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Klaunig JE, Li X, Wang Z. Role of xenobiotics in the induction and progression of fatty liver disease. Toxicol Res (Camb) 2018; 7:664-680. [PMID: 30090613 PMCID: PMC6062016 DOI: 10.1039/c7tx00326a] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 05/09/2018] [Indexed: 12/12/2022] Open
Abstract
Non-alcoholic fatty liver disease is a major cause of chronic liver pathology in humans. Fatty liver disease involves the accumulation of hepatocellular fat in hepatocytes that can progress to hepatitis. Steatohepatitis is categorized into alcoholic (ASH) or non-alcoholic (NASH) steatohepatitis based on the etiology of the insult. Both pathologies involve an initial steatosis followed by a progressive inflammation of the liver and eventual hepatic fibrosis (steatohepatitis) and cirrhosis. The involvement of pharmaceuticals and other chemicals in the initiation and progression of fatty liver disease has received increased study. This review will examine not only how xenobiotics initiate hepatic steatosis and steatohepatitis but also how the presence of fatty liver may modify the metabolism and pathologic effects of xenobiotics. The feeding of a high fat diet results in changes in the expression of nuclear receptors that are involved in adaptive and adverse liver effects following xenobiotic exposure. High fat diets also modulate cellular and molecular pathways involved in inflammation, metabolism, oxidative phosphorylation and cell growth. Understanding the role of hepatic steatosis and steatohepatitis on the sequelae of toxic and pathologic changes seen following xenobiotic exposure has importance in defining proper and meaningful human risk characterization of the drugs and other chemical agents.
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Affiliation(s)
- James E Klaunig
- Indiana University , School of Public Health , Bloomington , Indiana , USA .
| | - Xilin Li
- Indiana University , School of Public Health , Bloomington , Indiana , USA .
| | - Zemin Wang
- Indiana University , School of Public Health , Bloomington , Indiana , USA .
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Klaren WD, Vine D, Vogt S, Robertson LW. Spatial distribution of metals within the liver acinus and their perturbation by PCB126. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:16427-16433. [PMID: 28940161 PMCID: PMC5866157 DOI: 10.1007/s11356-017-0202-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 09/12/2017] [Indexed: 06/07/2023]
Abstract
Animal studies show that exposure to the environmental pollutant 3,3',4,4',5-pentachlorobiphenyl (PCB126) causes alterations in hepatic metals as measured in acid-digested volume-adjusted tissue. These studies lack the detail of the spatial distribution within the liver. Here we use X-ray fluorescence microscopy (XFM) to assess the spatial distribution of trace elements within liver tissue. Liver samples from male Sprague Dawley rats, treated either with vehicle or PCB126, were formalin fixed and paraffin embedded. Serial sections were prepared for traditional H&E staining or placed on silicon nitride windows for XFM. With XFM, metal gradients between the portal triad and the central vein were seen, especially with copper and iron. These gradients change with exposure to PCB126, even reverse. This is the first report of how micronutrients vary spatially within the liver and how they change in response to toxicant exposure. In addition, high concentrations of zinc clusters were discovered in the extracellular space. PCB126 treatment did not affect their presence, but did alter their elemental makeup suggesting a more general biological function. Further work is needed to properly evaluate the gradients and their alterations as well as classify the zinc clusters to determine their role in liver function and zinc homeostasis.
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Affiliation(s)
- William D Klaren
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA, USA
- Department of Occupational and Environmental Health, The University of Iowa, College of Public Health, 100 Oakdale Campus #219 IREH, Iowa City, IA, 52242-5000, USA
| | - David Vine
- Microscopy and X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, USA
| | - Stefan Vogt
- Microscopy and X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, USA
| | - Larry W Robertson
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA, USA.
- Department of Occupational and Environmental Health, The University of Iowa, College of Public Health, 100 Oakdale Campus #219 IREH, Iowa City, IA, 52242-5000, USA.
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Gadupudi GS, Elser BA, Sandgruber FA, Li X, Gibson-Corley KN, Robertson LW. PCB126 Inhibits the Activation of AMPK-CREB Signal Transduction Required for Energy Sensing in Liver. Toxicol Sci 2018; 163:440-453. [PMID: 29474705 PMCID: PMC5974782 DOI: 10.1093/toxsci/kfy041] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
3,3',4,4',5-pentachlorobiphenyl (PCB126), a dioxin-like PCB, elicits toxicity through a wide array of noncarcinogenic effects, including metabolic syndrome, wasting, and nonalcoholic fatty-liver disease. Previously, we reported decreases in the transcription of several enzymes involved in gluconeogenesis, before the early onset of lipid accumulation. Hence, this study was aimed at understanding the impact of resultant decreases gluconeogenic enzymes on growth, weight, and metabolism in the liver, upon extended exposure. Male Sprague Dawley rats (75-100 g), fed a defined AIN-93G diet, were injected (ip) with single dose of soy oil (5 ml/kg body weight; n = 14) or PCB126 (5 µmol/kg; n = 15), 28 days, prior euthanasia. A subset of rats from each group were fasted for 12 h (vehicle [n = 6] and PCB126 [n = 4]). Rats only showed significant weight loss between days 14 and 28 (p < .05) and some mortality (p = .0413). As in our previous studies, the expression levels of enzymes involved in gluconeogenesis (Pepck-c, G6Pase, Sds, Pc, and Ldh-A) and glycogenolysis (Pygl) were strongly downregulated. The decreased expression of these enzymes in PCB126-treated rats after a 12 h fast decreased hepatic glucose production from glycogen and gluconeogenic substrates, exacerbating the hypoglycemia. Additionally, PCB126 caused hepatic steatosis and decreased the expression of the transcription factor Pparα and its targets, necessary for fatty-acid oxidation. The observed metabolic disruption across multiple branches of fasting metabolism resulted from inhibition in the activation of enzyme AMPK and transcription factor CREB signaling, necessary for "sensing" energy-deprivation and the induction of enzymes that respond to the PCB126 triggered fuel crisis in liver.
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Affiliation(s)
- Gopi S Gadupudi
- Interdisciplinary Graduate Program in Human Toxicology, Graduate College, The University of Iowa, Iowa City, Iowa
- Department of Occupational and Environmental Health, College of Public Health
| | - Benjamin A Elser
- Interdisciplinary Graduate Program in Human Toxicology, Graduate College, The University of Iowa, Iowa City, Iowa
- Department of Occupational and Environmental Health, College of Public Health
| | - Fabian A Sandgruber
- Department of Occupational and Environmental Health, College of Public Health
| | - Xueshu Li
- Department of Occupational and Environmental Health, College of Public Health
| | | | - Larry W Robertson
- Interdisciplinary Graduate Program in Human Toxicology, Graduate College, The University of Iowa, Iowa City, Iowa
- Department of Occupational and Environmental Health, College of Public Health
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Gourronc FA, Robertson LW, Klingelhutz AJ. A delayed proinflammatory response of human preadipocytes to PCB126 is dependent on the aryl hydrocarbon receptor. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:16481-16492. [PMID: 28699004 PMCID: PMC5764822 DOI: 10.1007/s11356-017-9676-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 06/27/2017] [Indexed: 05/10/2023]
Abstract
Inflammation in adipose tissue is recognized as a causative factor in the development of type II diabetes. Adipocyte hypertrophy as well as bacterial and environmental factors have been implicated in causing inflammation in mature adipocytes. Exposure to persistent organic pollutants such as polychlorinated biphenyls (PCBs) has been associated with the development of type II diabetes. We show here that PCB126, a dioxin-like PCB, activates a robust proinflammatory state in fat cell precursors (preadipocytes). The response was found to be dependent on aryl hydrocarbon receptor (AhR) activation, although induction of the response was delayed compared to upregulation of CYP1A1, a classic AhR-responsive gene. Treatment of preadipocytes with a nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) inhibitor partially attenuated the PCB126-induced inflammatory response and partly, but not completely, ameliorated disruption of adipogenesis caused by PCB126. Our results indicate a role for PCB126 in mediating an inflammatory response through AhR in preadipocytes that interferes with adipogenesis.
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Affiliation(s)
- Francoise A Gourronc
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Larry W Robertson
- Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, IA, 52242, USA
| | - Aloysius J Klingelhutz
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA.
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, 2202 MERF, 375 Newton Road, Iowa City, IA, 52242, USA.
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Dhakal K, Gadupudi GS, Lehmler HJ, Ludewig G, Duffel MW, Robertson LW. Sources and toxicities of phenolic polychlorinated biphenyls (OH-PCBs). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:16277-16290. [PMID: 28744683 PMCID: PMC5785587 DOI: 10.1007/s11356-017-9694-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Accepted: 06/30/2017] [Indexed: 04/16/2023]
Abstract
Polychlorinated biphenyls (PCBs), a group of 209 congeners that differ in the number and position of chlorines on the biphenyl ring, are anthropogenic chemicals that belong to the persistent organic pollutants (POPs). For many years, PCBs have been a topic of interest because of their biomagnification in the food chain and their environmental persistence. PCBs with fewer chlorine atoms, however, are less persistent and more susceptible to metabolic attack, giving rise to chemicals characterized by the addition of one or more hydroxyl groups to the chlorinated biphenyl skeleton, collectively known as hydroxylated PCBs (OH-PCBs). In animals and plants, this biotransformation of PCBs to OH-PCBs is primarily carried out by cytochrome P-450-dependent monooxygenases. One of the reasons for infrequent detection of lower chlorinated PCBs in serum and other biological matrices is their shorter half-lives, and their metabolic transformation, resulting in OH-PCBs or their conjugates, such as sulfates and glucuronides, or macromolecule adducts. Recent biomonitoring studies have reported the presence of OH-PCBs in human serum. The occurrence of OH-PCBs, the size of this group (there are 837 mono-hydroxyl PCBs alone), and their wide spectra of physical characteristics (pKa's and log P's ranging over 5 to 6 orders of magnitude) give rise to a multiplicity of biological effects. Among those are bioactivation to electrophilic metabolites that can form covalent adducts with DNA and other macromolecules, interference with hormonal signaling, inhibition of enzymes that regulate cellular concentrations of active hormones, and interference with the transport of hormones. This new information creates an urgent need for a new perspective on these often overlooked metabolites.
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Affiliation(s)
- Kiran Dhakal
- Interdisciplinary Graduate Program in Human Toxicology, Graduate College, The University of Iowa, Iowa City, IA, USA
- Department of Occupational and Environmental Health, College of Public Health, The University of Iowa, 100 Oakdale Campus #219 IREH, Iowa City, IA, 52242-5000, USA
| | - Gopi S Gadupudi
- Interdisciplinary Graduate Program in Human Toxicology, Graduate College, The University of Iowa, Iowa City, IA, USA
- Department of Occupational and Environmental Health, College of Public Health, The University of Iowa, 100 Oakdale Campus #219 IREH, Iowa City, IA, 52242-5000, USA
| | - Hans-Joachim Lehmler
- Interdisciplinary Graduate Program in Human Toxicology, Graduate College, The University of Iowa, Iowa City, IA, USA
- Department of Occupational and Environmental Health, College of Public Health, The University of Iowa, 100 Oakdale Campus #219 IREH, Iowa City, IA, 52242-5000, USA
| | - Gabriele Ludewig
- Interdisciplinary Graduate Program in Human Toxicology, Graduate College, The University of Iowa, Iowa City, IA, USA
- Department of Occupational and Environmental Health, College of Public Health, The University of Iowa, 100 Oakdale Campus #219 IREH, Iowa City, IA, 52242-5000, USA
| | - Michael W Duffel
- Interdisciplinary Graduate Program in Human Toxicology, Graduate College, The University of Iowa, Iowa City, IA, USA
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, The University of Iowa, Iowa City, IA, USA
| | - Larry W Robertson
- Interdisciplinary Graduate Program in Human Toxicology, Graduate College, The University of Iowa, Iowa City, IA, USA.
- Department of Occupational and Environmental Health, College of Public Health, The University of Iowa, 100 Oakdale Campus #219 IREH, Iowa City, IA, 52242-5000, USA.
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56
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Deierlein AL, Rock S, Park S. Persistent Endocrine-Disrupting Chemicals and Fatty Liver Disease. Curr Environ Health Rep 2018; 4:439-449. [PMID: 28980219 DOI: 10.1007/s40572-017-0166-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW Non-alcoholic fatty liver disease (NAFLD) is the most prominent chronic liver disease in Western countries, affecting approximately 25% of the population worldwide. Sex-specific differences in the development of NAFLD are apparent. While obesity and insulin resistance are major contributors to the increasing prevalence of NAFLD, a growing body of literature suggests that exposure to persistent endocrine-disrupting chemicals (pEDCs) may also play a role. This review summarizes recent (2011 and later) scientific literature investigating exposures to pEDCs, specifically persistent organic pollutants (POPs), and NAFLD, with a focus on sex-specific associations. RECENT FINDINGS The overwhelming majority of studies were conducted in single-sex animal models and provide biological evidence that exposures to 2,3,7,8-tetrachlorodibenzo-p-dioxin polychlorinated biphenyls, and other POPs or POP mixtures are negatively associated with liver health. There were four cross-sectional epidemiological studies in humans that reported associations for several POPs, including polychlorinated biphenyls and perfluorinated chemicals, with elevated liver enzymes. Only one of these studies, using a sample of gastric bypass surgery patients, examined sex-specific associations of POPs and liver enzymes, finding adverse associations among women only. The noticeable lack of studies investigating how differences (i.e., biochemical, physiological, and behavioral) between men and women may influence associations of pEDCs and NAFLD represents a large research gap in environmental health. Sexual dimorphism in metabolic processes throughout the body, including the liver, is established but often overlooked in the designs and analyses of studies. Other factors identified in this review that may also act to modulate associations of environmental chemicals and NAFLD are reproductive status and dietary nutrient intakes, which also remain understudied in the literature. Despite knowledge of sexual dimorphism in the actions of pEDCs, as well as in metabolic processes related to NAFLD development, few experimental or epidemiological studies have investigated sex-dependent associations. Future studies, especially those in humans, should be designed to address this research need. Consideration of other factors, such as reproductive status, dietary intakes, and mixtures of chemicals with varying endocrine-disrupting capabilities, should be explored.
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Affiliation(s)
- Andrea L Deierlein
- College of Global Public Health, New York University, 715/719 Broadway 12th Floor, New York, NY, 10003, USA.
| | - Sarah Rock
- College of Global Public Health, New York University, 715/719 Broadway 12th Floor, New York, NY, 10003, USA
| | - Sally Park
- College of Global Public Health, New York University, 715/719 Broadway 12th Floor, New York, NY, 10003, USA
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57
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Siddiqui S, Lustig A, Carter A, Sankar M, Daimon CM, Premont RT, Etienne H, van Gastel J, Azmi A, Janssens J, Becker KG, Zhang Y, Wood W, Lehrmann E, Martin JG, Martin B, Taub DD, Maudsley S. Genomic deletion of GIT2 induces a premature age-related thymic dysfunction and systemic immune system disruption. Aging (Albany NY) 2017; 9:706-740. [PMID: 28260693 PMCID: PMC5391227 DOI: 10.18632/aging.101185] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 02/19/2017] [Indexed: 12/12/2022]
Abstract
Recent research has proposed that GIT2 (G protein-coupled receptor kinase interacting protein 2) acts as an integrator of the aging process through regulation of 'neurometabolic' integrity. One of the commonly accepted hallmarks of the aging process is thymic involution. At a relatively young age, 12 months old, GIT2-/- mice present a prematurely distorted thymic structure and dysfunction compared to age-matched 12 month-old wild-type control (C57BL/6) mice. Disruption of thymic structure in GIT2-/- (GIT2KO) mice was associated with a significant reduction in the expression of the cortical thymic marker, Troma-I (cytokeratin 8). Double positive (CD4+CD8+) and single positive CD4+ T cells were also markedly reduced in 12 month-old GIT2KO mice compared to age-matched control wild-type mice. Coincident with this premature thymic disruption in GIT2KO mice was the unique generation of a novel cervical 'organ', i.e. 'parathymic lobes'. These novel organs did not exhibit classical peripheral lymph node-like characteristics but expressed high levels of T cell progenitors that were reflexively reduced in GIT2KO thymi. Using signaling pathway analysis of GIT2KO thymus and parathymic lobe transcriptomic data we found that the molecular signaling functions lost in the dysfunctional GIT2KO thymus were selectively reinstated in the novel parathymic lobe - suggestive of a compensatory effect for the premature thymic disruption. Broader inspection of high-dimensionality transcriptomic data from GIT2KO lymph nodes, spleen, thymus and parathymic lobes revealed a systemic alteration of multiple proteins (Dbp, Tef, Per1, Per2, Fbxl3, Ddit4, Sin3a) involved in the multidimensional control of cell cycle clock regulation, cell senescence, cellular metabolism and DNA damage. Altered cell clock regulation across both immune and non-immune tissues therefore may be responsible for the premature 'aging' phenotype of GIT2KO mice.
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Affiliation(s)
- Sana Siddiqui
- Receptor Pharmacology Unit, Laboratory of Neurosciences, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, MD 21224, USA
| | - Ana Lustig
- Laboratory of Molecular Biology and Immunology, NIA, NIH, Baltimore, MD 21224, USA
| | - Arnell Carter
- Laboratory of Molecular Biology and Immunology, NIA, NIH, Baltimore, MD 21224, USA
| | - Mathavi Sankar
- Metabolism Unit, Laboratory of Clinical Investigation, NIA, NIH, Baltimore, MD 21224, USA
| | - Caitlin M Daimon
- Metabolism Unit, Laboratory of Clinical Investigation, NIA, NIH, Baltimore, MD 21224, USA
| | | | - Harmonie Etienne
- Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, Belgium
| | - Jaana van Gastel
- Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, Belgium
| | - Abdelkrim Azmi
- Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, Belgium
| | - Jonathan Janssens
- Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, Belgium
| | - Kevin G Becker
- Gene Expression and Genomics Unit, Research Resources Branch, NIA, NIH, Baltimore, MD 21224, USA
| | - Yongqing Zhang
- Gene Expression and Genomics Unit, Research Resources Branch, NIA, NIH, Baltimore, MD 21224, USA
| | - William Wood
- Gene Expression and Genomics Unit, Research Resources Branch, NIA, NIH, Baltimore, MD 21224, USA
| | - Elin Lehrmann
- Gene Expression and Genomics Unit, Research Resources Branch, NIA, NIH, Baltimore, MD 21224, USA
| | - James G Martin
- Research Institute of the MUHC, Centre for Translational Biology (CTB), Meakins-Christie Laboratories, McGill University, Montreal, QC, H4A 3J1, Canada
| | - Bronwen Martin
- Metabolism Unit, Laboratory of Clinical Investigation, NIA, NIH, Baltimore, MD 21224, USA
| | - Dennis D Taub
- Laboratory of Molecular Biology and Immunology, NIA, NIH, Baltimore, MD 21224, USA
| | - Stuart Maudsley
- Receptor Pharmacology Unit, Laboratory of Neurosciences, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, MD 21224, USA.,Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, Belgium
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58
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Kania-Korwel I, Wu X, Wang K, Lehmler HJ. Identification of lipidomic markers of chronic 3,3',4,4',5-pentachlorobiphenyl (PCB 126) exposure in the male rat liver. Toxicology 2017; 390:124-134. [PMID: 28890136 PMCID: PMC5633524 DOI: 10.1016/j.tox.2017.09.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/28/2017] [Accepted: 09/05/2017] [Indexed: 12/14/2022]
Abstract
Exposure to PCB 126, an environmentally relevant aryl hydrocarbon receptor agonist, is an environmental factor causing hepatic steatosis in rodent models; however, the lipidome of PCB 126-exposed rats has not been investigated in-depth. The objective of the present study was therefore to characterize dose-dependent changes in the lipid profile in the liver of male Sprague-Dawley rats exposed to PCB 126. Rats were exposed for three month to intraperitoneal injections of 0.01, 0.05 and 0.2μmol/kg bw PCB 126 in corn oil. Control animals were exposed in parallel and received corn oil alone. Lipids were extracted from whole liver homogenate and levels of polar lipids and fatty acids incorporated into triglycerides (FATAGs) were determined with tandem mass spectrometry using electrospray ionization. PCB 126 exposure increased the hepatic content of polar lipids and FATAGs. Protein adjusted levels of several polar lipid classes, in particular phosphatidylserine levels, decreased, whereas FATAGs levels typically increased with increasing PCB 126 dose. Sensitive, dose-dependent endpoints of PCB 126 exposure included an increase in levels of adrenic acid incorporated into triglycerides and changes in levels of certain ether-linked phospholipid and 1-alkyl/1-alkenyldiacylglycerol species, as determined using partial least square discriminant analysis (PLS-DA) and ANOVA. These changes in the composition of polar lipids and fatty acid in the liver of PCB 126 exposed rats identified several novel markers of PCB 126-mediated fatty liver disease that need to be validated in further studies.
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Affiliation(s)
- Izabela Kania-Korwel
- Department of Occupational Environmental Health, College of Public Health, The University of Iowa, Iowa City, IA, USA
| | - Xianai Wu
- Department of Occupational Environmental Health, College of Public Health, The University of Iowa, Iowa City, IA, USA
| | - Kai Wang
- Department of Biostatistics, College of Public Health, The University of Iowa, Iowa City, IA, USA
| | - Hans-Joachim Lehmler
- Department of Occupational Environmental Health, College of Public Health, The University of Iowa, Iowa City, IA, USA.
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Nadal A, Quesada I, Tudurí E, Nogueiras R, Alonso-Magdalena P. Endocrine-disrupting chemicals and the regulation of energy balance. Nat Rev Endocrinol 2017; 13:536-546. [PMID: 28524168 DOI: 10.1038/nrendo.2017.51] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Energy balance involves the adjustment of food intake, energy expenditure and body fat reserves through homeostatic pathways. These pathways include a multitude of biochemical reactions, as well as hormonal cues. Dysfunction of this homeostatic control system results in common metabolism-related pathologies, which include obesity and type 2 diabetes mellitus. Metabolism-disrupting chemicals (MDCs) are a particular class of endocrine-disrupting chemicals that affect energy homeostasis. MDCs affect multiple endocrine mechanisms and thus different cell types that are implicated in metabolic control. MDCs affect gene expression and the biosynthesis of key enzymes, hormones and adipokines that are essential for controlling energy homeostasis. This multifaceted spectrum of actions precludes compensatory responses and favours metabolic disorders. Herein, we review the main mechanisms used by MDCs to alter energy balance. This work should help to identify new MDCs, as well as novel targets of their action.
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Affiliation(s)
- Angel Nadal
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM) and Institute of Bioengineering, Miguel Hernández University of Elche, Avda Universidad s/n, 03202 Elche, Alicante, Spain
| | - Ivan Quesada
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM) and Institute of Bioengineering, Miguel Hernández University of Elche, Avda Universidad s/n, 03202 Elche, Alicante, Spain
| | - Eva Tudurí
- Instituto de Investigaciones Sanitarias (IDIS), Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CiMUS) and Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (CIBERobn), Avda. Barcelona s/n, 15706 Santiago de Compostela, Spain
| | - Rubén Nogueiras
- Instituto de Investigaciones Sanitarias (IDIS), Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CiMUS) and Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición (CIBERobn), Avda. Barcelona s/n, 15706 Santiago de Compostela, Spain
- Department of Physiology, Centro Singular de Investigación en Medicina Molecular y Enfermedades Crónicas (CiMUS), University of Santiago de Compostela, Calle San Francisco s/n, 15706 Santiago de Compostela, Spain
| | - Paloma Alonso-Magdalena
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM) and Institute of Bioengineering, Miguel Hernández University of Elche, Avda Universidad s/n, 03202 Elche, Alicante, Spain
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60
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Mediating Roles of PPARs in the Effects of Environmental Chemicals on Sex Steroids. PPAR Res 2017; 2017:3203161. [PMID: 28819354 PMCID: PMC5551527 DOI: 10.1155/2017/3203161] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 05/23/2017] [Accepted: 06/21/2017] [Indexed: 12/18/2022] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated nuclear receptors that are widely involved in various physiological functions. They are widely expressed through the reproductive system. Their roles in the metabolism and function of sex steroids and thus the etiology of reproductive disorders receive great concern. Various kinds of exogenous chemicals, especially environmental pollutants, exert their adverse impact on the reproductive system through disturbing the PPAR signaling pathway. Chemicals could bind to PPARs and modulate the transcription of downstream genes containing PPRE (peroxisome proliferator response element). This will lead to altered expression of genes related to metabolism of sex steroids and thus the abnormal physiological function of sex steroids. In this review, various kinds of environmental ligands are summarized and discussed. Their interactions with three types of PPARs are classified by various data from transcript profiles, PPRE reporter in cell line, in silico docking, and gene silencing. The review will contribute to the understanding of the roles of PPARs in the reproductive toxicology of environmental chemicals.
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61
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Heindel JJ, Blumberg B, Cave M, Machtinger R, Mantovani A, Mendez MA, Nadal A, Palanza P, Panzica G, Sargis R, Vandenberg LN, Vom Saal F. Metabolism disrupting chemicals and metabolic disorders. Reprod Toxicol 2017; 68:3-33. [PMID: 27760374 PMCID: PMC5365353 DOI: 10.1016/j.reprotox.2016.10.001] [Citation(s) in RCA: 626] [Impact Index Per Article: 89.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 09/04/2016] [Accepted: 10/13/2016] [Indexed: 01/09/2023]
Abstract
The recent epidemics of metabolic diseases, obesity, type 2 diabetes(T2D), liver lipid disorders and metabolic syndrome have largely been attributed to genetic background and changes in diet, exercise and aging. However, there is now considerable evidence that other environmental factors may contribute to the rapid increase in the incidence of these metabolic diseases. This review will examine changes to the incidence of obesity, T2D and non-alcoholic fatty liver disease (NAFLD), the contribution of genetics to these disorders and describe the role of the endocrine system in these metabolic disorders. It will then specifically focus on the role of endocrine disrupting chemicals (EDCs) in the etiology of obesity, T2D and NAFLD while finally integrating the information on EDCs on multiple metabolic disorders that could lead to metabolic syndrome. We will specifically examine evidence linking EDC exposures during critical periods of development with metabolic diseases that manifest later in life and across generations.
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Affiliation(s)
- Jerrold J Heindel
- National Institute of Environmental Health Sciences, Division of Extramural Research and Training Research Triangle Park, NC, USA.
| | - Bruce Blumberg
- University of California, Department of Developmental and Cell Biology, Irvine CA, USA
| | - Mathew Cave
- University of Louisville, Division of Gastroenterology, Hepatology and Nutrition, Louisville KY, USA
| | | | | | - Michelle A Mendez
- University of North Carolina at Chapel Hill, School of Public Health, Chapel Hill NC, USA
| | - Angel Nadal
- Institute of Bioengineering and CIBERDEM, Miguel Hernandez University of Elche, Elche, Alicante, Spain
| | - Paola Palanza
- University of Parma, Department of Neurosciences, Parma, Italy
| | - Giancarlo Panzica
- University of Turin, Department of Neuroscience and Neuroscience Institute Cavalieri Ottolenghi (NICO), Turin, Italy
| | - Robert Sargis
- University of Chicago, Section of Endocrinology, Diabetes and Metabolism, Department of Medicine Chicago, IL, USA
| | - Laura N Vandenberg
- University of Massachusetts, Department of Environmental Health Sciences, School of Public Health & Health Sciences, Amherst, MA, USA
| | - Frederick Vom Saal
- University of Missouri, Department of Biological Sciences, Columbia, MO, USA
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62
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Ivanov S, Semin M, Lagunin A, Filimonov D, Poroikov V. In Silico Identification of Proteins Associated with Drug-induced Liver Injury Based on the Prediction of Drug-target Interactions. Mol Inform 2017; 36. [PMID: 28145637 DOI: 10.1002/minf.201600142] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 01/16/2017] [Indexed: 12/13/2022]
Abstract
Drug-induced liver injury (DILI) is the leading cause of acute liver failure as well as one of the major reasons for drug withdrawal from clinical trials and the market. Elucidation of molecular interactions associated with DILI may help to detect potentially hazardous pharmacological agents at the early stages of drug development. The purpose of our study is to investigate which interactions with specific human protein targets may cause DILI. Prediction of interactions with 1534 human proteins was performed for the dataset with information about 699 drugs, which were divided into three categories of DILI: severe (178 drugs), moderate (310 drugs) and without DILI (211 drugs). Based on the comparison of drug-target interactions predicted for different drugs' categories and interpretation of those results using clustering, Gene Ontology, pathway and gene expression analysis, we identified 61 protein targets associated with DILI. Most of the revealed proteins were linked with hepatocytes' death caused by disruption of vital cellular processes, as well as the emergence of inflammation in the liver. It was found that interaction of a drug with the identified targets is the essential molecular mechanism of the severe DILI for the most of the considered pharmaceuticals. Thus, pharmaceutical agents interacting with many of the identified targets may be considered as candidates for filtering out at the early stages of drug research.
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Affiliation(s)
- Sergey Ivanov
- Institute of Biomedical Chemistry 10 building 8, Pogodinskaya str., 119121, Moscow, Russia.,Pirogov Russian National Research Medical University, Medico-Biological Faculty 1, Ostrovitianova str., 117997, Moscow, Russia
| | - Maxim Semin
- Institute of Biomedical Chemistry 10 building 8, Pogodinskaya str., 119121, Moscow, Russia.,Pirogov Russian National Research Medical University, Medico-Biological Faculty 1, Ostrovitianova str., 117997, Moscow, Russia
| | - Alexey Lagunin
- Institute of Biomedical Chemistry 10 building 8, Pogodinskaya str., 119121, Moscow, Russia.,Pirogov Russian National Research Medical University, Medico-Biological Faculty 1, Ostrovitianova str., 117997, Moscow, Russia
| | - Dmitry Filimonov
- Institute of Biomedical Chemistry 10 building 8, Pogodinskaya str., 119121, Moscow, Russia
| | - Vladimir Poroikov
- Institute of Biomedical Chemistry 10 building 8, Pogodinskaya str., 119121, Moscow, Russia
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63
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Liu Y, Hu K, Jia H, Jin G, Glatt H, Jiang H. Potent mutagenicity of some non-planar tri- and tetrachlorinated biphenyls in mammalian cells, human CYP2E1 being a major activating enzyme. Arch Toxicol 2016; 91:2663-2676. [DOI: 10.1007/s00204-016-1904-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 11/24/2016] [Indexed: 12/18/2022]
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64
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Gadupudi GS, Klingelhutz AJ, Robertson LW. Diminished Phosphorylation of CREB Is a Key Event in the Dysregulation of Gluconeogenesis and Glycogenolysis in PCB126 Hepatotoxicity. Chem Res Toxicol 2016; 29:1504-9. [PMID: 27509375 DOI: 10.1021/acs.chemrestox.6b00172] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The dioxin-like PCB126 elicits toxicity in various target organs. In rat liver, an alteration in the transcript levels of several genes involved in glucose and fatty acid metabolism provides insights into the origin of its hepatotoxicity. To explore the mechanisms, male Sprague-Dawley rats, fed an AIN-93G diet, were injected with PCB126 (1 or 5 μmol/kg) or corn oil and euthanized after 2 weeks. PCB126 significantly decreased serum glucose levels and the transcript levels of genes of many gluconeogenic and glycogenolytic enzymes under the transcriptional control of a nuclear transcription factor, cAMP response element-binding protein (CREB). As a novel finding, we show that PCB126 significantly decreases CREB phosphorylation, which is important for regulating both gluconeogenesis and fatty acid oxidation in the liver and explains CREB's integrative effects on both carbohydrate and lipid metabolism in PCB126 toxicity.
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Affiliation(s)
- Gopi S Gadupudi
- Interdisciplinary Graduate Program in Human Toxicology and Department of Occupational and Environmental Health, University of Iowa , Iowa City, Iowa 52242, United States
| | | | - Larry W Robertson
- Interdisciplinary Graduate Program in Human Toxicology and Department of Occupational and Environmental Health, University of Iowa , Iowa City, Iowa 52242, United States
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65
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Long-term in vivo polychlorinated biphenyl 126 exposure induces oxidative stress and alters proteomic profile on islets of Langerhans. Sci Rep 2016; 6:27882. [PMID: 27292372 PMCID: PMC4904407 DOI: 10.1038/srep27882] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 05/24/2016] [Indexed: 12/15/2022] Open
Abstract
It has been recently proposed that exposure to polychlorinated biphenyls (PCBs) is a risk factor to type 2 diabetes mellitus (DM2). We investigated this hypothesis using long-term in vivo PCB126 exposure to rats addressing metabolic, cellular and proteomic parameters. Male Wistar rats were exposed to PCB126 (0.1, 1 or 10 μg/kg of body weight/day; for 15 days) or vehicle by intranasal instillation. Systemic alterations were quantified by body weight, insulin and glucose tolerance, and blood biochemical profile. Pancreatic toxicity was measured by inflammatory parameters, cell viability and cycle, free radical generation, and proteomic profile on islets of Langerhans. In vivo PCB126 exposure enhanced the body weight gain, impaired insulin sensitivity, reduced adipose tissue deposit, and elevated serum triglycerides, cholesterol, and insulin levels. Inflammatory parameters in the pancreas and cell morphology, viability and cycle were not altered in islets of Langerhans. Nevertheless, in vivo PCB126 exposure increased free radical generation and modified the expression of proteins related to oxidative stress on islets of Langerhans, which are indicative of early β-cell failure. Data herein obtained show that long-term in vivo PCB126 exposure through intranasal route induced alterations on islets of Langerhans related to early end points of DM2.
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66
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Petriello MC, Hoffman JB, Sunkara M, Wahlang B, Perkins JT, Morris AJ, Hennig B. Dioxin-like pollutants increase hepatic flavin containing monooxygenase (FMO3) expression to promote synthesis of the pro-atherogenic nutrient biomarker trimethylamine N-oxide from dietary precursors. J Nutr Biochem 2016; 33:145-53. [PMID: 27155921 DOI: 10.1016/j.jnutbio.2016.03.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 03/22/2016] [Accepted: 03/28/2016] [Indexed: 01/26/2023]
Abstract
The etiology of cardiovascular disease (CVD) is impacted by multiple modifiable and non-modifiable risk factors including dietary choices, genetic predisposition, and environmental exposures. However, mechanisms linking diet, exposure to pollutants, and CVD risk are largely unclear. Recent studies identified a strong link between plasma levels of nutrient-derived Trimethylamine N-oxide (TMAO) and coronary artery disease. Dietary precursors of TMAO include carnitine and phosphatidylcholine, which are abundant in animal-derived foods. Dioxin-like pollutants can upregulate a critical enzyme responsible for TMAO formation, hepatic flavin containing monooxygenase 3 (FMO3), but a link between dioxin-like PCBs, upregulation of FMO3, and increased TMAO has not been reported. Here, we show that mice exposed acutely to dioxin-like PCBs exhibit increased hepatic FMO3 mRNA, protein, as well as an increase in circulating levels of TMAO following oral administration of its metabolic precursors. C57BL/6 mice were exposed to 5μmol PCB 126/kg mouse weight (1.63mg/kg). At 48h post-PCB exposure, mice were subsequently given a single gavage of phosphatidylcholine dissolved in corn oil. Exposure to 5 μmole/kg PCB 126 resulted in greater than 100-fold increase in FMO3 mRNA expression, robust induction of FMO3 protein, and a 5-fold increase in TMAO levels compared with vehicle treated mice. We made similar observations in mice exposed to PCB 77 (49.6mg/kg twice); stable isotope tracer studies revealed increased formation of plasma TMAO from an orally administered precursor trimethylamine (TMA). Taken together, these observations suggest a novel diet-toxicant interaction that results in increased production of a circulating biomarker of cardiovascular disease risk.
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Affiliation(s)
- Michael C Petriello
- Superfund Research Center, University of Kentucky, Lexington, KY, 40536; Department of Animal and Food Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40536; Lexington Veterans Affairs Medical Center, Lexington, KY, USA
| | - Jessie B Hoffman
- Superfund Research Center, University of Kentucky, Lexington, KY, 40536; Graduate Center for Nutritional Sciences, College of Medicine, University of Kentucky, Lexington, KY, 40536
| | - Manjula Sunkara
- Superfund Research Center, University of Kentucky, Lexington, KY, 40536; Division of Cardiovascular Medicine, College of Medicine, University of Kentucky, Lexington, KY, 40536
| | - Banrida Wahlang
- Superfund Research Center, University of Kentucky, Lexington, KY, 40536; Department of Animal and Food Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40536
| | - Jordan T Perkins
- Superfund Research Center, University of Kentucky, Lexington, KY, 40536
| | - Andrew J Morris
- Superfund Research Center, University of Kentucky, Lexington, KY, 40536; Lexington Veterans Affairs Medical Center, Lexington, KY, USA; Division of Cardiovascular Medicine, College of Medicine, University of Kentucky, Lexington, KY, 40536
| | - Bernhard Hennig
- Superfund Research Center, University of Kentucky, Lexington, KY, 40536; Department of Animal and Food Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40536.
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67
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Klaren WD, Gibson-Corley KN, Wels B, Simmons DL, McCormick ML, Spitz DR, Robertson LW. Assessment of the Mitigative Capacity of Dietary Zinc on PCB126 Hepatotoxicity and the Contribution of Zinc to Toxicity. Chem Res Toxicol 2016; 29:851-9. [PMID: 26967026 DOI: 10.1021/acs.chemrestox.6b00022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hepatic levels of the essential micronutrient, zinc, are diminished by several hepatotoxicants, and the dietary supplementation of zinc has proven protective in those cases. 3,3',4,4',5-Pentachlorobiphenyl (PCB126), a liver toxicant, alters hepatic nutrient homeostasis and lowers hepatic zinc levels. The current study was designed to determine the mitigative potential of dietary zinc in the toxicity associated with PCB126 and the role of zinc in that toxicity. Male Sprague-Dawley rats were divided into three dietary groups and fed diets deficient in zinc (7 ppm Zn), adequate in zinc (30 ppm Zn), and supplemented in zinc (300 ppm). The animals were maintained for 3 weeks on these diets, then given a single IP injection of vehicle or 1 or 5 μmol/kg PCB126. After 2 weeks, the animals were euthanized. Dietary zinc increased the level of ROS, the activity of CuZnSOD, and the expression of metallothionein but decreased the levels of hepatic manganese. PCB126 exposed rats exhibited classic signs of exposure, including hepatomegaly, increased hepatic lipids, increased ROS and CYP induction. Liver histology suggests some mild ameliorative properties of both zinc deficiency and zinc supplementation. Other metrics of toxicity (relative liver and thymus weights, hepatic lipids, and hepatic ROS) did not support this trend. Interestingly, the zinc supplemented high dose PCB126 group had mildly improved histology and less efficacious induction of investigated genes than did the low dose PCB126 group. Overall, decreases in zinc caused by PCB126 likely contribute little to the ongoing toxicity, and the mitigative/preventive capacity of zinc against PCB126 exposure seems limited.
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Affiliation(s)
- William D Klaren
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa , Iowa City, Iowa 52242, United States.,Department of Occupational and Environmental Health, College of Public Health, University of Iowa , Iowa City, Iowa 52242, United States
| | | | - Brian Wels
- State Hygienic Laboratory, University of Iowa , Ankeny, Iowa 50023, United States
| | - Donald L Simmons
- State Hygienic Laboratory, University of Iowa , Ankeny, Iowa 50023, United States
| | - Michael L McCormick
- Free Radical and Radiation Biology Program, University of Iowa Carver College of Medicine , Iowa City, Iowa 52242, United States
| | - Douglas R Spitz
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa , Iowa City, Iowa 52242, United States.,Free Radical and Radiation Biology Program, University of Iowa Carver College of Medicine , Iowa City, Iowa 52242, United States
| | - Larry W Robertson
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa , Iowa City, Iowa 52242, United States.,Department of Occupational and Environmental Health, College of Public Health, University of Iowa , Iowa City, Iowa 52242, United States
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