1
|
Liang M, Gao Y, Shen Y, Zhang X, Gu J, Ji G. Serum metabolism distribution in individuals exposed to dioxins: A case study of residents near the municipal solid waste incinerators in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 947:174431. [PMID: 38960151 DOI: 10.1016/j.scitotenv.2024.174431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 05/27/2024] [Accepted: 06/30/2024] [Indexed: 07/05/2024]
Abstract
Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) have attracted considerable attention owing to their environmental persistence, bioaccumulation, and high toxicity. This study aimed to investigate changes in serum metabolites following exposure to PCDD/Fs and to reveal a novel pathogenesis of PCDD/Fs. Serum samples were collected from 75 residents living near a municipal solid waste incinerator in China to analyse the relationship between PCDD/Fs and serum metabolic components. The serum level in the low-exposure group [19.07 (13.44-23.89) pg-TEQ/L] was significantly lower than that in the high-exposure group [115.60 (52.28-592.65) pg-TEQ/L]. Non-targeted metabolomic studies based on liquid chromatography-high resolution mass spectrometry have been applied to the metabolomic analysis of serum. Thirty-seven metabolites with significant differences among the different groups were identified as biomarkers. Pathway analysis revealed that high dioxin exposure perturbed various biological processes, including glycerol phospholipid metabolism and the interconversion of pentose and glucuronate. The results of a population health survey showed that the serum dioxin concentration in patients with diabetes was significantly higher than that in the control population. These findings suggest that dioxin exposure is associated with several potential adverse health risks, including inflammation, diabetes, and cardiovascular disease, through metabolic changes.
Collapse
Affiliation(s)
- Mengyuan Liang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Yuanyun Gao
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Yuehong Shen
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Xinyu Zhang
- School of Environmental Science and Engineering, Changzhou University, Changzhou 213164, China
| | - Jie Gu
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Guixiang Ji
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China.
| |
Collapse
|
2
|
Rakateli L, Huchzermeier R, van der Vorst EPC. AhR, PXR and CAR: From Xenobiotic Receptors to Metabolic Sensors. Cells 2023; 12:2752. [PMID: 38067179 PMCID: PMC10705969 DOI: 10.3390/cells12232752] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 11/23/2023] [Accepted: 11/30/2023] [Indexed: 12/18/2023] Open
Abstract
Traditionally, xenobiotic receptors are known for their role in chemical sensing and detoxification, as receptor activation regulates the expression of various key enzymes and receptors. However, recent studies have highlighted that xenobiotic receptors also play a key role in the regulation of lipid metabolism and therefore function also as metabolic sensors. Since dyslipidemia is a major risk factor for various cardiometabolic diseases, like atherosclerosis and non-alcoholic fatty liver disease, it is of major importance to understand the molecular mechanisms that are regulated by xenobiotic receptors. In this review, three major xenobiotic receptors will be discussed, being the aryl hydrocarbon receptor (AhR), pregnane X receptor (PXR) and the constitutive androstane receptor (CAR). Specifically, this review will focus on recent insights into the metabolic functions of these receptors, especially in the field of lipid metabolism and the associated dyslipidemia.
Collapse
Affiliation(s)
- Leonida Rakateli
- Institute for Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, 52074 Aachen, Germany; (L.R.); (R.H.)
- Aachen-Maastricht Institute for CardioRenal Disease (AMICARE), RWTH Aachen University, 52074 Aachen, Germany
| | - Rosanna Huchzermeier
- Institute for Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, 52074 Aachen, Germany; (L.R.); (R.H.)
- Aachen-Maastricht Institute for CardioRenal Disease (AMICARE), RWTH Aachen University, 52074 Aachen, Germany
| | - Emiel P. C. van der Vorst
- Institute for Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, 52074 Aachen, Germany; (L.R.); (R.H.)
- Aachen-Maastricht Institute for CardioRenal Disease (AMICARE), RWTH Aachen University, 52074 Aachen, Germany
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University Munich, 80336 Munich, Germany
- Interdisciplinary Center for Clinical Research (IZKF), RWTH Aachen University, 52074 Aachen, Germany
| |
Collapse
|
3
|
Kumbale CM, Zhang Q, Voit EO. Hepatic cholesterol biosynthesis and dioxin-induced dysregulation: A multiscale computational approach. Food Chem Toxicol 2023; 181:114086. [PMID: 37820785 PMCID: PMC10841405 DOI: 10.1016/j.fct.2023.114086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 09/18/2023] [Accepted: 10/03/2023] [Indexed: 10/13/2023]
Abstract
Humans are constantly exposed to lipophilic persistent organic pollutants (POPs) that accumulate in fatty foods. Among the numerous POPs, dioxins, in particular 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), can impact several organ systems. While the hazard is clearly recognized, it is still difficult to develop a comprehensive understanding of the overall health impacts of dioxins. As chemical toxicity testing is steadily adopting new approach methodologies (NAMs), it becomes imperative to develop computational models that can bridge the data gaps between in vitro testing and in vivo outcomes. As an effort to address this challenge, we propose a multiscale computational approach using a "template-and-anchor" (T&A) structure. A template is a high-level umbrella model that permits the integration of information from various, detailed anchor models. In the present study, we use this T&A approach to describe the effect of TCDD on cholesterol dynamics. Specifically, we represent hepatic cholesterol biosynthesis as an anchor model that is perturbed by TCDD, leading to steatosis, along with alterations of plasma cholesterol. In the future, incorporating pertinent information from all anchor models into the template model will allow the characterization of the global effects of dioxin, which can subsequently be translated into overall - and ultimately personalized - human health risk assessment.
Collapse
Affiliation(s)
- Carla M Kumbale
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
| | - Qiang Zhang
- Gangarosa Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA.
| | - Eberhard O Voit
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
| |
Collapse
|
4
|
Wang J, Lu P, Xie W. Atypical functions of xenobiotic receptors in lipid and glucose metabolism. MEDICAL REVIEW (2021) 2022; 2:611-624. [PMID: 36785576 PMCID: PMC9912049 DOI: 10.1515/mr-2022-0032] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/08/2022] [Indexed: 12/02/2022]
Abstract
Xenobiotic receptors are traditionally defined as xenobiotic chemical-sensing receptors, the activation of which transcriptionally regulates the expression of enzymes and transporters involved in the metabolism and disposition of xenobiotics. Emerging evidence suggests that "xenobiotic receptors" also have diverse endobiotic functions, including their effects on lipid metabolism and energy metabolism. Dyslipidemia is a major risk factor for cardiovascular disease, diabetes, obesity, metabolic syndrome, stroke, nonalcoholic fatty liver disease (NAFLD), and nonalcoholic steatohepatitis (NASH). Understanding the molecular mechanism by which transcriptional factors, including the xenobiotic receptors, regulate lipid homeostasis will help to develop preventive and therapeutic approaches. This review describes recent advances in our understanding the atypical roles of three xenobiotic receptors: aryl hydrocarbon receptor (AhR), pregnane X receptor (PXR), and constitutive androstane receptor (CAR), in metabolic disorders, with a particular focus on their effects on lipid and glucose metabolism. Collectively, the literatures suggest the potential values of AhR, PXR and CAR as therapeutic targets for the treatment of NAFLD, NASH, obesity and diabetes, and cardiovascular diseases.
Collapse
Affiliation(s)
- Jingyuan Wang
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Peipei Lu
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Wen Xie
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| |
Collapse
|
5
|
Wang Y, Jian S, Li W, Zhao L, Ye G, Shi F, Li L, Zou Y, Song X, Zhao X, Yin Z, Li Y, Tang H. Epigallocatechin-3-gallate ameliorates liver injury secondary to Pseudomonas aeruginosa pneumonia. Int Immunopharmacol 2022; 112:109239. [PMID: 36113316 DOI: 10.1016/j.intimp.2022.109239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/05/2022] [Accepted: 09/06/2022] [Indexed: 11/05/2022]
Abstract
Pseudomonas aeruginosa is a dangerous pathogen causing nosocomial pneumonia. P. aeruginosa infection-induced liver damage is another fatal threat, and antibiotic treatment is not effective in relieving P. aeruginosa virulence-triggered damage. We here evaluated the protective effect of epigallocatechin gallate (EGCG), a substance that inhibits virulence of P. aeruginosa through quorum quenching, on liver damage secondary to P. aeruginosa infection. Mice were pretreated with EGCG (20, 40, and 80 mg/kg) for 3 days, and then infected with P. aeruginosa through intratracheal instillation to model acute pneumonia. The mice were sacrificed after 24 h of infection, and samples were harvested for subsequent analysis. EGCG significantly decreased the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Histopathological changes of liver were significantly ameliorated by EGCG. It also significantly reduced oxidative stress that induced liver damage in P. aeruginosa infection, which relied not on the activation of the Nrf2-HO-1 pathway but on the upregulation of the activity of antioxidative enzymes. Then, the inflammatory response in the liver was tested. EGCG inhibited the release of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) by blocking the inflammation regulating signaling of the TLR4-myD88-NF-κB pathway. EGCG upregulated the activation of nuclear receptors to stronger the liver protective activity against P. aeruginosa infection. Conclusively, EGCG exhibited a significant hepatoprotective effective against P. aeruginosa infection.
Collapse
Affiliation(s)
- Yingjie Wang
- Department of Pharmacy, Sichuan Agricultural University, Chengdu 611130, China
| | - Shanqiu Jian
- Department of Pharmacy, Sichuan Agricultural University, Chengdu 611130, China
| | - Wen Li
- Animal Breeding and Genetics Key Laboratory of Sichuan Province, Sichuan Animal Science Academy, Chengdu 610066, China
| | - Ling Zhao
- Department of Pharmacy, Sichuan Agricultural University, Chengdu 611130, China
| | - Gang Ye
- Department of Pharmacy, Sichuan Agricultural University, Chengdu 611130, China
| | - Fei Shi
- Department of Pharmacy, Sichuan Agricultural University, Chengdu 611130, China
| | - Lixia Li
- Department of Pharmacy, Sichuan Agricultural University, Chengdu 611130, China
| | - Yuanfeng Zou
- Department of Pharmacy, Sichuan Agricultural University, Chengdu 611130, China
| | - Xu Song
- Department of Pharmacy, Sichuan Agricultural University, Chengdu 611130, China
| | - Xinghong Zhao
- Department of Pharmacy, Sichuan Agricultural University, Chengdu 611130, China
| | - Zhongqiong Yin
- Department of Pharmacy, Sichuan Agricultural University, Chengdu 611130, China
| | - Yinglun Li
- Department of Pharmacy, Sichuan Agricultural University, Chengdu 611130, China
| | - Huaqiao Tang
- Department of Pharmacy, Sichuan Agricultural University, Chengdu 611130, China.
| |
Collapse
|
6
|
Xu H, Jia Y, Sun Z, Su J, Liu QS, Zhou Q, Jiang G. Environmental pollution, a hidden culprit for health issues. ECO-ENVIRONMENT & HEALTH (ONLINE) 2022; 1:31-45. [PMID: 38078200 PMCID: PMC10702928 DOI: 10.1016/j.eehl.2022.04.003] [Citation(s) in RCA: 72] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 03/26/2022] [Accepted: 04/23/2022] [Indexed: 12/12/2023]
Abstract
The environmental and health impacts from the massive discharge of chemicals and subsequent pollution have been gaining increasing public concern. The unintended exposure to different pollutants, such as heavy metals, air pollutants and organic chemicals, may cause diverse deleterious effects on human bodies, resulting in the incidence and progression of different diseases. The article reviewed the outbreak of environmental pollution-related public health emergencies, the epidemiological evidence on certain pollution-correlated health effects, and the pathological studies on specific pollutant exposure. By recalling the notable historical life-threatening disasters incurred by local chemical pollution, the damning evidence was presented to criminate certain pollutants as the main culprit for the given health issues. The epidemiological data on the prevalence of some common diseases revealed a variety of environmental pollutants to blame, such as endocrine-disrupting chemicals (EDCs), fine particulate matters (PMs) and heavy metals. The retrospection of toxicological studies provided illustrative clues for evaluating ambient pollutant-induced health risks. Overall, environmental pollution, as the hidden culprit, should answer for the increasing public health burden, and more efforts are highly encouraged to strive to explore the cause-and-effect relationships through extensive epidemiological and pathological studies.
Collapse
Affiliation(s)
- Hanqing Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, and Zhejiang Provincial Key Lab for Subtropical Water Environment and Marine Biological Resources Protection, Wenzhou University, Wenzhou, 325035, China
| | - Yang Jia
- National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, and Zhejiang Provincial Key Lab for Subtropical Water Environment and Marine Biological Resources Protection, Wenzhou University, Wenzhou, 325035, China
| | - Zhendong Sun
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310000, China
| | - Jiahui Su
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qian S. Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Qunfang Zhou
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310000, China
- Institute of Environment and Health, Jianghan University, Wuhan, 430056, China
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310000, China
| |
Collapse
|
7
|
Liang Y, Tang Z, Jiang Y, Ai C, Peng J, Liu Y, Chen J, Xin X, Lei B, Zhang J, Cai Z. Lipid metabolism disorders associated with dioxin exposure in a cohort of Chinese male workers revealed by a comprehensive lipidomics study. ENVIRONMENT INTERNATIONAL 2021; 155:106665. [PMID: 34098336 DOI: 10.1016/j.envint.2021.106665] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/23/2021] [Accepted: 05/23/2021] [Indexed: 06/12/2023]
Abstract
Dioxins, environmentally stable and ubiquitous, have been found to induce metabolic changes especially in lipids and be related to multiple diseases. However, limited study is available on lipid alternations related to human exposure to dioxins. This study aims to explore the serum lipidomic characterization and to understand the underlying mechanisms of adverse health risks associated with dioxin exposure. A lipidomic study integrating nontargeted lipidomics, and targeted free fatty acid (FFA) and acyl-coenzyme A (acyl-CoA) analyses were conducted to investigate the 94 serum samples from two groups of male workers with remarkably different dioxin concentrations. The obtained results exhibited distinct lipidomic signatures between the high and low exposed groups. A total of 37 lipids were identified with the significant changes. The results revealed that dioxin exposure caused accumulations of triglyceride (TG), ceramide (Cer) and sphingoid (So), remodeling of glycerophospholipid (GP), imbalanced FFA metabolism, as well as upregulation of platelet-activating factor (PAF). These findings implied the associations between dioxin exposure and potential adverse health risks including inflammation, apoptosis, cardiovascular diseases (CVDs), and liver diseases. This study is the first to explain the associations between dioxin exposure and health effects at the level of lipid metabolism.
Collapse
Affiliation(s)
- Yanshan Liang
- Beijing Normal University-Hong Kong Baptist University United International College, Zhuhai, China; State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong Special Administrative Region
| | - Zhi Tang
- Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China; Department of Environmental and Occupational Health, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Yousheng Jiang
- Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Chunyan Ai
- Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Jinling Peng
- Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Yuan Liu
- Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Jinru Chen
- Songgang Preventive Health Center of Baoan District, Shenzhen, 518105, China
| | - Xiong Xin
- Beijing Normal University-Hong Kong Baptist University United International College, Zhuhai, China
| | - Bo Lei
- Beijing Normal University-Hong Kong Baptist University United International College, Zhuhai, China
| | - Jianqing Zhang
- Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China.
| | - Zongwei Cai
- Beijing Normal University-Hong Kong Baptist University United International College, Zhuhai, China; State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong Special Administrative Region.
| |
Collapse
|
8
|
Cholico GN, Fling RR, Zacharewski NA, Fader KA, Nault R, Zacharewski TR. Thioesterase induction by 2,3,7,8-tetrachlorodibenzo-p-dioxin results in a futile cycle that inhibits hepatic β-oxidation. Sci Rep 2021; 11:15689. [PMID: 34344994 PMCID: PMC8333094 DOI: 10.1038/s41598-021-95214-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 07/15/2021] [Indexed: 02/07/2023] Open
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a persistent environmental contaminant, induces steatosis by increasing hepatic uptake of dietary and mobilized peripheral fats, inhibiting lipoprotein export, and repressing β-oxidation. In this study, the mechanism of β-oxidation inhibition was investigated by testing the hypothesis that TCDD dose-dependently repressed straight-chain fatty acid oxidation gene expression in mice following oral gavage every 4 days for 28 days. Untargeted metabolomic analysis revealed a dose-dependent decrease in hepatic acyl-CoA levels, while octenoyl-CoA and dicarboxylic acid levels increased. TCDD also dose-dependently repressed the hepatic gene expression associated with triacylglycerol and cholesterol ester hydrolysis, fatty acid binding proteins, fatty acid activation, and 3-ketoacyl-CoA thiolysis while inducing acyl-CoA hydrolysis. Moreover, octenoyl-CoA blocked the hydration of crotonyl-CoA suggesting short chain enoyl-CoA hydratase (ECHS1) activity was inhibited. Collectively, the integration of metabolomics and RNA-seq data suggested TCDD induced a futile cycle of fatty acid activation and acyl-CoA hydrolysis resulting in incomplete β-oxidation, and the accumulation octenoyl-CoA levels that inhibited the activity of short chain enoyl-CoA hydratase (ECHS1).
Collapse
Affiliation(s)
- Giovan N Cholico
- Department of Biochemistry and Molecular Biology, Michigan State University, Biochemistry Building, 603 Wilson Road, East Lansing, MI, 48824, USA
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, 48824, USA
| | - Russell R Fling
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, 48824, USA
- Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
| | - Nicholas A Zacharewski
- Department of Biochemistry and Molecular Biology, Michigan State University, Biochemistry Building, 603 Wilson Road, East Lansing, MI, 48824, USA
| | - Kelly A Fader
- Department of Biochemistry and Molecular Biology, Michigan State University, Biochemistry Building, 603 Wilson Road, East Lansing, MI, 48824, USA
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, 48824, USA
| | - Rance Nault
- Department of Biochemistry and Molecular Biology, Michigan State University, Biochemistry Building, 603 Wilson Road, East Lansing, MI, 48824, USA
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, 48824, USA
| | - Timothy R Zacharewski
- Department of Biochemistry and Molecular Biology, Michigan State University, Biochemistry Building, 603 Wilson Road, East Lansing, MI, 48824, USA.
- Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, 48824, USA.
| |
Collapse
|
9
|
Olivero-Verbel J, Harkema JR, Roth RA, Ganey PE. Fenofibrate, a peroxisome proliferator-activated receptor-alpha agonist, blocks steatosis and alters the inflammatory response in a mouse model of inflammation-dioxin interaction. Chem Biol Interact 2021; 345:109521. [PMID: 34052195 DOI: 10.1016/j.cbi.2021.109521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 04/07/2021] [Accepted: 05/14/2021] [Indexed: 12/01/2022]
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (dioxin; TCDD) is an environmental contaminant that elicits a variety of toxic effects, many of which are mediated through activation of the aryl hydrocarbon receptor (AhR). Interaction between AhR and the peroxisome proliferator-activated receptor-alpha (PPAR-α), which regulates fatty acid metabolism, has been suggested. Furthermore, with recognition of the prevalence of inflammatory conditions, there is current interest in the potential for inflammatory stress to modulate the response to environmental agents. The aim of this work was to assess the interaction of TCDD with hepatic inflammation modulated by fenofibrate, a PPAR-α agonist. Female, C57BL/6 mice were treated orally with vehicle or fenofibrate (250 mg/kg) for 13 days, and then were given vehicle or 30 μg/kg TCDD. Four days later, the animals received an i.p. injection of lipopolysaccharide-galactosamine (LPS-GalN) (0.05x107 EU/kg and 500 mg/kg, respectively) to incite inflammation, or saline as vehicle control. After 4 h, the mice were euthanized, and blood and liver samples were collected for analysis. Livers of animals treated with TCDD with or without LPS-GalN had increased lipid deposition, and this effect was blocked by fenofibrate. In TCDD/LPS-GalN-treated mice, fenofibrate caused an increase in plasma activity of alanine aminotransferase, a marker of hepatocellular injury. TCDD reduced LPS-GalN-induced apoptosis, an effect that was prevented by fenofibrate pretreatment. LPS-GalN induced an increase in the concentration of interleukin-6 in plasma and accumulation of neutrophils in liver. TCDD exposure enhanced the former response and inhibited the latter one. These results suggest that fenofibrate counteracts the changes in lipid metabolism induced by TCDD but increases inflammation and liver injury in this model of inflammation-TCDD interaction.
Collapse
Affiliation(s)
- Jesus Olivero-Verbel
- Department of Pharmacology and Toxicology. Michigan State University, East Lansing, MI, USA; Environmental and Computational Chemistry Group, School of Pharmaceutical Sciences, University of Cartagena, Cartagena, 130014, Colombia
| | - Jack R Harkema
- Department of Pathobiology and Diagnostic Investigation, Institute for Integrative Toxicology, Michigan State University, USA
| | - Robert A Roth
- Department of Pharmacology and Toxicology. Michigan State University, East Lansing, MI, USA
| | - Patricia E Ganey
- Department of Pharmacology and Toxicology. Michigan State University, East Lansing, MI, USA.
| |
Collapse
|
10
|
Cano R, Pérez JL, Dávila LA, Ortega Á, Gómez Y, Valero-Cedeño NJ, Parra H, Manzano A, Véliz Castro TI, Albornoz MPD, Cano G, Rojas-Quintero J, Chacín M, Bermúdez V. Role of Endocrine-Disrupting Chemicals in the Pathogenesis of Non-Alcoholic Fatty Liver Disease: A Comprehensive Review. Int J Mol Sci 2021; 22:4807. [PMID: 34062716 PMCID: PMC8125512 DOI: 10.3390/ijms22094807] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/21/2021] [Accepted: 03/22/2021] [Indexed: 12/15/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is considered the most common liver disorder, affecting around 25% of the population worldwide. It is a complex disease spectrum, closely linked with other conditions such as obesity, insulin resistance, type 2 diabetes mellitus, and metabolic syndrome, which may increase liver-related mortality. In light of this, numerous efforts have been carried out in recent years in order to clarify its pathogenesis and create new prevention strategies. Currently, the essential role of environmental pollutants in NAFLD development is recognized. Particularly, endocrine-disrupting chemicals (EDCs) have a notable influence. EDCs can be classified as natural (phytoestrogens, genistein, and coumestrol) or synthetic, and the latter ones can be further subdivided into industrial (dioxins, polychlorinated biphenyls, and alkylphenols), agricultural (pesticides, insecticides, herbicides, and fungicides), residential (phthalates, polybrominated biphenyls, and bisphenol A), and pharmaceutical (parabens). Several experimental models have proposed a mechanism involving this group of substances with the disruption of hepatic metabolism, which promotes NAFLD. These include an imbalance between lipid influx/efflux in the liver, mitochondrial dysfunction, liver inflammation, and epigenetic reprogramming. It can be concluded that exposure to EDCs might play a crucial role in NAFLD initiation and evolution. However, further investigations supporting these effects in humans are required.
Collapse
Affiliation(s)
- Raquel Cano
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo 4004, Venezuela; (R.C.); (J.L.P.); (Á.O.); (Y.G.); (H.P.); (A.M.); (M.P.D.A.)
| | - José L. Pérez
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo 4004, Venezuela; (R.C.); (J.L.P.); (Á.O.); (Y.G.); (H.P.); (A.M.); (M.P.D.A.)
| | - Lissé Angarita Dávila
- Escuela de Nutrición y Dietética, Facultad de Medicina, Universidad Andres Bello, Sede Concepción 4260000, Chile;
| | - Ángel Ortega
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo 4004, Venezuela; (R.C.); (J.L.P.); (Á.O.); (Y.G.); (H.P.); (A.M.); (M.P.D.A.)
| | - Yosselin Gómez
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo 4004, Venezuela; (R.C.); (J.L.P.); (Á.O.); (Y.G.); (H.P.); (A.M.); (M.P.D.A.)
| | - Nereida Josefina Valero-Cedeño
- Carrera de Laboratorio Clínico, Facultad de Ciencias de la Salud, Universidad Estatal del Sur de Manabí, Jipijapa E482, Ecuador; (N.J.V.-C.); (T.I.V.C.)
| | - Heliana Parra
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo 4004, Venezuela; (R.C.); (J.L.P.); (Á.O.); (Y.G.); (H.P.); (A.M.); (M.P.D.A.)
| | - Alexander Manzano
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo 4004, Venezuela; (R.C.); (J.L.P.); (Á.O.); (Y.G.); (H.P.); (A.M.); (M.P.D.A.)
| | - Teresa Isabel Véliz Castro
- Carrera de Laboratorio Clínico, Facultad de Ciencias de la Salud, Universidad Estatal del Sur de Manabí, Jipijapa E482, Ecuador; (N.J.V.-C.); (T.I.V.C.)
| | - María P. Díaz Albornoz
- Endocrine and Metabolic Diseases Research Center, School of Medicine, University of Zulia, Maracaibo 4004, Venezuela; (R.C.); (J.L.P.); (Á.O.); (Y.G.); (H.P.); (A.M.); (M.P.D.A.)
| | - Gabriel Cano
- Insitute für Pharmazie, Freie Universitänt Berlin, Königin-Louise-Strabe 2-4, 14195 Berlin, Germany;
| | - Joselyn Rojas-Quintero
- Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA;
| | - Maricarmen Chacín
- Facultad de Ciencias de la Salud. Barranquilla, Universidad Simón Bolívar, Barranquilla 55-132, Colombia;
| | - Valmore Bermúdez
- Facultad de Ciencias de la Salud. Barranquilla, Universidad Simón Bolívar, Barranquilla 55-132, Colombia;
| |
Collapse
|
11
|
Liang Y, Tang Z, Jiang Y, Ai C, Peng J, Liu Y, Chen J, Zhang J, Cai Z. Serum metabolic changes associated with dioxin exposure in a Chinese male cohort. ENVIRONMENT INTERNATIONAL 2020; 143:105984. [PMID: 32712422 DOI: 10.1016/j.envint.2020.105984] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 07/03/2020] [Accepted: 07/13/2020] [Indexed: 06/11/2023]
Abstract
Dioxins, a group of persistent organic pollutants, have been proved to correlate with ranges of diseases by activating the aryl hydrocarbon receptor (AhR). However, previous dioxin toxicity studies primarily focused on the activation of AhR with signaling pathways at gene and protein levels. The investigation of underlying mechanisms at the metabolic level is still necessary. In this study, serum samples of 48 and 47 healthy participants with the highest and lowest dioxin levels based on quartile distribution of the serum dioxin concentrations of 215 male adults were selected for metabolomics analysis by using liquid chromatography coupled with orbitrap high-resolution mass spectrometry to investigate dioxin-related metabolic responses. The identified potential biomarkers included acylcarnitines, fatty acids and derivatives, glycerophospholipids, etc. suggested that metabolic pathways such as fatty acid β-oxidation, essential fatty acid metabolism, arachidonic acid metabolism, glycerophospholipid and sphingolipid metabolism and purine metabolism were disturbed by dioxin exposure. The results indicated that people with high dioxin exposure levels were at the potential health risks of inflammation, liver and cardiovascular diseases. The metabolic findings may help understand the link between dioxin exposure and the diseases.
Collapse
Affiliation(s)
- Yanshan Liang
- Beijing Normal University-Hong Kong Baptist University United International College, Zhuhai, China; State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong Special Administrative Region; Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Zhi Tang
- Shenzhen Center for Disease Control and Prevention, Shenzhen, China; Department of Environmental and Occupational Health, School of Public Health, Guangdong Medical University, Dongguan, China
| | - Yousheng Jiang
- Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Chunyan Ai
- Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Jinling Peng
- Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Yuan Liu
- Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Jinru Chen
- Songgang Preventive Health Center of Baoan District, Shenzhen, China
| | - Jianqing Zhang
- Shenzhen Center for Disease Control and Prevention, Shenzhen, China.
| | - Zongwei Cai
- Beijing Normal University-Hong Kong Baptist University United International College, Zhuhai, China; State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong Special Administrative Region.
| |
Collapse
|
12
|
Vitamin B12 and folic acid alleviate symptoms of nutritional deficiency by antagonizing aryl hydrocarbon receptor. Proc Natl Acad Sci U S A 2020; 117:15837-15845. [PMID: 32571957 DOI: 10.1073/pnas.2006949117] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Despite broad appreciation of their clinical utility, it has been unclear how vitamin B12 and folic acid (FA) function at the molecular level to directly prevent their hallmark symptoms of deficiency like anemia or birth defects. To this point, B12 and FA have largely been studied as cofactors for enzymes in the one-carbon (1C) cycle in facilitating the de novo generation of nucleotides and methylation of DNA and protein. Here, we report that B12 and FA function as natural antagonists of aryl hydrocarbon receptor (AhR). Our studies indicate that B12 and FA bind AhR directly as competitive antagonists, blocking AhR nuclear localization, XRE binding, and target gene induction mediated by AhR agonists like 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and 6-formylindolo[3,2-b]carbazole (FICZ). In mice, TCDD treatment replicated many of the hallmark symptoms of B12/FA deficiency and cotreatment with aryl hydrocarbon portions of B12/FA rescued mice from these toxic effects. Moreover, we found that B12/FA deficiency in mice induces AhR transcriptional activity and accumulation of erythroid progenitors and that it may do so in an AhR-dependent fashion. Consistent with these results, we observed that human cancer samples with deficient B12/FA uptake demonstrated higher transcription of AhR target genes and lower transcription of pathways implicated in birth defects. In contrast, there was no significant difference observed between samples with mutated and intact 1C cycle proteins. Thus, we propose a model in which B12 and FA blunt the effect of natural AhR agonists at baseline to prevent the symptoms that arise with AhR overactivation.
Collapse
|
13
|
Choi EM, Suh KS, Park SY, Yun S, Chin SO, Rhee SY, Chon S. Orientin reduces the inhibitory effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on adipogenic differentiation and insulin signaling pathway in murine 3T3-L1 adipocytes. Chem Biol Interact 2020; 318:108978. [PMID: 32044341 DOI: 10.1016/j.cbi.2020.108978] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 02/03/2020] [Accepted: 02/06/2020] [Indexed: 12/14/2022]
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) accumulates in human body, probably influencing adipocyte differentiation and causing various toxic effects, including wasting syndrome. Recently, orientin, a phenolic compound abundant in natural health products, has been shown to have antioxidant properties. We investigated the protective effects of orientin against TCDD-induced adipocyte dysfunction and its underlying mechanisms. In this study, orientin suppressed TCDD-induced loss of lipid accumulation. Orientin inhibited TCDD-driven decreases in the levels of peroxisome proliferator-activated receptor γ and adiponectin. Orientin also reduced TCDD-induced prostaglandin E2, and cytosolic phospholipase A2α levels, and increased TCDD-inhibited peroxisome proliferator-activated receptor gamma coactivator 1-alpha levels in 3T3-L1 adipocytes. TCDD reduced the levels of insulin receptor substrate 1 and glucose transporter 4, and decreased insulin-stimulated glucose uptake activity; however, orientin diminished these TCDD-induced effects. These results suggest that orientin may have beneficial effects on the prevention of TCDD-induced wasting syndrome and type II diabetes mellitus accompanied by insulin resistance.
Collapse
Affiliation(s)
- Eun Mi Choi
- Department of Endocrinology & Metabolism, College of Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Kwang Sik Suh
- Department of Endocrinology & Metabolism, College of Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - So Young Park
- Department of Endocrinology & Metabolism, College of Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea; Department of Endocrinology & Metabolism, Kyung Hee University Hospital, Seoul, 02447, Republic of Korea
| | - Soojin Yun
- Department of Medicine, Graduate School, Kyung Hee University, Seoul, 02447, Republic of Korea; Department of Endocrinology & Metabolism, Kyung Hee University Hospital, Seoul, 02447, Republic of Korea
| | - Sang Ouk Chin
- Department of Endocrinology & Metabolism, College of Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea; Department of Endocrinology & Metabolism, Kyung Hee University Hospital, Seoul, 02447, Republic of Korea
| | - Sang Youl Rhee
- Department of Endocrinology & Metabolism, College of Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea; Department of Endocrinology & Metabolism, Kyung Hee University Hospital, Seoul, 02447, Republic of Korea
| | - Suk Chon
- Department of Endocrinology & Metabolism, College of Medicine, Kyung Hee University, Seoul, 02447, Republic of Korea; Department of Endocrinology & Metabolism, Kyung Hee University Hospital, Seoul, 02447, Republic of Korea.
| |
Collapse
|
14
|
Screening a mouse liver gene expression compendium identifies modulators of the aryl hydrocarbon receptor (AhR). Toxicology 2015. [PMID: 26215100 DOI: 10.1016/j.tox.2015.07.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the biological and toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), dioxin-like compounds (DLC) as well as some drugs and endogenous tryptophan metabolites. Short-term activation of AhR can lead to hepatocellular steatosis, and chronic activation can lead to liver cancer in mice and rats. Analytical approaches were developed to identify biosets in a genomic database in which AhR activity was altered. A set of 63 genes was identified (the AhR gene expression biomarker) that was dependent on AhR for regulation after exposure to TCDD or benzo[a]pyrene and includes the known AhR targets Cyp1a1 and Cyp1b1. A fold-change rank-based test (Running Fisher's test; p-value ≤ 10(-4)) was used to evaluate the similarity between the AhR biomarker and a test set of 37 and 41 biosets positive or negative, respectively for AhR activation. The test resulted in a balanced accuracy of 95%. The rank-based test was used to identify factors that activate or suppress AhR in an annotated mouse liver/mouse primary hepatocyte gene expression database of ∼ 1850 comparisons. In addition to the expected activation of AhR by TCDD and DLC, AhR was activated by AP20189 and phenformin. AhR was suppressed by phenobarbital and 1,4-Bis[2-(3,5-dichloropyridyloxy)] benzene (TCPOBOP) in a constitutive activated receptor (CAR)-dependent manner and pregnenolone-16α-carbonitrile in a pregnane X receptor (PXR)-dependent manner. Inactivation of individual genes in nullizygous models led to AhR activation (Pxr, Ghrhr, Taf10) or suppression (Ahr, Ilst6st, Hnf1a). This study describes a novel screening strategy for identifying factors in mouse liver that perturb AhR in a gene expression compendium.
Collapse
|
15
|
Choi YJ, Lee CH, Lee KY, Jung SH, Lee BH. Increased hepatic Fatty Acid uptake and esterification contribute to tetracycline-induced steatosis in mice. Toxicol Sci 2015; 145:273-82. [PMID: 25745068 DOI: 10.1093/toxsci/kfv049] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Tetracycline induces microvesicular steatosis, which has a poor long-term prognosis and a higher risk of steatohepatitis development compared with macrovesicular steatosis. Recent gene expression studies indicated that tetracycline treatment affects the expression of many genes associated with fatty acid transport and esterification. In this study, we investigated the role of fatty acid transport and esterification in tetracycline-induced steatosis. Intracellular lipid accumulation and the protein expression of fatty acid translocase (FAT or CD36) and diacylglycerol acyltransferase (DGAT) 2 were increased in both mouse liver and HepG2 cells treated with tetracycline at 50 mg/kg (intraperitoneal injection, i.p.) and 100 μM, respectively. Tetracycline increased the cellular uptake of boron-dipyrromethene-labeled C16 fatty acid, which was abolished by CD36 RNA interference. Oleate-induced cellular lipid accumulation was further enhanced by co-incubation with tetracycline. Tetracycline downregulated extracellular signal-regulated kinase (ERK) phosphorylation, which negatively regulated DGAT2 expression. U0126, a specific ERK inhibitor, also increased DGAT2 expression and cellular lipid accumulation. DGAT1 and 2 knock-down with specific small interfering (si)-RNA completely abrogated the steatogenic effect of tetracycline in HepG2 cells. Taken together, our data showed that tetracycline induces lipid accumulation by facilitating fatty acid transport and triglyceride esterification by upregulating CD36 and DGAT2, respectively.
Collapse
Affiliation(s)
- You-Jin Choi
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742, Republic of Korea
| | - Chae-Hyeon Lee
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742, Republic of Korea
| | - Kang-Yo Lee
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742, Republic of Korea
| | - Seung-Hwan Jung
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742, Republic of Korea
| | - Byung-Hoon Lee
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742, Republic of Korea
| |
Collapse
|
16
|
Bahia CA, Guimarães RM, Asmus CIRF. Alterações nos marcadores hepáticos decorrentes da exposição ambiental a organoclorados no Brasil. ACTA ACUST UNITED AC 2014. [DOI: 10.1590/1414-462x201400020005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Objetivos:Estimar a magnitude da associação entre a exposição a resíduos de pesticidas organoclorados (OC) e alterações de marcadores hepáticos.Método: Estudo seccional conduzido em população exposta a OC residente em Cidade dos Meninos,Duque de Caxias (RJ), Brasil (n=354). Foram calculadas as taxas de alterações dos marcadores hepáticos (Alanina aminotransferase (ALT), Aspartato aminotransferase (AST), fosfatase alcalina, gama glutamil transpeptidase (GGT) e albumina) e, em seguida, por meio de regressão logística binária não condicional, foi estimada a associação entre a presença ou não de alterações e os grupos de exposição, criados com base na exposição a alimentos, solo e água contaminados no local. Razões de chance (Odds ratio- OR) brutas e ajustadas para os grupos de exposição e para os fatores de confusão e seus respectivos intervalos de confiança (IC95%) foram obtidos.Resultados:Após ajuste pela regressão logística, os resultados do presente estudo apontam para nenhuma associação entre alterações em enzimas hepáticas e a exposição a OC.Conclusão:O achado sugere que o metabolismo que envolve a distribuição e a biotransformação de OC no organismo não envolve toxicidade direta ao fígado.
Collapse
|
17
|
Activation of the aryl hydrocarbon receptor sensitizes mice to nonalcoholic steatohepatitis by deactivating mitochondrial sirtuin deacetylase Sirt3. Mol Cell Biol 2013; 33:2047-55. [PMID: 23508103 DOI: 10.1128/mcb.01658-12] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Nonalcoholic steatohepatitis (NASH) is a liver disorder that still demands improved treatment. Understanding the pathogenesis of NASH will help to develop novel approaches to prevent or treat this disease. In this study, we revealed a novel function of the aryl hydrocarbon receptor (AhR) in NASH. Transgenic or pharmacological activation of AhR heightened animal sensitivity to NASH induced by the methionine- and choline-deficient (MCD) diet, which was reasoned to be due to increased hepatic steatosis, production of reactive oxygen species (ROS), and lipid peroxidation. Mechanistically, the increased ROS production in AhR-activated mouse liver was likely a result of a lower superoxide dismutase 2 (SOD2) activity and compromised clearance of ROS. Activation of AhR induced tetrachlorodibenzo-p-dioxin (TCDD)-inducible poly(ADP-ribose) polymerase (TiPARP) gene expression, depleted NAD(+), deactivated the mitochondrial sirtuin deacetylase 3 (Sirt3), increased SOD2 acetylation, and thereby decreased SOD2 activity. We also showed that Sirt3 ablation sensitized mice to NASH, whereas adenoviral overexpression of Sirt3 alleviated the NASH phenotype in AhR-transgenic mice. We conclude that activation of AhR sensitizes mice to NASH by facilitating both the "first hit" of steatosis and the "second hit" of oxidative stress. Our results suggest that the use of AhR antagonists might be a viable approach to prevent and treat NASH. Manipulation of the expression or activity of Sirt3 may also represent a novel approach to manage NASH.
Collapse
|
18
|
Forgacs AL, Dere E, Angrish MM, Zacharewski TR. Comparative analysis of temporal and dose-dependent TCDD-elicited gene expression in human, mouse, and rat primary hepatocytes. Toxicol Sci 2013; 133:54-66. [PMID: 23418086 DOI: 10.1093/toxsci/kft028] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)-elicited time- and dose-dependent differential gene expression was compared in human, mouse, and rat primary hepatocytes. Comprehensive time course (10 nM TCDD or dimethyl sulfoxide vehicle control for 1, 2, 4, 8, 12, 24, and 48h) studies identified 495, 2305, and 711 differentially expressed orthologous genes in human, mouse, and rat hepatocytes, respectively. However, only 16 orthologs were differentially expressed across all three species, with the majority of orthologs exhibiting species-specific expression (399 human, 2097 mouse, and 533 rat), consistent with species-specific expression reported in other in vitro and in vivo comparative studies. TCDD also elicited the dose-dependent induction of 397 human, 100 mouse, and 443 rat genes at 12h and 615 human, 426 mouse, and 314 rat genes at 24h. Comparable EC50 values were obtained for AhR battery genes including Cyp1a1 (0.1 nM human, 0.05 nM mouse, 0.08 nM rat at 24h) and Tiparp (0.97 nM human, 0.63 nM mouse, 0.14 nM rat at 12h). Overrepresented functions and pathways included amino acid metabolism in humans, immune response in mice, and energy homeostasis in rats. Differentially expressed genes functionally associated with lipid transport, processing, and metabolism were overrepresented in all three species but exhibited species-specific expression consistent with the induction of hepatic steatosis in mice but not in rats following a single oral gavage of TCDD. Furthermore, human primary hepatocytes showed lipid accumulation following 48h of treatment with TCDD, suggesting that AhR-mediated steatosis in mice more closely resembles human hepatic fat accumulation compared with that in rats. Collectively, these results suggest that species-specific gene expression profiles mediate the species-specific effects of TCDD despite the conservation of the AhR and its signaling mechanism.
Collapse
Affiliation(s)
- Agnes L Forgacs
- Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA
| | | | | | | |
Collapse
|
19
|
Nash JT, Szabo DT, Carey GB. Polybrominated diphenyl ethers alter hepatic phosphoenolpyruvate carboxykinase enzyme kinetics in male Wistar rats: implications for lipid and glucose metabolism. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2013; 76:142-156. [PMID: 23294302 DOI: 10.1080/15287394.2012.738457] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Xenobiotics such as phenobarbital, 2,3,7,8-tetrachlorodibenzo-p-dioxin, and Aroclor 1254 significantly suppress the activity of a key gluconeogenic and glyceroneogenic enzyme, phosphoenolpyruvate carboxykinase (PEPCK), suggesting that xenobiotics disrupt hepatic glucose and fat metabolism. The effects of polybrominated diphenyl ethers (PBDE), a family of synthetic flame-retardant chemicals, on PEPCK activity is unknown. This study investigated the effect of DE-71, a commercial PBDE mixture, on PEPCK enzyme kinetics. Forty-eight 1-mo-old male Wistar rats were gavaged daily with either corn oil or corn oil containing 14 mg/kg DE-71 for 3, 14, or 28 d (n = 8/group). At each time point, fasting plasma glucose, insulin, and C-peptide were measured and hepatic PEPCK activity, lipid content, and three cytochrome P-450 enzymes (CYP1A, -2B, and -3A) were assayed. PBDE treatment for 28 d significantly decreased PEPCK Vmax ( μ mol/min/g liver weight) by 43% and increased liver lipid by 20%, compared to control. CYP1A, -2B, and -3A Vmax values were enhanced by 5-, 6-, and 39-fold, respectively, at both 14 and 28 d in treated rats compared to control. There was a significant inverse and temporal correlation between CYP3A and PEPCK Vmax for the treatment group. Fasting plasma glucose, insulin, and C-peptide levels were not markedly affected by treatment, but the glucose:insulin ratio was significantly higher in treated compared to control rats. Data suggest that in vivo PBDE treatment compromises liver glucose and lipid metabolism, and may influence whole-body insulin sensitivity.
Collapse
Affiliation(s)
- Jessica T Nash
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire 03824, USA
| | | | | |
Collapse
|
20
|
Angrish MM, Mets BD, Jones AD, Zacharewski TR. Dietary fat is a lipid source in 2,3,7,8-tetrachlorodibenzo-ρ-dioxin (TCDD)-elicited hepatic steatosis in C57BL/6 mice. Toxicol Sci 2012; 128:377-86. [PMID: 22539624 DOI: 10.1093/toxsci/kfs155] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
2,3,7,8-Tetrachlorodibenzo-ρ-dioxin (TCDD) increases fatty acid (FA) transport and FA levels resulting in hepatic steatosis in mice. Diet as a source of lipids was investigated using customized diets, stearoyl-CoA desaturase 1 (Scd1) null mice, and (14)C-oleate (18:1n9) uptake studies. C57BL/6 mice fed with 5, 10, or 15% fat or 50, 60 or 70% carbohydrate diets exhibited increased relative liver weight following gavage with 30 µg/kg TCDD for 168 h. Hepatic lipid extract analysis from mice fed with 5, 10, and 15% fat diets identified a dose-dependent increase in total FAs induced by TCDD. Mice fed with fat diet also exhibited a dose-dependent increase in the dietary essential linoleic (18:2n6) and α-linolenic (18:3n3) acids. No dose-dependent FA increase was detected on carbohydrate diets, suggesting dietary fat as a source of lipids in TCDD-induced steatosis as opposed to de novo lipogenesis. TCDD also induced oleate levels threefold in Scd1 null mice that are incapable of desaturating stearate (18:0). This is consistent with oleate representing > 90% of all monounsaturated FAs in rodent chow. Moreover, TCDD increased hepatic (14)C-oleate levels twofold in wild type and 2.4-fold in Scd1 null mice concurrent with the induction of intestinal and hepatic lipid transport genes (Slc27a, Fabp, Ldlr, Cd36, and Apob). In addition, computational scanning identified putative dioxin response elements and in vivo ChIP-chip analysis revealed regions of aryl hydrocarbon receptor (AhR) enrichment in lipid transport genes differentially regulated by TCDD. Collectively, these results suggest the AhR mediates increased uptake of dietary fats that contribute to TCDD-elicited hepatic steatosis.
Collapse
|
21
|
He J, Lee JH, Febbraio M, Xie W. The emerging roles of fatty acid translocase/CD36 and the aryl hydrocarbon receptor in fatty liver disease. Exp Biol Med (Maywood) 2011; 236:1116-21. [DOI: 10.1258/ebm.2011.011128] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The fatty acid translocase (FAT)/CD36 belongs to the class B scavenger receptor family. In addition to the known functions of CD36 in the uptake of oxidized low-density lipoprotein by macrophages and uptake of fatty acids by adipose tissues, skeletal muscle and heart, emerging evidence has pointed to an equally important function of CD36 in the uptake of fatty acids in the liver and the pathogenesis of fatty liver disease. Recent reports have also suggested CD36 as a shared transcriptional target of several ligand-sensing and lipogenic transcriptional factors, such as the aryl hydrocarbon receptor, and several nuclear hormone receptors, such as pregnane X receptor, liver X receptor and peroxisome proliferator activated receptor γ. Non-alcoholic fatty liver disease is common and medically significant, because it is closely related to metabolic syndrome and has a potential to progress into the more harmful non-alcoholic steatohepatitis. It is hoped that CD36 and their transcriptional regulators can represent novel therapeutic targets for the prevention and management of fatty liver disease.
Collapse
Affiliation(s)
- Jinhan He
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA 15261
| | - Jung Hoon Lee
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA 15261
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA 02115
| | - Maria Febbraio
- Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Wen Xie
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA 15261
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| |
Collapse
|
22
|
Lu H, Cui W, Klaassen CD. Nrf2 protects against 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced oxidative injury and steatohepatitis. Toxicol Appl Pharmacol 2011; 256:122-35. [PMID: 21846477 DOI: 10.1016/j.taap.2011.07.019] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 07/28/2011] [Accepted: 07/29/2011] [Indexed: 01/07/2023]
Abstract
Previous studies demonstrate that Nrf2, a master regulator of antioxidative responses, is essential in mediating induction of many antioxidative enzymes by acute activation of the AhR. However, the role of Nrf2 in protecting against oxidative stress and DNA damage induced by sustained activation of the AhR remains unknown and was investigated herein. Tissue and blood samples were collected from wild-type (WT) and Nrf2-null mice 21 days after administration of a low-toxic dose (10 μg/kg ip) of TCDD. Only Nrf2-null mice lost body weight after TCDD treatment; however, blood levels of ALT were not markedly changed in either genotype, indicating a lack of extensive necrosis. Compared to livers of TCDD-treated WT mice, livers of TCDD-treated Nrf2-null mice had: 1) degenerated hepatocytes, lobular inflammation, marked fat accumulation, and higher mRNA expression of inflammatory and fibrotic genes; 2) depletion of glutathione, elevation in lipid peroxidation and marker of DNA damage; 3) attenuated induction of phase-II enzymes Nqo1, Gsta1/2, and Ugt2b35 mRNAs, but higher induction of cytoprotective Ho-1, Prdx1, Trxr1, Gclc, and Epxh1 mRNAs; 4) higher mRNA expression of Fgf21 and triglyceride-synthesis genes, but down-regulation of bile-acid-synthesis genes and cholesterol-efflux transporters; and 5) trend of induction/activation of c-jun and NF-kB. Additionally, TCDD-treated Nrf2-null mice had impaired adipogenesis in white adipose tissue. In conclusion, Nrf2 protects livers of mice against oxidative stress, DNA damage, and steatohepatitis induced by TCDD-mediated sustained activation of the AhR. The aggravated hepatosteatosis in TCDD-treated Nrf2-null mice is due to increased lipogenesis in liver and impaired lipogenesis in white adipose tissue.
Collapse
Affiliation(s)
- Hong Lu
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, Kansas 66160, USA.
| | | | | |
Collapse
|
23
|
Ciftci O, Ozdemir I. Protective effects of quercetin and chrysin against 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced oxidative stress, body wasting and altered cytokine productions in rats. Immunopharmacol Immunotoxicol 2011; 33:504-8. [DOI: 10.3109/08923973.2010.543686] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
24
|
Lee JH, Wada T, Febbraio M, He J, Matsubara T, Lee MJ, Gonzalez FJ, Xie W. A novel role for the dioxin receptor in fatty acid metabolism and hepatic steatosis. Gastroenterology 2010; 139:653-63. [PMID: 20303349 PMCID: PMC2910786 DOI: 10.1053/j.gastro.2010.03.033] [Citation(s) in RCA: 192] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 01/31/2010] [Accepted: 03/11/2010] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS The aryl hydrocarbon receptor (AhR) also known as the dioxin receptor or xenobiotic receptor is a member of the basic helix-loop-helix/period AhR nuclear translocator single minded family. The goal of this study was to determine the endobiotic role of AhR in hepatic steatosis. METHODS Wild-type, constitutively activated AhR transgenic, AhR null and CD36/fatty acid translocase null mice were used to investigate the role of AhR in steatosis and the involvement of CD36 in the steatotic effect of AhR. The promoters of the mouse and human CD36 genes were cloned and their regulation by AhR was analyzed. RESULTS Activation of AhR induced spontaneous hepatic steatosis characterized by the accumulation of triglycerides. The steatotic effect of AhR likely is owing to the combined up-regulation of CD36 and fatty acid transport proteins, suppression of fatty acid oxidation, inhibition of hepatic export of triglycerides, increase in peripheral fat mobilization, and increased hepatic oxidative stress. Promoter analysis established CD36 as a novel transcriptional target of AhR. Activation of AhR in liver cells induced CD36 gene expression and enhanced fatty acid uptake. The steatotic effect of an AhR agonist was inhibited in CD36-/- mice. CONCLUSIONS Our study reveals a novel link between AhR-induced steatosis and the expression of CD36. Industrial or military exposures to dioxin and related compounds have been linked to increased prevalence of fatty liver in human beings. Results from this study may help to establish AhR and its target CD36 as novel therapeutic and preventive targets for fatty liver disease.
Collapse
Affiliation(s)
- Jung Hoon Lee
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA 15261
| | - Taira Wada
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA 15261
| | - Maria Febbraio
- Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195
| | - Jinhan He
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA 15261
| | - Tsutomu Matsubara
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Min Jae Lee
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA 15261
| | - Frank J. Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Wen Xie
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA 15261
- Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15261
| |
Collapse
|
25
|
Nishiumi S, Yoshida M, Azuma T, Yoshida KI, Ashida H. 2,3,7,8-tetrachlorodibenzo-p-dioxin impairs an insulin signaling pathway through the induction of tumor necrosis factor-alpha in adipocytes. Toxicol Sci 2010; 115:482-91. [PMID: 20181658 DOI: 10.1093/toxsci/kfq052] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes a wasting syndrome characterized by a loss of body weight accompanied by a decrease in adipose tissue weight, i.e., insulin resistance-like symptoms. Therefore, the effects of TCDD on an insulin signaling pathway in mature 3T3-L1 adipocytes were investigated to obtain insight into the underlying mechanisms. TCDD downregulated expression of insulin receptor beta-subunit (IRbeta), insulin receptor substrate 1 (IRS1), and glucose transporter 4 (GLUT4) and decreased insulin-stimulated glucose uptake activity. TCDD also upregulated expression of TNF-alpha, one of insulin resistance-inducing factors. Anti-TNF-alpha neutralization antibody and silencing of TNF-alpha receptor 1 (TNFR1) diminished the TCDD-induced downregulation of IRbeta, IRS1, and GLUT4. Moreover, the experiments using small interfering RNA for an aryl hydrocarbon receptor (AhR) revealed that the TCDD-evoked changes of IRbeta, IRS1, GLUT4, and TNF-alpha were dependent on AhR. TCDD also stimulated the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2 and c-Jun N-terminal kinase (JNK), and their inhibitors abrogated the TCDD-induced downregulation of IRbeta, IRS1, and GLUT4; upregulation of TNF-alpha; and activation of NF-kappaB. Taken together, TCDD stimulates expression and secretion of TNF-alpha in adipocytes through activation of AhR, ERK1/2, and JNK, and the secreted TNF-alpha causes the downregulation of IRbeta, IRS1, and GLUT4 through TNFR1, resulting in insulin resistance.
Collapse
Affiliation(s)
- Shin Nishiumi
- Division of Gastroenterology, Department of Internal Medicine, Graduate School of Medicine, Kobe University, Kobe, Hyogo 650-0017, Japan.
| | | | | | | | | |
Collapse
|
26
|
North CM, Crawford RB, Lu H, Kaminski NE. Simultaneous in vivo time course and dose response evaluation for TCDD-induced impairment of the LPS-stimulated primary IgM response. Toxicol Sci 2009; 112:123-32. [PMID: 19675145 PMCID: PMC2769062 DOI: 10.1093/toxsci/kfp187] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Accepted: 07/28/2009] [Indexed: 11/14/2022] Open
Abstract
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a potent suppressor of humoral immunity but the specific molecular mechanisms responsible for immunosuppression by TCDD are poorly understood. In vivo and in vitro studies of the primary humoral IgM response demonstrated that the B cell is a sensitive cell type to modulation by TCDD. We hypothesized that in vivo administration of TCDD disrupts expression of transcription factors controlling B cell to plasma cell differentiation. Female C57BL6 mice were treated with a single dose of TCDD (3, 10, or 30 microg/kg) and/or vehicle (sesame oil). On day 4 post-TCDD administration mice were sensitized with 25 microg lipopolysacchride (LPS) by intraperitioneal injection to stimulate an immune response. Splenocytes were isolated on subsequent days following LPS, up to 3 days post-LPS, and the expression of IgM, XBP-1, PAX5, BCL-6, and Blimp-1 was assessed. TCDD treatment dose-dependently suppressed LPS-induced IgM antibody-forming cell number, which was correlated with decreased frequency of CD19+ CD138+ cells. Gene expression analysis revealed that TCDD caused a dose-dependent suppression of Igmicro chain, Igkappa chain, IgJ chain, XBP-1, and Blimp-1. TCDD also dose-dependently suppressed LPS-stimulated increases in Blimp-1 protein expression in CD19+ B cells. The deregulation of Blimp-1 expression by TCDD provides a partial explanation for the concomitant suppression of the IgM response and confirms previous observations established in vitro.
Collapse
Affiliation(s)
- Colin M. North
- Center for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824
- Department of Pharmacology & Toxicology, Michigan State University, East Lansing, Michigan 48824
| | - Robert B. Crawford
- Center for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824
- Department of Pharmacology & Toxicology, Michigan State University, East Lansing, Michigan 48824
| | - Haitian Lu
- Center for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824
- Department of Pharmacology & Toxicology, Michigan State University, East Lansing, Michigan 48824
| | - Norbert E. Kaminski
- Center for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824
- Department of Pharmacology & Toxicology, Michigan State University, East Lansing, Michigan 48824
| |
Collapse
|
27
|
Brey CW, Nelder MP, Hailemariam T, Gaugler R, Hashmi S. Krüppel-like family of transcription factors: an emerging new frontier in fat biology. Int J Biol Sci 2009; 5:622-36. [PMID: 19841733 PMCID: PMC2757581 DOI: 10.7150/ijbs.5.622] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 09/28/2009] [Indexed: 12/26/2022] Open
Abstract
In mammals, adipose tissue stores energy in the form of fat. The ability to regulate fat storage is essential for the growth, development and reproduction of most animals, thus any abnormalities caused by excess fat accumulation can result in pathological conditions which are linked to several interrelated diseases, such as cardiovascular diseases, diabetes, and obesity. In recent years significant effort has been applied to understand basic mechanism of fat accumulation in mammalian system. Work in mouse has shown that the family of Krüppel-like factors (KLFs), a conserved and important class of transcription factors, regulates adipocyte differentiation in mammals. However, how fat storage is coordinated in response to positive and negative feedback signals is still poorly understood. To address mechanisms underlying fat storage we have studied two Caenorhabditis elegans KLFs and demonstrate that both worm klfs are key regulators of fat metabolism in C. elegans. These results provide the first in vivo evidence supporting essential regulatory roles for KLFs in fat metabolism in C. elegans and shed light on the human counterpart in disease-gene association. This finding allows us to pursue a more comprehensive approach to understand fat biology and provides an opportunity to learn about the cascade of events that regulate KLF activation, repression and interaction with other factors in exerting its biological function at an organismal level. In this review, we provide an overview of the most current information on the key regulatory components in fat biology, synthesize the diverse literature, pose new questions, and propose a new model organism for understanding fat biology using KLFs as the central theme.
Collapse
Affiliation(s)
- Christopher W Brey
- Center for Vector Biology, Rutgers University, New Brunswick, New Jersey 08901, USA
| | | | | | | | | |
Collapse
|
28
|
Ishida T, Takeda T, Koga T, Yahata M, Ike A, Kuramoto C, Taketoh J, Hashiguchi I, Akamine A, Ishii Y, Yamada H. Attenuation of 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity by resveratrol: a comparative study with different routes of administration. Biol Pharm Bull 2009; 32:876-81. [PMID: 19420757 DOI: 10.1248/bpb.32.876] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The activation of aryl hydrocarbon receptor with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is known to be antagonized by co-treatment with resveratrol. However, such a protective effect has been suggested from studies using subcutaneous injection of this polyphenol. To evaluate the practical usefulness of resveratrol, this study examined the protective effect of oral resveratrol on the sub-acute toxic effects of TCDD in C57BL/6J mice. A TCDD-induced wasting syndrome was not alleviated by treating mice for 28 d with oral resveratrol. However, subcutaneous injection of resveratrol for 5 d significantly improved the symptoms. Neither oral nor subcutaneous administration of resveratrol alleviated TCDD-induced hepatomegaly and thymic atrophy. Steatosis produced by TCDD was markedly counteracted by co-treatment with oral resveratrol, whereas resveratrol injected subcutaneously had no effect. The reason for the lack of protective effect via the latter dosing route was assumed to be due to the minor accumulation of hepatic lipids 5 d after TCDD treatment. To clarify the mechanisms, the activity of ethoxyresorufin O-deethylase and the content of thiobarbituric acid-reactive substances in the liver were measured. Both indices increased by TCDD treatment were significantly suppressed by subcutaneous injection of resveratrol. In contrast, oral resveratrol failed to rescue them. In agreement with the greater protective effects of subcutaneously-injected resveratrol, pharmacokinetic studies indicated that the area under the curve extrapolated to infinity (AUC(infinity)) was 8.2-times greater following subcutaneous injection compared with oral administration. These data suggest that 1) oral resveratrol is attractive candidate as an agent capable of combating dioxin toxicity and 2) increasing the bioavailability of this polyphenol enhances its protective effect.
Collapse
Affiliation(s)
- Takumi Ishida
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Ishida T, Ishizaki M, Tsutsumi S, Ishii Y, Yamada H. Piperine, a Pepper Ingredient, Improves the Hepatic Increase in Free Fatty Acids Caused by 2,3,7,8-Tetrachlorodibenzo-p-dioxin. ACTA ACUST UNITED AC 2008. [DOI: 10.1248/jhs.54.551] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Takumi Ishida
- Graduate School of Pharmaceutical Sciences, Kyushu University
| | - Mizuho Ishizaki
- Graduate School of Pharmaceutical Sciences, Kyushu University
| | - Siho Tsutsumi
- Graduate School of Pharmaceutical Sciences, Kyushu University
| | - Yuji Ishii
- Graduate School of Pharmaceutical Sciences, Kyushu University
| | - Hideyuki Yamada
- Graduate School of Pharmaceutical Sciences, Kyushu University
| |
Collapse
|