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Eti NA, Flor S, Iqbal K, Scott RL, Klenov VE, Gibson-Corley KN, Soares MJ, Ludewig G, Robertson LW. PCB126 induced toxic actions on liver energy metabolism is mediated by AhR in rats. Toxicology 2022; 466:153054. [PMID: 34848246 PMCID: PMC8748418 DOI: 10.1016/j.tox.2021.153054] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 11/18/2021] [Accepted: 11/25/2021] [Indexed: 02/01/2023]
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor involved in the regulation of biological responses to more planar aromatic hydrocarbons, like TCDD. We previously described the sequence of events following exposure of male rats to a dioxin-like polychlorinated biphenyl (PCB) congener, 3,3',4,4',5-pentachlorobiphenyl (PCB126), that binds avidly to the AhR and causes various types of toxicity including metabolic syndrome, fatty liver, and disruption of energy homeostasis. The purpose of this study was, to investigate the role of AhR to mediate those toxic manifestations following sub-acute exposure to PCB126 and to examine possible sex differences in effects. For this goal, we created an AhR knockout (AhR-KO) model using CRISPR/Cas9. Comparison was made to the wild type (WT) male and female Holtzman Sprague Dawley rats. Rats were injected with a single IP dose of corn oil vehicle or 5 μmol/kg PCB126 in corn oil and necropsied after 28 days. PCB126 caused significant weight loss, reduced relative thymus weights, and increased relative liver weights in WT male and female rats, but not in AhR-KO rats. Similarly, significant pathologic changes were visible which included necrosis and regeneration in female rats, micro- and macro-vesicular hepatocellular vacuolation in males, and a paucity of glycogen in livers of both sexes in WT rats only. Hypoglycemia and lower IGF1, and reduced serum non-esterified fatty acids (NEFAs) were found in serum of both sexes of WT rats, low serum cholesterol levels only in the females, and no changes in AhR-KO rats. The expression of genes encoding enzymes related to xenobiotic metabolism (e.g. CYP1A1), gluconeogenesis, glycogenolysis, and fatty acid oxidation were unaffected in the AhR-KO rats following PCB126 exposure as opposed to WT rats where expression was significantly upregulated (PPARα, females only) or downregulated suggesting a disrupted energy homeostasis. Interestingly, Acox2, Hmgcs, G6Pase and Pc were affected in both sexes, the gluconeogenesis and glucose transporter genes Pck1, Glut2, Sds, and Crem only in male WT-PCB rats. These results show the essential role of the AhR in glycogenolysis, gluconeogenesis, and fatty acid oxidation, i.e. in the regulation of energy production and homeostasis, but also demonstrate a significant difference in the effects of PCB126 in males verses females, suggesting higher vulnerability of glucose homeostasis in males and more changes in fatty acid/lipid homeostasis in females. These differences in effects, which may apply to more/all AhR agonists, should be further analyzed to identify health risks to specific groups of highly exposed human populations.
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Affiliation(s)
- Nazmin Akter Eti
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA, United States
| | - Susanne Flor
- Department of Radiation Oncology, University of Iowa, Iowa City, IA, United States
| | - Khursheed Iqbal
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS, United States
| | - Regan L Scott
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS, United States
| | - Violet E Klenov
- Department of Ob/Gyn, University of Iowa, Iowa City, IA, United States
| | - Katherine N Gibson-Corley
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, TN, United States
| | - Michael J Soares
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, KS, United States
| | - Gabriele Ludewig
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA, United States
| | - Larry W Robertson
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, IA, United States.
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Klenov V, Flor S, Ganesan S, Adur M, Eti N, Iqbal K, Soares MJ, Ludewig G, Ross JW, Robertson LW, Keating AF. The Aryl hydrocarbon receptor mediates reproductive toxicity of polychlorinated biphenyl congener 126 in rats. Toxicol Appl Pharmacol 2021; 426:115639. [PMID: 34256052 PMCID: PMC8500329 DOI: 10.1016/j.taap.2021.115639] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/02/2021] [Accepted: 07/03/2021] [Indexed: 12/16/2022]
Abstract
Polychlorinated biphenyls (PCBs) are endocrine disrupting chemicals with documented, though mechanistically ill-defined, reproductive toxicity. The toxicity of dioxin-like PCBs, such as PCB126, is mediated via the aryl hydrocarbon receptor (AHR) in non-ovarian tissues. The goal of this study was to examine the uterine and ovarian effects of PCB126 and test the hypothesis that the AHR is required for PCB126-induced reproductive toxicity. Female Holzman-Sprague Dawley wild type (n = 14; WT) and Ahr knock out (n = 11; AHR-/-) rats received a single intraperitoneal injection of either corn oil vehicle (5 ml/kg: WT_O and AHR-/-_O) or PCB126 (1.63 mg/kg in corn oil: WT_PCB and AHR-/-_PCB) at four weeks of age. The estrous cycle was synchronized and ovary and uterus were collected 28 days after exposure. In WT rats, PCB126 exposure reduced (P < 0.05) body and ovary weight, uterine gland number, uterine area, progesterone, 17β-estradiol and anti-Müllerian hormone level, secondary and antral follicle and corpora lutea number but follicle stimulating hormone level increased (P < 0.05). In AHR-/- rats, PCB126 exposure increased (P ≤ 0.05) circulating luteinizing hormone level. Ovarian or uterine mRNA abundance of biotransformation, and inflammation genes were altered (P < 0.05) in WT rats due to PCB126 exposure. In AHR-/- rats, the transcriptional effects of PCB126 were restricted to reductions (P < 0.05) in three inflammatory genes. These findings support a functional role for AHR in the female reproductive tract, illustrate AHR's requirement in PCB126-induced reprotoxicity, and highlight the potential risk of dioxin-like compounds on female reproduction.
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Affiliation(s)
- Violet Klenov
- Dept of Ob/Gyn, University of Iowa, United States of America
| | - Susanne Flor
- Interdisciplinary Graduate Program in Human Toxicology and Dept of Occupational and Environmental Health, University of Iowa, United States of America
| | - Shanthi Ganesan
- Dept of Animal Science, Iowa State University, United States of America
| | - Malavika Adur
- Dept of Animal Science, Iowa State University, United States of America
| | - Nazmin Eti
- Interdisciplinary Graduate Program in Human Toxicology and Dept of Occupational and Environmental Health, University of Iowa, United States of America
| | - Khursheed Iqbal
- Institute for Reproduction and Perinatal Research and Department of Pathology, University of Kansas Medical Center, Kansas City, KS, United States of America
| | - Michael J Soares
- Institute for Reproduction and Perinatal Research and Department of Pathology, University of Kansas Medical Center, Kansas City, KS, United States of America; Departments of Pediatrics and Obstetrics and Gynecology, University of Kansas Medical Center, Kansas City, KS, United States of America; Center for Perinatal Research, Children's Research Institute, Children's Mercy, Kansas City, MO, United States of America
| | - Gabriele Ludewig
- Interdisciplinary Graduate Program in Human Toxicology and Dept of Occupational and Environmental Health, University of Iowa, United States of America
| | - Jason W Ross
- Dept of Animal Science, Iowa State University, United States of America
| | - Larry W Robertson
- Interdisciplinary Graduate Program in Human Toxicology and Dept of Occupational and Environmental Health, University of Iowa, United States of America
| | - Aileen F Keating
- Dept of Animal Science, Iowa State University, United States of America.
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Li Y, Liu S, Cheng H, Chen X, Shen X, Cai Y. Dynamic transcriptome response in Meretrix meretrix to Aroclor 1254 exposure. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 207:111485. [PMID: 33254386 DOI: 10.1016/j.ecoenv.2020.111485] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 06/12/2023]
Abstract
Polychlorinated biphenyls (PCBs) are well-known persistent organic pollutants; they have toxic effects on the immune system, reproductive system, and endocrine system by changing the metabolism of the body. To elucidate the underlying molecular mechanism, the clam Meretrix meretrix was exposed to 10 and 1000 ng/L Aroclor 1254 and natural seawater (control). Samples from clams exposed to natural seawater and those exposed to Aroclor 1254 for 1 and 3 days were individually collected for transcriptome analysis. After assembly, more than 535,157 transcripts with a mean length of 949 bp and an N50 length of 1279 bp were obtained; a final set of 177,142 unigenes was generated. In the present study, 5101 differentially expressed genes were identified. The differentially expressed genes were related to detoxification metabolism, oxidative stress, immune response, and endocrine system disruption. Of these genes, under the Aroclor 1254 exposure, cytochrome P450 20A1 (2.06-4.46 folds), glutathione S-transferase (2.25-3.80 folds), multidrug resistance-associated protein 1-like (1.49-2.92 folds), peroxidase-like protein (1.33-4.26 folds), lysozyme (1.61-2.05 folds), bcl-2 like 1 protein (1.14-2.29 folds) and vitellogenin (1.09-1.19 folds) showed been significantly induced expressed. At the same time, some genes were down regulated, including cytochrome P450 2J5 (-1.20 ~ -2.86 folds), cytochrome P450 3A24 (-1.40 ~ -4.08 folds), C1q (-1.27 ~ -1.66 folds), Sulfotransferase (-1.51 ~ -1.84 folds), monocarboxylate transporter 10 (-1.30 ~ -4.70 folds), 3-beta hydroxysteroid dehydrogenase (-1.43 ~ -2.81 folds) and beta-galactosidase (-1.23 ~ -2.23 folds). Furthermore, it showed that the expression levels of CYP2J5, glutathione S-transferase, 3-beta hydroxysteroid dehydrogenase and beta-galactosidase had time responses and dose responses. The present study provided insights into the toxic effects of Aroclor 1254 exposure in M. meretrix.
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Affiliation(s)
- Yongqi Li
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Shishi Liu
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Hanliang Cheng
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Xiangning Chen
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
| | - Xin Shen
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China.
| | - Yuefeng Cai
- Jiangsu Key Laboratory of Marine Bioresources and Environment/Jiangsu Key Laboratory of Marine Biotechnology, Jiangsu Ocean University, Lianyungang 222005, China; Co-Innovation Center of Jiangsu Marine Bio-Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China.
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Szaefer H, Licznerska B, Cykowiak M, Baer-Dubowska W. Expression of CYP2S1 and CYP2W1 in breast cancer epithelial cells and modulation of their expression by synthetic methoxy stilbenes. Pharmacol Rep 2019; 71:1001-1005. [PMID: 31561186 DOI: 10.1016/j.pharep.2019.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 08/08/2019] [Accepted: 08/13/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND "Orphan" cytochromes are a new group of P450 cytochromes without a fully recognized biological role. The expression of these CYPs in tumors is higher than that in normal tissues, which makes them attractive as chemopreventive and/or therapeutic targets. In this study, we compared the effect of synthetic methoxy stilbenes and resveratrol on the expression of two orphan cytochromes, CYP2S1 and CYP2W1, in breast cancer cells. METHODS Breast cancer cells, lines MCF7 and MDA-MB-231, were treated for 72 h with tested compounds. The expression of CYP2S1 and CYP2W1 was evaluated at the transcript and protein levels by RT-PCR and Western blot, respectively. RESULTS The constitutive expression of both isoforms was confirmed at the mRNA and protein levels. CYP2S1 and CYP2W1 showed higher expression in MDA-MB-231 cells. In MCF7 cells treated with stilbenes, the expression of both CYPs was increased at the mRNA level, whereas at the protein level this effect was confirmed for CYP2S1 alone. In contrast, in estrogen receptor-negative MDA-MB-231 cells treated with stilbenes, the expression of both CYPs decreased, but mostly at the transcript level. CONCLUSIONS The results of the present study confirmed the constitutive expression of CYP2S1 and CYP2W1 in breast cancer cells, although their relatively low level of expression suggests that they may be less involved in the transformation of therapeutic agents in these types of tumors. Stilbenes, particularly 3MS and 4MS, can modulate the expression of "orphan" CYPs more efficiently than resveratrol.
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Affiliation(s)
- Hanna Szaefer
- Department of Pharmaceutical Biochemistry, Poznan University of Medical Sciences, Poznań, Poland.
| | - Barbara Licznerska
- Department of Pharmaceutical Biochemistry, Poznan University of Medical Sciences, Poznań, Poland
| | - Marta Cykowiak
- Department of Pharmaceutical Biochemistry, Poznan University of Medical Sciences, Poznań, Poland
| | - Wanda Baer-Dubowska
- Department of Pharmaceutical Biochemistry, Poznan University of Medical Sciences, Poznań, Poland
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Fekry MI, Xiao Y, Berg JZ, Guengerich FP. A Role for the Orphan Human Cytochrome P450 2S1 in Polyunsaturated Fatty Acid ω-1 Hydroxylation Using an Untargeted Metabolomic Approach. Drug Metab Dispos 2019; 47:1325-1332. [PMID: 31511258 PMCID: PMC6800448 DOI: 10.1124/dmd.119.089086] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 09/06/2019] [Indexed: 12/14/2022] Open
Abstract
Cytochrome P450 (P450) 2S1 is one of the orphan P450s, known to be expressed but not having a defined function with an endogenous substrate or in drug oxidations. Although it has been clearly demonstrated to catalyze reductive reactions, its role in NADPH-dependent oxidations has been ambiguous. In our efforts to characterize orphan human P450 enzymes, we used an untargeted liquid chromatography-mass spectromterymetabolomic approach with recombinant human P450 2S1 and extracts of rat stomach and intestine, sites of P450 2S1 localization in humans and animals. The search yielded several candidates, including the product 19-hydroxyarachidonic acid. Subsequent 18O analysis and in vitro studies with commercial arachidonic acid and 19-hydroxyarachidonic acid were used to validate ω-1 hydroxylation of the former molecule as a NADPH- and O2-dependent reaction. Steady-state kinetic assays were done for ω-1 hydroxylation reactions of P450 2S1 with several other long-chain fatty acids, including arachidonic, linoleic, α-linolenic, eicosapentaenoic, and docosapentaenoic acids. Rates of hydroxylation were slow, but no detectable activity was seen with either medium-chain length or saturated fatty acids. P450 2S1 is known to be expressed, at least at the mRNA level, to the extent of some other non-3A subfamily P450s in the human gastrointestinal tract, and the activity may be relevant. We conclude that P450 2S1 is a fatty acid ω-1 hydroxylase, although the physiologic relevance of these oxidations remains to be established. The metabolomic approaches we employed in this study are feasible for orphan P450s and other enzymes, in regard to annotation of function, in mammals and other organisms. SIGNIFICANCE STATEMENT: An untargeted mass spectrometry approach was utilized to identify ω-1 hydroxylation of arachidonic acid as an oxidative reaction catalyzed by human cytochrome P450 2S1. The enzyme also catalyzes the relatively slow ω-1 hydroxylation of several other unsaturated long-chain fatty acids.
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Affiliation(s)
- Mostafa I Fekry
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee (M.I.F., Y.X., J.Z.B., F.P.G.); and Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, Egypt (M.I.F.)
| | - Yi Xiao
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee (M.I.F., Y.X., J.Z.B., F.P.G.); and Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, Egypt (M.I.F.)
| | - Jeannette Zinggeler Berg
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee (M.I.F., Y.X., J.Z.B., F.P.G.); and Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, Egypt (M.I.F.)
| | - F Peter Guengerich
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee (M.I.F., Y.X., J.Z.B., F.P.G.); and Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, Egypt (M.I.F.)
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Sultana H, Watanabe K, Rana MM, Takashima R, Ohashi A, Komai M, Shirakawa H. Effects of Vitamin K₂ on the Expression of Genes Involved in Bile Acid Synthesis and Glucose Homeostasis in Mice with Humanized PXR. Nutrients 2018; 10:nu10080982. [PMID: 30060524 PMCID: PMC6116188 DOI: 10.3390/nu10080982] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 07/24/2018] [Accepted: 07/25/2018] [Indexed: 01/07/2023] Open
Abstract
Pregnane X receptor (PXR) is a nuclear receptor activated by various compounds, including prescribed drugs and dietary ingredients. Ligand-specific activation of PXR alters drug metabolism and affects many other physiological conditions. Species-specific ligand preference is a considerable challenge for studies of PXR function. To increase translational value of the results of mouse studies, humanized mouse model expressing human PXR (hPXR) has been developed. Menaquinone-4 (MK-4), one of vitamin K₂ analogs prescribed in osteoporosis, is a PXR ligand. We hypothesized that MK-4 could modulate the physiological conditions endogenously influenced by PXR, including those that have not been yet properly elucidated. In the present study, we investigated the effects of a single oral treatment with MK-4 on hepatic gene expression in wild-type and hPXR mice by using quantitative RT-PCR and DNA microarray. MK-4 administration altered mRNA levels of genes involved in drug metabolism (Abca3, Cyp2s1, Sult1b1), bile acid synthesis (Cyp7a1, Cyp8b1), and energy homeostasis (Aldoc, Slc2a5). Similar mRNA changes of CYP7A1 and CYP8B1 were observed in human hepatocarcinoma HepG2 cells treated with MK-4. These results suggest that MK-4 may modulate bile acid synthesis. To our knowledge, this is the first report showing the effect of MK-4 in hPXR mice.
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Affiliation(s)
- Halima Sultana
- Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan.
| | - Kimika Watanabe
- Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan.
| | - Md Masud Rana
- Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan.
| | - Rie Takashima
- Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan.
| | - Ai Ohashi
- Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan.
| | - Michio Komai
- Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan.
| | - Hitoshi Shirakawa
- Laboratory of Nutrition, Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8572, Japan.
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Nobutani K, Miyoshi J, Musch MW, Nishiyama M, Watanabe J, Kaneko A, Yamamoto M, Yoshida M, Kono T, Jeong H, Chang EB. Daikenchuto (TU-100) alters murine hepatic and intestinal drug metabolizing enzymes in an in vivo dietary model: effects of gender and withdrawal. Pharmacol Res Perspect 2018; 5. [PMID: 28971602 PMCID: PMC5625165 DOI: 10.1002/prp2.361] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 08/15/2017] [Accepted: 08/21/2017] [Indexed: 12/16/2022] Open
Abstract
Herbal medicines and natural products used for maintenance of health or treatment of diseases have many biological effects, including altering the pharmacokinetics and metabolism of other medications. Daikenchuto (TU‐100), an aqueous extract of ginger, ginseng, and Japanese green pepper fruit, is a commonly prescribed Kampo (Japanese herbal medicine) for postoperative ileus or bloating. The effects of TU‐100 on drug metabolism have not been investigated. In this study, we analyzed the effect of TU‐100 on expression of key drug‐metabolizing enzymes (DMEs) and drug transporters (DTs) in murine liver and gastrointestinal tract using a dietary model. Liver, jejunum, and proximal colon were analyzed for phase I and II DMEs and DT mRNA expression by reverse transcription (RT) first by nonquantitative and followed by quantitative polymerase chain reaction (PCR) and protein expression. Liver, jejunum, and proximal colon expressed some identical but also unique DMEs and DTs. TU‐100 increased the greatest changes in cytochrome (Cyp) 2b10 and Cyp3a11 and Mdr1a. Basal and TU‐100 stimulated levels of DME and DT expression were gender‐dependent, dose‐dependent and reversible after cessation of TU‐100 supplementation, except for some changes in the intestine. Quantitative Western blot analysis of protein extracts confirmed the quantitative PCR results.
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Affiliation(s)
- Kentaro Nobutani
- Department of Medicine, Knapp Center for Biomedical Center, The University of Chicago, Chicago, Illinois
| | - Jun Miyoshi
- Department of Medicine, Knapp Center for Biomedical Center, The University of Chicago, Chicago, Illinois
| | - Mark W Musch
- Department of Medicine, Knapp Center for Biomedical Center, The University of Chicago, Chicago, Illinois
| | - Mitsue Nishiyama
- Tsumura Research Laboratories, Tsumura & Co., Ami, Ibaraki, Japan
| | - Junko Watanabe
- Tsumura Research Laboratories, Tsumura & Co., Ami, Ibaraki, Japan
| | - Atsushi Kaneko
- Tsumura Research Laboratories, Tsumura & Co., Ami, Ibaraki, Japan
| | | | - Masaru Yoshida
- Division of Gastroenterology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Toru Kono
- Center for Clinical and Biomedical Research, Sapporo Higashi Tokushukai Hospital, Sapporo, Hokkaido, Japan.,Division of Gastroenterologic and General Surgery, Department of Surgery, Asahikawa Medical University, Asahikawa, Hokkaido, Japan
| | - Hyunyoung Jeong
- Departments of Pharmacy Practice and Biopharmaceutical Sciences, College of Pharmacy, University of Illinois, Chicago, Illinois
| | - Eugene B Chang
- Department of Medicine, Knapp Center for Biomedical Center, The University of Chicago, Chicago, Illinois
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Klaren WD, Gadupudi GS, Wels B, Simmons DL, Olivier AK, Robertson LW. Progression of micronutrient alteration and hepatotoxicity following acute PCB126 exposure. Toxicology 2015; 338:1-7. [PMID: 26410179 DOI: 10.1016/j.tox.2015.09.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 09/16/2015] [Accepted: 09/22/2015] [Indexed: 11/26/2022]
Abstract
Polychlorinated Biphenyls (PCBs) are industrial chemicals that have become a persistent threat to human health due to ongoing exposure. A subset of PCBs, known as dioxin-like PCBs, pose a special threat given their potent hepatic effects. Micronutrients, especially Cu, Zn and Se, homeostatic dysfunction is commonly seen after exposure to dioxin-like PCBs. This study investigates whether micronutrient alteration is the byproduct of the ongoing hepatotoxicity, marked by lipid accumulation, or a concurrent, yet independent event of hepatic damage. A time course study was carried out using male Sprague-Dawley rats with treatments of PCB126, the prototypical dioxin-like PCB, resulting in 6 different time points. Animals were fed a purified diet, based on AIN-93G, for three weeks to ensure micronutrient equilibration. A single IP injection of either tocopherol-stripped soy oil vehicle (5 mL/kg) or 5 μmol/kg PCB126 dose in vehicle was given at various time points resulting in exposures of 9h, 18 h, 36 h, 3 days, 6 days, and 12 days. Mild hepatic vacuolar change was seen as early as 36 h with drastic changes at the later time points, 6 and 12 days. Micronutrient alterations, specifically Cu, Zn, and Se, were not seen until after day 3 and only observed in the liver. No alterations were seen in the duodenum, suggesting that absorption and excretion may not be involved. Micronutrient alterations occur with ROS formation, lipid accumulation, and hepatomegaly. To probe the mechanistic underpinnings, alteration of gene expression of several copper chaperones was investigated; only metallothionein appeared elevated. These data suggest that the disruption in micronutrient status is a result of the hepatic injury elicited by PCB126 and is mediated in part by metallothionein.
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Affiliation(s)
- W D Klaren
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, Iowa, USA; Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, Iowa, USA
| | - G S Gadupudi
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, Iowa, USA; Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, Iowa, USA
| | - B Wels
- State Hygienic Laboratory, University of Iowa, Ankeny, Iowa, USA
| | - D L Simmons
- State Hygienic Laboratory, University of Iowa, Ankeny, Iowa, USA
| | - A K Olivier
- Department of Pathology, University of Iowa, Iowa City, Iowa, USA
| | - L W Robertson
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, Iowa, USA; Department of Occupational and Environmental Health, College of Public Health, University of Iowa, Iowa City, Iowa, USA.
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9
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Watson JD, Prokopec SD, Smith AB, Okey AB, Pohjanvirta R, Boutros PC. TCDD dysregulation of 13 AHR-target genes in rat liver. Toxicol Appl Pharmacol 2014; 274:445-54. [DOI: 10.1016/j.taap.2013.12.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 12/02/2013] [Accepted: 12/05/2013] [Indexed: 12/20/2022]
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10
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Lai IK, Klaren WD, Li M, Wels B, Simmons DL, Olivier AK, Haschek WM, Wang K, Ludewig G, Robertson LW. Does dietary copper supplementation enhance or diminish PCB126 toxicity in the rodent liver? Chem Res Toxicol 2013; 26:634-44. [PMID: 23527585 DOI: 10.1021/tx400049s] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Copper is essential for the function of the mitochondrial electron transport chain and several antioxidant proteins. However, in its free form copper can participate in Fenton-like reactions that produce reactive hydroxyl radicals. Aryl-hydrocarbon receptor (AhR) agonists, including the most potent polychlorinated biphenyl (PCB) congener, 3,3',4,4',5-pentachlorobiphenyl (PCB126), increase copper levels in rodent livers. This is accompanied by biochemical and toxic changes. To assess the involvement of copper in PCB toxicity, male Sprague-Dawley rats were fed an AIN-93G diet with differing dietary copper levels: low (2 ppm), adequate (6 ppm), and high (10 ppm). After three weeks, rats from each group were given a single ip injection of corn oil (control), 1, or 5 μmol/kg body weight PCB126. Two weeks following injections, biochemical and morphological markers of hepatic toxicity, trace metal status, and hepatic gene expression of metalloproteins were evaluated. Increasing dietary copper was associated with elevated tissue levels of copper and ceruloplasmin. In the livers of PCB126-treated rats, the hallmark signs of AhR activation were present, including increased cytochrome P450 and lipid levels and decreased glutathione. In addition, a doubling of hepatic copper levels was seen, and overall metal homeostasis was disturbed, resulting in decreased hepatic selenium, manganese, zinc, and iron. Expression of key metalloproteins was either decreased (cytochrome c oxidase), unchanged (ceruloplasmin and CuZnSOD), or increased (tyrosinase and metallothioneins 1 and 2) with exposure to PCB126. Increases in metallothionein may contribute/reflect the increased copper seen. Alterations in dietary copper did not amplify or abrogate the hepatic toxicity of PCB126. PCB126 toxicity, i.e., oxidative stress and steatosis, is clearly associated with disturbed metal homeostasis. Understanding the mechanisms of this disturbance may provide tools to prevent liver toxicity by other AhR agonists.
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Affiliation(s)
- Ian K Lai
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa , UI Research Park, #219 IREH, Iowa City, Iowa 52242-5000, USA
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Kania-Korwel I, Barnhart CD, Stamou M, Truong KM, El-Komy MH, Lein PJ, Veng-Pedersen P, Lehmler HJ. 2,2',3,5',6-Pentachlorobiphenyl (PCB 95) and its hydroxylated metabolites are enantiomerically enriched in female mice. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:11393-401. [PMID: 22974126 PMCID: PMC3475189 DOI: 10.1021/es302810t] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Epidemiological and laboratory studies link polychlorinated biphenyls and their metabolites to adverse neurodevelopmental outcomes. Several neurotoxic PCB congeners are chiral and undergo enantiomeric enrichment in mammalian species, which may modulate PCB developmental neurotoxicity. This study measures levels and enantiomeric enrichment of PCB 95 and its hydroxylated metabolites (OH-PCBs) in adult female C57Bl/6 mice following subchronic exposure to racemic PCB 95. Tissue levels of PCB 95 and OH-PCBs increased with increasing dose. Dose-dependent enantiomeric enrichment of PCB 95 was observed in brain and other tissues. OH-PCBs also displayed enantiomeric enrichment in blood and liver, but were not detected in adipose and brain. In light of data suggesting enantioselective effects of chiral PCBs on molecular targets linked to PCB developmental neurotoxicity, our observations highlight the importance of accounting for PCB and OH-PCB enantiomeric enrichment in the assessment of PCB developmental neurotoxicity.
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Affiliation(s)
- Izabela Kania-Korwel
- Department of Occupational and Environmental Health, College of Public Health, The University of Iowa, Iowa City, Iowa
| | - Christopher D. Barnhart
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California
| | - Marianna Stamou
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California
| | - Kim M. Truong
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California
| | | | - Pamela J. Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California
| | - Peter Veng-Pedersen
- Division of Pharmaceutics, College of Pharmacy, The University of Iowa, Iowa City, Iowa
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, College of Public Health, The University of Iowa, Iowa City, Iowa
- Corresponding Author: Dr. Hans-Joachim Lehmler, The University of Iowa, Department of Occupational and Environmental Health, University of Iowa Research Park, #221 IREH, Iowa City, IA 52242-5000, Phone: (319) 335-4310, Fax: (319) 335-4290,
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