1
|
Asgharzadeh F, Memarzia A, Alikhani V, Beigoli S, Boskabady MH. Peroxisome proliferator-activated receptors: Key regulators of tumor progression and growth. Transl Oncol 2024; 47:102039. [PMID: 38917593 PMCID: PMC11254173 DOI: 10.1016/j.tranon.2024.102039] [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: 10/31/2023] [Revised: 04/30/2024] [Accepted: 06/20/2024] [Indexed: 06/27/2024] Open
Abstract
One of the main causes of death on the globe is cancer. Peroxisome-proliferator-activated receptors (PPARs) are nuclear hormone receptors, including PPARα, PPARδ and PPARγ, which are important in regulating cancer cell proliferation, survival, apoptosis, and tumor growth. Activation of PPARs by endogenous or synthetic compounds regulates tumor progression in various tissues. Although each PPAR isotype suppresses or promotes tumor development depending on the specific tissues or ligands, the mechanism is still unclear. PPARs are receiving interest as possible therapeutic targets for a number of disorders. Numerous clinical studies are being conducted on PPARs as possible therapeutic targets for cancer. Therefore, this review will focus on the existing and future uses of PPARs agonists and antagonists in treating malignancies. PubMed, Science Direct, and Scopus databases were searched regarding the effect of PPARs on various types of cancers until the end of May 2023. The results of the review articles showed the therapeutic influence of PPARs on a wide range of cancer on in vitro, in vivo and clinical studies. However, further experimental and clinical studies are needed to be conducted on the influence of PPARs on various cancers.
Collapse
Affiliation(s)
- Fereshteh Asgharzadeh
- Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Physiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Arghavan Memarzia
- Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Physiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Vida Alikhani
- Department of Physiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Physiology, Faculty of Medicine, Gonabad University of Medical Sciences, Gonabad, Iran
| | - Sima Beigoli
- Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammad Hossein Boskabady
- Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Physiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
| |
Collapse
|
2
|
Pan Y, Li Y, Fan H, Cui H, Chen Z, Wang Y, Jiang M, Wang G. Roles of the peroxisome proliferator-activated receptors (PPARs) in the pathogenesis of hepatocellular carcinoma (HCC). Biomed Pharmacother 2024; 177:117089. [PMID: 38972148 DOI: 10.1016/j.biopha.2024.117089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 06/27/2024] [Accepted: 07/01/2024] [Indexed: 07/09/2024] Open
Abstract
Hepatocellular carcinoma (HCC) holds a prominent position among global cancer types. Classically, HCC manifests in individuals with a genetic predisposition when they encounter risk elements, particularly in the context of liver cirrhosis. Peroxisome proliferator-activated receptors (PPARs), which are transcription factors activated by fatty acids, belong to the nuclear hormone receptor superfamily and play a pivotal role in the regulation of energy homeostasis. At present, three distinct subtypes of PPARs have been recognized: PPARα, PPARγ, and PPARβ/δ. They regulate the transcription of genes responsible for cellular development, energy metabolism, inflammation, and differentiation. In recent years, with the rising incidence of HCC, there has been an increasing focus on the mechanisms and roles of PPARs in HCC. PPARα primarily mediates the occurrence and development of HCC by regulating glucose and lipid metabolism, inflammatory responses, and oxidative stress. PPARβ/δ is closely related to the self-renewal ability of liver cancer stem cells (LCSCs) and the formation of the tumor microenvironment. PPARγ not only influences tumor growth by regulating the glucose and lipid metabolism of HCC, but its agonists also have significant clinical significance for the treatment of HCC. Therefore, this review offers an exhaustive examination of the role of the three PPAR subtypes in HCC progression, focusing on their mediation of critical cellular processes such as glucose and lipid metabolism, inflammation, oxidative stress, and other pivotal signaling pathways. At the end of the review, we discuss the merits and drawbacks of existing PPAR-targeted therapeutic strategies and suggest a few alternative combinatorial therapeutic approaches that diverge from conventional methods.
Collapse
Affiliation(s)
- Yujie Pan
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin 130021, China
| | - Yunkuo Li
- Department of Urology, The First Hospital of Jilin University, Changchun, Jilin 130021, China
| | - Hongyu Fan
- Department of Orthopedic Surgery, Second Affiliated Hospital of Harbin Medical University, No. 246 Baojian Road, Harbin 150086, China
| | - Huijuan Cui
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin 130021, China
| | - Zhiyue Chen
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin 130021, China
| | - Yunzhu Wang
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin 130021, China
| | - Mengyu Jiang
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin 130021, China
| | - Guixia Wang
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin 130021, China.
| |
Collapse
|
3
|
Carswell G, Chamberlin J, Bennett BD, Bushel PR, Chorley BN. Persistent gene expression and DNA methylation alterations linked to carcinogenic effects of dichloroacetic acid. Front Oncol 2024; 14:1389634. [PMID: 38764585 PMCID: PMC11099211 DOI: 10.3389/fonc.2024.1389634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 04/18/2024] [Indexed: 05/21/2024] Open
Abstract
Background Mechanistic understanding of transient exposures that lead to adverse health outcomes will enhance our ability to recognize biological signatures of disease. Here, we measured the transcriptomic and epigenomic alterations due to exposure to the metabolic reprogramming agent, dichloroacetic acid (DCA). Previously, we showed that exposure to DCA increased liver tumor incidence in B6C3F1 mice after continuous or early life exposures significantly over background level. Methods Using archived formalin-fixed liver samples, we utilized modern methodologies to measure gene expression and DNA methylation levels to link to previously generated phenotypic measures. Gene expression was measured by targeted RNA sequencing (TempO-seq 1500+ toxicity panel: 2754 total genes) in liver samples collected from 10-, 32-, 57-, and 78-week old mice exposed to deionized water (controls), 3.5 g/L DCA continuously in drinking water ("Direct" group), or DCA for 10-, 32-, or 57-weeks followed by deionized water until sample collection ("Stop" groups). Genome-scaled alterations in DNA methylation were measured by Reduced Representation Bisulfite Sequencing (RRBS) in 78-week liver samples for control, Direct, 10-week Stop DCA exposed mice. Results Transcriptomic changes were most robust with concurrent or adjacent timepoints after exposure was withdrawn. We observed a similar pattern with DNA methylation alterations where we noted attenuated differentially methylated regions (DMRs) in the 10-week Stop DCA exposure groups compared to the Direct group at 78-weeks. Gene pathway analysis indicated cellular effects linked to increased oxidative metabolism, a primary mechanism of action for DCA, closer to exposure windows especially early in life. Conversely, many gene signatures and pathways reversed patterns later in life and reflected more pro-tumorigenic patterns for both current and prior DCA exposures. DNA methylation patterns correlated to early gene pathway perturbations, such as cellular signaling, regulation and metabolism, suggesting persistence in the epigenome and possible regulatory effects. Conclusion Liver metabolic reprogramming effects of DCA interacted with normal age mechanisms, increasing tumor burden with both continuous and prior DCA exposure in the male B6C3F1 rodent model.
Collapse
Affiliation(s)
- Gleta Carswell
- Center for Computational Toxicology and Exposure, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States
| | - John Chamberlin
- Center for Computational Toxicology and Exposure, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States
- Oak Ridge Institute for Science and Education, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States
| | - Brian D. Bennett
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, United States
| | - Pierre R. Bushel
- Massive Genome Informatics Group, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, United States
- Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, NC, United States
| | - Brian N. Chorley
- Center for Computational Toxicology and Exposure, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States
| |
Collapse
|
4
|
Klaunig JE, Bevan C, Gollapudi B. Assessment of the mode of action of perchloroethylene-induced mouse liver tumors. Toxicol Ind Health 2024; 40:272-291. [PMID: 38523547 DOI: 10.1177/07482337241240188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
Perchloroethylene (PCE) is used as a solvent and chemical intermediate. Following chronic inhalation exposure, PCE selectively induced liver tumors in mice. Understanding the mode of action (MOA) for PCE carcinogenesis in mice is important in defining its possible human cancer risk. The proposed MOA is based on the extensive examination of the peer-reviewed studies that have assessed the mouse liver effects of PCE and its major oxidative metabolite trichloroacetic acid (TCA). Similar to PCE, TCA has also been demonstrated to liver tumors selectively in mice following chronic exposure. The Key Events (KE) of the proposed PCE MOA involve oxidative metabolism of PCE to TCA [KE 1]; activation of the peroxisome proliferator-activated receptor alpha (PPARα) [KE 2]; alteration in hepatic gene expression including cell growth pathways [KE 3]; increase in cell proliferation [KE 4]; selective clonal expansion of hepatic preneoplastic foci [KE 5]; and formation of hepatic neoplasms [KE 6]. The scientific evidence supporting the PPARα MOA for PCE is strong and satisfies the requirements for a MOA analysis. The PPARα liver tumor MOA in rodents has been demonstrated not to occur in humans; thus, human liver cancer risk to PCE is not likely.
Collapse
Affiliation(s)
- James E Klaunig
- School of Public Health, Indiana University, Bloomington, IN, USA
| | | | | |
Collapse
|
5
|
Wu K, Lin F. Lipid Metabolism as a Potential Target of Liver Cancer. J Hepatocell Carcinoma 2024; 11:327-346. [PMID: 38375401 PMCID: PMC10875169 DOI: 10.2147/jhc.s450423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 01/25/2024] [Indexed: 02/21/2024] Open
Abstract
Hepatocellular carcinoma (HCC) stands as a severe malignant tumor with a profound impact on overall health, often accompanied by an unfavorable prognosis. Despite some advancements in the diagnosis and treatment of this disease, improving the prognosis of HCC remains a formidable challenge. It is noteworthy that lipid metabolism plays a pivotal role in the onset, development, and progression of tumor cells. Existing research indicates the potential application of targeting lipid metabolism in the treatment of HCC. This review aims to thoroughly explore the alterations in lipid metabolism in HCC, offering a detailed account of the potential advantages associated with innovative therapeutic strategies targeting lipid metabolism. Targeting lipid metabolism holds promise for potentially enhancing the prognosis of HCC.
Collapse
Affiliation(s)
- Kangze Wu
- Department of Hepatobiliary Surgery, Shaoxing People’s Hospital, Shaoxing, People’s Republic of China
| | - Feizhuan Lin
- Department of Hepatobiliary Surgery, Shaoxing People’s Hospital, Shaoxing, People’s Republic of China
| |
Collapse
|
6
|
Qiu YY, Zhang J, Zeng FY, Zhu YZ. Roles of the peroxisome proliferator-activated receptors (PPARs) in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Pharmacol Res 2023; 192:106786. [PMID: 37146924 DOI: 10.1016/j.phrs.2023.106786] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 04/28/2023] [Accepted: 05/02/2023] [Indexed: 05/07/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of disease phenotypes which start with simple steatosis and lipid accumulation in the hepatocytes - a typical histological lesions characteristic. It may progress to non-alcoholic steatohepatitis (NASH) that is characterized by hepatic inflammation and/or fibrosis and subsequent onset of NAFLD-related cirrhosis and hepatocellular carcinoma (HCC). Due to the central role of the liver in metabolism, NAFLD is regarded as a result of and contribution to the metabolic abnormalities seen in the metabolic syndrome. Peroxisome proliferator-activated receptors (PPARs) has three subtypes, which govern the expression of genes responsible for energy metabolism, cellular development, inflammation, and differentiation. The agonists of PPARα, such as fenofibrate and clofibrate, have been used as lipid-lowering drugs in clinical practice. Thiazolidinediones (TZDs) - ligands of PPARγ, such as rosiglitazone and pioglitazone, are also used in the treatment of type 2 diabetes (T2D) with insulin resistance (IR). Increasing evidence suggests that PPARβ/δ agonists have potential therapeutic effects in improving insulin sensitivity and lipid metabolism disorders. In addition, PPARs ligands have been considered as potential therapeutic drugs for hypertension, atherosclerosis (AS) or diabetic nephropathy. Their crucial biological roles dictate the significance of PPARs-targeting in medical research and drug discovery. Here, it reviews the biological activities, ligand selectivity and biological functions of the PPARs family, and discusses the relationship between PPARs and the pathogenesis of NAFLD and metabolic syndrome. This will open new possibilities for PPARs application in medicine, and provide a new idea for the treatment of fatty liver and related diseases.
Collapse
Affiliation(s)
- Yuan-Ye Qiu
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; Faculty of Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China.
| | - Jing Zhang
- University International College, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China.
| | - Fan-Yi Zeng
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; School of Pharmacy, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; Shanghai Institute of Medical Genetics, Shanghai Children's Hospital, Shanghai Jiao Tong University, 24/1400 West Beijing Road, Shanghai, 200040, China.
| | - Yi Zhun Zhu
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; Faculty of Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; School of Pharmacy, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China.
| |
Collapse
|
7
|
Cao W, Zhang Y, Li A, Yu P, Song L, Liang J, Cao N, Gao J, Xu R, Ma Y, Tang X. Curcumin reverses hepatic epithelial mesenchymal transition induced by trichloroethylene by inhibiting IL-6R/STAT3. Toxicol Mech Methods 2021; 31:589-599. [PMID: 34233590 DOI: 10.1080/15376516.2021.1941463] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVE Epithelial mesenchymal transition (EMT) and inflammation have been identified as carcinogenic agents. This study aims to investigate whether inhibition of trichloroethylene (TCE) associated hepatocellular carcinoma (HCC) by curcumin is associated with inflammation and EMT. METHODS In the current study, TCE sub-chronic cell model was induced in vitro, and the effects of TCE on cell proliferation, migration, invasion, and expression of functional proteins were verified by Western blot, MTT, clone formation, wound healing, Transwell. The detoxification effect of curcumin on TCE was explored by a mouse tumor-bearing experiment. RESULTS TCE induces hepatocyte migration, colony formation, and EMT in vitro. In vivo studies have shown that curcumin significantly reduces the mortality of mice and control the occurrence and size of liver tumors by inhibiting the IL-6/STAT3 signaling pathway. In vitro, curcumin inhibits the proliferation of HepG2 cells as determined by MTT assay. In addition, curcumin significantly inhibited the protein expression of IL-6R, STAT3, snail, survivin, and cyclin D1 in THLE-2 and HepG2 cells induced by IL-6. CONCLUSION Curcumin has anti-inflammatory and anti-proliferative effects, and inhibits the development of HCC induced by TCE by reversing IL-6/STAT3 mediated EMT.
Collapse
Affiliation(s)
- Weiya Cao
- Medical School, Anhui University of Science and Technology, Huainan, China.,Institute of Environment-friendly Materials and Occupational Health, Anhui University of Science and Technology, Wuhu, China
| | - Yinci Zhang
- Medical School, Anhui University of Science and Technology, Huainan, China.,Institute of Environment-friendly Materials and Occupational Health, Anhui University of Science and Technology, Wuhu, China
| | - Amin Li
- Medical School, Anhui University of Science and Technology, Huainan, China.,Institute of Environment-friendly Materials and Occupational Health, Anhui University of Science and Technology, Wuhu, China
| | - Pan Yu
- Medical School, Anhui University of Science and Technology, Huainan, China.,Institute of Environment-friendly Materials and Occupational Health, Anhui University of Science and Technology, Wuhu, China
| | - Li Song
- Medical School, Anhui University of Science and Technology, Huainan, China.,Institute of Environment-friendly Materials and Occupational Health, Anhui University of Science and Technology, Wuhu, China
| | - Jiaojiao Liang
- Medical School, Anhui University of Science and Technology, Huainan, China.,Institute of Environment-friendly Materials and Occupational Health, Anhui University of Science and Technology, Wuhu, China
| | - Niandie Cao
- Medical School, Anhui University of Science and Technology, Huainan, China.,Institute of Environment-friendly Materials and Occupational Health, Anhui University of Science and Technology, Wuhu, China
| | - Jiafeng Gao
- Medical School, Anhui University of Science and Technology, Huainan, China.,Institute of Environment-friendly Materials and Occupational Health, Anhui University of Science and Technology, Wuhu, China
| | - Ruyue Xu
- Medical School, Anhui University of Science and Technology, Huainan, China.,Institute of Environment-friendly Materials and Occupational Health, Anhui University of Science and Technology, Wuhu, China
| | - Yongfang Ma
- Medical School, Anhui University of Science and Technology, Huainan, China.,Institute of Environment-friendly Materials and Occupational Health, Anhui University of Science and Technology, Wuhu, China
| | - Xiaolong Tang
- Medical School, Anhui University of Science and Technology, Huainan, China.,Institute of Environment-friendly Materials and Occupational Health, Anhui University of Science and Technology, Wuhu, China
| |
Collapse
|
8
|
Dalaijamts C, Cichocki JA, Luo YS, Rusyn I, Chiu WA. PBPK modeling of impact of nonalcoholic fatty liver disease on toxicokinetics of perchloroethylene in mice. Toxicol Appl Pharmacol 2020; 400:115069. [PMID: 32445755 DOI: 10.1016/j.taap.2020.115069] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/13/2020] [Accepted: 05/19/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Nonalcoholic fatty liver disease (NAFLD), a major cause of chronic liver disease in the Western countries with increasing prevalence worldwide, may substantially affect chemical toxicokinetics and thereby modulate chemical toxicity. OBJECTIVES This study aims to use physiologically-based pharmacokinetic (PBPK) modeling to characterize the impact of NAFLD on toxicokinetics of perchloroethylene (perc). METHODS Quantitative measures of physiological and biochemical changes associated with the presence of NAFLD induced by high-fat or methionine/choline-deficient diets in C57B1/6 J mice are incorporated into a previously developed PBPK model for perc and its oxidative and conjugative metabolites. Impacts on liver fat and volume, as well as blood:air and liver:air partition coefficients, are incorporated into the model. Hierarchical Bayesian population analysis using Markov chain Monte Carlo simulation is conducted to characterize uncertainty, as well as disease-induced variability in toxicokinetics. RESULTS NAFLD has a major effect on toxicokinetics of perc, with greater oxidative and lower conjugative metabolism as compared to healthy mice. The NAFLD-updated PBPK model accurately predicts in vivo metabolism of perc through oxidative and conjugative pathways in all tissues across disease states and strains, but underestimated parent compound concentrations in blood and liver of NAFLD mice. CONCLUSIONS We demonstrate the application of PBPK modeling to predict the effects of pre-existing disease conditions as a variability factor in perc metabolism. These results suggest that non-genetic factors such as diet and pre-existing disease can be as influential as genetic factors in altering toxicokinetics of perc, and thus are likely contribute substantially to population variation in its adverse effects.
Collapse
Affiliation(s)
- Chimeddulam Dalaijamts
- Interdisciplinary Faculty of Toxicology, Texas A&M University, College Station, TX, USA; Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, USA
| | - Joseph A Cichocki
- Interdisciplinary Faculty of Toxicology, Texas A&M University, College Station, TX, USA; Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, USA
| | - Yu-Syuan Luo
- Interdisciplinary Faculty of Toxicology, Texas A&M University, College Station, TX, USA; Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, USA
| | - Ivan Rusyn
- Interdisciplinary Faculty of Toxicology, Texas A&M University, College Station, TX, USA; Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, USA
| | - Weihsueh A Chiu
- Interdisciplinary Faculty of Toxicology, Texas A&M University, College Station, TX, USA; Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, USA.
| |
Collapse
|
9
|
Choudhary NS, Kumar N, Duseja A. Peroxisome Proliferator-Activated Receptors and Their Agonists in Nonalcoholic Fatty Liver Disease. J Clin Exp Hepatol 2019; 9:731-739. [PMID: 31889755 PMCID: PMC6926194 DOI: 10.1016/j.jceh.2019.06.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 06/23/2019] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases worldwide. In addition to the liver-related morbidity and mortality, NAFLD is now also associated with various extrahepatic diseases. Pathogenesis of NAFLD is multifactorial with limited pharmacotherapy options for the treatment of patients with NAFLD. Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that are involved in the transcriptional regulation of lipid metabolism, glucose homeostasis, energy balance, inflammation, and atherosclerosis. PPAR agonists are attractive options for treatment of NAFLD as they can act at multiple targets involved in the pathogenesis of NAFLD. We reviewed the available literature on the pathophysiological role of PPARs and use of PPAR agonists in the treatment of NAFLD. Original studies and review articles available on PubMed regarding the role of PPARs in the pathogenesis and utility of PPAR agonists in the treatment of NAFLD were included in this review article. ClinicalTrials.gov and Clinical Trials Registry-India sites were searched for ongoing studies on saroglitazar. The available literature suggests that PPARs play an important role in the pathogenesis of NAFLD. Use of PPAR gamma agonists is associated with histological improvement in NAFLD. Dual PPAR agonists with no or minimal PPAR gamma activity are being explored in the treatment of NAFLD. Because of the pathophysiological role of PPARs in NAFLD, PPAR agonists are attractive options for the treatment of patients with NAFLD. Dual PPAR agonists without significant gamma activity appear promising for the treatment of NAFLD.
Collapse
Affiliation(s)
- Narendra S. Choudhary
- Institute of Liver Transplantation and Regenerative Medicine, Medanta the Medicity, Gurugram, India
| | | | - Ajay Duseja
- Department of Hepatology, Postgraduate Institute of Medical Education and Research, Chandigarh, India,Address for correspondence: Dr. Ajay Duseja MD, DM, FAMS, FAASLD, FACG, FSGEI Professor, Department of Hepatology, Sector 12, Postgraduate Institute of Medical Education and Research, Chandigarh, 160012, India.
| |
Collapse
|
10
|
Venkatratnam A, Furuya S, Kosyk O, Gold A, Bodnar W, Konganti K, Threadgill DW, Gillespie KM, Aylor DL, Wright FA, Chiu WA, Rusyn I. Editor's Highlight: Collaborative Cross Mouse Population Enables Refinements to Characterization of the Variability in Toxicokinetics of Trichloroethylene and Provides Genetic Evidence for the Role of PPAR Pathway in Its Oxidative Metabolism. Toxicol Sci 2018; 158:48-62. [PMID: 28369613 DOI: 10.1093/toxsci/kfx065] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Background Trichloroethylene (TCE) is a known carcinogen in humans and rodents. Previous studies of inter-strain variability in TCE metabolism were conducted in multi-strain panels of classical inbred mice with limited genetic diversity to identify gene-environment interactions associated with chemical exposure. Objectives To evaluate inter-strain variability in TCE metabolism and identify genetic determinants that are associated with TCE metabolism and effects using Collaborative Cross (CC), a large panel of genetically diverse strains of mice. Methods We administered a single oral dose of 0, 24, 80, 240, or 800 mg/kg of TCE to mice from 50 CC strains, and collected organs 24 h post-dosing. Levels of trichloroacetic acid (TCA), a major oxidative metabolite of TCE were measured in multiple tissues. Protein expression and activity levels of TCE-metabolizing enzymes were evaluated in the liver. Liver transcript levels of known genes perturbed by TCE exposure were also quantified. Genetic association mapping was performed on the acquired phenotypes. Results TCA levels varied in a dose- and strain-dependent manner in liver, kidney, and serum. The variability in TCA levels among strains did not correlate with expression or activity of a number of enzymes known to be involved in TCE oxidation. Peroxisome proliferator-activated receptor alpha (PPARα)-responsive genes were found to be associated with strain-specific differences in TCE metabolism. Conclusions This study shows that CC mouse population is a valuable tool to quantitatively evaluate inter-individual variability in chemical metabolism and to identify genes and pathways that may underpin population differences.
Collapse
Affiliation(s)
- Abhishek Venkatratnam
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843.,Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Shinji Furuya
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843
| | - Oksana Kosyk
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Avram Gold
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Kranti Konganti
- Department of Molecular and Cellular Medicine, Texas A&M University, College Station, Texas 77843
| | - David W Threadgill
- Department of Molecular and Cellular Medicine, Texas A&M University, College Station, Texas 77843
| | - Kevin M Gillespie
- Bioinformatics Research Center and Departments of Statistics and Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695
| | - David L Aylor
- Bioinformatics Research Center and Departments of Statistics and Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695
| | - Fred A Wright
- Bioinformatics Research Center and Departments of Statistics and Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695
| | - Weihsueh A Chiu
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843
| |
Collapse
|
11
|
Tate MJ, Walmsley RM. The influence of exogenous metabolism on the specificity of in vitro mammalian genotoxicity tests. Mutagenesis 2018; 32:491-499. [PMID: 28992092 DOI: 10.1093/mutage/gex017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A two-part study was designed to determine whether the inclusion of the rodent liver 'S9' exogenous metabolic activating system contributes to the generation of misleading positive results by the regulator-required in vitro mammalian genotoxicity tests. The mono-oxygenase enzymes in S9 produce direct-acting DNA-reactive electrophiles, and are included in in vitro genotoxicity tests to enhance the detection of substances which only become genotoxic following metabolism. However, as the S9 system lacks 'detoxifying' phase 2 factors it was hypothesised that increased chemical metabolism per se may lead to an increase in irrelevant S9 test outcomes in safety assessment. To test this, 89 compounds with positive or negative carcinogenicity data were identified, which produced negative Ames test data (+/- S9), and only produced positive in vitro mammalian test data in the presence of S9. This allowed a determination of whether or not misleading predictions of carcinogenicity by the in vitro mammalian tests were more or less prevalent in the presence of S9. A subset of these compounds was then tested with and without S9 in the GADD45a-GFP genotoxicity test, in order to determine whether misleading in vitro mammalian positive results were generally more prevalent with S9, or reflected particular tests' liabilities. This study suggests that the use of S9 metabolic activation in in vitro genotoxicity tests does not increase the prevalence of misleading positive results in in vitro mammalian genotoxicity assays, at least amongst Ames negative compounds.
Collapse
Affiliation(s)
| | - Richard M Walmsley
- Gentronix Ltd, Alderley Edge, Cheshire SK10 4TG, UK.,University of Manchester, Manchester M13 9PL, UK
| |
Collapse
|
12
|
Zeller A, Pfuhler S, Albertini S, Bringezu F, Czich A, Dietz Y, Fautz R, Hewitt NJ, Kirst A, Kasper P. A critical appraisal of the sensitivity of in vivo genotoxicity assays in detecting human carcinogens. Mutagenesis 2018; 33:179-193. [DOI: 10.1093/mutage/gey005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 03/20/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Andreas Zeller
- Pharmaceutical Sciences, pRED Innovation Center Basel, F. Hoffmann-La Roche Ltd, Grenzacherstrasse, Basel, Switzerland
| | - Stefan Pfuhler
- Procter & Gamble, Global Product Stewardship, Human Safety, Mason Business Centre, Mason, OH, USA
| | - Silvio Albertini
- Pharmaceutical Sciences, pRED Innovation Center Basel, F. Hoffmann-La Roche Ltd, Grenzacherstrasse, Basel, Switzerland
| | | | - Andreas Czich
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt, Germany
| | - Yasmin Dietz
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt, Germany
| | | | | | | | - Peter Kasper
- Federal Institute for Drugs and Medical Devices (BfArM), Kurt-Georg-Kiesinger-Allee, Bonn, Germany
| |
Collapse
|
13
|
Leveraging human genetic and adverse outcome pathway (AOP) data to inform susceptibility in human health risk assessment. Mamm Genome 2018; 29:190-204. [DOI: 10.1007/s00335-018-9738-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/31/2018] [Indexed: 12/19/2022]
|
14
|
Corton JC, Peters JM, Klaunig JE. The PPARα-dependent rodent liver tumor response is not relevant to humans: addressing misconceptions. Arch Toxicol 2017; 92:83-119. [PMID: 29197930 DOI: 10.1007/s00204-017-2094-7] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 10/12/2017] [Indexed: 12/17/2022]
Abstract
A number of industrial chemicals and therapeutic agents cause liver tumors in rats and mice by activating the nuclear receptor peroxisome proliferator-activated receptor α (PPARα). The molecular and cellular events by which PPARα activators induce rodent hepatocarcinogenesis have been extensively studied elucidating a number of consistent mechanistic changes linked to the increased incidence of liver neoplasms. The weight of evidence relevant to the hypothesized mode of action (MOA) for PPARα activator-induced rodent hepatocarcinogenesis is summarized here. Chemical-specific and mechanistic data support concordance of temporal and dose-response relationships for the key events associated with many PPARα activators. The key events (KE) identified in the MOA are PPARα activation (KE1), alteration in cell growth pathways (KE2), perturbation of hepatocyte growth and survival (KE3), and selective clonal expansion of preneoplastic foci cells (KE4), which leads to the apical event-increases in hepatocellular adenomas and carcinomas (KE5). In addition, a number of concurrent molecular and cellular events have been classified as modulating factors, because they potentially alter the ability of PPARα activators to increase rodent liver cancer while not being key events themselves. These modulating factors include increases in oxidative stress and activation of NF-kB. PPARα activators are unlikely to induce liver tumors in humans due to biological differences in the response of KEs downstream of PPARα activation. This conclusion is based on minimal or no effects observed on cell growth pathways and hepatocellular proliferation in human primary hepatocytes and absence of alteration in growth pathways, hepatocyte proliferation, and tumors in the livers of species (hamsters, guinea pigs and cynomolgus monkeys) that are more appropriate human surrogates than mice and rats at overlapping dose levels. Despite this overwhelming body of evidence and almost universal acceptance of the PPARα MOA and lack of human relevance, several reviews have selectively focused on specific studies that, as discussed, contradict the consensus opinion and suggest uncertainty. In the present review, we systematically address these most germane suggested weaknesses of the PPARα MOA.
Collapse
Affiliation(s)
- J Christopher Corton
- Integrated Systems Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, 109 T.W. Alexander Dr, MD-B105-03, Research Triangle Park, NC, 27711, USA.
| | - Jeffrey M Peters
- The Department of Veterinary and Biomedical Sciences and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, 16803, USA
| | - James E Klaunig
- Department of Environmental Health, Indiana University, Bloomington, IN, 47402, USA
| |
Collapse
|
15
|
Wehmas LC, DeAngelo AB, Hester SD, Chorley BN, Carswell G, Olson GR, George MH, Carter JH, Eldridge SR, Fisher A, Vallanat B, Wood CE. Metabolic Disruption Early in Life is Associated With Latent Carcinogenic Activity of Dichloroacetic Acid in Mice. Toxicol Sci 2017; 159:354-365. [PMID: 28962523 PMCID: PMC6223632 DOI: 10.1093/toxsci/kfx146] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Early-life environmental factors can influence later-life susceptibility to cancer. Recent evidence suggests that metabolic pathways may mediate this type of latency effect. Previously, we reported that short-term exposure to dichloroacetic acid (DCA) increased liver cancer in mice 84 weeks after exposure was stopped. Here, we evaluated time course dynamics for key events related to this effect. This study followed a stop-exposure design in which 28-day-old male B6C3F1 mice were given the following treatments in drinking water for up to 93 weeks: deionized water (dH2O, control); 3.5 g/l DCA continuously; or 3.5 g/l DCA for 4-52 weeks followed by dH2O. Effects were evaluated at eight interim time points. A short-term biomarker study was used to evaluate DCA effects at 6, 15, and 30 days. Liver tumor incidence was higher in all DCA treatment groups, including carcinomas in 82% of mice previously treated with DCA for only 4 weeks. Direct effects of DCA in the short-term study included decreased liver cell proliferation and marked mRNA changes related to mitochondrial dysfunction and altered cell metabolism. However, all observed short-term effects of DCA were ultimately reversible, and prior DCA treatment did not affect liver cell proliferation, apoptosis, necrosis, or DNA sequence variants with age. Key intermediate events resulting from transient DCA exposure do not fit classical cytotoxic, mitogenic, or genotoxic modes of action for carcinogenesis, suggesting a distinct mechanism associated with early-life metabolic disruption.
Collapse
Affiliation(s)
- Leah C. Wehmas
- National Health and Environmental Effects Research
Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC,
USA
| | - Anthony B. DeAngelo
- National Health and Environmental Effects Research
Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC,
USA
| | - Susan D. Hester
- National Health and Environmental Effects Research
Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC,
USA
| | - Brian N. Chorley
- National Health and Environmental Effects Research
Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC,
USA
| | - Gleta Carswell
- National Health and Environmental Effects Research
Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC,
USA
| | - Greg R. Olson
- Toxicologic Pathology Associates, Jefferson, AK,
USA
| | - Michael H. George
- National Health and Environmental Effects Research
Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC,
USA
| | | | | | - Anna Fisher
- National Health and Environmental Effects Research
Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC,
USA
| | - Beena Vallanat
- National Health and Environmental Effects Research
Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC,
USA
| | - Charles E. Wood
- National Health and Environmental Effects Research
Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC,
USA
| |
Collapse
|
16
|
Becker RA, Dellarco V, Seed J, Kronenberg JM, Meek B, Foreman J, Palermo C, Kirman C, Linkov I, Schoeny R, Dourson M, Pottenger LH, Manibusan MK. Quantitative weight of evidence to assess confidence in potential modes of action. Regul Toxicol Pharmacol 2017; 86:205-220. [DOI: 10.1016/j.yrtph.2017.02.017] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/17/2017] [Accepted: 02/18/2017] [Indexed: 12/31/2022]
|
17
|
Liss KHH, Finck BN. PPARs and nonalcoholic fatty liver disease. Biochimie 2017; 136:65-74. [PMID: 27916647 PMCID: PMC5380579 DOI: 10.1016/j.biochi.2016.11.009] [Citation(s) in RCA: 202] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 11/23/2016] [Accepted: 11/28/2016] [Indexed: 02/07/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) encompasses a range of liver pathology ranging from simple steatosis to varying degrees of inflammation, hepatocyte injury and fibrosis. Without intervention it can progress to end-stage liver disease and hepatocellular carcinoma. Given its close association with obesity, the prevalence of NAFLD has increased dramatically worldwide. Currently, there are no FDA-approved medications for the treatment of NAFLD and although lifestyle modifications with appropriate diet and exercise have been shown to be beneficial, this has been difficult to achieve and sustain for the majority of patients. As such, the search for effective therapeutic agents is an active area of research. Peroxisome proliferator-activated receptors (PPARs) belong to a class of nuclear receptors. Because of their key role in the transcriptional regulation of mediators of glucose and lipid metabolism, PPAR ligands have been investigated as possible therapeutic agents. Here we review the current evidence from preclinical and clinical studies investigating the therapeutic potential of PPAR ligands for the treatment of NAFLD.
Collapse
Affiliation(s)
- Kim H H Liss
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Brian N Finck
- Department of Medicine, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| |
Collapse
|
18
|
Cichocki JA, Furuya S, Konganti K, Luo YS, McDonald TJ, Iwata Y, Chiu WA, Threadgill DW, Pogribny IP, Rusyn I. Impact of Nonalcoholic Fatty Liver Disease on Toxicokinetics of Tetrachloroethylene in Mice. J Pharmacol Exp Ther 2017; 361:17-28. [PMID: 28148637 DOI: 10.1124/jpet.116.238790] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 01/30/2017] [Indexed: 12/19/2022] Open
Abstract
Lifestyle factors and chronic pathologic states are important contributors to interindividual variability in susceptibility to xenobiotic-induced toxicity. Nonalcoholic fatty liver disease (NAFLD) is an increasingly prevalent condition that can dramatically affect chemical metabolism. We examined the effect of NAFLD on toxicokinetics of tetrachloroethylene (PERC), a ubiquitous environmental contaminant that requires metabolic activation to induce adverse health effects. Mice (C57Bl/6J, male) were fed a low-fat diet (LFD), high-fat diet (HFD), or methionine/folate/choline-deficient diet (MCD) to model a healthy liver, steatosis, or nonalcoholic steatohepatitis (NASH), respectively. After 8 weeks, mice were orally administered a single dose of PERC (300 mg/kg) or vehicle (aqueous Alkamuls-EL620) and euthanized at various time points (1-36 hours). Levels of PERC and its metabolites were measured in blood/serum, liver, and fat. Effects of diets on liver gene expression and tissue:air partition coefficients were evaluated. We found that hepatic levels of PERC were 6- and 7.6-fold higher in HFD- and MCD-fed mice compared with LFD-fed mice; this was associated with an increased PERC liver:blood partition coefficient. Liver and serum Cmax for trichloroacetate (TCA) was lower in MCD-fed mice; however, hepatic clearance of TCA was profoundly reduced by HFD or MCD feeding, leading to TCA accumulation. Hepatic mRNA/protein expression and ex vivo activity assays revealed decreased xenobiotic metabolism in HFD- and MCD-, compared with LFD-fed, groups. In conclusion, experimental NAFLD was associated with modulation of xenobiotic disposition and metabolism and increased hepatic exposure to PERC and TCA. Underlying NAFLD may be an important susceptibility factor for PERC-associated hepatotoxicity.
Collapse
Affiliation(s)
- Joseph A Cichocki
- Department of Veterinary Integrative Biosciences (J.A.C; S.F; Y.S.L; Y.I; W.C; I.R), Texas A&M Institute for Genome Sciences and Society (K.K; D.W.T; I.R), Department of Environmental and Occupational Health (T.J.M), and Department of Molecular and Cellular Medicine (D.W.T), Texas A&M University, College Station, Texas; and National Center for Toxicological Research, US FDA, Jefferson, Arkansas (I.P)
| | - Shinji Furuya
- Department of Veterinary Integrative Biosciences (J.A.C; S.F; Y.S.L; Y.I; W.C; I.R), Texas A&M Institute for Genome Sciences and Society (K.K; D.W.T; I.R), Department of Environmental and Occupational Health (T.J.M), and Department of Molecular and Cellular Medicine (D.W.T), Texas A&M University, College Station, Texas; and National Center for Toxicological Research, US FDA, Jefferson, Arkansas (I.P)
| | - Kranti Konganti
- Department of Veterinary Integrative Biosciences (J.A.C; S.F; Y.S.L; Y.I; W.C; I.R), Texas A&M Institute for Genome Sciences and Society (K.K; D.W.T; I.R), Department of Environmental and Occupational Health (T.J.M), and Department of Molecular and Cellular Medicine (D.W.T), Texas A&M University, College Station, Texas; and National Center for Toxicological Research, US FDA, Jefferson, Arkansas (I.P)
| | - Yu-Syuan Luo
- Department of Veterinary Integrative Biosciences (J.A.C; S.F; Y.S.L; Y.I; W.C; I.R), Texas A&M Institute for Genome Sciences and Society (K.K; D.W.T; I.R), Department of Environmental and Occupational Health (T.J.M), and Department of Molecular and Cellular Medicine (D.W.T), Texas A&M University, College Station, Texas; and National Center for Toxicological Research, US FDA, Jefferson, Arkansas (I.P)
| | - Thomas J McDonald
- Department of Veterinary Integrative Biosciences (J.A.C; S.F; Y.S.L; Y.I; W.C; I.R), Texas A&M Institute for Genome Sciences and Society (K.K; D.W.T; I.R), Department of Environmental and Occupational Health (T.J.M), and Department of Molecular and Cellular Medicine (D.W.T), Texas A&M University, College Station, Texas; and National Center for Toxicological Research, US FDA, Jefferson, Arkansas (I.P)
| | - Yasuhiro Iwata
- Department of Veterinary Integrative Biosciences (J.A.C; S.F; Y.S.L; Y.I; W.C; I.R), Texas A&M Institute for Genome Sciences and Society (K.K; D.W.T; I.R), Department of Environmental and Occupational Health (T.J.M), and Department of Molecular and Cellular Medicine (D.W.T), Texas A&M University, College Station, Texas; and National Center for Toxicological Research, US FDA, Jefferson, Arkansas (I.P)
| | - Weihsueh A Chiu
- Department of Veterinary Integrative Biosciences (J.A.C; S.F; Y.S.L; Y.I; W.C; I.R), Texas A&M Institute for Genome Sciences and Society (K.K; D.W.T; I.R), Department of Environmental and Occupational Health (T.J.M), and Department of Molecular and Cellular Medicine (D.W.T), Texas A&M University, College Station, Texas; and National Center for Toxicological Research, US FDA, Jefferson, Arkansas (I.P)
| | - David W Threadgill
- Department of Veterinary Integrative Biosciences (J.A.C; S.F; Y.S.L; Y.I; W.C; I.R), Texas A&M Institute for Genome Sciences and Society (K.K; D.W.T; I.R), Department of Environmental and Occupational Health (T.J.M), and Department of Molecular and Cellular Medicine (D.W.T), Texas A&M University, College Station, Texas; and National Center for Toxicological Research, US FDA, Jefferson, Arkansas (I.P)
| | - Igor P Pogribny
- Department of Veterinary Integrative Biosciences (J.A.C; S.F; Y.S.L; Y.I; W.C; I.R), Texas A&M Institute for Genome Sciences and Society (K.K; D.W.T; I.R), Department of Environmental and Occupational Health (T.J.M), and Department of Molecular and Cellular Medicine (D.W.T), Texas A&M University, College Station, Texas; and National Center for Toxicological Research, US FDA, Jefferson, Arkansas (I.P)
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences (J.A.C; S.F; Y.S.L; Y.I; W.C; I.R), Texas A&M Institute for Genome Sciences and Society (K.K; D.W.T; I.R), Department of Environmental and Occupational Health (T.J.M), and Department of Molecular and Cellular Medicine (D.W.T), Texas A&M University, College Station, Texas; and National Center for Toxicological Research, US FDA, Jefferson, Arkansas (I.P)
| |
Collapse
|
19
|
Cichocki JA, Guyton KZ, Guha N, Chiu WA, Rusyn I, Lash LH. Target Organ Metabolism, Toxicity, and Mechanisms of Trichloroethylene and Perchloroethylene: Key Similarities, Differences, and Data Gaps. J Pharmacol Exp Ther 2016; 359:110-23. [PMID: 27511820 PMCID: PMC5034707 DOI: 10.1124/jpet.116.232629] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 08/09/2016] [Indexed: 01/18/2023] Open
Abstract
Trichloroethylene (TCE) and perchloroethylene or tetrachloroethylene (PCE) are high-production volume chemicals with numerous industrial applications. As a consequence of their widespread use, these chemicals are ubiquitous environmental contaminants to which the general population is commonly exposed. It is widely assumed that TCE and PCE are toxicologically similar; both are simple olefins with three (TCE) or four (PCE) chlorines. Nonetheless, despite decades of research on the adverse health effects of TCE or PCE, few studies have directly compared these two toxicants. Although the metabolic pathways are qualitatively similar, quantitative differences in the flux and yield of metabolites exist. Recent human health assessments have uncovered some overlap in target organs that are affected by exposure to TCE or PCE, and divergent species- and sex-specificity with regard to cancer and noncancer hazards. The objective of this minireview is to highlight key similarities, differences, and data gaps in target organ metabolism and mechanism of toxicity. The main anticipated outcome of this review is to encourage research to 1) directly compare the responses to TCE and PCE using more sensitive biochemical techniques and robust statistical comparisons; 2) more closely examine interindividual variability in the relationship between toxicokinetics and toxicodynamics for TCE and PCE; 3) elucidate the effect of coexposure to these two toxicants; and 4) explore new mechanisms for target organ toxicity associated with TCE and/or PCE exposure.
Collapse
Affiliation(s)
- Joseph A Cichocki
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas (J.A.C., W.A.C., I.R.); International Agency for Research on Cancer, Lyon, France (K.Z.G., N.G.); Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan (L.H.L.)
| | - Kathryn Z Guyton
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas (J.A.C., W.A.C., I.R.); International Agency for Research on Cancer, Lyon, France (K.Z.G., N.G.); Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan (L.H.L.)
| | - Neela Guha
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas (J.A.C., W.A.C., I.R.); International Agency for Research on Cancer, Lyon, France (K.Z.G., N.G.); Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan (L.H.L.)
| | - Weihsueh A Chiu
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas (J.A.C., W.A.C., I.R.); International Agency for Research on Cancer, Lyon, France (K.Z.G., N.G.); Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan (L.H.L.)
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas (J.A.C., W.A.C., I.R.); International Agency for Research on Cancer, Lyon, France (K.Z.G., N.G.); Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan (L.H.L.)
| | - Lawrence H Lash
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas (J.A.C., W.A.C., I.R.); International Agency for Research on Cancer, Lyon, France (K.Z.G., N.G.); Department of Pharmacology, Wayne State University School of Medicine, Detroit, Michigan (L.H.L.)
| |
Collapse
|
20
|
Cave MC, Clair HB, Hardesty JE, Falkner KC, Feng W, Clark BJ, Sidey J, Shi H, Aqel BA, McClain CJ, Prough RA. Nuclear receptors and nonalcoholic fatty liver disease. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1859:1083-1099. [PMID: 26962021 DOI: 10.1016/j.bbagrm.2016.03.002] [Citation(s) in RCA: 196] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 02/29/2016] [Accepted: 03/01/2016] [Indexed: 02/08/2023]
Abstract
Nuclear receptors are transcription factors which sense changing environmental or hormonal signals and effect transcriptional changes to regulate core life functions including growth, development, and reproduction. To support this function, following ligand-activation by xenobiotics, members of subfamily 1 nuclear receptors (NR1s) may heterodimerize with the retinoid X receptor (RXR) to regulate transcription of genes involved in energy and xenobiotic metabolism and inflammation. Several of these receptors including the peroxisome proliferator-activated receptors (PPARs), the pregnane and xenobiotic receptor (PXR), the constitutive androstane receptor (CAR), the liver X receptor (LXR) and the farnesoid X receptor (FXR) are key regulators of the gut:liver:adipose axis and serve to coordinate metabolic responses across organ systems between the fed and fasting states. Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease and may progress to cirrhosis and even hepatocellular carcinoma. NAFLD is associated with inappropriate nuclear receptor function and perturbations along the gut:liver:adipose axis including obesity, increased intestinal permeability with systemic inflammation, abnormal hepatic lipid metabolism, and insulin resistance. Environmental chemicals may compound the problem by directly interacting with nuclear receptors leading to metabolic confusion and the inability to differentiate fed from fasting conditions. This review focuses on the impact of nuclear receptors in the pathogenesis and treatment of NAFLD. Clinical trials including PIVENS and FLINT demonstrate that nuclear receptor targeted therapies may lead to the paradoxical dissociation of steatosis, inflammation, fibrosis, insulin resistance, dyslipidemia and obesity. Novel strategies currently under development (including tissue-specific ligands and dual receptor agonists) may be required to separate the beneficial effects of nuclear receptor activation from unwanted metabolic side effects. The impact of nuclear receptor crosstalk in NAFLD is likely to be profound, but requires further elucidation. This article is part of a Special Issue entitled: Xenobiotic nuclear receptors: New Tricks for An Old Dog, edited by Dr. Wen Xie.
Collapse
Affiliation(s)
- Matthew C Cave
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202, USA; The Robley Rex Veterans Affairs Medical Center, Louisville, KY 40206, USA; The KentuckyOne Health Jewish Hospital Liver Transplant Program, Louisville, KY 40202, USA.
| | - Heather B Clair
- Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Josiah E Hardesty
- Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - K Cameron Falkner
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Wenke Feng
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Barbara J Clark
- Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Jennifer Sidey
- Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Hongxue Shi
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Bashar A Aqel
- Department of Medicine, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Scottsdale, AZ 85054, USA
| | - Craig J McClain
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Louisville School of Medicine, Louisville, KY 40202, USA; Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY 40202, USA; The Robley Rex Veterans Affairs Medical Center, Louisville, KY 40206, USA; The KentuckyOne Health Jewish Hospital Liver Transplant Program, Louisville, KY 40202, USA
| | - Russell A Prough
- Department of Biochemistry and Molecular Genetics, University of Louisville School of Medicine, Louisville, KY 40202, USA
| |
Collapse
|
21
|
Yoo HS, Cichocki JA, Kim S, Venkatratnam A, Iwata Y, Kosyk O, Bodnar W, Sweet S, Knap A, Wade T, Campbell J, Clewell HJ, Melnyk SB, Chiu WA, Rusyn I. The Contribution of Peroxisome Proliferator-Activated Receptor Alpha to the Relationship Between Toxicokinetics and Toxicodynamics of Trichloroethylene. Toxicol Sci 2015; 147:339-49. [PMID: 26136231 DOI: 10.1093/toxsci/kfv134] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Exposure to the ubiquitous environmental contaminant trichloroethylene (TCE) is associated with cancer and non-cancer toxicity in both humans and rodents. Peroxisome proliferator-activated receptor-alpha (PPARα) is thought to be playing a role in liver toxicity in rodents through activation of the receptor by the TCE metabolite trichloroacetic acid (TCA). However, most studies using genetically altered mice have not assessed the potential for PPARα to alter TCE toxicokinetics, which may lead to differences in TCA internal doses and hence confound inferences as to the role of PPARα in TCE toxicity. To address this gap, male and female wild type (129S1/SvImJ), Pparα-null, and humanized PPARα (hPPARα) mice were exposed intragastrically to 400 mg/kg TCE in single-dose (2, 5 and 12 h) and repeat-dose (5 days/week, 4 weeks) studies. Interestingly, following either a single- or repeat-dose exposure to TCE, levels of TCA in liver and kidney were lower in Pparα-null and hPPARα mice as compared with those in wild type mice. Levels of trichloroethanol (TCOH) were similar in all strains. TCE-exposed male mice consistently had higher levels of TCA and TCOH in all tissues compared with females. Additionally, in both single- and repeat-dose studies, a similar degree of induction of PPARα-responsive genes was observed in liver and kidney of hPPARα and wild type mice, despite the difference in hepatic and renal TCA levels. Additional sex- and strain-dependent effects were observed in the liver, including hepatocyte proliferation and oxidative stress, which were not dependent on TCA or TCOH levels. These data demonstrate that PPARα status affects the levels of the putative PPARα agonist TCA following TCE exposure. Therefore, interpretations of studies using Pparα-null and hPPARα mice need to consider the potential contribution of genotype-dependent toxicokinetics to observed differences in toxicity, rather than attributing such differences only to receptor-mediated toxicodynamic effects.
Collapse
Affiliation(s)
- Hong Sik Yoo
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina
| | - Joseph A Cichocki
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Sungkyoon Kim
- Graduate School of Public Health, Seoul National University, Seoul, Republic of Korea
| | - Abhishek Venkatratnam
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina; Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Yasuhiro Iwata
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Oksana Kosyk
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina
| | - Wanda Bodnar
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina
| | - Stephen Sweet
- Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas
| | - Anthony Knap
- Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas
| | - Terry Wade
- Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas
| | - Jerry Campbell
- The Hamner Institutes for Health Sciences, Research Triangle Park, North Carolina; and
| | - Harvey J Clewell
- The Hamner Institutes for Health Sciences, Research Triangle Park, North Carolina; and
| | - Stepan B Melnyk
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Weihsueh A Chiu
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA;
| |
Collapse
|
22
|
Yoo HS, Bradford BU, Kosyk O, Shymonyak S, Uehara T, Collins LB, Bodnar WM, Ball LM, Gold A, Rusyn I. Comparative analysis of the relationship between trichloroethylene metabolism and tissue-specific toxicity among inbred mouse strains: liver effects. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2015; 78:15-31. [PMID: 25424544 PMCID: PMC4281929 DOI: 10.1080/15287394.2015.958417] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Trichloroethylene (TCE) is a widely used organic solvent. Although TCE is classified as carcinogenic to humans, substantial gaps remain in our understanding of interindividual variability in TCE metabolism and toxicity, especially in the liver. A hypothesis was tested that amounts of oxidative metabolites of TCE in mouse liver are associated with hepatic-specific toxicity. Oral dosing with TCE was conducted in subacute (600 mg/kg/d; 5 d; 7 inbred mouse strains) and subchronic (100 or 400 mg/kg/d; 1, 2, or 4 wk; 2 inbred mouse strains) designs. The quantitative relationship was evaluated between strain-, dose-, and time-dependent formation of TCE metabolites from cytochrome P-450-mediated oxidation (trichloroacetic acid [TCA], dichloroacetic acid [DCA], and trichloroethanol) and glutathione conjugation [S-(1,2-dichlorovinyl)-L-cysteine and S-(1,2-dichlorovinyl)glutathione] in serum and liver, and various hepatic toxicity phenotypes. In subacute study, interstrain variability in TCE metabolite amounts was observed in serum and liver. No marked induction of Cyp2e1 protein levels in liver was detected. Serum and hepatic levels of TCA and DCA were correlated with increased transcription of peroxisome proliferator-marker genes Cyp4a10 and Acox1 but not with degree of induction in hepatocellular proliferation. In subchronic study, serum and liver levels of oxidative metabolites gradually decreased over time despite continuous dosing. Hepatic protein levels of CYP2E1, ADH, and ALDH2 were unaffected by treatment with TCE. While the magnitude of induction of peroxisome proliferator-marker genes also declined, hepatocellular proliferation increased. This study offers a unique opportunity to provide a scientific data-driven rationale for some of the major assumptions in human health assessment of TCE.
Collapse
Affiliation(s)
- Hong Sik Yoo
- a Department of Environmental Sciences and Engineering , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina , USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Guyton KZ, Hogan KA, Scott CS, Cooper GS, Bale AS, Kopylev L, Barone S, Makris SL, Glenn B, Subramaniam RP, Gwinn MR, Dzubow RC, Chiu WA. Human health effects of tetrachloroethylene: key findings and scientific issues. ENVIRONMENTAL HEALTH PERSPECTIVES 2014; 122:325-34. [PMID: 24531164 PMCID: PMC3984230 DOI: 10.1289/ehp.1307359] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Accepted: 02/11/2014] [Indexed: 05/07/2023]
Abstract
BACKGROUND The U.S. Environmental Protection Agency (EPA) completed a toxicological review of tetrachloroethylene (perchloroethylene, PCE) in February 2012 in support of the Integrated Risk Information System (IRIS). OBJECTIVES We reviewed key findings and scientific issues regarding the human health effects of PCE described in the U.S. EPA's Toxicological Review of Tetrachloroethylene (Perchloroethylene). METHODS The updated assessment of PCE synthesized and characterized a substantial database of epidemiological, experimental animal, and mechanistic studies. Key scientific issues were addressed through modeling of PCE toxicokinetics, synthesis of evidence from neurological studies, and analyses of toxicokinetic, mechanistic, and other factors (tumor latency, severity, and background rate) in interpreting experimental animal cancer findings. Considerations in evaluating epidemiological studies included the quality (e.g., specificity) of the exposure assessment methods and other essential design features, and the potential for alternative explanations for observed associations (e.g., bias or confounding). DISCUSSION Toxicokinetic modeling aided in characterizing the complex metabolism and multiple metabolites that contribute to PCE toxicity. The exposure assessment approach-a key evaluation factor for epidemiological studies of bladder cancer, non-Hodgkin lymphoma, and multiple myeloma-provided suggestive evidence of carcinogenicity. Bioassay data provided conclusive evidence of carcinogenicity in experimental animals. Neurotoxicity was identified as a sensitive noncancer health effect, occurring at low exposures: a conclusion supported by multiple studies. Evidence was integrated from human, experimental animal, and mechanistic data sets in assessing adverse health effects of PCE. CONCLUSIONS PCE is likely to be carcinogenic to humans. Neurotoxicity is a sensitive adverse health effect of PCE.
Collapse
|
24
|
Corton JC, Cunningham ML, Hummer BT, Lau C, Meek B, Peters JM, Popp JA, Rhomberg L, Seed J, Klaunig JE. Mode of action framework analysis for receptor-mediated toxicity: The peroxisome proliferator-activated receptor alpha (PPARα) as a case study. Crit Rev Toxicol 2013; 44:1-49. [PMID: 24180432 DOI: 10.3109/10408444.2013.835784] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Several therapeutic agents and industrial chemicals induce liver tumors in rodents through the activation of the peroxisome proliferator-activated receptor alpha (PPARα). The cellular and molecular events by which PPARα activators induce rodent hepatocarcinogenesis has been extensively studied and elucidated. This review summarizes the weight of evidence relevant to the hypothesized mode of action (MOA) for PPARα activator-induced rodent hepatocarcinogenesis and identifies gaps in our knowledge of this MOA. Chemical-specific and mechanistic data support concordance of temporal and dose-response relationships for the key events associated with many PPARα activators including a phthalate ester plasticizer di(2-ethylhexyl) phthalate (DEHP) and the drug gemfibrozil. While biologically plausible in humans, the hypothesized key events in the rodent MOA, for PPARα activators, are unlikely to induce liver tumors in humans because of toxicodynamic and biological differences in responses. This conclusion is based on minimal or no effects observed on growth pathways, hepatocellular proliferation and liver tumors in humans and/or species (including hamsters, guinea pigs and cynomolgous monkeys) that are more appropriate human surrogates than mice and rats at overlapping dose levels. Overall, the panel concluded that significant quantitative differences in PPARα activator-induced effects related to liver cancer formation exist between rodents and humans. On the basis of these quantitative differences, most of the workgroup felt that the rodent MOA is "not relevant to humans" with the remaining members concluding that the MOA is "unlikely to be relevant to humans". The two groups differed in their level of confidence based on perceived limitations of the quantitative and mechanistic knowledge of the species differences, which for some panel members strongly supports but cannot preclude the absence of effects under unlikely exposure scenarios.
Collapse
|
25
|
Fang ZZ, Krausz KW, Tanaka N, Li F, Qu A, Idle JR, Gonzalez FJ. Metabolomics reveals trichloroacetate as a major contributor to trichloroethylene-induced metabolic alterations in mouse urine and serum. Arch Toxicol 2013; 87:1975-1987. [PMID: 23575800 DOI: 10.1007/s00204-013-1053-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 03/26/2013] [Indexed: 01/14/2023]
Abstract
Trichloroethylene (TCE)-induced liver toxicity and carcinogenesis is believed to be mediated in part by activation of the peroxisome proliferator-activated receptor α (PPARα). However, the contribution of the two TCE metabolites, dichloroacetate (DCA) and trichloroacetate (TCA) to the toxicity of TCE, remains unclear. The aim of the present study was to determine the metabolite profiles in serum and urine upon exposure of mice to TCE, to aid in determining the metabolic response to TCE exposure and the contribution of DCA and TCA to TCE toxicity. C57BL/6 mice were administered TCE, TCA, or DCA, and urine and serum subjected to ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOFMS)-based global metabolomics analysis. The ions were identified through searching metabolomics databases and by comparison with authentic standards, and quantitated using multiple reactions monitoring. Quantitative polymerase chain reaction of mRNA, biochemical analysis, and liver histology were also performed. TCE exposure resulted in a decrease in urine of metabolites involved in fatty acid metabolism, resulting from altered expression of PPARα target genes. TCE treatment also induced altered phospholipid homeostasis in serum, as revealed by increased serum lysophosphatidylcholine 18:0 and 18:1, and phosphatidylcholine metabolites. TCA administration revealed similar metabolite profiles in urine and serum upon TCE exposure, which correlated with a more robust induction of PPARα target gene expression associated with TCA than DCA treatment. These data show the metabolic response to TCE exposure and demonstrate that TCA is the major contributor to TCE-induced metabolite alterations observed in urine and serum.
Collapse
Affiliation(s)
- Zhong-Ze Fang
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 37, Room 3106, Bethesda, MD, 20892, USA
| | - Kristopher W Krausz
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 37, Room 3106, Bethesda, MD, 20892, USA
| | - Naoki Tanaka
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 37, Room 3106, Bethesda, MD, 20892, USA
| | - Fei Li
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 37, Room 3106, Bethesda, MD, 20892, USA
| | - Aijuan Qu
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 37, Room 3106, Bethesda, MD, 20892, USA
| | - Jeffrey R Idle
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 37, Room 3106, Bethesda, MD, 20892, USA
| | - Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Building 37, Room 3106, Bethesda, MD, 20892, USA.
| |
Collapse
|
26
|
PPARs Signaling and Cancer in the Gastrointestinal System. PPAR Res 2012; 2012:560846. [PMID: 23028383 PMCID: PMC3458283 DOI: 10.1155/2012/560846] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 07/23/2012] [Accepted: 08/07/2012] [Indexed: 12/27/2022] Open
Abstract
Nowadays, the study of the peroxisome proliferators activated receptors (PPARs) as potential targets for cancer prevention and therapy has gained a strong interest. From a biological point of view, the overall responsibility of PPARs in cancer development and progression is still controversial since several studies report both antiproliferative and tumor-promoting actions for these signaling molecules in human cancer cells and animal models. In this paper, we discuss PPARs functions in the context of different types of gastrointestinal cancer.
Collapse
|
27
|
Peyrou M, Ramadori P, Bourgoin L, Foti M. PPARs in Liver Diseases and Cancer: Epigenetic Regulation by MicroRNAs. PPAR Res 2012; 2012:757803. [PMID: 23024649 PMCID: PMC3449131 DOI: 10.1155/2012/757803] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 06/27/2012] [Indexed: 12/19/2022] Open
Abstract
Peroxisome-proliferator-activated receptors (PPARs) are ligand-activated nuclear receptors that exert in the liver a transcriptional activity regulating a whole spectrum of physiological functions, including cholesterol and bile acid homeostasis, lipid/glucose metabolism, inflammatory responses, regenerative mechanisms, and cell differentiation/proliferation. Dysregulations of the expression, or activity, of specific PPAR isoforms in the liver are therefore believed to represent critical mechanisms contributing to the development of hepatic metabolic diseases, disorders induced by hepatic viral infections, and hepatocellular adenoma and carcinoma. In this regard, specific PPAR agonists have proven to be useful to treat these metabolic diseases, but for cancer therapies, the use of PPAR agonists is still debated. Interestingly, in addition to previously described mechanisms regulating PPARs expression and activity, microRNAs are emerging as new important regulators of PPAR expression and activity in pathophysiological conditions and therefore may represent future therapeutic targets to treat hepatic metabolic disorders and cancers. Here, we reviewed the current knowledge about the general roles of the different PPAR isoforms in common chronic metabolic and infectious liver diseases, as well as in the development of hepatic cancers. Recent works highlighting the regulation of PPARs by microRNAs in both physiological and pathological situations with a focus on the liver are also discussed.
Collapse
Affiliation(s)
- Marion Peyrou
- Department of Cell Physiology and Metabolism, Faculty of Medicine, Centre Médical Universiatire (CMU), 1206 Geneva, Switzerland
| | - Pierluigi Ramadori
- Department of Cell Physiology and Metabolism, Faculty of Medicine, Centre Médical Universiatire (CMU), 1206 Geneva, Switzerland
| | - Lucie Bourgoin
- Department of Cell Physiology and Metabolism, Faculty of Medicine, Centre Médical Universiatire (CMU), 1206 Geneva, Switzerland
| | - Michelangelo Foti
- Department of Cell Physiology and Metabolism, Faculty of Medicine, Centre Médical Universiatire (CMU), 1206 Geneva, Switzerland
| |
Collapse
|
28
|
PPARs and xenobiotic-induced adverse effects: relevance to human health. PPAR Res 2011; 2010:954639. [PMID: 21804817 PMCID: PMC3124005 DOI: 10.1155/2010/954639] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Accepted: 12/31/2010] [Indexed: 11/17/2022] Open
|
29
|
Singh S, Saini D, Mehta S, Choquesillo-Lazarte D. Synthesis, spectroscopic, and thermal analyses of binuclear mixed ligand Co(II) and Ni(II) complexes. J COORD CHEM 2011. [DOI: 10.1080/00958972.2011.575133] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Sukhjinder Singh
- a Department of Chemistry and Centre of Advanced Studies in Chemistry , Panjab University , Chandigarh 160014 , India
| | - Deepika Saini
- a Department of Chemistry and Centre of Advanced Studies in Chemistry , Panjab University , Chandigarh 160014 , India
| | - S.K. Mehta
- a Department of Chemistry and Centre of Advanced Studies in Chemistry , Panjab University , Chandigarh 160014 , India
| | - Duane Choquesillo-Lazarte
- b Laboratorio de Estudios Cristalograficos, IACT-CSIC, Edf. Inst. Lopez Neyra, P.T. Ciencias de la Salud , Avenida del Conociminento s/n, Armilla (Granada)-18100 , Spain
| |
Collapse
|
30
|
Bradford BU, Lock EF, Kosyk O, Kim S, Uehara T, Harbourt D, DeSimone M, Threadgill DW, Tryndyak V, Pogribny IP, Bleyle L, Koop DR, Rusyn I. Interstrain differences in the liver effects of trichloroethylene in a multistrain panel of inbred mice. Toxicol Sci 2011; 120:206-17. [PMID: 21135412 PMCID: PMC3044200 DOI: 10.1093/toxsci/kfq362] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Accepted: 11/17/2010] [Indexed: 12/11/2022] Open
Abstract
Trichloroethylene (TCE) is a widely used industrial chemical and a common environmental contaminant. It is a well-known carcinogen in rodents and a probable carcinogen in humans. Studies utilizing panels of mouse inbred strains afford a unique opportunity to understand both metabolic and genetic basis for differences in responses to TCE. We tested the hypothesis that strain- and liver-specific toxic effects of TCE are genetically controlled and that the mechanisms of toxicity and susceptibility can be uncovered by exploring responses to TCE using a diverse panel of inbred mouse strains. TCE (2100 mg/kg) or corn oil vehicle was administered by gavage to 6- to 8-week-old male mice of 15 mouse strains. Serum and liver were collected at 2, 8, and 24 h postdosing and were analyzed for TCE metabolites, hepatocellular injury, and gene expression of liver. TCE metabolism, as evident from the levels of individual oxidative and conjugative metabolites, varied considerably between strains. TCE treatment-specific effect on the liver transcriptome was strongly dependent on genetic background. Peroxisome proliferator-activated receptor-mediated molecular networks, consisting of the metabolism genes known to be induced by TCE, represent some of the most pronounced molecular effects of TCE treatment in mouse liver that are dependent on genetic background. Conversely, cell death, liver necrosis, and immune-mediated response pathways, which are altered by TCE treatment in liver, are largely genetic background independent. These studies provide better understanding of the mechanisms of TCE-induced toxicity anchored on metabolism and genotype-phenotype correlations that may define susceptibility or resistance.
Collapse
Affiliation(s)
| | - Eric F. Lock
- Department of Statistics and Operations Research, and
| | - Oksana Kosyk
- Department of Environmental Sciences and Engineering
| | - Sungkyoon Kim
- Department of Environmental Sciences and Engineering
| | - Takeki Uehara
- Department of Environmental Sciences and Engineering
| | - David Harbourt
- Department of Curriculum in Toxicology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Michelle DeSimone
- Department of Curriculum in Toxicology, University of North Carolina, Chapel Hill, North Carolina 27599
| | - David W. Threadgill
- Department of Curriculum in Toxicology, University of North Carolina, Chapel Hill, North Carolina 27599
- Department of Genetics, North Carolina State University, Raleigh, North Carolina 27695
| | | | - Igor P. Pogribny
- National Center for Toxicological Research, Jefferson, Arkansas 72079
| | - Lisa Bleyle
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, Oregon 97239
| | - Dennis R. Koop
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, Oregon 97239
| | - Ivan Rusyn
- Department of Environmental Sciences and Engineering
- Department of Curriculum in Toxicology, University of North Carolina, Chapel Hill, North Carolina 27599
| |
Collapse
|
31
|
Nelson GM, Ahlborn GJ, Allen JW, Ren H, Corton JC, Waalkes MP, Kitchin KT, Diwan BA, Knapp G, Delker DA. Transcriptional changes associated with reduced spontaneous liver tumor incidence in mice chronically exposed to high dose arsenic. Toxicology 2009; 266:6-15. [PMID: 19822182 PMCID: PMC7316389 DOI: 10.1016/j.tox.2009.10.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 09/14/2009] [Accepted: 10/04/2009] [Indexed: 12/16/2022]
Abstract
Exposure of male C3H mice in utero (from gestational days 8-18) to 85ppm sodium arsenite via the dams' drinking water has previously been shown to increase liver tumor incidence by 2 years of age. However, in our companion study (Ahlborn et al., 2009), continuous exposure to 85ppm sodium arsenic (from gestational day 8 to postnatal day 365) did not result in increased tumor incidence, but rather in a significant reduction (0% tumor incidence). The purpose of the present study was to examine the gene expression responses that may lead to the apparent protective effect of continuous arsenic exposure. Genes in many functional categories including cellular growth and proliferation, gene expression, cell death, oxidative stress, protein ubiquitination, and mitochondrial dysfunction were altered by continuous arsenic treatment. Many of these genes are known to be involved in liver cancer. One such gene associated with rodent hepatocarcinogenesis, Scd1, encodes stearoyl-CoA desaturase and was down-regulated by continuous arsenic treatment. An overlap between the genes in our study affected by continuous arsenic exposure and those from the literature affected by long-term caloric restriction suggests that reduction in the spontaneous tumor incidence under both conditions may involve similar gene pathways such as fatty acid metabolism, apoptosis, and stress response.
Collapse
Affiliation(s)
- Gail M. Nelson
- United States Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC 27711, United States
| | - Gene J. Ahlborn
- United States Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC 27711, United States
| | - James W. Allen
- United States Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC 27711, United States
| | - Hongzu Ren
- United States Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC 27711, United States
- NHEERL Toxicogenomics Core, US-EPA, Research Triangle Park, NC 27711, United States
| | - J. Christopher Corton
- United States Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC 27711, United States
- NHEERL Toxicogenomics Core, US-EPA, Research Triangle Park, NC 27711, United States
| | - Michael P. Waalkes
- National Cancer Institute at NIEHS, Laboratory of Comparative Carcinogenesis, Research Triangle Park, NC, United States
| | - Kirk T. Kitchin
- United States Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC 27711, United States
| | | | - Geremy Knapp
- United States Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC 27711, United States
| | - Don A. Delker
- United States Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Research Triangle Park, NC 27711, United States
| |
Collapse
|
32
|
Elfaki DAH, Bjornsson E, Lindor KD. Review article: nuclear receptors and liver disease--current understanding and new therapeutic implications. Aliment Pharmacol Ther 2009; 30:816-25. [PMID: 19706148 DOI: 10.1111/j.1365-2036.2009.04104.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND The important role of nuclear receptors and their contribution to liver function in both physiological and pathological conditions has come to attention in recent years and has advanced our understanding of several liver diseases. These findings led to the introduction of targeting nuclear receptors as treatment strategies for various liver diseases. AIMS To review the new insights brought by the study of nuclear receptors to our understanding of the molecular basis of various liver diseases, and to summarize some of the recent studies that evaluated the efficacy of targeting nuclear receptor as a new approach in treating liver diseases. METHODS Review of articles, using PubMed and article references. RESULTS Nuclear receptor ligands in patients with liver diseases have been associated with a variety of toxicities. Some clinical results have not met the expectations predicted from animal experiments. Mechanistic explanations at the molecular level are needed for preventing toxicity and improving outcomes from nuclear receptor ligands. CONCLUSION The use of various nuclear receptor ligands in liver diseases is a promising approach that can benefit many patients suffering from these devastating diseases. However, we are far from a full understanding of the molecular mechanisms by which these receptors work.
Collapse
Affiliation(s)
- D A H Elfaki
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55901, USA
| | | | | |
Collapse
|
33
|
Sweeney LM, Kirman CR, Gargas ML, Dugard PH. Contribution of trichloroacetic acid to liver tumors observed in perchloroethylene (perc)-exposed mice. Toxicology 2009; 260:77-83. [DOI: 10.1016/j.tox.2009.03.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Revised: 03/06/2009] [Accepted: 03/13/2009] [Indexed: 10/21/2022]
|
34
|
Evidence for the involvement of xenobiotic-responsive nuclear receptors in transcriptional effects upon perfluoroalkyl acid exposure in diverse species. Reprod Toxicol 2009; 27:266-277. [PMID: 19162173 DOI: 10.1016/j.reprotox.2008.12.011] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 12/12/2008] [Accepted: 12/22/2008] [Indexed: 12/18/2022]
Abstract
Humans and ecological species have been found to have detectable body burdens of a number of perfluorinated alkyl acids (PFAA) including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). In mouse and rat liver these compounds elicit transcriptional and phenotypic effects similar to peroxisome proliferator chemicals (PPC) that work through the nuclear receptor peroxisome proliferator-activated receptor alpha (PPAR alpha). Recent studies indicate that along with PPAR alpha other nuclear receptors are required for transcriptional changes in the mouse liver after PFOA exposure including the constitutive activated receptor (CAR) and pregnane X receptor (PXR) that regulate xenobiotic metabolizing enzymes (XME). To determine the potential role of CAR/PXR in mediating effects of PFAAs in rat liver, we performed a meta-analysis of transcript profiles from published studies in which rats were exposed to PFOA or PFOS. We compared the profiles to those produced by exposure to prototypical activators of CAR, (phenobarbital (PB)), PXR (pregnenolone 16 alpha-carbonitrile (PCN)), or PPAR alpha (WY-14,643 (WY)). As expected, PFOA and PFOS elicited transcript profile signatures that included many known PPAR alpha target genes. Numerous XME genes were also altered by PFOA and PFOS but not WY. These genes exhibited expression changes shared with PB or PCN. Reexamination of the transcript profiles from the livers of chicken or fish exposed to PFAAs indicated that PPAR alpha, CAR, and PXR orthologs were not activated. Our results indicate that PFAAs under these experimental conditions activate PPAR alpha, CAR, and PXR in rats but not chicken and fish. Lastly, we discuss evidence that human populations with greater CAR expression have lower body burdens of PFAAs.
Collapse
|