; 65:989-94. [DOI: 10.1016/j.etp.2013.02.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 01/11/2013] [Accepted: 02/03/2013] [Indexed: 02/01/2023]
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20
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Kato Y, Tamaki S, Haraguchi K, Ikushiro SI, Sekimoto M, Ohta C, Endo T, Koga N, Yamada S, Degawa M. Comparative study on 2,2′,4,5,5′-pentachlorobiphenyl-mediated decrease in serum thyroxine level between C57BL/6 and its transthyretin-deficient mice. Toxicol Appl Pharmacol 2012; 263:323-9. [DOI: 10.1016/j.taap.2012.07.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Revised: 07/05/2012] [Accepted: 07/06/2012] [Indexed: 11/29/2022]
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21
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Parham F, Wise A, Axelrad DA, Guyton KZ, Portier C, Zeise L, Zoeller RT, Woodruff TJ. Adverse effects in risk assessment: modeling polychlorinated biphenyls and thyroid hormone disruption outcomes in animals and humans. ENVIRONMENTAL RESEARCH 2012; 116:74-84. [PMID: 22575326 PMCID: PMC4955584 DOI: 10.1016/j.envres.2012.04.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 03/19/2012] [Accepted: 04/04/2012] [Indexed: 05/02/2023]
Abstract
There is a growing need for quantitative approaches to extrapolate relationships between chemical exposures and early biological perturbations from animals to humans given increasing use of biological assays to evaluate toxicity pathways. We have developed such an approach using polychlorinated biphenyls (PCBs) and thyroid hormone (TH) disruption as a case study. We reviewed and identified experimental animal literature from which we developed a low-dose, linear model of PCB body burdens and decrements in free thyroxine (FT(4)) and total thyroxine (TT(4)), accounting for 33 PCB congeners; extrapolated the dose-response from animals to humans; and compared the animal dose-response to the dose-response of PCB body burdens and TH changes from eleven human epidemiological studies. We estimated a range of potencies for PCB congeners (over 4 orders of magnitude), with the strongest for PCB 126. Our approach to developing toxic equivalency models produced relative potencies similar to the toxicity equivalency factors (TEFs) from the World Health Organization (WHO). We generally found that the dose-response extrapolated from the animal studies tends to under-predict the dose-response estimated from human epidemiological studies. A quantitative approach to evaluating the relationship between chemical exposures and TH perturbations, based on animal data can be used to assess human health consequences of thyroid toxicity and inform decision-making.
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Affiliation(s)
- Fred Parham
- National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Amber Wise
- Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, USA
| | - Daniel A. Axelrad
- Office of Policy, U.S. Environmental Protection Agency (USEPA), Washington, DC, USA
| | - Kathryn Z. Guyton
- National Center for Environmental Assessment, Office of Research and Development, USEPA, Washington, DC, USA
| | | | - Lauren Zeise
- Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, Oakland, CA, USA
| | | | - Tracey J. Woodruff
- Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, USA
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A possible mechanism for 2,2',4,4',5,5'-hexachlorobiphenyl-mediated decrease in serum thyroxine level in mice. Toxicol Appl Pharmacol 2011; 254:48-55. [PMID: 21569787 DOI: 10.1016/j.taap.2011.04.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2010] [Revised: 04/23/2011] [Accepted: 04/25/2011] [Indexed: 11/22/2022]
Abstract
Serum total thyroxine (T₄) level was markedly decreased, without significant increases in the levels of hepatic T₄-UDP-glucuronosyltransferase (T₄-UGT) and serum thyroid-stimulating hormone, 3 days after treatment with 2,2',4,4',5,5'-hexachlorobiphenyl (CB153) (100mg/kg, ip) in both 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-sensitive C57BL/6 and TCDD-resistant DBA/2 mice. Likewise, in either strain of mice, no CB153-mediated changes in the binding levels of [(125)I]T₄ to serum proteins, such as transthyretin, albumin, and thyroxine binding globulin, were observed, while in CB153-pretreated C57BL/6 mice, but not in CB153-pretreated DBA/2 mice, the levels of biliary [(125)I]₄T and [(125)I]T₄-glucuronide at 90-120 min after injection of [(125)I]T₄ slightly increased, as compared with those in the corresponding control mice. Concerning tissue distribution of [(125)I]T₄, liver-selective increases in the [(125)I]T₄ accumulation by CB153-pretreatment were observed in both C57BL/6 and DBA/2 mice, and the hepatic levels of [(125)I]T₄ in the C57BL/6 and DBA/2 mice became more than 44% and 34% of the [(125)I]T₄ dosed, respectively. The present findings indicated that the CB153-mediated decreases in the level of serum total T₄in C57BL/6 and DBA/2 mice occur mainly through an increase in the accumulation of T₄ in the liver.
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Nakagami A, Koyama T, Kawasaki K, Negishi T, Ihara T, Kuroda Y, Yoshikawa Y. Maternal plasma polychlorinated biphenyl levels in cynomolgus monkeys (Macaca fascicularis) affect infant social skills in mother-infant interaction. Dev Psychobiol 2010; 53:79-88. [DOI: 10.1002/dev.20493] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Sonne C. Health effects from long-range transported contaminants in Arctic top predators: An integrated review based on studies of polar bears and relevant model species. ENVIRONMENT INTERNATIONAL 2010; 36:461-491. [PMID: 20398940 DOI: 10.1016/j.envint.2010.03.002] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 03/06/2010] [Accepted: 03/10/2010] [Indexed: 05/29/2023]
Abstract
The aim of this review is to provide a thorough overview of the health effects from the complexed biomagnified mixture of long-range transported industrial organochlorines (OCs), polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs) and mercury (Hg) on polar bear (Ursus maritimus) health. Multiple scientific studies of polar bears indicate negative relationships between exposure to these contaminants and health parameters; however, these are all of a correlative nature and do not represent true cause-and-effects. Therefore, information from controlled studies of farmed Norwegian Arctic foxes (Vulpes lagopus) and housed East and West Greenland sledge dogs (Canis familiaris) were included as supportive weight of evidence in the clarification of contaminant exposure and health effects in polar bears. The review showed that hormone and vitamin concentrations, liver, kidney and thyroid gland morphology as well as reproductive and immune systems of polar bears are likely to be influenced by contaminant exposure. Furthermore, exclusively based on polar bear contaminant studies, bone density reduction and neurochemical disruption and DNA hypomethylation of the brain stem seemed to occur. The range of tissue concentration, at which these alterations were observed in polar bears, were ca. 1-70,000 ng/g lw for OCs (blood plasma concentrations of some PCB metabolites even higher), ca. 1-1000 ng/g lw for PBDEs and for PFCs and Hg 114-3052 ng/g ww and 0.1-50 microg/g ww, respectively. Similar concentrations were found in farmed foxes and housed sledge dogs while the lack of dose response designs did not allow an estimation of threshold levels for oral exposure and accumulated tissue concentrations. Nor was it possible to pinpoint a specific group of contaminants being more important than others nor analyze their interactions. For East Greenland polar bears the corresponding daily SigmaOC and SigmaPBDE oral exposure was estimated to be 35 and 0.34 microg/kg body weight, respectively. Furthermore, PFC concentrations, at which population effect levels could occur, are likely to be reached around year 2012 for the East Greenland polar bear subpopulation if current increasing temporal trends continue. Such proposed reproductive population effects were supported by physiological based pharmacokinetic (PBPK) modelling of critical body residues (CBR) with risk quotients >or=1 for SigmaPCB, dieldrin, SigmaPFC and SigmaOHC (organohalogen contaminant). The estimated daily TEQ for East Greenland polar bears and East Greenland sledge dogs were 32-281-folds above WHO SigmaTEQ guidelines for humans. Compared to human tolerable daily intake (TDI), these were exceeded for PCBs, dieldrin, chlordanes and SigmaHCH in East Greenland polar bears. Comparisons like these should be done with caution, but together with the CBR modelling and T-score estimations, these were the only available tools for polar bear risk evaluation. In conclusion, polar bears seem to be susceptible to contaminant induced stress that may have an overall sub-clinical impact on their health and population status via impacts on their immune and reproductive systems.
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Affiliation(s)
- Christian Sonne
- Section for Contaminants, Effects and Marine Mammals, Department of Arctic Environment, National Environmental Research Institute, University of Aarhus, DK-4000 Roskilde, Denmark.
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Martin L, Klaassen CD. Differential effects of polychlorinated biphenyl congeners on serum thyroid hormone levels in rats. Toxicol Sci 2010; 117:36-44. [PMID: 20573785 DOI: 10.1093/toxsci/kfq187] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Polychlorinated biphenyls (PCBs) are known to reduce serum thyroxine (T(4)) in rats, but the relative effects of individual PCB congeners on thyroid hormones are not known. Thus, male Sprague-Dawley rats were administered Aroclor 1254, Aroclor 1242 (4, 8, 16, or 32 mg/kg/day), PCB 95 (2,2',3,5',6-pentachlorobiphenyl), PCB 99 (2,2',4,4',5-pentachlorobiphenyl), PCB 118 (2,3',4,4',5-pentachlorobiphenyl) (2, 4, 8, or 16 mg/kg/day), PCB 126 (3,3'4,4',5-pentachlorobiphenyl) (2.5, 5, 10, 20, or 40 microg/kg/day), TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) (0.14, 0.43, 1.3, or 3.9 microg/kg/day), or corn oil via oral gavage for 7 days. Rats were necropsied 24 h after the last dose. Serum thyroid hormone levels were evaluated by radioimmunoassay, and induction of hepatic Cyp1a (a TCDD-inducible protein) and Cyp2b (a phenobarbital [PB]-inducible protein) activity was determined by ethoxyresorufin-O-deethylase and pentoxyresorufin-O-deethylase assays, respectively. Significant increases in Cyp1a activity occurred in response to PCBs, except PCB 95 and PCB 99. Aroclor 1254, PCB 99, and PCB 118 significantly induced Cyp2b activity. Serum total T(4) and free T(4) were dramatically reduced in response to each of the seven treatments in a dose-dependent manner. The marked T(4) reductions occurred in response to Aroclor 1254, PCB 99 (a PB-type congener), and PCB 118 (a mixed-type congener). In contrast, reductions in serum triiodothyronine (total and free) were variable and mild, and serum thyroid-stimulating hormone was not significantly affected by any of the compounds. These data indicate that the PB and mixed-type PCB congeners are more effective than the TCDD-type PCB congeners at reducing serum T(4).
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Affiliation(s)
- Lori Martin
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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Orn U, Klasson-Wehler E. Metabolism of 2,2, 4,4-tetrabromodiphenyl ether in rat and mouse. Xenobiotica 2010. [DOI: 10.3109/xen.28.2.199] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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27
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Xiao W, Li K, Wu Q, Nishimura N, Chang X, Zhou Z. Influence of persistent thyroxine reduction on spermatogenesis in rats neonatally exposed to 2,2',4,4',5,5'-hexa-chlorobiphenyl. ACTA ACUST UNITED AC 2010; 89:18-25. [PMID: 20025066 DOI: 10.1002/bdrb.20213] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The aim of the present study is to determine the long-term testicular effects of neonatal exposure to PCB153. METHODS Sprague-Dawley (SD) rats were treated by oral gavage with PCB153 in corn oil at doses of 0, 0.025, and 2.5 mg/kg per day from postnatal day 3 (PND 3) to PND7. The rats were sacrificed on PND 8 and PND 77. TUNEL in situ detection for testis apoptosis, immunohistochemical staining of thyroid gland for thyroxine (T4), semi-quantitative RT-PCR for mRNA expression, and radioimmunoassay (RIA) for serum hormone levels were performed. RESULTS Neonatal treatment with PCB153 at both doses had no obvious effects on body weight, testis weight, testis histology, and germ cell apoptosis, but decreased T4 staining in thyroid gland was observed on PND 8. On PND 77, neonatal treatment with 2.5 mg/kg per day of PCB153 significantly reduced daily sperm product (DSP). Serum levels of thyroxine (T4) and free thyroxine (FT4) decreased, but there were no differences in thyroid-stimulating hormone (TSH) level between the control and exposed groups. Gap junction connexin43 (CX43) and cyclin-dependent kinase inhibitor (CDKI) P27kip1 mRNA expression, which was associated with Sertoli cell differentiation, was significantly reduced after PCB153 treatment on PND 8 but not on PND 77. Androgen-binding protein (ABP) and androgen receptor (AR) mRNA expression, which indicates Sertoli cell maturation, was suppressed on PND 77 after neonatal PCB153 exposure. CONCLUSIONS The findings in this study suggest that neonatal exposure to PCB153 induces persistent T4 reduction, which disturbs Sertoli cell function, and subsequently results in alterations in adult spermatogenesis. Birth Defects Res (Part B) 89:18-25, 2010. (c) 2009 Wiley-Liss, Inc.
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Affiliation(s)
- Wusheng Xiao
- School of Public Health, Fudan University, Shanghai, China
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Goodman JE, Kerper LE, Boyce CP, Prueitt RL, Rhomberg LR. Weight-of-evidence analysis of human exposures to dioxins and dioxin-like compounds and associations with thyroid hormone levels during early development. Regul Toxicol Pharmacol 2010; 58:79-99. [PMID: 20416351 DOI: 10.1016/j.yrtph.2010.04.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Revised: 03/19/2010] [Accepted: 04/15/2010] [Indexed: 11/29/2022]
Abstract
Thyroid hormones play a critical role in the proper development of brain function and cell growth. Several epidemiological studies have been conducted to assess potential associations between pre- and post-natal exposure to dioxins or dioxin-like compounds (DLCs) and the levels of circulating thyroid hormones during early development. Dioxins and DLCs include chlorinated dibenzo-p-dioxins, chlorinated dibenzofurans, and mono- and non-ortho polychlorinated biphenyls (PCBs). We identified a total of 23 relevant epidemiological studies (21 cohort studies and 1 case-control study) that measured exposures to various types of dioxins and DLCs as well as markers of thyroid function, such as thyroid stimulating hormone (TSH), total thyroxine (T4), free T4, total triiodothyroxine (T3), free T3, and thyroid-binding globulin concentrations in cord blood or circulation. While some of the studies reported associations between concentrations of dioxins and/or DLCs and some biomarkers of thyroid function, the majority of the observed associations were not statistically significant. Moreover, there were no clear and consistent effects across studies for any of the hormone levels examined, and while a number of studies showed a statistically significant association with exposure for a given marker of thyroid function, other studies showed either no change or changes in the opposite direction for the same thyroid function marker. Similarly, when the results were analyzed considering developmental stage, there generally were no clear and consistent effects at any age from birth through 12 years of age. The absence of a clear correlation between background exposures to dioxins and DLCs and thyroid function biomarkers during development is not consistent with the hypothesis that background exposures to these chemicals cause effects on thyroid function during development.
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Kovacic P, Edwards C. Integrated approach to the mechanisms of thyroid toxins: electron transfer, reactive oxygen species, oxidative stress, cell signaling, receptors, and antioxidants. J Recept Signal Transduct Res 2010; 30:133-42. [DOI: 10.3109/10799891003702678] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Yang JM, Salmon AG, Marty MA. Development of TEFs for PCB congeners by using an alternative biomarker--thyroid hormone levels. Regul Toxicol Pharmacol 2010; 56:225-36. [PMID: 20043972 DOI: 10.1016/j.yrtph.2009.12.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2009] [Revised: 12/08/2009] [Accepted: 12/22/2009] [Indexed: 01/04/2023]
Abstract
Polychlorinated biphenyls (PCBs) are ubiquitous toxic contaminants. Health risk assessment for this class of chemicals is complex: the current toxic equivalency factor (TEF) method covers dioxin-like (DL-) PCBs, dibenzofurans, and dioxins, but excludes non-DL-PCBs. To address this deficiency, we evaluated published data for several PCB congeners to determine common biomarkers of effect. We found that the most sensitive biomarkers for DL-non-ortho-PCB 77 and PCB 126 are liver enzyme (e.g., ethoxyresorufin-O-deethylase, EROD) induction, circulating thyroxine (T4) decrease, and brain dopamine (DA) elevation. For DL-ortho-PCB 118 and non-DL-ortho-PCB 28 and PCB 153, the most sensitive biomarkers are brain DA decrease and circulating T4 decrease. The only consistent biomarker for both DL- and non-DL-PCBs is circulating T4 decrease. The calculated TEF-(TH), based on the effective dose to decrease T4 by 30% (ED(30)) with reference to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), is identical to both TEF-(WHO98) and TEF-(WHO05) for TCDD and DL-PCBs (correlation coefficients are r=1.00, P<0.001; and r=0.99, P<0.001, respectively). We conclude that T4 decrease is a prospective biomarker for generating a new TEF scheme which includes some non-DL-congeners. The new TEF-(TH) parallels the TEF-(WHO) for DL-PCBs and, most importantly, is useful for non-DL-PCBs in risk assessment to address thyroid endocrine disruption and potentially the neurotoxic effects of PCBs.
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Affiliation(s)
- Jian-Ming Yang
- Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, Oakland, CA 94612, USA.
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31
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Kato Y, Haraguchi K, Kubota M, Seto Y, Okura T, Ikushiro SI, Koga N, Yamada S, Degawa M. A Possible Mechanism for the Decrease in Serum Thyroxine Level by a 2,3,7,8-Tetrachlorodibenzo-p-dioxin-Like Polychlorinated Biphenyl Congener, 3,3′,4,4′,5-Pentachlorobiphenyl in Mice. Drug Metab Dispos 2009; 38:150-6. [DOI: 10.1124/dmd.109.029348] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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32
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Chang SC, Ehresman DJ, Bjork JA, Wallace KB, Parker GA, Stump DG, Butenhoff JL. Gestational and lactational exposure to potassium perfluorooctanesulfonate (K+PFOS) in rats: Toxicokinetics, thyroid hormone status, and related gene expression. Reprod Toxicol 2009; 27:387-399. [DOI: 10.1016/j.reprotox.2009.01.005] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 12/29/2008] [Accepted: 01/07/2009] [Indexed: 10/21/2022]
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Kobayashi K, Miyagawa M, Wang RS, Suda M, Sekiguchi S, Honma T. Effects of in utero exposure to 2,2',4,4',5,5'-hexachlorobiphenyl on postnatal development and thyroid function in rat offspring. INDUSTRIAL HEALTH 2009; 47:189-197. [PMID: 19367049 DOI: 10.2486/indhealth.47.189] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Exposure to polychlorobiphenyls (PCBs) has been reported to affect endocrine glands; however, little is known about the precise toxicological properties of individual PCBs. We determined whether prenatal exposure to 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153), a di-ortho-substituted non-coplanar congener, affects postnatal development in rat offspring. Pregnant Sprague-Dawley rats were given PCB 153 (0, 1, or 4 mg/kg/d) orally from gestational day (GD) 10 to 16, and somatic parameters and thyroid functions in offspring were examined. We found no dose-dependent changes in body weight, body length, tail length, or weight of liver, kidney, testis, seminal vesicle, prostate, ovary, relative organ weight, anogenital distance (AGD), or AGD index in offspring at 1, 3 or 9 wk of age. We observed no compound-related changes in the plasma concentrations of thyroxine (T(4)), tri-iodothyronine (T(3)) or thyroid-stimulating hormone (TSH), although there was a significant difference in T(3) only in 1-wk-old males. In addition, thyroid glands from PCB 153 groups had normal T(4) responses to exogenous TSH in vivo. These findings suggest that low doses of PCB 153 given prenatally (GD 10-16, 1-4 mg/kg/d) might have little effect on postnatal somatic growth or thyroid development of male and female rat offspring under the experimental conditions of the present study.
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Affiliation(s)
- Kenichi Kobayashi
- National Institute of Occupational Safety and Health, 6-21-1 Nagao, Tama-Ku, Kawasaki 214-8585, Japan
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Honma T, Suda M, Miyagawa M, Wang RS, Kobayashi K, Sekiguchi S. Alteration of brain neurotransmitters in female rat offspring induced by prenatal administration of 16 and 64 mg/kg of 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153). INDUSTRIAL HEALTH 2009; 47:11-21. [PMID: 19218753 DOI: 10.2486/indhealth.47.11] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
PCB153 (2,2',4,4',5,5'-hexachlorobiphenyl), a non-coplanar PCB and the congener most widely distributed in the environment, was orally administered to pregnant Sprague-Dawley (Crj: CD (SD) IGS) rats from gestation day 10 through 16 at doses of 0 (control), 16 and 64 mg/kg body weight. Female pups were sacrificed at 1, 3, 6, and 9 wk, and at 1 yr of age to evaluate the differences in brain neurotransmitters and their metabolites between PCB153-exposed and control groups. Brain levels of norepinephrine (NE), 3-methoxy-4-hydroxyphenylglycol (MHPG), dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), serotonin (5HT), 5-hydroxyindoleacetic acid (5HIAA), acetylcholine (ACh), and choline (Ch) in discrete brain regions or in whole brain were measured. At 1 to 3 wk after birth, brain levels of DA, DOPAC, HVA, 5HT and 5HIAA in PCB-exposed groups were higher than those of the control group. At 9 wk after birth, DA turnover was reduced in half of the four brain areas examined (forebrain and hindbrain), and 5HIAA levels were increased in all brain areas in the PCB-treated group compared to those of the control group. At 1 yr after birth, the levels of DA, DOPAC, and HVA in the hippocampus, hypothalamus, and medulla oblongata were lower in the PCB-exposed groups than in the control group. Prenatal exposure to PCB153 stimulated the turnover of 5HT neurons in the brain of female offspring at early stages (1 to 9 wk) of development. On the other hand, the turnover of DA neurons in the PCB-exposed groups was reduced in late stages (9 wk to 1 yr) of development compared with that of the control group. The brain neurotransmitters of dams treated with PCB were assayed at 3 wk after delivery (15 wk old), and decreases in DA, DOPAC, and HVA were observed. PCB153 reduced the activity of DA neurons in the brain of dams. These results are discussed in relation to health effects observed in humans exposed to PCBs.
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Affiliation(s)
- Takeshi Honma
- Department of Health Effects Research, National Institute of Occupational Safety and Health, Tama-ku, Kawasaki, Japan
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Kobayashi K, Miyagawa M, Wang RS, Suda M, Sekiguchi S, Honma T. Effects of in utero exposure to 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153) on somatic growth and endocrine status in rat offspring. Congenit Anom (Kyoto) 2008; 48:151-7. [PMID: 18983581 DOI: 10.1111/j.1741-4520.2008.00199.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Exposure to polychlorobiphenyl (PCB) mixtures at an early stage of development has been reported to affect endocrine glands; however, little is known about the precise toxicological properties of individual PCB. The present study was undertaken to determine whether prenatal exposure to 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153), a di-ortho-substituted non-coplanar congener, affects postnatal development in rat offspring. Pregnant Sprague-Dawley rats (Crj: CD (SD) IGS) were given PCB 153 (0, 16, or 64 mg/kg/day) orally from gestational day (GD) 10 through GD 16, and developmental parameters in the male and female offspring were examined. We found no dose-dependent changes in body weight, body length (nose-anus length), tail length, or the weights of kidneys, testes, ovaries and uterus in offspring at 1 or 3 weeks of age. Liver weights were increased in the PCB 153-treated groups, although we observed a significant difference only in males. Anogenital distance was unaffected in the PCB 153-treated groups. We observed a significant dose-dependent decrease in the plasma concentrations of thyroxine and tri-iodothyronine, whereas those of thyroid-stimulating hormone were not significantly changed. In addition, there were no dose-dependent changes in plasma concentrations of growth hormone and insulin-like growth factor-I in any dose group. These findings suggest that prenatal exposure to PCB 153 (GD 10-16, 16-64 mg/kg/day) may alter the thyroid status in rat offspring to some extent without affecting somatic growth or its related hormonal parameters.
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Affiliation(s)
- Kenichi Kobayashi
- National Institute of Occupational Safety and Health, Kawasaki, Japan.
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36
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Dallaire R, Dewailly E, Ayotte P, Muckle G, Laliberté C, Bruneau S. Effects of prenatal exposure to organochlorines on thyroid hormone status in newborns from two remote coastal regions in Québec, Canada. ENVIRONMENTAL RESEARCH 2008; 108:387-392. [PMID: 18814871 DOI: 10.1016/j.envres.2008.08.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Revised: 06/20/2008] [Accepted: 08/07/2008] [Indexed: 05/26/2023]
Abstract
BACKGROUND Several prospective studies have revealed that prenatal exposure to polychlorinated biphenyls (PCBs) and other organochlorine compounds (OCs) affect neurodevelopment during infancy. One of the mechanisms by which PCBs might interfere with neurodevelopment is a deficit in thyroid hormone (TH) concentrations. OBJECTIVES We investigated the potential impact of transplacental exposure to PCBs and hexachlorobenzene (HCB) on TH concentrations in neonates from two remote coastal populations exposed to OCs through the consumption of seafood products. METHODS Blood samples were collected at birth from the umbilical cord of neonates from Nunavik (n=410) and the Lower North Shore of the St. Lawrence River (n=260) (Québec, Canada) for thyroid parameters [thyroid-stimulating hormone (TSH), free T4 (fT4), total T3 (tT3), and thyroxine-binding globuline (TBG)] and contaminants analyses. RESULTS In multivariate models, umbilical cord plasma concentrations of PCB 153, the predominant PCB congener, were not associated with TH and TSH levels in both populations. Prenatal exposure to HCB was positively associated with fT4 levels at birth in both populations (Nunavik, beta=0.12, p=0.04; St. Lawrence, beta=0.19, p<0.01), whereas TBG concentrations were negatively associated with PCB 153 concentrations (beta=-0.13, p=0.05) in the St. Lawrence cohort. CONCLUSION OCs levels were not associated to a reduction in THs in neonates from our two populations. Essential nutrients derived from seafood such as iodine may have prevented the negative effects of OCs on the thyroid economy during fetal development.
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Affiliation(s)
- Renée Dallaire
- Public Health Research Unit, Laval University Medical Research Centre-Centre Hospitalier, Universitaire de Québec, Québec City, Québec, Canada
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Crofton KM, Zoeller RT. Mode of Action: Neurotoxicity Induced by Thyroid Hormone Disruption During Development—Hearing Loss Resulting From Exposure to PHAHs. Crit Rev Toxicol 2008; 35:757-69. [PMID: 16417043 DOI: 10.1080/10408440591007304] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
An increasing incorporation of mode of action (MOA) information into risk assessments has led to examination of animal MOAs to determine relevance to humans. We examined a specific MOA for developmental neurotoxicity using the MOA/Human Relevance Framework (Meek et al., 2003). The postulated MOA of ototoxicity in rats involves early postnatal exposure to polychlorinated biphenyls (PCBs) via lactation, an upregulation of hepatic uridine diphosphoglucuronyltransferases (UGTs), and subsequent hypothyroxinemia during a critical period of cochlear development, with the ultimate neurotoxic consequence of hearing loss. This review concludes with high confidence in the animal MOA and medium confidence for the interspecies concordance for the key events in the MOA. Possible interspecies differences in toxicodynamic factors moderate confidence in some key events. In addition, there is a question of whether ambient human exposures are large enough to cause human fetal hypothyroxinemia to the degree needed to cause hearing loss. Data gaps identified by this analysis include a need to characterize the induciblity of human fetal UGTs and the comparative sensitivity of UGT induction by xenobiotics in rats and humans. Research on these areas of uncertainty will increase confidence that this MOA for PCBs is not likely to not occur in humans, assuming normal conditions of limited ambient exposure.
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Affiliation(s)
- Kevin M Crofton
- US Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.
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Todaka T, Hori T, Hirakawa H, Kajiwara J, Yasutake D, Onozuka D, Iida T, Furue M. Congener-specific analysis of non-dioxin-like polychlorinated biphenyls in blood collected from 127 elderly residents in Nakagawa Town, Fukuoka Prefecture, Japan. CHEMOSPHERE 2008; 73:865-72. [PMID: 18768207 DOI: 10.1016/j.chemosphere.2008.07.058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2008] [Revised: 07/19/2008] [Accepted: 07/21/2008] [Indexed: 05/16/2023]
Abstract
We conducted congener-specific analysis of non-dioxin-like polychlorinated biphenyls (non-dioxin-like PCBs) in blood collected in February 2004 from 127 elderly residents living in Nakagawa Town, Fukuoka Prefecture, Japan. The present study is one of the few studies in which 56 non-dioxin-like PCBs congeners were measured in human blood. Of the 127 elderly residents, 51 were men (mean: 68.1 years) and 76 were women (mean: 68.1 years). Among 197 non-dioxin-like PCB congeners, 56 were identified in the blood of elderly residents. The arithmetic mean total concentrations of 56 non-dioxin-like PCBs congeners in the blood of elderly men and women in Nakagawa Town were 419 (median: 378) and 363 (median: 323)ngg(-1)lipid, respectively, and the concentrations were in the range of 172-1102 and 119-1226ngg(-1)lipid, respectively, indicating that the total concentrations in elderly men are significantly higher than those in elderly women. The contamination of non-dioxin-like PCBs in the blood of elderly men and women in Fukuoka Prefecture was found to have decreased compared to past levels. The ratios of hexachlorinated biphenyls (hexaCBs) to the total concentrations of 56 non-dioxin-like PCBs congeners in the blood of elderly men and women were 44.6% and 45.6%, respectively, which was particularly high compared with those of other congeners. 2,2',4,4',5,5'-HexaCB (#153) among hexaCBs congeners, the most abundant congener in the blood of elderly men and women, contributed approximately 23.0% and 23.5% to the total concentrations of 56 non-dioxin-like PCBs congeners, respectively. Furthermore, 2,2',3,4,4',5'-hexaCB (#138), 2,3,3',4',5,6-hexaCB (#163)/2,3,3',4',5',6-hexaCB (#164), 2,2',3,4,4',5,5'-heptaCB (#180), and 2,2',3,4,4',5,6'-heptaCB (#182)/2,2',3,4',5,5',6-heptaCB (#187) also showed high ratios to the total concentrations of 56 non-dioxin-like PCBs congeners detected in the blood of elderly men and women. A statistical examination of the relationship between the total concentrations of 56 non-dioxin-like PCBs congeners in blood and the age of elderly residents who were over 60 years indicated statistically significant correlations between the total concentrations of these PCBs congeners and the age of elderly women. However, similar correlations were not observed in elderly men. The results of the present study have indicated the current levels of non-dioxin-like PCBs in the blood of elderly men and women in Fukuoka Prefecture, Japan and can be used as baseline data for those over age 60.
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Affiliation(s)
- Takashi Todaka
- Department of Dermatology, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan.
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Schell LM, Gallo MV, Denham M, Ravenscroft J, DeCaprio AP, Carpenter DO. Relationship of thyroid hormone levels to levels of polychlorinated biphenyls, lead, p,p'- DDE, and other toxicants in Akwesasne Mohawk youth. ENVIRONMENTAL HEALTH PERSPECTIVES 2008; 116:806-13. [PMID: 18560538 PMCID: PMC2430238 DOI: 10.1289/ehp.10490] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Accepted: 02/25/2008] [Indexed: 05/02/2023]
Abstract
BACKGROUND It is well documented that acute exposure to high levels of persistent organic pollutants, such as polychlorinated biphenyls (PCBs), p,p'-dichlorophenyldichloroethylene (p,p'-DDE), and hexachlorobenzene (HCB), can affect human health including thyroid function. Chronic exposure to multiple toxicants is common but difficult to analyze, and most prior studies have focused on adults or newborns, creating a gap in our understanding of multitoxicant effects among adolescents. OBJECTIVE We investigated whether levels of PCBs, p,p'-DDE, HCB, mirex, lead, and mercury reflecting past chronic exposure are associated with alterations in levels of thyroid-stimulating hormone (TSH), triiodothyronine (T(3)), total thyroxine (TT(4)), and free thyroxine (FT(4)) among older children and adolescents. METHODS The sample consists of youth from the Akwesasne Mohawk Nation (n=232) who reside in proximity to several industries that have contaminated the local environment. We used multiple regression analysis to examine the effect of PCB groupings, p,p'-DDE, HCB, lead, and mercury on thyroid hormones after adjusting for sociodemographic covariates and controlling for all other toxicants. RESULTS Exposure to PCBs affects the thyroid hormone profile in adolescents. The group of persistent PCBs was positively associated with TSH but inversely related to FT(4). Nonpersistent PCBs were significantly and negatively related to FT(4) only. HCB was negatively associated with T(4), and lead was positively associated with T(3). Breast-fed adolescents had higher levels of persistent PCBs and p,p'-DDE but not of nonpersistent PCBs or any other toxicant when compared with non-breast-fed adolescents. Though having lower levels of persistent PCBs and p,p'-DDE, non-breast-fed adolescents exhibited significant relationships between persistent PCBs and TSH and FT(4), but breast-fed adolescents did not. It appears that PCBs from breast milk obscure the relationship between prenatal PCB exposure and thyroid function by adding random variation in PCB levels. CONCLUSION Our results demonstrate a reduction in thyroid function in adolescents in relation to their current serum levels of PCBs. These observations are consistent with the hypothesis that pre-natal exposure to PCBs alters thyroid function in a long-lasting manner but does not exclude the possibility that postnatal exposure is influential also.
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Affiliation(s)
- Lawrence M Schell
- Department of Anthropology, University at Albany, State University of New York, Albany, New York 12222, USA.
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Harris SA, Jones JL. Fish consumption and PCB-associated health risks in recreational fishermen on the James River, Virginia. ENVIRONMENTAL RESEARCH 2008; 107:254-263. [PMID: 18395199 DOI: 10.1016/j.envres.2008.01.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2007] [Revised: 01/22/2008] [Accepted: 01/30/2008] [Indexed: 05/26/2023]
Abstract
Consumption of sport-caught fish contaminated with high levels of polychlorinated biphenyls (PCBs) may pose human health risks. To obtain estimates of fish consumption and fishing behaviors in recreational fishermen in Virginia, on-site interviews (n=143; 134 men and 9 women) were conducted at seven public boat landings along the James River. Using existing PCB concentration data from James River fish tissue samples collected from 1997, and 1999 to 2001, default and point estimates were calculated and Monte Carlo analyses conducted to estimate potential risks under different consumption scenarios. A mean of 55 fish meals/yr and 14 James River sport-caught fish (JRSCF) meals/yr were reported. Caucasians fished less often (mean of 58 d), consumed less fish (mean of 43 meals/yr) and had smaller portion sizes (mean of 11.7 oz) compared to other races combined (130 d; 82 meals/yr; and 15.6 oz). On average, respondents reported consuming 10 meals of James River catfish a year (5 kg/yr). Risk estimates produced from Monte Carlo analysis were consistently lower than the default and point estimates. Several individuals exceeded acceptable risk levels and the mean cancer and non-cancer risks among catfish consumers exceeded acceptable levels. Eighteen percent of individuals had no knowledge of fish advisories in Virginia and 4% of the subjects indicated they would consume fish under advisory. Based on reported consumption, a significant risk to recreational fishermen, as a result of consuming PCB-contaminated catfish, was found. Risks associated with consuming other species were within acceptable limits.
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Affiliation(s)
- Shelley A Harris
- Division of Population Studies and Surveillance, Cancer Care Ontario, 620 University Avenue, Toronto, Ontario, Canada.
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Gauger KJ, Giera S, Sharlin DS, Bansal R, Iannacone E, Zoeller RT. Polychlorinated biphenyls 105 and 118 form thyroid hormone receptor agonists after cytochrome P4501A1 activation in rat pituitary GH3 cells. ENVIRONMENTAL HEALTH PERSPECTIVES 2007; 115:1623-30. [PMID: 18007995 PMCID: PMC2072832 DOI: 10.1289/ehp.10328] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Accepted: 08/15/2007] [Indexed: 05/17/2023]
Abstract
BACKGROUND Polychlorinated biphenyls (PCBs) may interfere with thyroid hormone (TH) signaling by reducing TH levels in blood, by exerting direct effects on TH receptors (TRs), or both. OBJECTIVE Our objective was to identify individual PCBs that directly affect TH signaling by acting on the TR. METHODS We administered a mixture of six PCB congeners based on their ortho substitution pattern, including PCBs 77 and 126 (non-ortho), PCBs 105 and 118 (mono-ortho), and PCBs 138 and 153 (di-ortho), to pregnant Sprague-Dawley rats from gestational days (G) 6 to 16. This mixture, or various combinations of the components, was also evaluated in a transient transfection system using GH3 cells. RESULTS The mixture reduced serum TH levels in pregnant rats on G16 but simultaneously up-regulated the expression of malic enzyme in liver. It also functioned as a TR agonist in vitro; however, none of the individual PCB congeners comprising this mixture were active in this system. Using the aryl hydrocarbon receptor (AhR) antagonist alpha-naphthoflavone, and the cytochrome P450 (CYP)1A1 antagonist ellipticine, we show that the effect of the mixture on the thyroid hormone response element required AhR and CYP1A1. CONCLUSIONS We propose that PCB 126 induces CYP1A1 through the AhR in GH3 cells, and that CYP1A1 activates PCB 105 and/or 118 to a form a compound that acts as a TR agonist. These data suggest that some tissues may be especially vulnerable to PCBs interfering directly with TH signaling due to their capacity to express CYP1A1 in response to coplanar PCBs (or other dioxin-like molecules) if sufficient mono-ortho PCBs are present.
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Affiliation(s)
- Kelly J. Gauger
- Molecular and Cellular Biology Program, University of Massachusetts Amherst, Massachusetts, USA
- Pioneer Valley Life Science Institute, Baystate Medical Center, Spingfield, Massachusetts, USA
| | - Stefanie Giera
- Molecular and Cellular Biology Program, University of Massachusetts Amherst, Massachusetts, USA
- Institute of Pharmacology and Toxicology, Department of Toxicology, University of Tübingen, Tübingen, Germany
| | - David S. Sharlin
- Molecular and Cellular Biology Program, University of Massachusetts Amherst, Massachusetts, USA
| | - Ruby Bansal
- Department of Biology, Morrill Science Center, University of Massachusetts, Amherst, Massachusetts, USA
| | - Eric Iannacone
- Molecular and Cellular Biology Program, University of Massachusetts Amherst, Massachusetts, USA
- Fairleigh Dickinson University, Madison, New Jersey, USA
| | - R. Thomas Zoeller
- Molecular and Cellular Biology Program, University of Massachusetts Amherst, Massachusetts, USA
- Department of Biology, Morrill Science Center, University of Massachusetts, Amherst, Massachusetts, USA
- Address correspondence to R.T. Zoeller, Biology Department, University of Massachusetts, 611 North Pleasant St., Amherst, MA 01003 USA. Telephone: (413) 545-2088. Fax: (413) 545-3243. E-mail:
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Otake T, Yoshinaga J, Enomoto T, Matsuda M, Wakimoto T, Ikegami M, Suzuki E, Naruse H, Yamanaka T, Shibuya N, Yasumizu T, Kato N. Thyroid hormone status of newborns in relation to in utero exposure to PCBs and hydroxylated PCB metabolites. ENVIRONMENTAL RESEARCH 2007; 105:240-6. [PMID: 17490634 DOI: 10.1016/j.envres.2007.03.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 03/02/2007] [Accepted: 03/27/2007] [Indexed: 05/15/2023]
Abstract
The associations between in utero exposure to polychlorinated biphenyls (PCBs) or hydroxylated PCB metabolites (OH-PCBs), and free thyroxin (fT4) or thyroid-stimulating hormone (TSH) status in the newborn were investigated as a pilot study of a large-scale epidemiologic study on in utero PCB or OH-PCB exposure and thyroid function of the newborns. Umbilical cord tissue was used as the media for the biological monitoring of PCBs/OH-PCBs exposure in utero. For the measurement of fT4 and TSH, a heel-prick blood sample spotted on filter paper, which is called Guthrie card, is collected from each neonate at day 4-6 postpartum for this study when the mass screening sampling was performed. We showed that the concentration of total OH-PCBs and one of the OH-PCB congeners (OH-PCB 187) was related significantly to higher fT4 level of newborns. On the other hand, the concentration of total PCBs and PCB congeners (PCB 118, 138, 153, and 180) showed no relationship with fT4 and TSH level of the newborns. The results obtained in this pilot study indicated the possibility that in utero OH-PCBs exposure affects thyroid hormone status of newborns.
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Affiliation(s)
- Takamitsu Otake
- Department of Environmental Studies, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8563, Japan
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Mastorakos G, Karoutsou EI, Mizamtsidi M, Creatsas G. The menace of endocrine disruptors on thyroid hormone physiology and their impact on intrauterine development. Endocrine 2007; 31:219-37. [PMID: 17906368 DOI: 10.1007/s12020-007-0030-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Revised: 04/19/2007] [Accepted: 05/01/2007] [Indexed: 10/22/2022]
Abstract
The delivery of the appropriate thyroid hormones quantity to target tissues in euthyroidism is the result of unopposed synthesis, transport, metabolism, and excretion of these hormones. Thyroid hormones homeostasis depends on the maintenance of the circulating 'free' thyroid hormone reserves and on the development of a dynamic balance between the 'free' hormones reserves and those of the 'bound' hormones with the transport proteins. Disturbance of this hormone system, which is in constant interaction with other hormone systems, leads to an adaptational counter-response targeting to re-establish a new homeostatic equilibrium. An excessive disturbance is likely to result, however, in hypo- or hyper- thyroid clinical states. Endocrine disruptors are chemical substances forming part of 'natural' contaminating agents found in most ecosystems. There is abundant evidence that several key components of the thyroid hormones homeostasis are susceptible to the action of endocrine disruptors. These chemicals include some chlorinated organic compounds, polycyclic aromatic hydrocarbons, herbicides, and pharmaceutical agents. Intrauterine exposure to endocrine disruptors that either mimic or antagonize thyroid hormones can produce permanent developmental disorders in the structure and functioning of the brain, leading to behavioral changes. Steroid receptors are important determinants of the consequences of endocrine disruptors. Their interaction with thyroid hormones complicates the effect of endocrine disruptors. The aim of this review is to present the effect of endocrine disruptors on thyroid hormones physiology and their potential impact on intrauterine development.
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Affiliation(s)
- George Mastorakos
- Endocrine Unit, Second Department of Obstretics and Gynecology, Aretaieion Hospital, Athens University Medical School, Athens 10674, Greece.
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Kimura-Kuroda J, Nagata I, Kuroda Y. Disrupting effects of hydroxy-polychlorinated biphenyl (PCB) congeners on neuronal development of cerebellar Purkinje cells: a possible causal factor for developmental brain disorders? CHEMOSPHERE 2007; 67:S412-20. [PMID: 17223178 DOI: 10.1016/j.chemosphere.2006.05.137] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/26/2006] [Indexed: 05/13/2023]
Abstract
Polychlorinated biphenyls (PCBs) and hydroxy-PCB (OH-PCB) metabolites are widely distributed bioaccumulative environmental chemicals and have similar chemical structures to those of thyroid hormones (THs). Previously, we reported that THs are essential for neuronal development and the low doses of two OH-PCBs, namely, 4-OH-2',3,3',4',5'-pentachlorobiphenyl (4'-OH-PeCB-106) and 4-OH-2',3,3',4',5,5'-hexachlorobiphenyl (4'-OH-HxCB-159), inhibited the TH-dependent dendritic development of Purkinje cells in mouse cerebellar cultures using serum-free defined medium. To determine which type of OH-PCBs affect neuronal development, we further examined several OH-PCBs and other estrogenic chemicals using this simple and sensitive assay system. Two-way ANOVA was used to assess the effects of OH-PCBs and other chemicals on both factors of their concentrations and with/without T4 in the assay of TH-dependent dendritic development of Purkinje cells. Aside from the two OH-PCBs, 4-OH-2',3,4',5,6'-pentachlorobiphenyl (4'-OH-PeCB-121) and bisphenol A significantly inhibited the TH-dependent dendritic development of Purkinje cells, whereas 4-OH-2',3,3',5',6'-pentachlorobiphenyl (4'-OH-PeCB-112), 4-OH-2',3,3',5,5',6'-hexachlorobiphenyl (4'-OH-HxCB-165), 4-OH-2,2',3,4',5,5',6-heptachlorobiphenyl (4-OH-HpCB-187), progesterone and nonylphenol did not induce any inhibition, but significantly promoted the dendritic extension of Purkinje cells in the absence of THs. Other estrogenic chemicals, including beta-estradiol, diethyl stilbestrol and p-octylphenol did not show significant inhibitory or promoting effects. From these results, it is suggested that exposure to OH-PCBs and other environmental chemicals may disrupt normal neuronal development and cause some developmental brain disorders, such as LD, ADHD, and autism.
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Affiliation(s)
- Junko Kimura-Kuroda
- Department of Brain Structure, Tokyo Metropolitan Institute for Neuroscience, Tokyo 183-8526, Japan.
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LeRoy KD, Thomas P, Khan IA. Thyroid hormone status of Atlantic croaker exposed to Aroclor 1254 and selected PCB congeners. Comp Biochem Physiol C Toxicol Pharmacol 2006; 144:263-71. [PMID: 17110171 DOI: 10.1016/j.cbpc.2006.09.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Revised: 09/25/2006] [Accepted: 09/25/2006] [Indexed: 11/25/2022]
Abstract
Atlantic croaker (Micropogonias undulatus) were exposed to the polychlorinated biphenyl (PCB) mixture (Aroclor 1254) or one of three individual congeners (planar PCB 77 or ortho-substituted PCB 47 and PCB 153) in the diet for 30 days to investigate the effects of PCBs on circulating thyroid hormones, thyroxine (T4) and triiodothyronine (T3). Aroclor 1254 (0.2 and 1.0 mg/kg body mass/day) decreased plasma T3 levels consistently, but the effects on T4 levels were inconsistent from year to year. Exposure to PCB 153 (0.1 and 1.0 mg/kg body mass/day) significantly lowered both T4 and T3, while PCB 47 at the same doses had no effect on thyroid hormone levels. The lower doses of PCB 77 (0.004, 0.01 and 0.02 mg/kg body mass/day) had no effect on T4 or T3, whereas the highest dose (0.1 mg/kg body mass/day) increased T4 levels significantly. The results of the present study demonstrate that exposure to PCBs at environmentally realistic concentrations can have profound effects on the thyroid status of Atlantic croaker. The ortho-substituted PCB 153 appears to contribute at least partially to the deleterious effects of Aroclor 1254 on thyroid status, whereas the planar PCB 77 at concentrations present in the mixture is unlikely to alter thyroid hormone levels.
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Affiliation(s)
- Kimberly D LeRoy
- The University of Texas at Austin, Marine Science Institute, 750 Channel View Drive, Port Aransas, Texas 78373, USA
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46
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Rylander L, Wallin E, Jönssson BAG, Stridsberg M, Erfurth EM, Hagmar L. Associations between CB-153 and p,p'-DDE and hormone levels in serum in middle-aged and elderly men. CHEMOSPHERE 2006; 65:375-81. [PMID: 16554082 DOI: 10.1016/j.chemosphere.2006.02.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2005] [Revised: 01/30/2006] [Accepted: 02/08/2006] [Indexed: 05/07/2023]
Abstract
BACKGROUND Animal and epidemiologic data indicate that exposure to persistent organochlorine pollutants (POPs) may disrupt the hypothalamus-pituitary-thyroid (HPT) and the hypothalamus-pituitary-gonadal (HPG) axes. We have assessed whether the POP-biomarkers 2,2'4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethene (p,p'-DDE) affect thyrotropin (TSH), thyroid hormones, gonadotropins or sex hormone concentrations in men. METHODS Lipid adjusted serum concentrations of CB-153, and p,p'-DDE, were determined in 196 men (median age 59 years, range 48-82). Hormone analyses in serum were performed with immunoassays. The effect of CB-153 and p,p'-DDE (as continuous or categorized variables) were evaluated by linear regression models, adjusting for potential confounders. RESULTS There was a significant positive association between p,p'-DDE and TSH. An increase of 100 ng/g lipid of p,p'-DDE corresponded to an increase of 0.03 mU/l (95% Confidence Interval (CI) 0.01, 0.05) in TSH level. The explanatory value (R(2)) of the multivariate model was only 7%. Moreover, there was a significant negative association between p,p'-DDE and estradiol. An increase of 100 ng/g lipid of p,p'-DDE corresponded to a decrease of 0.57 pmol/l (95% CI -1.0, -0.12) in estradiol level. The R(2)-value was only 4%. No associations were observed between any of the POP biomarkers and the other hormones. CONCLUSIONS The positive association between p,p'-DDE and TSH and the negative association between p,p'-DDE and estradiol, among middle-aged and elderly men, were not accompanied by associations between the POP-markers and thyroxin, testosterone, and gonadotropins, respectively. The results gives some additional support for that POP exposure may affect HPT- and HPG-axes also in humans, but the overall epidemiological data are still not coherent enough to allow any firm conclusions.
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Affiliation(s)
- Lars Rylander
- Division of Occupational and Environmental Medicine and Psychiatric Epidemiology, Department of Laboratory Medicine, Lund University, Lund University Hospital, SE-221 85 Lund, Sweden
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47
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Lehigh Shirey EA, Jelaso Langerveld A, Mihalko D, Ide CF. Polychlorinated biphenyl exposure delays metamorphosis and alters thyroid hormone system gene expression in developing Xenopus laevis. ENVIRONMENTAL RESEARCH 2006; 102:205-14. [PMID: 16720020 DOI: 10.1016/j.envres.2006.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2005] [Revised: 03/29/2006] [Accepted: 04/03/2006] [Indexed: 05/09/2023]
Abstract
Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants that disrupt thyroid hormone (TH) system function in numerous species. Previous studies have shown delayed metamorphosis in developing Xenopus laevis frogs exposed to PCBs, but the underlying molecular mechanisms have not been thoroughly investigated. In this research, developing X. laevis tadpoles were exposed to environmentally relevant concentrations (5, 50ppb) of Aroclor 1254 (A1254), a PCB mixture, dissolved in water and 0.25% dimethyl sulfoxide. Quantitative real-time reverse transcriptase polymerase chain reaction was used to measure expression of several TH system genes, other genes that regulate growth and development, and a xenobiotic response gene. Exposure to 50ppb A1254 significantly delayed metamorphosis and significantly altered gene expression of three thyroid system genes: transthyretin and types II and III deiodinase. Since all three genes regulate the amount of available, biologically active TH, PCB-induced changes in the expression of these genes may underlie alterations in metamorphic timing.
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49
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Opinion of the Scientific Panel on contaminants in the food chain [CONTAM] related to the presence of non dioxin-like polychlorinated biphenyls (PCB) in feed and food. EFSA J 2005. [DOI: 10.2903/j.efsa.2005.284] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Wang SL, Su PH, Jong SB, Guo YL, Chou WL, Päpke O. In utero exposure to dioxins and polychlorinated biphenyls and its relations to thyroid function and growth hormone in newborns. ENVIRONMENTAL HEALTH PERSPECTIVES 2005; 113:1645-50. [PMID: 16263525 PMCID: PMC1310932 DOI: 10.1289/ehp.7994] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The aim of this study is to examine the association between transplacental exposure to dioxins/polychlorinated biphenyls (PCBs) and thyroid and growth hormones in newborns. We recruited 118 pregnant women, between 25 and 34 years of age, at the obstetric clinic. Personal data collected included reproductive and medical histories and physical factors. Clinicians gathered placental and umbilical cord serum upon delivery and carefully scored the 118 newborns, making both structural and functional assessments. We analyzed placentas for 17 polychlorinated dibenzo-p-dioxins and dibenzofurans and 12 dioxin-like PCB congeners with the World Health Organization-defined toxic equivalent factors, and six indicator PCBs by high-resolution gas chromatography and high-resolution mass spectrometry. We analyzed thyroid and growth hormones from cord serum using radioimmunoassay. Insulin-like growth factor (IGF)-1, IGF-binding globulin-3, and thyroxine x thyroid-stimulating hormone (T4 x TSH) were significantly associated with increased placental weight and Quetelet index (in kilograms per square meter; correlation coefficient r = 0.2-0.3; p < 0.05). Multivariate analyses showed independently and significantly decreased free T4 (FT4) x TSH with increasing non-ortho PCBs (r = -0.2; p < 0.05). We suggest that significant FT4 feedback alterations to the hypothalamus result from in utero exposure to non-ortho PCBs. Considering the vast existence of bioaccumulated dioxins and PCBs and the resultant body burden in modern society, we suggest routine screening of both thyroid hormone levels and thyroid function in newborns.
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Affiliation(s)
- Shu-Li Wang
- Division of Environmental Health and Occupational Medicine, National Health Research Institutes, and Graduate Institute of Occupational Safety and Health, Kaohsiung Medical University, Kaohsiung, Taiwan.
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