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Yu X, Zhang Y, Cogliati B, Klaassen CD, Kumar S, Cheng X, Bu P. Distinct bile acid alterations in response to a single administration of PFOA and PFDA in mice. Toxicology 2024; 502:153719. [PMID: 38181850 PMCID: PMC10922993 DOI: 10.1016/j.tox.2023.153719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/22/2023] [Accepted: 12/30/2023] [Indexed: 01/07/2024]
Abstract
Per- and polyfluoroalkyl substances (PFASs), a group of synthetic chemicals that were once widely used for industrial purposes and in consumer products, are widely found in the environment and in human blood due to their extraordinary resistance to degradation. Once inside the body, PFASs can activate nuclear receptors such as PPARα and CAR. The present study aimed to investigate the impact of perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA) on liver structure and functions, as well as bile acid homeostasis in mice. A single administration of 0.1 mmole/kg of PFDA, not PFOA, elevated serum ALT and bilirubin levels and caused cholestasis in WT mice. PFDA increased total and various bile acid species in serum but decreased them in the liver. Furthermore, in mouse livers, PFDA, not PFOA, down-regulated mRNA expression of uptake transporters (Ntcp, Oatp1a1, 1a4, 1b2, and 2b1) but induced efflux transporters (Bcrp, Mdr2, and Mrp2-4). In addition, PFDA, not PFOA, decreased Cyp7a1, 7b1, 8b1, and 27a1 mRNA expression in mouse livers with concomitant hepatic accumulation of cholesterol. In contrast, in PPARα-null mice, PFDA did not increase serum ALT, bilirubin, or total bile acids, but produced prominent hepatosteatosis; and the observed PFDA-induced expression changes of transporters and Cyps in WT mice were largely attenuated or abolished. In CAR-null mice, the observed PFDA-induced bile acid alterations in WT mice were mostly sustained. These results indicate that, at the dose employed, PFDA has more negative effects than PFOA on liver function. PPARα appears to play a major role in mediating most of PFDA-induced effects, which were absent or attenuated in PPARα-null mice. Lack of PPARα, however, exacerbated hepatic steatosis. Our findings indicate separated roles of PPARα in mediating the adaptive responses to PFDA: protective against hepatosteatosis but exacerbating cholestasis.
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Affiliation(s)
- Xiaoxiao Yu
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, 8000 Utopia Parkway, Jamaica, NY 11439, United States
| | - Youcai Zhang
- Department of Pharmacology and Toxicology, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, PR China
| | - Bruno Cogliati
- Division of Liver Diseases, Icahn School of Medicine at Mount Sinai, 1425 Madison Ave., New York, NY 10029, United States; Department of Pathology, School of Veterinary Medicine and Animal Science, University of Sao Paulo, 05508-270, Sao Paulo, Brazil
| | - Curtis D Klaassen
- University of Kansas Medical Center, Kansas City, KS 66103, United States
| | - Sanaya Kumar
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, 8000 Utopia Parkway, Jamaica, NY 11439, United States
| | - Xingguo Cheng
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, 8000 Utopia Parkway, Jamaica, NY 11439, United States
| | - Pengli Bu
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, 8000 Utopia Parkway, Jamaica, NY 11439, United States.
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Malliou F, Andriopoulou CE, Kofinas A, Katsogridaki A, Leondaritis G, Gonzalez FJ, Michaelidis TM, Darsinou M, Skaltsounis LA, Konstandi M. Oleuropein Promotes Neural Plasticity and Neuroprotection via PPARα-Dependent and Independent Pathways. Biomedicines 2023; 11:2250. [PMID: 37626746 PMCID: PMC10452728 DOI: 10.3390/biomedicines11082250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
Oleuropein (OLE), a main constituent of olives, displays a pleiotropic beneficial dynamic in health and disease; the effects are based mainly on its antioxidant and hypolipidemic properties, and its capacity to protect the myocardium during ischemia. Furthermore, OLE activates the peroxisome proliferator-activated receptor (PPARα) in neurons and astrocytes, providing neuroprotection against noxious biological reactions that are induced following cerebral ischemia. The current study investigated the effect of OLE in the regulation of various neural plasticity indices, emphasizing the role of PPARα. For this purpose, 129/Sv wild-type (WT) and Pparα-null mice were treated with OLE for three weeks. The findings revealed that chronic treatment with OLE up-regulated the brain-derived neurotrophic factor (BDNF) and its receptor TrkB in the prefrontal cortex (PFC) of mice via activation of the ERK1/2, AKT and PKA/CREB signaling pathways. No similar effects were observed in the hippocampus. The OLE-induced effects on BDNF and TrkB appear to be mediated by PPARα, because no similar alterations were observed in the PFC of Pparα-null mice. Notably, OLE did not affect the neurotrophic factors NT3 and NT4/5 in both brain tissues. However, fenofibrate, a selective PPARα agonist, up-regulated BDNF and NT3 in the PFC of mice, whereas the drug induced NT4/5 in both brain sites tested. Interestingly, OLE provided neuroprotection in differentiated human SH-SY5Y cells against β-amyloid and H2O2 toxicity independently from PPARα activation. In conclusion, OLE and similar drugs, acting either as PPARα agonists or via PPARα independent mechanisms, could improve synaptic function/plasticity mainly in the PFC and to a lesser extent in the hippocampus, thus beneficially affecting cognitive functions.
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Affiliation(s)
- Foteini Malliou
- Department of Pharmacology, Faculty of Medicine, University of Ioannina, 45110 Ioannina, Greece; (F.M.); (C.E.A.); (A.K.); (A.K.); (G.L.)
| | - Christina E. Andriopoulou
- Department of Pharmacology, Faculty of Medicine, University of Ioannina, 45110 Ioannina, Greece; (F.M.); (C.E.A.); (A.K.); (A.K.); (G.L.)
| | - Aristeidis Kofinas
- Department of Pharmacology, Faculty of Medicine, University of Ioannina, 45110 Ioannina, Greece; (F.M.); (C.E.A.); (A.K.); (A.K.); (G.L.)
| | - Allena Katsogridaki
- Department of Pharmacology, Faculty of Medicine, University of Ioannina, 45110 Ioannina, Greece; (F.M.); (C.E.A.); (A.K.); (A.K.); (G.L.)
| | - George Leondaritis
- Department of Pharmacology, Faculty of Medicine, University of Ioannina, 45110 Ioannina, Greece; (F.M.); (C.E.A.); (A.K.); (A.K.); (G.L.)
- Institute of Biosciences (I.BS.), University Research Center of Ioannina (U.R.C.I.), 45110 Ioannina, Greece
| | - Frank J. Gonzalez
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD 20814, USA;
| | - Theologos M. Michaelidis
- Department of Biological Applications & Technology, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece; (T.M.M.); (M.D.)
- Biomedical Research Institute, Foundation for Research and Technology-Hellas, 45110 Ioannina, Greece
| | - Marousa Darsinou
- Department of Biological Applications & Technology, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece; (T.M.M.); (M.D.)
| | - Leandros A. Skaltsounis
- Department of Pharmacognosy, Faculty of Pharmacy, National and Kapodestrian University of Athens, 11527 Athens, Greece;
| | - Maria Konstandi
- Department of Pharmacology, Faculty of Medicine, University of Ioannina, 45110 Ioannina, Greece; (F.M.); (C.E.A.); (A.K.); (A.K.); (G.L.)
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Zhu X, Liu Q, Patterson AD, Sharma AK, Amin SG, Cohen SM, Gonzalez FJ, Peters JM. Accumulation of Linoleic Acid by Altered Peroxisome Proliferator-Activated Receptor-α Signaling Is Associated with Age-Dependent Hepatocarcinogenesis in Ppara Transgenic Mice. Metabolites 2023; 13:936. [PMID: 37623879 PMCID: PMC10456914 DOI: 10.3390/metabo13080936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/03/2023] [Accepted: 08/06/2023] [Indexed: 08/26/2023] Open
Abstract
Long-term ligand activation of PPARα in mice causes hepatocarcinogenesis through a mechanism that requires functional PPARα. However, hepatocarcinogenesis is diminished in both Ppara-null and PPARA-humanized mice, yet both lines develop age-related liver cancer independently of treatment with a PPARα agonist. Since PPARα is a master regulator of liver lipid metabolism in the liver, lipidomic analyses were carried out in wild-type, Ppara-null, and PPARA-humanized mice treated with and without the potent agonist GW7647. The levels of hepatic linoleic acid in Ppara-null and PPARA-humanized mice were markedly higher compared to wild-type controls, along with overall fatty liver. The number of liver CD4+ T cells was also lower in Ppara-null and PPARA-humanized mice and was negatively correlated with the elevated linoleic acid. Moreover, more senescent hepatocytes and lower serum TNFα and IFNγ levels were observed in Ppara-null and PPARA-humanized mice with age. These studies suggest a new role for PPARα in age-associated hepatocarcinogenesis due to altered lipid metabolism in Ppara-null and PPARA-humanized mice and the accumulation of linoleic acid as part of an overall fatty liver that is associated with loss of CD4+ T cells in the liver in both transgenic models. Since fatty liver is a known causal risk factor for liver cancer, Ppara-null and PPARA-humanized mice are valuable models for examining the mechanisms of PPARα and age-dependent hepatocarcinogenesis.
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Affiliation(s)
- Xiaoyang Zhu
- Department of Veterinary and Biomedical Science, The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, State College, PA 16802, USA; (Q.L.); (A.D.P.); (J.M.P.)
| | - Qing Liu
- Department of Veterinary and Biomedical Science, The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, State College, PA 16802, USA; (Q.L.); (A.D.P.); (J.M.P.)
| | - Andrew D. Patterson
- Department of Veterinary and Biomedical Science, The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, State College, PA 16802, USA; (Q.L.); (A.D.P.); (J.M.P.)
| | - Arun K. Sharma
- Department of Pharmacology, The Pennsylvania State University, Hershey, PA 17033, USA; (A.K.S.); (S.G.A.)
| | - Shantu G. Amin
- Department of Pharmacology, The Pennsylvania State University, Hershey, PA 17033, USA; (A.K.S.); (S.G.A.)
| | - Samuel M. Cohen
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA;
| | - Frank J. Gonzalez
- Laboratory of Metabolism, National Cancer Institute, Bethesda, MD 20892, USA;
| | - Jeffrey M. Peters
- Department of Veterinary and Biomedical Science, The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, State College, PA 16802, USA; (Q.L.); (A.D.P.); (J.M.P.)
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Zou H, Gong Y, Ye H, Yuan C, Li T, Zhang J, Ren L. Dietary regulation of peroxisome proliferator-activated receptors in metabolic syndrome. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 116:154904. [PMID: 37267691 DOI: 10.1016/j.phymed.2023.154904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 05/15/2023] [Accepted: 05/28/2023] [Indexed: 06/04/2023]
Abstract
BACKGROUND Peroxisome proliferator-activated receptors (PPARs) are a class of ligand-activated nuclear transcription factors, members of the type nuclear receptor superfamily, with three subtypes, namely PPARα, PPARβ/δ, and PPARγ, which play a key role in the metabolic syndrome. In the past decades, a large number of studies have shown that natural products can act by regulating metabolic pathways mediated by PPARs. PURPOSE This work summarizes the physiological importance and clinical significance of PPARs and reviews the experimental evidence that natural products mediate metabolic syndrome via PPARs. METHODS This study reviews relevant literature on clinical trials, epidemiology, animals, and cell cultures published in NCBI PubMed, Scopus, Web of Science, Google Scholar, and other databases from 2001 to October 2022. Search keywords were "natural product" OR "botanical" OR "phytochemical" AND "PPAR" as well as free text words. RESULTS The modulatory involvement of PPARs in the metabolic syndrome has been supported by prior research. It has been observed that many natural products can treat metabolic syndrome by altering PPARs. The majority of currently described natural compounds are mild PPAR-selective agonists with therapeutic effects that are equivalent to synthetic medicines but less harmful adverse effects. CONCLUSION PPAR agonists can be combined with natural products to treat and prevent metabolic syndrome. Further human investigations are required because it is unknown how natural products cause harm and how they might have negative impacts.
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Affiliation(s)
- Haoyang Zou
- College of Food Science and Engineering, Jilin University, Changchun 130062, China
| | - Yiyao Gong
- College of Food Science and Engineering, Jilin University, Changchun 130062, China
| | - Haiqing Ye
- College of Food Science and Engineering, Jilin University, Changchun 130062, China
| | - Cuiping Yuan
- Institute of Agro-food Technology, Jilin Academy of Agricultural Sciences, Changchun 130033, China
| | - Tiezhu Li
- Institute of Agro-food Technology, Jilin Academy of Agricultural Sciences, Changchun 130033, China
| | - Jie Zhang
- College of Food Science and Engineering, Jilin University, Changchun 130062, China.
| | - Li Ren
- College of Food Science and Engineering, Jilin University, Changchun 130062, China.
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Engel C, Meade R, Harroun N, Penrose A, Shafqat M, Jin X, DeSilva G, Semenkovich C, Zayed M. Altered Peroxisome Proliferator-Activated Receptor Alpha Signaling in Variably Diseased Peripheral Arterial Segments. Front Cardiovasc Med 2022; 9:834199. [PMID: 35783870 PMCID: PMC9248745 DOI: 10.3389/fcvm.2022.834199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 05/04/2022] [Indexed: 11/25/2022] Open
Abstract
Objective Peripheral atherosclerosis that accumulates in the extracranial carotid and lower extremity arteries can lead to significant morbidity and mortality. However, atherosclerotic disease progression is often not homogenous and is accelerated by diabetes. We previously observed increased phospholipid content in minimally (Min)-diseased arterial segments compared to maximally (Max)-diseased segments. Since Peroxisome Proliferator-Activated Receptor alpha (PPARα) is a key regulator of lipid metabolism, we hypothesized that it may have differential expression and signaling in Min vs. Max-diseased peripheral arterial segments. Methods Eighteen patients who underwent carotid endarterectomy (CEA), and 34 patients who underwent major lower extremity amputation were prospectively enrolled into a vascular tissue biobank. Min and Max-diseased segments were obtained in real-time from CEA plaque and amputated lower extremity arterial segments. mRNA and protein were isolated from specimens and the relative expression of ppara, and its downstream genes Acyl-CoA Oxidase 1 (acox1) and Carnitine Palmitoyltransferase 1A (cpt1a) were also evaluated. We evaluated gene expression and protein content relative to atherosclerotic disease severity and clinical diabetes status. Gene expression was also evaluated relative to Hemoglobin A1c and serum lipid profiles. Results In CEA segments of patients with diabetes, we observed significantly higher ppara and acox1 gene expression (p < 0.01 and p < 0.001 respectively), and higher PPARα protein content (p < 0.05). Hemoglobin A1c significantly correlated with expression of ppara (R2 = 0.66, p < 0.001), acox1 (R2 = 0.31, p < 0.05), and cpt1a (R2 = 0.4, p < 0.05). There was no significant difference in gene expression between Min vs. Max-diseased CEA plaque segments. Conversely, in lower extremity arterial segments of patients with diabetes, we observed significantly lower ppara, acox1, and cpt1a expression (p < 0.05, p < 0.001, and p < 0.0001 respectively). Interestingly, CPT1A content was lower in arterial segments of patients with diabetes (p < 0.05). Hemoglobin A1c and HDL-cholesterol had negative correlations with ppara (R2 = 0.44, p < 0.05; R2 = 0.42, p < 0.05; respectively). Conclusion This study demonstrates the significant differential expression of ppara and its immediate downstream genes in human carotid and lower extremity arteries relative to disease severity and diabetes. These findings highlight that mechanisms that influence atheroprogression in the carotid and lower extremities peripheral arteries are not homogenous and can be impacted by patient diabetes status and serum cholesterol profiles. Further elucidating these differential molecular mechanisms can help improve targeted therapy of atherosclerosis in different peripheral arterial beds.
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Affiliation(s)
- Connor Engel
- Section of Vascular Surgery, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Rodrigo Meade
- Section of Vascular Surgery, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Nikolai Harroun
- Section of Vascular Surgery, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Amanda Penrose
- Section of Vascular Surgery, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Mehreen Shafqat
- Section of Vascular Surgery, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Xiaohua Jin
- Section of Vascular Surgery, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Gayan DeSilva
- Section of Vascular Surgery, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Clay Semenkovich
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University in St. Louis School of Medicine, St. Louis, MO, United States
| | - Mohamed Zayed
- Section of Vascular Surgery, Department of Surgery, Washington University in St. Louis School of Medicine, St. Louis, MO, United States,Division of Molecular Cell Biology, Washington University in St. Louis School of Medicine, St. Louis, MO, United States,Department of Biomedical Engineering, McKelvey School of Engineering, Washington University in St. Louis, St. Louis, MO, United States,Veterans Affairs St. Louis Health Care System, St. Louis, MO, United States,*Correspondence: Mohamed Zayed,
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Su S, Billy LJ, Chang S, Gonzalez FJ, Patterson AD, Peters JM. The role of mouse and human peroxisome proliferator-activated receptor-α in modulating the hepatic effects of perfluorooctane sulfonate in mice. Toxicology 2022; 465:153056. [PMID: 34861291 PMCID: PMC10292111 DOI: 10.1016/j.tox.2021.153056] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 11/16/2021] [Accepted: 11/29/2021] [Indexed: 12/13/2022]
Abstract
Perfluorooctane sulfonate (PFOS) is a stable environmental contaminant that can activate peroxisome proliferator-activated receptor alpha (PPARα). In the present work, the specific role of mouse and human PPARα in mediating the hepatic effects of PFOS was examined in short-term studies using wild type, Ppara-null and PPARA-humanized mice. Mice fed 0.006 % PFOS for seven days (∼10 mg/kg/day), or 0.003 % PFOS for twenty-eight days (∼5 mg/kg/day), exhibited higher liver and serum PFOS concentrations compared to controls. Relative liver weights were also higher following exposure to dietary PFOS in all three genotypes as compared vehicle fed control groups. Histopathological examination of liver sections from mice treated for twenty-eight days with 0.003 % PFOS revealed a phenotype consistent with peroxisome proliferation, in wild-type and PPARA-humanized mice that was not observed in Ppara-null mice. With both exposures, expression of the PPARα target genes, Acox1, Cyp4a10, was significantly increased in wild type mice but not in Ppara-null or PPARA-humanized mice. By contrast, expression of the constitutive androstane receptor (CAR) target gene, Cyp2b10, and the pregnane X receptor (PXR) target gene, Cyp3a11, were higher in response to PFOS administration in all three genotypes compared to controls for both exposure periods. These results indicate that mouse PPARα can be activated in the liver by PFOS causing increased expression of Acox1, Cyp4a10 and histopathological changes in the liver. While histopathological analyses indicated the presence of mouse PPARα-dependent hepatic peroxisome proliferation in wild-type (a response associated with activation of PPARα) and a similar phenotype in PPARA-humanized mice, the lack of increased Acox1 and Cyp4a10 mRNA by PFOS in PPARA-humanized mice indicates that the human PPARα was not as responsive to PFOS as mouse PPARα with this dose regimen. Moreover, results indicate that hepatomegaly caused by PFOS does not require mouse or human PPARα and could be due to effects induced by activation of CAR and/or PXR.
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Affiliation(s)
- Shengzhong Su
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, United States.
| | - Laura J Billy
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, United States
| | - Sue Chang
- Corporate Occupational Medicine, 3M Company, St. Paul, MN, United States
| | - Frank J Gonzalez
- Laboratory of Metabolism, National Cancer Institute, Bethesda, MD, United States
| | - Andrew D Patterson
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, United States
| | - Jeffrey M Peters
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA, United States
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Hinds TD, Kipp ZA, Xu M, Yiannikouris FB, Morris AJ, Stec DF, Wahli W, Stec DE. Adipose-Specific PPARα Knockout Mice Have Increased Lipogenesis by PASK-SREBP1 Signaling and a Polarity Shift to Inflammatory Macrophages in White Adipose Tissue. Cells 2021; 11:4. [PMID: 35011564 PMCID: PMC8750478 DOI: 10.3390/cells11010004] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 12/16/2022] Open
Abstract
The nuclear receptor PPARα is associated with reducing adiposity, especially in the liver, where it transactivates genes for β-oxidation. Contrarily, the function of PPARα in extrahepatic tissues is less known. Therefore, we established the first adipose-specific PPARα knockout (PparaFatKO) mice to determine the signaling position of PPARα in adipose tissue expansion that occurs during the development of obesity. To assess the function of PPARα in adiposity, female and male mice were placed on a high-fat diet (HFD) or normal chow for 30 weeks. Only the male PparaFatKO animals had significantly more adiposity in the inguinal white adipose tissue (iWAT) and brown adipose tissue (BAT) with HFD, compared to control littermates. No changes in adiposity were observed in female mice compared to control littermates. In the males, the loss of PPARα signaling in adipocytes caused significantly higher cholesterol esters, activation of the transcription factor sterol regulatory element-binding protein-1 (SREBP-1), and a shift in macrophage polarity from M2 to M1 macrophages. We found that the loss of adipocyte PPARα caused significantly higher expression of the Per-Arnt-Sim kinase (PASK), a kinase that activates SREBP-1. The hyperactivity of the PASK-SREBP-1 axis significantly increased the lipogenesis proteins fatty acid synthase (FAS) and stearoyl-Coenzyme A desaturase 1 (SCD1) and raised the expression of genes for cholesterol metabolism (Scarb1, Abcg1, and Abca1). The loss of adipocyte PPARα increased Nos2 in the males, an M1 macrophage marker indicating that the population of macrophages had changed to proinflammatory. Our results demonstrate the first adipose-specific actions for PPARα in protecting against lipogenesis, inflammation, and cholesterol ester accumulation that leads to adipocyte tissue expansion in obesity.
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Affiliation(s)
- Terry D. Hinds
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY 40508, USA; (Z.A.K.); (M.X.); (F.B.Y.)
- Barnstable Brown Diabetes Center, University of Kentucky, Lexington, KY 40508, USA
- Markey Cancer Center, University of Kentucky, Lexington, KY 40508, USA
| | - Zachary A. Kipp
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY 40508, USA; (Z.A.K.); (M.X.); (F.B.Y.)
| | - Mei Xu
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY 40508, USA; (Z.A.K.); (M.X.); (F.B.Y.)
| | - Frederique B. Yiannikouris
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY 40508, USA; (Z.A.K.); (M.X.); (F.B.Y.)
- Barnstable Brown Diabetes Center, University of Kentucky, Lexington, KY 40508, USA
| | - Andrew J. Morris
- Division of Cardiovascular Medicine, College of Medicine, University of Kentucky, Lexington, KY 40508, USA;
- Lexington Veterans Affairs Medical Center, Lexington, KY 40508, USA
| | - Donald F. Stec
- Small Molecule NMR Facility Core, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37235, USA;
| | - Walter Wahli
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Clinical Sciences Building, Singapore 308232, Singapore;
- Toxalim Research Center in Food Toxicology (UMR 1331), INRAE, ENVT, INP—PURPAN, UPS, Université de Toulouse, F-31300 Toulouse, France
- Center for Integrative Genomics, Université de Lausanne, Le Génopode, CH-1015 Lausanne, Switzerland
| | - David E. Stec
- Department of Physiology & Biophysics, Cardiorenal and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, MS 39216, USA
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Yang Z, Roth K, Agarwal M, Liu W, Petriello MC. The transcription factors CREBH, PPARa, and FOXO1 as critical hepatic mediators of diet-induced metabolic dysregulation. J Nutr Biochem 2021; 95:108633. [PMID: 33789150 PMCID: PMC8355060 DOI: 10.1016/j.jnutbio.2021.108633] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 01/31/2021] [Accepted: 03/09/2021] [Indexed: 02/06/2023]
Abstract
The liver is a critical mediator of lipid and/or glucose homeostasis and is a primary organ involved in dynamic changes during feeding and fasting. Additionally, hepatic-centric pathways are prone to dysregulation during pathophysiological states including metabolic syndrome (MetS) and non-alcoholic fatty liver disease. Omics platforms and GWAS have elucidated genes related to increased risk of developing MetS and related disorders, but mutations in these metabolism-related genes are rare and cannot fully explain the increasing prevalence of MetS-related pathologies worldwide. Complex interactions between diet, lifestyle, environmental factors, and genetic predisposition jointly determine inter-individual variability of disease risk. Given the complexity of these interactions, researchers have focused on master regulators of metabolic responses incorporating and mediating the impact of multiple environmental cues. Transcription factors are DNA binding, terminal executors of signaling pathways that modulate the cellular responses to complex metabolic stimuli and are related to the control of hepatic lipid and glucose homeostasis. Among numerous hepatic transcription factors involved in regulating metabolism, three emerge as key players in transducing nutrient sensing, which are dysregulated in MetS-related perturbations in both clinical and preclinical studies: cAMP Responsive Element Binding Protein 3 Like 3 (CREB3L3), Peroxisome Proliferator Activated Receptor Alpha (PPAR), and Forkhead Box O1 (FOXO1). Additionally, these three transcription factors appear to be amenable to dietary and/or nutrient-based therapies, being potential targets of nutritional therapy. In this review we aim to describe the activation, regulation, and impact of these transcription factors in the context of metabolic homeostasis. We also summarize their perspectives in MetS and nutritional therapies.
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Affiliation(s)
- Zhao Yang
- Institute of Environmental Health Sciences (IEHS), Wayne State University, Detroit, MI, USA
| | - Katherine Roth
- Institute of Environmental Health Sciences (IEHS), Wayne State University, Detroit, MI, USA
| | - Manisha Agarwal
- Department of Pharmacology, School of Medicine, Wayne State University, Detroit, MI, USA
| | - Wanqing Liu
- Department of Pharmacology, School of Medicine, Wayne State University, Detroit, MI, USA; Department of Pharmaceutical Sciences, College of Pharmacy, Wayne State University, Detroit, MI, USA
| | - Michael C Petriello
- Institute of Environmental Health Sciences (IEHS), Wayne State University, Detroit, MI, USA; Department of Pharmacology, School of Medicine, Wayne State University, Detroit, MI, USA.
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9
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Foreman JE, Koga T, Kosyk O, Kang BH, Zhu X, Cohen SM, Billy LJ, Sharma AK, Amin S, Gonzalez FJ, Rusyn I, Peters JM. Species differences between mouse and human PPARα in modulating the hepatocarcinogenic effects of perinatal exposure to a high-affinity human PPARα agonist in mice. Toxicol Sci 2021; 183:81-92. [PMID: 34081146 DOI: 10.1093/toxsci/kfab068] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Evidence suggests that species differences exist between rodents and humans in their biological responses to ligand activation of PPARα. Moreover, neonatal/postnatal rodents may be more sensitive to the effects of activating PPARα. Thus, the present studies examined the effects of chronic ligand activation of PPARα initiated during early neonatal development and continued into adulthood on hepatocarcinogenesis in mice. Wild-type, Ppara-null, or PPARA-humanized mice were administered a potent, high affinity human PPARα agonist GW7647, and cohorts of mice were examined over time. Activation of PPARα with GW7647 increased expression of known PPARα target genes in liver and was associated with hepatomegaly, increased hepatic cytotoxicity and necrosis, increased expression of hepatic MYC, and a high incidence of hepatocarcinogenesis in wild-type mice. These effects did not occur or were largely diminished in Ppara-null and PPARA-humanized mice, although background levels of hepatocarcinogenesis were also noted in both Ppara-null and PPARA-humanized mice. More fatty change (steatosis) was also observed in both Ppara-null and PPARA-humanized mice independent of GW7647 administration. Results from these studies indicate that the mouse PPARα is required to mediate hepatocarcinogenesis induced by GW7647 in mice and that activation of the human PPARα with GW7647 in PPARA-humanized mice are diminished compared to wild-type mice. Ppara-null and PPARA-humanized mice are valuable tools for examining species differences in the mechanisms of PPARα-induced hepatocarcinogenesis, but background levels of liver cancer observed in aged Ppara-null and PPARA-humanized mice must be considered when interpreting results from studies that use these models. These results also demonstrate that early life exposure to a potent human PPARα agonist does not enhance sensitivity to hepatocarcinogenesis.
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Affiliation(s)
- Jennifer E Foreman
- Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania
| | - Takayuki Koga
- Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania
| | - Oksana Kosyk
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina
| | - Boo-Hyon Kang
- Non-clinical Research Institute, Yangji, Yongin, 17162, Gu Chemon, Myeon, Cheoin-, Si, Gyeonggi-Do Korea
| | - Xiaoyang Zhu
- Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania
| | - Samuel M Cohen
- Havlik-Wall Professor of Oncology, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, 68198-3135
| | - Laura J Billy
- Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania
| | - Arun K Sharma
- Department of Pharmacology, The Pennsylvania State University, Hershey, Pennsylvania
| | - Shantu Amin
- Department of Pharmacology, The Pennsylvania State University, Hershey, Pennsylvania
| | - Frank J Gonzalez
- Laboratory of Metabolism, National Cancer Institute, Bethesda, Maryland
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas
| | - Jeffrey M Peters
- Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania
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10
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Foreman JE, Koga T, Kosyk O, Kang BH, Zhu X, Cohen SM, Billy LJ, Sharma AK, Amin S, Gonzalez FJ, Rusyn I, Peters JM. Diminished hepatocarcinogenesis by a potent, high affinity human PPARα agonist in PPARA-humanized mice. Toxicol Sci 2021; 183:70-80. [PMID: 34081128 DOI: 10.1093/toxsci/kfab067] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Ppara-null and PPARA-humanized mice are refractory to hepatocarcinogenesis caused by the peroxisome proliferator-activated receptor-α (PPARα) agonist Wy-14,643. However, the duration of these earlier studies was limited to approximately one year of treatment, and the ligand used has higher affinity for the mouse PPARα compared to the human PPARα. Thus, the present study examined the effect of long-term administration of a potent, high affinity human PPARα agonist (GW7647) on hepatocarcinogenesis in wild-type, Ppara-null, or PPARA-humanized mice. In wild-type mice, GW7647 caused hepatic expression of known PPARα target genes, hepatomegaly, hepatic MYC expression, hepatic cytotoxicity, and a high incidence of hepatocarcinogenesis. By contrast, these effects were essentially absent in Ppara-null mice or diminished in PPARA-humanized mice, although hepatocarcinogenesis was observed in both genotypes. Enhanced fatty change (steatosis) was also observed in both Ppara-null and PPARA-humanized mice independent of GW7647. PPARA-humanized mice administered GW7647 also exhibited increased necrosis after five weeks of treatment. Results from these studies demonstrate that the mouse PPARα is required for hepatocarcinogenesis induced by GW7647 administered throughout adulthood. Results also indicate that a species difference exists between rodent and human PPARα in the response to ligand activation of PPARα. The hepatocarcinogenesis observed in control and treated Ppara-null mice is likely mediated in part by increased hepatic fatty change, whereas the hepatocarcinogenesis observed in PPARA-humanized mice may also be due to enhanced fatty change and cytotoxicity that could be influenced by minimal activity of the human PPARα in this mouse line on downstream mouse PPARα target genes. The Ppara-null and PPARA-humanized mouse models are valuable tools for examining the mechanisms of PPARα-induced hepatocarcinogenesis but the background level of liver cancer must be controlled for in the design and interpretation of studies that use these mice.
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Affiliation(s)
- Jennifer E Foreman
- Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania
| | - Takayuki Koga
- Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania
| | - Oksana Kosyk
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina
| | - Boo-Hyon Kang
- Non-clinical Research Institute, Chemon, Yangji-Myeon, Yongin, 17162, Gu Cheoin-, Si, Gyeonggi-Do Korea
| | - Xiaoyang Zhu
- Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania
| | - Samuel M Cohen
- Havlik-Wall Professor of Oncology, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, 68198-3135
| | - Laura J Billy
- Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania
| | - Arun K Sharma
- Department of Pharmacology, The Pennsylvania State University, Hershey, Pennsylvania
| | - Shantu Amin
- Department of Pharmacology, The Pennsylvania State University, Hershey, Pennsylvania
| | - Frank J Gonzalez
- Laboratory of Metabolism, National Cancer Institute, Bethesda, Maryland
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas
| | - Jeffrey M Peters
- Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania
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11
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Azar S, Udi S, Drori A, Hadar R, Nemirovski A, Vemuri KV, Miller M, Sherill-Rofe D, Arad Y, Gur-Wahnon D, Li X, Makriyannis A, Ben-Zvi D, Tabach Y, Ben-Dov IZ, Tam J. Reversal of diet-induced hepatic steatosis by peripheral CB1 receptor blockade in mice is p53/miRNA-22/SIRT1/PPARα dependent. Mol Metab 2020; 42:101087. [PMID: 32987186 PMCID: PMC7563015 DOI: 10.1016/j.molmet.2020.101087] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 09/03/2020] [Accepted: 09/17/2020] [Indexed: 02/06/2023] Open
Abstract
OBJECTIVE The endocannabinoid (eCB) system is increasingly recognized as being crucially important in obesity-related hepatic steatosis. By activating the hepatic cannabinoid-1 receptor (CB1R), eCBs modulate lipogenesis and fatty acid oxidation. However, the underlying molecular mechanisms are largely unknown. METHODS We combined unbiased bioinformatics techniques, mouse genetic manipulations, multiple pharmacological, molecular, and cellular biology approaches, and genomic sequencing to systematically decipher the role of the hepatic CB1R in modulating fat utilization in the liver and explored the downstream molecular mechanisms. RESULTS Using an unbiased normalized phylogenetic profiling analysis, we found that the CB1R evolutionarily coevolves with peroxisome proliferator-activated receptor-alpha (PPARα), a key regulator of hepatic lipid metabolism. In diet-induced obese (DIO) mice, peripheral CB1R blockade (using AM6545) induced the reversal of hepatic steatosis and improved liver injury in WT, but not in PPARα-/- mice. The antisteatotic effect mediated by AM6545 in WT DIO mice was accompanied by increased hepatic expression and activity of PPARα as well as elevated hepatic levels of the PPARα-activating eCB-like molecules oleoylethanolamide and palmitoylethanolamide. Moreover, AM6545 was unable to rescue hepatic steatosis in DIO mice lacking liver sirtuin 1 (SIRT1), an upstream regulator of PPARα. Both of these signaling molecules were modulated by the CB1R as measured in hepatocytes exposed to lipotoxic conditions or treated with CB1R agonists in the absence/presence of AM6545. Furthermore, using microRNA transcriptomic profiling, we found that the CB1R regulated the hepatic expression, acetylation, and transcriptional activity of p53, resulting in the enhanced expression of miR-22, which was found to specifically target SIRT1 and PPARα. CONCLUSIONS We provide strong evidence for a functional role of the p53/miR-22/SIRT1/PPARα signaling pathway in potentially mediating the antisteatotic effect of peripherally restricted CB1R blockade.
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Affiliation(s)
- Shahar Azar
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Shiran Udi
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Adi Drori
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rivka Hadar
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Alina Nemirovski
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Kiran V Vemuri
- Center for Drug Discovery, Northeastern University, Boston, MA, USA
| | - Maya Miller
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hadassah Medical School, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dana Sherill-Rofe
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hadassah Medical School, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yhara Arad
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hadassah Medical School, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Devorah Gur-Wahnon
- Laboratory of Medical Transcriptomics, Department of Nephrology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Xiaoling Li
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | | | - Danny Ben-Zvi
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hadassah Medical School, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yuval Tabach
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Hadassah Medical School, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Iddo Z Ben-Dov
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Joseph Tam
- Obesity and Metabolism Laboratory, Institute for Drug Research, School of Pharmacy, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.
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12
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Piao L, Dorotea D, Jiang S, Koh EH, Oh GT, Ha H. Impaired Peroxisomal Fitness in Obese Mice, a Vicious Cycle Exacerbating Adipocyte Dysfunction via Oxidative Stress. Antioxid Redox Signal 2019; 31:1339-1351. [PMID: 31530170 PMCID: PMC6859694 DOI: 10.1089/ars.2018.7614] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Aims: Peroxisome is a critical organelle for fatty acid oxidation (FAO) and metabolism of reactive oxygen species (ROS). Increased oxidative stress in adipose tissue contributes to the development of insulin resistance and metabolic syndrome in obesity. This study aimed to investigate the role of peroxisomal fitness in maintaining adipocyte function, which has been under-rated in the obesity research area. Results: Reduced peroxisomal gene expressions in white adipose tissue (WAT) of obese mice suggested a close correlation between peroxisomes and obesity. Peroxisomal biogenesis factor 5 siRNA increased cellular ROS and inflammatory mediators in 3T3-L1 adipocytes. On the contrary, hydrogen peroxide or tumor necrosis factor-α treatment significantly decreased biogenesis- and function-related peroxisomal proteins, suggesting a positive feedback loop of ROS/inflammation and peroxisomal dysfunction. Correspondingly, catalase (a major peroxisomal antioxidant)-knockout mice fed with high-fat diet (HFD) exhibited suppressed peroxisomal proteins along with increased oxidative stress and accelerated obesity. In response to fenofibrate (a peroxisomal proliferator) treatment, WAT of HFD-fed wild-type mice showed not only increases in peroxisomal biogenesis and FAO but also attenuated features of adipocyte dysfunction and obesity. However, these results were not observed in peroxisome proliferator-activated receptor-alpha null obese mice. Innovation: Impaired peroxisomal fitness enhanced oxidative stress and inflammation in adipocytes, which exacerbates obesity. Conclusion: Adipose tissue peroxisomal homeostasis plays an important role in attenuating the features of obesity, and it can be a potential therapeutic target of obesity.
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Affiliation(s)
- Lingjuan Piao
- Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, Seoul, Republic of Korea.,Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Debra Dorotea
- Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, Seoul, Republic of Korea
| | - Songling Jiang
- Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, Seoul, Republic of Korea
| | - Eun Hee Koh
- Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul, Republic of Korea.,Department of Internal Medicine, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Goo Taeg Oh
- Department of Life Sciences, Ewha Womans University, Seoul, Republic of Korea
| | - Hunjoo Ha
- Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, Seoul, Republic of Korea
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13
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Stec DE, Gordon DM, Hipp JA, Hong S, Mitchell ZL, Franco NR, Robison JW, Anderson CD, Stec DF, Hinds TD. Loss of hepatic PPARα promotes inflammation and serum hyperlipidemia in diet-induced obesity. Am J Physiol Regul Integr Comp Physiol 2019; 317:R733-R745. [PMID: 31483154 DOI: 10.1152/ajpregu.00153.2019] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Agonists for PPARα are used clinically to reduce triglycerides and improve high-density lipoprotein (HDL) cholesterol levels in patients with hyperlipidemia. Whether the mechanism of PPARα activation to lower serum lipids occurs in the liver or other tissues is unknown. To determine the function of hepatic PPARα on lipid profiles in diet-induced obese mice, we placed hepatocyte-specific peroxisome proliferator-activated receptor-α (PPARα) knockout (PparaHepKO) and wild-type (Pparafl/fl) mice on high-fat diet (HFD) or normal fat diet (NFD) for 12 wk. There was no significant difference in weight gain, percent body fat mass, or percent body lean mass between the groups of mice in response to HFD or NFD. Interestingly, the PparaHepKO mice on HFD had worsened hepatic inflammation and a significant shift in the proinflammatory M1 macrophage population. These changes were associated with higher hepatic fat mass and decreased hepatic lean mass in the PparαHepKO on HFD but not in NFD as measured by Oil Red O and noninvasive EchoMRI analysis (31.1 ± 2.8 vs. 20.2 ± 1.5, 66.6 ± 2.5 vs. 76.4 ± 1.5%, P < 0.05). We did find that this was related to significantly reduced peroxisomal gene function and lower plasma β-hydroxybutyrate in the PparaHepKO on HFD, indicative of reduced metabolism of fats in the liver. Together, these provoked higher plasma triglyceride and apolipoprotein B100 levels in the PparaHepKO mice compared with Pparafl/fl on HFD. These data indicate that hepatic PPARα functions to control inflammation and liver triglyceride accumulation that prevent hyperlipidemia.
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Affiliation(s)
- David E Stec
- Department of Physiology & Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, Mississippi
| | - Darren M Gordon
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, Ohio
| | - Jennifer A Hipp
- Department of Pathology, University of Toledo College of Medicine, Toledo, Ohio
| | - Stephen Hong
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, Ohio
| | - Zachary L Mitchell
- Department of Physiology & Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, Mississippi
| | - Natalia R Franco
- Department of Physiology & Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, Mississippi
| | - J Walker Robison
- Department of Physiology & Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, Mississippi
| | - Christopher D Anderson
- Department of Surgery and Medicine, University of Mississippi Medical Center, Jackson, Mississippi
| | - Donald F Stec
- Small Molecule NMR Facility Core, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee
| | - Terry D Hinds
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, Ohio
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14
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Konstandi M, Kypreos KE, Matsubara T, Xepapadaki E, Shah YM, Krausz K, Andriopoulou CE, Kofinas A, Gonzalez FJ. Adrenoceptor-related decrease in serum triglycerides is independent of PPARα activation. FEBS J 2019; 286:4328-4341. [PMID: 31230416 DOI: 10.1111/febs.14966] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 04/05/2019] [Accepted: 05/19/2019] [Indexed: 12/15/2022]
Abstract
Adrenoceptor (AR)-linked pathways belong to the major components of the stress response system and are associated with the pathophysiology of diseases within the spectrum of metabolic syndrome. In this study, the role of adrenoceptor stimulation in serum triglyceride (TG) regulation in mice was investigated. For this purpose, α1 -ARs were activated with phenylephrine (PH) and β1/2 -ARs with isoprenaline (ISOP). Both AR agonists markedly reduced serum TG levels independently of PPARα activation. These drugs also significantly activated the hormone-sensitive lipase in the white adipose tissue indicating increased mobilization of TGs in this tissue. In addition, PH and ISOP up-regulated Lpl, Nr4A, Dgat1, Mttp, Aadac and Cd36 genes, critical in TG regulation, whereas the observed decrease in serum TG levels was independent of the hepatic very low-density lipoprotein (VLDL)-TG secretion. Interestingly, PH and ISOP also inactivated the hepatic insulin/PI3k/AKT/FoxO1 signaling pathway, holding a critical role in the regulation of genes involved in TG synthesis. Taken together, the findings of the present study indicate that stimulation of α1 - and β1/2 -ARs markedly reduced serum TG steady-state levels as a result of alterations in TG synthesis, uptake, transport, hydrolysis, metabolism and clearance, an effect induced by PPARα independent mechanisms.
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Affiliation(s)
- Maria Konstandi
- Department of Pharmacology, Faculty of Medicine, University of Ioannina, Greece.,Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Kyriakos E Kypreos
- Department of Pharmacology, Faculty of Medicine, University of Patras, Rio, Greece
| | - Tsutomu Matsubara
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.,Department of Anatomy and Regenerative Biology, Graduate School of Medicine, Osaka City University, Japan
| | - Eva Xepapadaki
- Department of Pharmacology, Faculty of Medicine, University of Patras, Rio, Greece
| | - Yatrik M Shah
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.,Department of Molecular and Integrative Physiology, Medical School, University of Michigan, Ann Arbor, MI, USA
| | - Kristopher Krausz
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | | | - Aristeidis Kofinas
- Department of Pharmacology, Faculty of Medicine, University of Ioannina, Greece
| | - Frank J Gonzalez
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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15
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Peters JM, Kim DJ, Bility MT, Borland MG, Zhu B, Gonzalez FJ. Regulatory mechanisms mediated by peroxisome proliferator-activated receptor-β/δ in skin cancer. Mol Carcinog 2019; 58:1612-1622. [PMID: 31062422 DOI: 10.1002/mc.23033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 04/12/2019] [Accepted: 04/15/2019] [Indexed: 12/21/2022]
Abstract
Considerable progress has been made during the past 20 years towards elucidating the role of peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) in skin cancer. In 1999, the original notion that PPARβ/δ was involved with epithelial cell function was postulated based on a correlation between PPARβ/δ expression and the induction of messenger RNAs encoding proteins that mediate terminal differentiation in keratinocytes. Subsequent studies definitively revealed that PPARβ/δ could induce terminal differentiation and inhibit proliferation of keratinocytes. Molecular mechanisms have since been discovered to explain how this nuclear receptor can be targeted for preventing and treating skin cancer. This includes the regulation of terminal differentiation, mitotic signaling, endoplasmic reticulum stress, and cellular senescence. Interestingly, the effects of activating PPARβ/δ can preferentially target keratinocytes with genetic mutations associated with skin cancer. This review provides the history and current understanding of how PPARβ/δ can be targeted for both nonmelanoma skin cancer and melanoma and postulates how future approaches that modulate PPARβ/δ signaling may be developed for the prevention and treatment of these diseases.
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Affiliation(s)
- Jeffrey M Peters
- Department of Veterinary and Biomedical Sciences, The Center of Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania
| | - Dae J Kim
- Department of Molecular Science, School of Medicine, University of Texas Rio Grande Valley, Edinburg, Texas
| | - Moses T Bility
- Department of Infectious Diseases and Microbiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Michael G Borland
- Department of Chemistry & Biochemistry, Bloomsburg University of Pennsylvania, Bloomsburg, Pennsylvania
| | - Bokai Zhu
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
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16
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Russell JA, Brunton PJ. Giving a good start to a new life via maternal brain allostatic adaptations in pregnancy. Front Neuroendocrinol 2019; 53:100739. [PMID: 30802468 DOI: 10.1016/j.yfrne.2019.02.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 01/29/2019] [Accepted: 02/21/2019] [Indexed: 12/23/2022]
Abstract
Successful pregnancy requires adjustments to multiple maternal homeostatic mechanisms, governed by the maternal brain to support and enable survival of the growing fetus and placenta. Such adjustments fit the concept of allostasis (stability through change) and have a cost: allostatic load. Allostasis is driven by ovarian, anterior pituitary, placental and feto-placental hormones acting on the maternal brain to promote adaptations that support the pregnancy and protect the fetus. Many women carry an existing allostatic load into pregnancy, from socio-economic circumstances, poor mental health and in 'developed' countries, also from obesity. These pregnancies have poorer outcomes indicating negative interactions (failing allostasis) between pre-pregnancy and pregnancy allostatic loads. Use of animal models, such as adult prenatally stressed female offspring with abnormal neuroendocrine, metabolic and behavioural phenotypes, to probe gene expression changes, and epigenetic mechanisms in the maternal brain in adverse pregnancies are discussed, with the prospect of ameliorating poor pregnancy outcomes.
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Affiliation(s)
- John A Russell
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland, UK
| | - Paula J Brunton
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland, UK; Zhejiang University-University of Edinburgh Institute, Haining, Zhejiang, PR China.
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17
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Ferrara-Romeo I, Martínez P, Blasco MA. Mice lacking RAP1 show early onset and higher rates of DEN-induced hepatocellular carcinomas in female mice. PLoS One 2018; 13:e0204909. [PMID: 30307978 PMCID: PMC6187989 DOI: 10.1371/journal.pone.0204909] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 09/17/2018] [Indexed: 02/07/2023] Open
Abstract
RAP1, a component of the telomere-protective shelterin complex, has been shown to have both telomeric and non-telomeric roles. In the liver, RAP1 is involved in the regulation of metabolic transcriptional programs. RAP1-deficient mice develop obesity and hepatic steatosis, these phenotypes being more severe in females than in males. As hepatic steatosis and obesity have been related to increased liver cancer in mice and humans, we set out to address whether RAP1 deficiency resulted in increased liver cancer upon chemical liver carcinogenesis. We found that Rap1-/- females were more susceptible to DEN-induced liver damage and hepatocellular carcinoma (HCC). DEN-treated Rap1-/- female livers showed an earlier onset of both premalignant and malignant liver lesions, which were characterized by increased abundance of γH2AX-positive cells, increased proliferation and shorter telomeres. These findings highlight an important role for RAP1 in protection from liver damage and liver cancer.
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Affiliation(s)
- Iole Ferrara-Romeo
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, Madrid, Spain
| | - Paula Martínez
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, Madrid, Spain
| | - Maria A. Blasco
- Telomeres and Telomerase Group, Molecular Oncology Program, Spanish National Cancer Centre (CNIO), Melchor Fernández Almagro 3, Madrid, Spain
- * E-mail:
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18
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Wang R, Li H, Yang X, Xue X, Deng L, Shen J, Zhang M, Zhao L, Zhang C. Genetically Obese Human Gut Microbiota Induces Liver Steatosis in Germ-Free Mice Fed on Normal Diet. Front Microbiol 2018; 9:1602. [PMID: 30079055 PMCID: PMC6062601 DOI: 10.3389/fmicb.2018.01602] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 06/27/2018] [Indexed: 12/29/2022] Open
Abstract
Dysbiotic gut microbiota contributes to genetically obese phenotype in human. However, the effect of genetic obesity-associated gut microbiota on host hepatic metabolic deteriorations remains largely unknown. Gut microbiota from a genetically obese human donor before and after a dietary weight loss program was transplanted into germ-free C57BL/6J male mice, grouped as PreM and PostM groups, respectively. The gut microbiome, liver pathology and transcriptome response in the gnotobiotic mice were evaluated. After being fed on normal chow diet for 4 weeks, PreM group developed liver macrovesicular steatosis accompanied with higher concentrations of hepatic triglyceride and cholesterol, while PostM group exhibited normal hepatic physiology. The gut microbiota in PreM and PostM groups was significantly different from each other and was more resembling with their respective donor. RNA-sequencing revealed that, in comparison with PostM group, PreM group showed a foregoing pro-steatotic transcriptional response in liver featuring by the repression of lipid beta-oxidation and the activation of lipid absorption and cholesterol uptake before the pathology of liver steatosis. Moreover, peroxisome proliferator-activated receptor alpha (PPARα), which was repressed in PreM group, may act as crucial regulator of the hepatic transcriptional profile of lipid metabolism between two groups. Our results show that gut microbiota from a genetically obese human promotes the onset of liver steatosis by impacting hepatic transcriptional profile of lipid metabolism in mice. This adds new evidence that gut microbiota may play a causative role in the development of non-alcoholic fatty liver disease.
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Affiliation(s)
- Ruirui Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Hui Li
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xin Yang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xinhe Xue
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Liman Deng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Jian Shen
- Ministry of Education Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China
| | - Menghui Zhang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Liping Zhao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.,Ministry of Education Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China.,Department of Biochemistry and Microbiology, School of Environmental and Biological Sciences, Rutgers New Jersey Institute for Food, Nutrition, and Health, Rutgers University-New Brunswick, New Brunswick, NJ, United States
| | - Chenhong Zhang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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19
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Malliou F, Andreadou I, Gonzalez FJ, Lazou A, Xepapadaki E, Vallianou I, Lambrinidis G, Mikros E, Marselos M, Skaltsounis AL, Konstandi M. The olive constituent oleuropein, as a PPARα agonist, markedly reduces serum triglycerides. J Nutr Biochem 2018; 59:17-28. [PMID: 29960113 DOI: 10.1016/j.jnutbio.2018.05.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 04/30/2018] [Accepted: 05/14/2018] [Indexed: 02/06/2023]
Abstract
Oleuropein (OLE), a main constituent of olive, exhibits antioxidant and hypolipidemic effects, while it reduces the infarct size in chow- and cholesterol-fed rabbits. Peroxisome proliferator-activated receptor α (PPARα) has essential roles in the control of lipid metabolism and energy homeostasis. This study focused on the mechanisms underlying the hypolipidemic activity of OLE and, specifically, on the role of PPARα activation in the OLE-induced effect. Theoretical approach using Molecular Docking Simulations and luciferase reporter gene assay indicated that OLE is a ligand of PPARα. The effect of OLE (100 mg/kg, p.o., per day, ×6 weeks) on serum triglyceride (TG) and cholesterol levels was also assessed in adult male wild-type and Ppara-null mice. Molecular Docking Simulations, Luciferase reporter gene assay and gene expression analysis indicated that OLE is a PPARα agonist that up-regulates several PPARα target genes in the liver. This effect was associated with a significant reduction of serum TG and cholesterol levels. In contrast, OLE had no effect in Ppara-null mice, indicating a direct involvement of PPARα in the OLE-induced serum TG and cholesterol reduction. Activation of hormone-sensitive lipase in the white adipose tissue (WAT) and the liver of wild-type mice and up-regulation of several hepatic factors involved in TG uptake, transport, metabolism and clearance may also contribute in the OLE-induced TG reduction. In summary, OLE has a beneficial effect on TG homeostasis via PPARα activation. OLE also activates the hormone sensitive lipase in the WAT and liver and up-regulates several hepatic genes with essential roles in TG homeostasis.
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Affiliation(s)
- Foteini Malliou
- University of Ioannina, Faculty of Medicine, Department of Pharmacology, Ioannina GR-45110, Greece
| | - Ioanna Andreadou
- National & Kapodistrian University of Athens, Faculty of Pharmacy, Athens, Greece
| | - Frank J Gonzalez
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda 20892, MD, USA
| | - Antigone Lazou
- Aristotle University of Thessaloniki, School of Biology, Laboratory of Animal Physiology, Thessaloniki 54124, Greece
| | - Eva Xepapadaki
- University of Patras, School of Medicine, Department of Pharmacology, Rio, Greece
| | - Ioanna Vallianou
- Aristotle University of Thessaloniki, School of Biology, Laboratory of Animal Physiology, Thessaloniki 54124, Greece
| | - George Lambrinidis
- National & Kapodistrian University of Athens, Faculty of Pharmacy, Athens, Greece
| | - Emmanuel Mikros
- National & Kapodistrian University of Athens, Faculty of Pharmacy, Athens, Greece
| | - Marios Marselos
- University of Ioannina, Faculty of Medicine, Department of Pharmacology, Ioannina GR-45110, Greece
| | | | - Maria Konstandi
- University of Ioannina, Faculty of Medicine, Department of Pharmacology, Ioannina GR-45110, Greece.
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20
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Li G, Brocker CN, Xie C, Yan T, Noguchi A, Krausz KW, Xiang R, Gonzalez FJ. Hepatic peroxisome proliferator-activated receptor alpha mediates the major metabolic effects of Wy-14643. J Gastroenterol Hepatol 2018; 33:1138-1145. [PMID: 29141109 PMCID: PMC6334298 DOI: 10.1111/jgh.14046] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 10/13/2017] [Accepted: 11/06/2017] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIM Peroxisome proliferator-activated receptor alpha (PPARα) is a molecular target of various fibrate drugs clinically used to lower serum lipids. However, the tissue-specific functions of PPARα remain to be elucidated. This study aimed to explore the tissue-specific functions of PPARα in response to Wy-14643. METHODS A hepatocyte-specific Ppara knockout mouse line was used to explore the impact of hepatic PPARα activity on the systemic response to treatment with the potent PPARα agonist Wy-14643. RESULTS Wy-14643 mainly activated hepatic PPARα and regulated the expression of PPARα target genes in liver. Hepatic Ppara disruption abolished the triglyceride lowering effects of Wy-14643, prevented agonist-induced hypophagia, and ablated PPARα target gene response in the liver. CONCLUSIONS These findings indicate that Wy-14643 treatment mainly activates hepatic PPARα, and the hypolipidemic and hypophagic effects of Wy-14643 are dependent on PPARα activation within hepatocytes.
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Affiliation(s)
- Guolin Li
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA,Laboratory of Aging Biochemistry, College of Life Sciences, Changsha, Hunan, China,The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Chad N Brocker
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Cen Xie
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Tingting Yan
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Audrey Noguchi
- Murine Phenotyping Core, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Kristopher W Krausz
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Rong Xiang
- The State Key Laboratory of Medical Genetics and School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
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21
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Kanagaratham C, Chiwara V, Ho B, Moussette S, Youssef M, Venuto D, Jeannotte L, Bourque G, de Sanctis JB, Radzioch D, Naumova AK. Loss of the zona pellucida-binding protein 2 (Zpbp2) gene in mice impacts airway hypersensitivity and lung lipid metabolism in a sex-dependent fashion. Mamm Genome 2018. [PMID: 29536159 DOI: 10.1007/s00335-018-9743-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The human chromosomal region 17q12-q21 is one of the best replicated genome-wide association study loci for childhood asthma. The associated SNPs span a large genomic interval that includes several protein-coding genes. Here, we tested the hypothesis that the zona pellucida-binding protein 2 (ZPBP2) gene residing in this region contributes to asthma pathogenesis using a mouse model. We tested the lung phenotypes of knock-out (KO) mice that carry a deletion of the Zpbp2 gene. The deletion attenuated airway hypersensitivity (AHR) in female, but not male, mice in the absence of allergic sensitization. Analysis of the lipid profiles of their lungs showed that female, but not male, KO mice had significantly lower levels of sphingosine-1-phosphate (S1P), very long-chain ceramides (VLCCs), and higher levels of long-chain ceramides compared to wild-type controls. Furthermore, in females, lung resistance following methacholine challenge correlated with lung S1P levels (Pearson correlation coefficient 0.57) suggesting a link between reduced AHR in KO females, Zpbp2 deletion, and S1P level regulation. In livers, spleens and blood plasma, however, VLCC, S1P, and sphingosine levels were reduced in both KO females and males. We also find that the Zpbp2 deletion was associated with gain of methylation in the adjacent DNA regions. Thus, we demonstrate that the mouse ortholog of ZPBP2 has a role in controlling AHR in female mice. Our data also suggest that Zpbp2 may act through regulation of ceramide metabolism. These findings highlight the importance of phospholipid metabolism for sexual dimorphism in AHR.
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Affiliation(s)
| | - Victoria Chiwara
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Bianca Ho
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Sanny Moussette
- The Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Mina Youssef
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - David Venuto
- McGill University and Genome Quebec Innovation Centre, Montreal, QC, Canada
| | - Lucie Jeannotte
- Département de Biologie moléculaire, Biochimie medicale & Pathologie, Faculté de médecine, Université Laval, Québec, QC, Canada.,Centre de recherche sur le cancer de l'Université Laval, CRCHU de Québec-Université Laval, L'Hôtel-Dieu de Québec, Québec, QC, Canada
| | - Guillaume Bourque
- Department of Human Genetics, McGill University, Montreal, QC, Canada.,McGill University and Genome Quebec Innovation Centre, Montreal, QC, Canada
| | - Juan Bautista de Sanctis
- Institute of Immunology, Faculty of Medicine, Universidad Central de Venezuela, Sabana Grande, Caracas, Venezuela
| | - Danuta Radzioch
- Department of Human Genetics, McGill University, Montreal, QC, Canada.,The Research Institute of the McGill University Health Centre, Montreal, QC, Canada.,Division of Experimental Medicine, Faculty of Medicine, McGill University, Montreal, QC, Canada.,Infectious Diseases and Immunity in Global Health Program (IDIGH), The Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Anna K Naumova
- Department of Human Genetics, McGill University, Montreal, QC, Canada. .,The Research Institute of the McGill University Health Centre, Montreal, QC, Canada. .,Department of Obstetrics and Gynecology, McGill University, Montreal, QC, Canada.
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22
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Zhang Y, Zhang Y, Klaassen CD, Cheng X. Alteration of Bile Acid and Cholesterol Biosynthesis and Transport by Perfluorononanoic Acid (PFNA) in Mice. Toxicol Sci 2018; 162:225-233. [PMID: 29112762 PMCID: PMC6693384 DOI: 10.1093/toxsci/kfx237] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Perfluorochemicals produce hepatotoxic effects via activation of peroxisome proliferator-activated receptor alpha (PPARα) and constitutive androstane receptor (CAR) nuclear receptors in animals. Bile formation is one major liver function. But it remains unknown whether perfluorochemicals alter metabolism of bile acids (BAs) in liver. The present study was designed to determine the impact of perfluorononanoic acid (PFNA) on BA and cholesterol homeostasis in mice. A single dose of PFNA (0.1 mmol/kg) was intraperitoneally administered to adult male wild-type (WT), PPARα-null, and CAR-null mice. PFNA caused cholestasis in the WT mice, indicated by increased serum alanine aminotransferase, hyperbilirubinemia, elevated BA concentrations in mouse serum, and appearance of bile plugs in mouse liver. In addition, PFNA decreased total and some individual BAs in mouse liver. PFNA increased the concentrations of total and taurine-conjugated, as well as some individual BAs in the serum of WT and CAR-null mice but not in PPARα-null mice, indicating a PPARα-dependent mechanism. PFNA decreased mRNA expression of most BA-related transporters (sodium-taurocholate cotransporting polypeptide, organic anion transporting polypeptide [Oatp]1a1, Oatp1b2, and bile salt export pump) and BA biosynthetic enzymes (Cyp7a1, 7b1, 8b1, and 27a1) in mouse liver, but increased mRNA expression of some efflux transporters (breast cancer resistance protein, multidrug resistance transporter 2, multidrug resistance-associated protein [Mrp] 2, Mrp3, and Mrp4), primarily via a PPARα-dependent mechanism. Moreover, PFNA increased free and total cholesterol in mouse liver but not in mouse serum. Furthermore, PFNA increased mRNA expression of sterol transporters, namely Abca1, g1, g5/g8, and steroidogenic acute regulatory protein via PPARα. In conclusion, PFNA produced cholestasis in mouse liver, and the activation of PPARα plays a central role in regulating BA and cholesterol metabolism and transport in mouse serum and liver.
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Affiliation(s)
- Yue Zhang
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John’s University, Jamaica, New York 11439
| | - Youcai Zhang
- Department of Pharmacology and Toxicology, School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072, P.R. China
| | - Curtis D Klaassen
- Department of Environmental & Occupational Health Sciences, School of Public Health, University of Washington, Seattle, Washington 98195
| | - Xingguo Cheng
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John’s University, Jamaica, New York 11439
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23
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Hines IN, Kremer M, Moore SM, Wheeler MD. Impaired T cell-mediated hepatitis in peroxisome proliferator activated receptor alpha (PPARα)-deficient mice. Biol Res 2018; 51:5. [PMID: 29448959 PMCID: PMC5815252 DOI: 10.1186/s40659-018-0153-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 02/06/2018] [Indexed: 12/16/2022] Open
Abstract
Background Peroxisome proliferator activated receptor alpha (PPARα), a regulator of enzymes involved in β oxidation, has been reported to influence lymphocyte activation. The purpose of this study was to determine whether PPARα plays a role in T cell-mediated hepatitis induced by Concanavalin A (ConA). Methods Wild type (wt) or PPARα-deficient (PPARα−/−) mice were treated with ConA (15 mg/kg) by intravenous injection 0, 10 or 24 h prior to sacrifice and serum and tissue collection for analysis of tissue injury, cytokine response, T cell activation and characterization. Results Ten and 24 h following ConA administration, wt mice had significant liver injury as demonstrated by serum transaminase levels, inflammatory cell infiltrate, hepatocyte apoptosis, and expression of several cytokines including interleukin 4 (IL4) and interferon gamma (IFNγ). In contrast, PPARα−/− mice were protected from ConA-induced liver injury with significant reductions in serum enzyme release, greatly reduced inflammatory cell infiltrate, hepatocellular apoptosis, and IFNγ expression, despite having similar levels of hepatic T cell activation and IL4 expression. This resistance to liver injury was correlated with reduced numbers of hepatic natural killer T (NKT) cells and their in vivo responsiveness to alpha-galactosylceramide. Interestingly, adoptive transfer of either wt or PPARα−/− splenocytes reconstituted ConA liver injury and cytokine production in lymphocyte-deficient, severe combined immunodeficient mice implicating PPARα within the liver, possibly through support of IL15 expression and/or suppression of IL12 production and not the lymphocyte as the key regulator of T cell activity and ConA-induced liver injury. Conclusion Taken together, these data suggest that PPARα within the liver plays an important role in ConA-mediated liver injury through regulation of NKT cell recruitment and/or survival.
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Affiliation(s)
- Ian N Hines
- Department of Nutrition Science, College of Allied Health Sciences, East Carolina University, Health Sciences Bldg. Room 4165F, Greenville, NC, 27834, USA. .,Department of Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA.
| | - Michael Kremer
- Department of General Surgery, University of Ulm, Ulm, Germany.,Department of Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Sherri M Moore
- Department of Nutrition Science, College of Allied Health Sciences, East Carolina University, Health Sciences Bldg. Room 4165F, Greenville, NC, 27834, USA
| | - Michael D Wheeler
- Department of Nutrition Science, College of Allied Health Sciences, East Carolina University, Health Sciences Bldg. Room 4165F, Greenville, NC, 27834, USA.,Department of Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
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24
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Li G, Brocker CN, Yan T, Xie C, Krausz KW, Xiang R, Gonzalez FJ. Metabolic adaptation to intermittent fasting is independent of peroxisome proliferator-activated receptor alpha. Mol Metab 2017; 7:80-89. [PMID: 29146411 PMCID: PMC5784329 DOI: 10.1016/j.molmet.2017.10.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/19/2017] [Accepted: 10/24/2017] [Indexed: 12/15/2022] Open
Abstract
Background Peroxisome proliferator-activated receptor alpha (PPARA) is a major regulator of fatty acid oxidation and severe hepatic steatosis occurs during acute fasting in Ppara-null mice. Thus, PPARA is considered an important mediator of the fasting response; however, its role in other fasting regiments such as every-other-day fasting (EODF) has not been investigated. Methods Mice were pre-conditioned using either a diet containing the potent PPARA agonist Wy-14643 or an EODF regimen prior to acute fasting. Ppara-null mice were used to assess the contribution of PPARA activation during the metabolic response to EODF. Livers were collected for histological, biochemical, qRT-PCR, and Western blot analysis. Results Acute fasting activated PPARA and led to steatosis, whereas EODF protected against fasting-induced hepatic steatosis without affecting PPARA signaling. In contrast, pretreatment with Wy-14,643 did activate PPARA signaling but did not ameliorate acute fasting-induced steatosis and unexpectedly promoted liver injury. Ppara ablation exacerbated acute fasting-induced hypoglycemia, hepatic steatosis, and liver injury in mice, whereas these detrimental effects were absent in response to EODF, which promoted PPARA-independent fatty acid metabolism and normalized serum lipids. Conclusions These findings indicate that PPARA activation prior to acute fasting cannot ameliorate fasting-induced hepatic steatosis, whereas EODF induced metabolic adaptations to protect against fasting-induced steatosis without altering PPARA signaling. Therefore, PPARA activation does not mediate the metabolic adaptation to fasting, at least in preventing acute fasting-induced steatosis. Wy-14,643 activates PPARA but does not alleviate acute fasting-induced steatosis. EODF prevents acute fasting-induced steatosis but does not activate PPARA. EODF protects against fasting-induced steatosis, even in Ppara-null mice. EODF normalizes serum acylcarnitines in Ppara-null mice.
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Affiliation(s)
- Guolin Li
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; Laboratory of Aging Biochemistry, College of Life Sciences, Hunan Normal University, Changsha 410081, China; The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, China.
| | - Chad N Brocker
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tingting Yan
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Cen Xie
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kristopher W Krausz
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rong Xiang
- The State Key Laboratory of Medical Genetics & School of Life Sciences, Central South University, Changsha 41001, China
| | - Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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25
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Fang ZZ, Tanaka N, Lu D, Jiang CT, Zhang WH, Zhang C, Du Z, Fu ZW, Gao P, Cao YF, Sun HZ, Zhu ZT, Cai Y, Krausz KW, Yao Z, Gonzalez FJ. Role of the lipid-regulated NF-κB/IL-6/STAT3 axis in alpha-naphthyl isothiocyanate-induced liver injury. Arch Toxicol 2016; 91:2235-2244. [PMID: 27853831 DOI: 10.1007/s00204-016-1877-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 10/20/2016] [Indexed: 12/15/2022]
Abstract
Alpha-naphthyl isothiocyanate (ANIT)-induced liver damage is regarded as a useful model to study drug-induced cholestatic hepatitis. Ultra-performance liquid chromatography coupled with electrospray ionization quadrupole mass spectrometry (UPLC-ESI-QTOF MS)-based metabolomics revealed clues to the mechanism of ANIT-induced liver injury, which facilitates the elucidation of drug-induced liver toxicity. 1-Stearoyl-2-hydroxy-sn-glycero-3-phosphocholine (LPC 18:0) and 1-oleoyl-2-hydroxy-sn-glycero-3-phosphocholine (LPC 18:1) were significantly increased in serum from ANIT-treated mice, and this increase resulted from altered expression of genes encoding the lipid metabolism enzymes Chka and Scd1. ANIT also increased NF-κB/IL-6/STAT3 signaling, and in vitro luciferase reporter gene assays revealed that LPC 18:0 and LPC 18:1 can activate NF-κB in a concentration-dependent manner. Activation of PPARα through feeding mice a Wy-14,643-containing diet (0.1%) reduced ANIT-induced liver injury, as indicated by lowered ALT and AST levels, and liver histology. In conclusion, the present study demonstrated a role for the lipid-regulated NF-κB/IL-6/STAT3 axis in ANIT-induced hepatotoxicity, and that PPARα may be a potential therapeutic target for the prevention of drug-induced cholestatic liver injury.
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Affiliation(s)
- Zhong-Ze Fang
- Department of Toxicology, School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin, 300070, China.,Laboratory of Metabolism, Center for Cancer Research, National Institutes of Health, Building 37, Room 3106, Bethesda, MD, 20892, USA.,Department of Immunology, Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin Medical University, Tianjin, 30070, China.,Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences and The First Affiliated Hospital of Liaoning Medical University, No. 457, Zhongshan Road, Dalian, 116023, China.,Key Laborotary of Liaoning Tumor Clinical Metabolomics (KLLTCM), Jinzhou, Liaoning, China
| | - Naoki Tanaka
- Laboratory of Metabolism, Center for Cancer Research, National Institutes of Health, Building 37, Room 3106, Bethesda, MD, 20892, USA.,Department of Metabolic Regulation, Shinshu University Graduate School of Medicine, Matsumoto, 390-8621, Japan
| | - Dan Lu
- Department of Immunology, Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin Medical University, Tianjin, 30070, China
| | - Chang-Tao Jiang
- Laboratory of Metabolism, Center for Cancer Research, National Institutes of Health, Building 37, Room 3106, Bethesda, MD, 20892, USA
| | - Wei-Hua Zhang
- Department of Colorectal Surgery, Tianjin Union Medical Center, Tianjin, 300121, China
| | - Chunze Zhang
- Department of Colorectal Surgery, Tianjin Union Medical Center, Tianjin, 300121, China
| | - Zuo Du
- Department of Toxicology, School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin, 300070, China
| | - Zhi-Wei Fu
- Department of Toxicology, School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin, 300070, China
| | - Peng Gao
- Key Laborotary of Liaoning Tumor Clinical Metabolomics (KLLTCM), Jinzhou, Liaoning, China.,Clinical Laboratory, Dalian Sixth People's Hospital, Dalian, 116031, China
| | - Yun-Feng Cao
- Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences and The First Affiliated Hospital of Liaoning Medical University, No. 457, Zhongshan Road, Dalian, 116023, China.,Key Laborotary of Liaoning Tumor Clinical Metabolomics (KLLTCM), Jinzhou, Liaoning, China
| | - Hong-Zhi Sun
- Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences and The First Affiliated Hospital of Liaoning Medical University, No. 457, Zhongshan Road, Dalian, 116023, China.,Key Laborotary of Liaoning Tumor Clinical Metabolomics (KLLTCM), Jinzhou, Liaoning, China
| | - Zhi-Tu Zhu
- Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences and The First Affiliated Hospital of Liaoning Medical University, No. 457, Zhongshan Road, Dalian, 116023, China.,Key Laborotary of Liaoning Tumor Clinical Metabolomics (KLLTCM), Jinzhou, Liaoning, China
| | - Yan Cai
- Laboratory of Metabolism, Center for Cancer Research, National Institutes of Health, Building 37, Room 3106, Bethesda, MD, 20892, USA
| | - Kristopher W Krausz
- Laboratory of Metabolism, Center for Cancer Research, National Institutes of Health, Building 37, Room 3106, Bethesda, MD, 20892, USA
| | - Zhi Yao
- Department of Immunology, Tianjin Key Laboratory of Cellular and Molecular Immunology, Tianjin Medical University, Tianjin, 30070, China.
| | - Frank J Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Institutes of Health, Building 37, Room 3106, Bethesda, MD, 20892, USA.
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26
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Peroxisome proliferator-activated receptor α-dependent renoprotection of murine kidney by irbesartan. Clin Sci (Lond) 2016; 130:1969-1981. [PMID: 27496805 DOI: 10.1042/cs20160343] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 08/05/2016] [Indexed: 12/27/2022]
Abstract
Activation of renal peroxisome proliferator-activated receptor α (PPARα) is renoprotective, but there is no safe PPARα activator for patients with chronic kidney disease (CKD). Studies have reported that irbesartan (Irbe), an angiotensin II receptor blocker (ARB) widely prescribed for CKD, activates hepatic PPARα. However, Irbe's renal PPARα-activating effects and the role of PPARα signalling in the renoprotective effects of Irbe are unknown. Herein, these aspects were investigated in healthy kidneys of wild-type (WT) and Ppara-null (KO) mice and in the murine protein-overload nephropathy (PON) model respectively. The results were compared with those of losartan (Los), another ARB that does not activate PPARα. PPARα and its target gene expression were significantly increased only in the kidneys of Irbe-treated WT mice and not in KO or Los-treated mice, suggesting that the renal PPARα-activating effect was Irbe-specific. Irbe-treated-PON-WT mice exhibited decreased urine protein excretion, tubular injury, oxidative stress (OS), and pro-inflammatory and apoptosis-stimulating responses, and they exhibited maintenance of fatty acid metabolism. Furthermore, the expression of PPARα and that of its target mRNAs encoding proteins involved in OS, pro-inflammatory responses, apoptosis and fatty acid metabolism was maintained upon Irbe treatment. These renoprotective effects of Irbe were reversed by the PPARα antagonist MK886 and were not detected in Irbe-treated-PON-KO mice. These results suggest that Irbe activates renal PPARα and that the resultant increased PPARα signalling mediates its renoprotective effects.
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Zhang L, Krishnan P, Ehresman DJ, Smith PB, Dutta M, Bagley BD, Chang SC, Butenhoff JL, Patterson AD, Peters JM. Editor's Highlight: Perfluorooctane Sulfonate-Choline Ion Pair Formation: A Potential Mechanism Modulating Hepatic Steatosis and Oxidative Stress in Mice. Toxicol Sci 2016; 153:186-97. [PMID: 27413108 DOI: 10.1093/toxsci/kfw120] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The mechanisms underlying perfluorooctane sulfonate (PFOS)-induced steatosis remain unclear. The hypothesis that PFOS causes steatosis and other hepatic effects by forming an ion pair with choline was examined. C57BL/6 mice were fed either a control diet or a marginal methionine/choline-deficient (mMCD) diet, with and without 0.003, 0.006, or 0.012% potassium PFOS. Dietary PFOS caused a dose-dependent decrease in body weight, and increases in the relative liver weight, hepatic triglyceride concentration and serum markers of liver toxicity and oxidative stress. Some of these effects were exacerbated in mice fed the mMCD diet supplemented with 0.012% PFOS compared with those fed the control diet supplemented with 0.012% PFOS. Surprisingly, serum PFOS concentrations were higher while liver PFOS concentrations were lower in mMCD-fed mice compared with corresponding control-fed mice. To determine if supplemental dietary choline could prevent PFOS-induced hepatic effects, C57BL/6 mice were fed a control diet, or a choline supplemental diet (1.2%) with or without 0.003% PFOS. Lipidomic analysis demonstrated that PFOS caused alterations in hepatic lipid metabolism in the PFOS-fed mice compared with controls, and supplemental dietary choline prevented these PFOS-induced changes. Interestingly, dietary choline supplementation also prevented PFOS-induced oxidative damage. These studies are the first to suggest that PFOS may cause hepatic steatosis and oxidative stress by effectively reducing the choline required for hepatic VLDL production and export by forming an ion pair with choline, and suggest that choline supplementation may prevent and/or treat PFOS-induced hepatic steatosis and oxidative stress.
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Affiliation(s)
- Limin Zhang
- *Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Prasad Krishnan
- *Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
| | | | - Philip B Smith
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Mainak Dutta
- *Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
| | | | | | | | - Andrew D Patterson
- *Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
| | - Jeffrey M Peters
- *Department of Veterinary and Biomedical Science and Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802
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Gariani K, Menzies KJ, Ryu D, Wegner CJ, Wang X, Ropelle ER, Moullan N, Zhang H, Perino A, Lemos V, Kim B, Park Y, Piersigilli A, Pham TX, Yang Y, Ku CS, Koo SI, Fomitchova A, Cantó C, Schoonjans K, Sauve AA, Lee J, Auwerx J. Eliciting the mitochondrial unfolded protein response by nicotinamide adenine dinucleotide repletion reverses fatty liver disease in mice. Hepatology 2016; 63:1190-204. [PMID: 26404765 PMCID: PMC4805450 DOI: 10.1002/hep.28245] [Citation(s) in RCA: 271] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 09/22/2015] [Indexed: 02/06/2023]
Abstract
UNLABELLED With no approved pharmacological treatment, nonalcoholic fatty liver disease (NAFLD) is now the most common cause of chronic liver disease in Western countries and its worldwide prevalence continues to increase along with the growing obesity epidemic. Here, we show that a high-fat high-sucrose (HFHS) diet, eliciting chronic hepatosteatosis resembling human fatty liver, lowers hepatic nicotinamide adenine dinucleotide (NAD(+) ) levels driving reductions in hepatic mitochondrial content, function, and adenosine triphosphate (ATP) levels, in conjunction with robust increases in hepatic weight, lipid content, and peroxidation in C57BL/6J mice. To assess the effect of NAD(+) repletion on the development of steatosis in mice, nicotinamide riboside, a precursor of NAD(+) biosynthesis, was added to the HFHS diet, either as a preventive strategy or as a therapeutic intervention. We demonstrate that NR prevents and reverts NAFLD by inducing a sirtuin (SIRT)1- and SIRT3-dependent mitochondrial unfolded protein response, triggering an adaptive mitohormetic pathway to increase hepatic β-oxidation and mitochondrial complex content and activity. The cell-autonomous beneficial component of NR treatment was revealed in liver-specific Sirt1 knockout mice (Sirt1(hep-/-) ), whereas apolipoprotein E-deficient mice (Apoe(-/-) ) challenged with a high-fat high-cholesterol diet affirmed the use of NR in other independent models of NAFLD. CONCLUSION Our data warrant the future evaluation of NAD(+) boosting strategies to manage the development or progression of NAFLD.
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Affiliation(s)
- Karim Gariani
- Laboratory of Integrative and Systems PhysiologyÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Keir J. Menzies
- Laboratory of Integrative and Systems PhysiologyÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland,Interdisciplinary School of Health SciencesUniversity of OttawaOttawaOntarioCanada
| | - Dongryeol Ryu
- Laboratory of Integrative and Systems PhysiologyÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Casey J. Wegner
- Department of Nutritional SciencesUniversity of ConnecticutStorrsCT
| | - Xu Wang
- Laboratory of Integrative and Systems PhysiologyÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Eduardo R. Ropelle
- Laboratory of Molecular Biology of Exercise, School of Applied ScienceUniversity of CampinasLimeiraSão PauloBrazil
| | - Norman Moullan
- Laboratory of Integrative and Systems PhysiologyÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Hongbo Zhang
- Laboratory of Integrative and Systems PhysiologyÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Alessia Perino
- Metabolic SignalingÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Vera Lemos
- School of Life SciencesÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Bohkyung Kim
- Department of Nutritional SciencesUniversity of ConnecticutStorrsCT
| | - Young‐Ki Park
- Department of Nutritional SciencesUniversity of ConnecticutStorrsCT
| | - Alessandra Piersigilli
- School of Life SciencesÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland,Institute of Animal PathologyUniversity of BernBernSwitzerland
| | - Tho X. Pham
- Department of Nutritional SciencesUniversity of ConnecticutStorrsCT
| | - Yue Yang
- Department of Nutritional SciencesUniversity of ConnecticutStorrsCT
| | - Chai Siah Ku
- Department of Nutritional SciencesUniversity of ConnecticutStorrsCT
| | - Sung I. Koo
- Department of Nutritional SciencesUniversity of ConnecticutStorrsCT
| | - Anna Fomitchova
- Department of Nutritional SciencesUniversity of ConnecticutStorrsCT
| | - Carlos Cantó
- Nestlé Institute of Health SciencesLausanneSwitzerland
| | - Kristina Schoonjans
- School of Life SciencesÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | | | - Ji‐Young Lee
- Department of Nutritional SciencesUniversity of ConnecticutStorrsCT
| | - Johan Auwerx
- Laboratory of Integrative and Systems PhysiologyÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
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Nitrooleic Acid Attenuates Lipid Metabolic Disorders and Liver Steatosis in DOCA-Salt Hypertensive Mice. PPAR Res 2015; 2015:480348. [PMID: 25861250 PMCID: PMC4377523 DOI: 10.1155/2015/480348] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Accepted: 09/14/2014] [Indexed: 11/17/2022] Open
Abstract
Nitrooleic acid (OA-NO2) is endogenous ligands for peroxisome proliferator-activated receptors. The present study was aimed at investigating the beneficial effects of OA-NO2 on the lipid metabolism and liver steatosis in deoxycorticosterone acetate- (DOCA-) salt induced hypertensive mice model. Male C57BL/6 mice were divided to receive DOCA-salt plus OA-NO2 or DOCA-salt plus vehicle and another group received neither DOCA-salt nor OA-NO2 (control group). After 3-week treatment with DOCA-salt plus 1% sodium chloride in drinking fluid, the hypertension was noted; however, OA-NO2 had no effect on the hypertension. In DOCA-salt treated mice, the plasma triglyceride and total cholesterol levels were significantly increased compared to control mice, and pretreatment with OA-NO2 significantly reduced these parameters. Further, the histopathology of liver exhibited more lipid distribution together with more serious micro- and macrovesicular steatosis after DOCA-salt treatment and that was consistent with liver tissue triglyceride and nonesterified fatty acids (NEFA) content. The mice pretreated with OA-NO2 showed reduced liver damage accompanied with low liver lipid content. Moreover, the liver TBARS, together with the expressions of gp91phox and p47phox, were parallelly decreased. These findings indicated that OA-NO2 had the protective effect on liver injury against DOCA-salt administration and the beneficial effect could be attributed to its antihyperlipidemic activities.
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Watkins AM, Wood CR, Lin MT, Abbott BD. The effects of perfluorinated chemicals on adipocyte differentiation in vitro. Mol Cell Endocrinol 2015; 400:90-101. [PMID: 25448844 DOI: 10.1016/j.mce.2014.10.020] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 10/24/2014] [Accepted: 10/24/2014] [Indexed: 12/22/2022]
Abstract
The 3T3-L1 preadipocyte culture system has been used to examine numerous compounds that influence adipocyte differentiation or function. The perfluoroalkyl acids (PFAAs), used as surfactants in a variety of industrial applications, are of concern as environmental contaminants that are detected worldwide in human serum and animal tissues. This study was designed to evaluate the potential for PFAAs to affect adipocyte differentiation and lipid accumulation using mouse 3T3-L1 cells. Cells were treated with perfluorooctanoic acid (PFOA) (5-100 µM), perfluorononanoic acid (PFNA) (5-100 µM), perfluorooctane sulfonate (PFOS) (50-300 µM), perfluorohexane sulfonate (PFHxS) (40-250 µM), the peroxisome proliferator activated receptor (PPAR) PPARα agonist Wyeth-14,643 (WY-14,643), and the PPARγ agonist rosiglitazone. The PPARγ agonist was included as a positive control as this pathway is critical to adipocyte differentiation. The PPARα agonist was included as the PFAA compounds are known activators of this pathway. Cells were assessed morphometrically and biochemically for number, size, and lipid content. RNA was extracted for qPCR analysis of 13 genes selected for their importance in adipocyte differentiation and lipid metabolism. There was a significant concentration-related increase in cell number and decreased cell size after exposure to PFOA, PFHxS, PFOS, and PFNA. All four PFAA treatments produced a concentration-related decrease in the calculated average area occupied by lipid per cell. However, total triglyceride levels per well increased with a concentration-related trend for all compounds, likely due to the increased cell number. Expression of mRNA for the selected genes was affected by all exposures and the specific impacts depended on the particular compound and concentration. Acox1 and Gapdh were upregulated by all six compounds. The strongest overall effect was a nearly 10-fold induction of Scd1 by PFHxS. The sulfonated PFAAs produced numerous, strong changes in gene expression similar to the effects after treatment with the PPARγ agonist rosiglitazone. By comparison, the effects on gene expression were muted for the carboxylated PFAAs and for the PPARα agonist WY-14,643. In summary, all perfluorinated compounds increased cell number, decreased cell size, increased total triglyceride, and altered expression of genes associated with adipocyte differentiation and lipid metabolism.
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Affiliation(s)
- Andrew M Watkins
- Developmental Toxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Lab, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27709, USA.
| | - Carmen R Wood
- Developmental Toxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Lab, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27709, USA
| | - Mimi T Lin
- Developmental Toxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Lab, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27709, USA
| | - Barbara D Abbott
- Developmental Toxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Lab, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27709, USA
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Liu HH, Li JJ. Aging and dyslipidemia: a review of potential mechanisms. Ageing Res Rev 2015; 19:43-52. [PMID: 25500366 DOI: 10.1016/j.arr.2014.12.001] [Citation(s) in RCA: 156] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 11/25/2014] [Accepted: 12/01/2014] [Indexed: 01/02/2023]
Abstract
Elderly adults constitute a rapidly growing part of the global population, thus resulting in an increase in morbidity and mortality related to cardiovascular disease (CVD), which remains the major cause of death in elderly population, including men and women. Dyslipidemia is a well-established risk factor for CVD and is estimated to account for more than half of the worldwide cases of coronary artery disease (CAD). Many studies have shown a strong correlation between serum cholesterol levels and risk of developing CAD. In this paper, we review the changes of plasma lipids that occur in men and women during aging and the potential mechanisms of age-related disorders of lipoprotein metabolism covering humans and/or animals, in which changes of the liver sinusoidal endothelium, postprandial lipemia, insulin resistance induced by free fatty acid (FFA), growth hormone (GH), androgen (only for men) and expression and activity of peroxisome proliferator-activated receptor α (PPARα) are mainly focused.
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Pang T, Kaufman A, Choi J, Gill A, Drummond M, Hugh T, Samra J. Peroxisome proliferator-activated receptor-α staining is associated with worse outcome in colorectal liver metastases. Mol Clin Oncol 2014; 3:308-316. [PMID: 25798259 DOI: 10.3892/mco.2014.482] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 12/09/2014] [Indexed: 01/01/2023] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) are a family of nuclear receptors involved in lipid metabolism and liver response to injury. We hypothesised that differences in the expression of PPARs may reflect differences in the cellular microenvironment of the liver and, consequently, in the behaviour of colorectal liver metastases. Of the 145 patients who underwent hepatectomy for colorectal liver metastases between 1998 and 2007, 103 had adequate tissue for PPAR staining and histological re-evaluation. The histological characteristics evaluated included sinusoidal dilatation, perisinusoidal fibrosis, ballooning and steatosis. PPAR- α and-γ staining was performed and the results were correlated with clinical and survival data. Lobular inflammation and sinusoidal dilatation were the most common histopathological abnormalities. A total of 50% of the patients were PPAR- α-negative and 34% were PPAR- γ-negative. More patients exhibited lobular inflammation in the PPAR- α -positive group (P=0.023) compared to patients with negative PPAR- α staining, as seen on the multivariate analysis. PPAR- γpositivity was associated with oxaliplatin use, surgical margins ≥1 mm and a trend towards a lesser degree of fibrosis. The median follow-up in this cohort of patients was 48 months. Patients with PPAR- α staining had a worse overall survival (median, 36 vs. 79 months, P=0.037) compared to those with no PPAR- α staining. There was no correlation between PPAR- α or-γpositivity and disease-free survival. In conclusion, PPAR- α staining is associated with lobular inflammation and worse overall survival in patients with colorectal liver metastases. The exact mechanism underlying this finding remains unclear and further research into the diagnostic and therapeutic implications is required.
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Affiliation(s)
- Tony Pang
- Upper Gastrointestinal Surgical Unit, Royal North Shore Hospital and North Shore Private Hospital ; Northern Clinical School, University of Sydney
| | - Antony Kaufman
- Department of Anatomical Pathology, Royal North Shore Hospital
| | - Julian Choi
- Upper Gastrointestinal Surgical Unit, Royal North Shore Hospital and North Shore Private Hospital
| | - Anthony Gill
- Northern Clinical School, University of Sydney ; Cancer Diagnosis and Pathology Group, Kolling Institute of Medicine, Royal North Shore Hospital, St. Leonards, NSW 2065
| | - Martin Drummond
- Upper Gastrointestinal Surgical Unit, Royal North Shore Hospital and North Shore Private Hospital
| | - Thomas Hugh
- Upper Gastrointestinal Surgical Unit, Royal North Shore Hospital and North Shore Private Hospital ; Northern Clinical School, University of Sydney
| | - Jaswinder Samra
- Upper Gastrointestinal Surgical Unit, Royal North Shore Hospital and North Shore Private Hospital ; Northern Clinical School, University of Sydney ; Australian School of Advanced Medicine, Macquarie University, Macquarie Park, NSW 2109, Australia
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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: 161] [Impact Index Per Article: 14.6] [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.
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Kimura R, Takahashi N, Lin S, Goto T, Murota K, Nakata R, Inoue H, Kawada T. DHA attenuates postprandial hyperlipidemia via activating PPARα in intestinal epithelial cells. J Lipid Res 2013; 54:3258-68. [PMID: 24133194 DOI: 10.1194/jlr.m034942] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
It is known that peroxisome proliferator-activated receptor (PPAR)α, whose activation reduces hyperlipidemia, is highly expressed in intestinal epithelial cells. Docosahexaenoic acid (DHA) could improve postprandial hyperlipidemia, however, its relationship with intestinal PPARα activation is not revealed. In this study, we investigated whether DHA can affect postprandial hyperlipidemia by activating intestinal PPARα using Caco-2 cells and C57BL/6 mice. The genes involved in fatty acid (FA) oxidation and oxygen consumption rate were increased, and the secretion of triacylglyceride (TG) and apolipoprotein B (apoB) was decreased in DHA-treated Caco-2 cells. Additionally, intestinal FA oxidation was induced, and TG and apoB secretion from intestinal epithelial cells was reduced, resulting in the attenuation of plasma TG and apoB levels after oral administration of olive oil in DHA-rich oil-fed mice compared with controls. However, no increase in genes involved in FA oxidation was observed in the liver. Furthermore, the effects of DHA on intestinal lipid secretion and postprandial hyperlipidemia were abolished in PPARα knockout mice. In conclusion, the present work suggests that DHA can inhibit the secretion of TG from intestinal epithelial cells via PPARα activation, which attenuates postprandial hyperlipidemia.
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Affiliation(s)
- Rino Kimura
- Laboratory of Molecular Function of Food, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
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Rommelaere S, Millet V, Gensollen T, Bourges C, Eeckhoute J, Hennuyer N, Baugé E, Chasson L, Cacciatore I, Staels B, Pitari G, Galland F, Naquet P. PPARalpha regulates the production of serum Vanin-1 by liver. FEBS Lett 2013; 587:3742-8. [DOI: 10.1016/j.febslet.2013.09.046] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 09/29/2013] [Indexed: 11/25/2022]
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Konstandi M, Shah YM, Matsubara T, Gonzalez FJ. Role of PPARα and HNF4α in stress-mediated alterations in lipid homeostasis. PLoS One 2013; 8:e70675. [PMID: 23967086 PMCID: PMC3743822 DOI: 10.1371/journal.pone.0070675] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 06/20/2013] [Indexed: 12/13/2022] Open
Abstract
Stress is a risk factor for several cardiovascular pathologies. PPARα holds a fundamental role in control of lipid homeostasis by directly regulating genes involved in fatty acid transport and oxidation. Importantly, PPARα agonists are effective in raising HDL-cholesterol and lowering triglycerides, properties that reduce the risk for cardiovascular diseases. This study investigated the role of stress and adrenergic receptor (AR)-related pathways in PPARα and HNF4α regulation and signaling in mice following repeated restraint stress or treatment with AR-antagonists administered prior to stress to block AR-linked pathways. Repeated restraint stress up-regulated Pparα and its target genes in the liver, including Acox, Acot1, Acot4, Cyp4a10, Cyp4a14 and Lipin2, an effect that was highly correlated with Hnf4α. In vitro studies using primary hepatocyte cultures treated with epinephrine or AR-agonists confirmed that hepatic AR/cAMP/PKA/CREB- and JNK-linked pathways are involved in PPARα and HNF4α regulation. Notably, restraint stress, independent of PPARα, suppressed plasma triglyceride levels. This stress-induced effect could be attributed in part to hormone sensitive lipase activation in the white adipose tissue, which was not prevented by the increased levels of perilipin. Overall, this study identifies a mechanistic basis for the modification of lipid homeostasis following stress and potentially indicates novel roles for PPARα and HNF4α in stress-induced lipid metabolism.
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Affiliation(s)
- Maria Konstandi
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America.
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Goudarzi M, Koga T, Khozoie C, Mak TD, Kang BH, Fornace AJ, Peters JM. PPARβ/δ modulates ethanol-induced hepatic effects by decreasing pyridoxal kinase activity. Toxicology 2013; 311:87-98. [PMID: 23851158 DOI: 10.1016/j.tox.2013.07.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 06/29/2013] [Accepted: 07/02/2013] [Indexed: 12/20/2022]
Abstract
Because of the significant morbidity and lethality caused by alcoholic liver disease (ALD), there remains a need to elucidate the regulatory mechanisms that can be targeted to prevent and treat ALD. Toward this goal, minimally invasive biomarker discovery represents an outstanding approach for these purposes. The mechanisms underlying ALD include hepatic lipid accumulation. As the peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) has been shown to inhibit steatosis, the present study examined the role of PPARβ/δ in ALD coupling metabolomic, biochemical and molecular biological analyses. Wild-type and Pparβ/δ-null mice were fed either a control or 4% ethanol diet and examined after 4-7 months of treatment. Ethanol fed Pparβ/δ-null mice exhibited steatosis after short-term treatment compared to controls, the latter effect appeared to be due to increased activity of sterol regulatory element binding protein 1c (SREBP1c). The wild-type and Pparβ/δ-null mice fed the control diet showed clear differences in their urinary metabolomic profiles. In particular, metabolites associated with arginine and proline metabolism, and glycerolipid metabolism, were markedly different between genotypes suggesting a constitutive role for PPARβ/δ in the metabolism of these amino acids. Interestingly, urinary excretion of taurine was present in ethanol-fed wild-type mice but markedly lower in similarly treated Pparβ/δ-null mice. Evidence suggests that PPARβ/δ modulates pyridoxal kinase activity by altering Km, consistent with the observed decreased in urinary taurine excretion. These data collectively suggest that PPARβ/δ prevents ethanol-induced hepatic effects by inhibiting hepatic lipogenesis, modulation of amino acid metabolism, and altering pyridoxal kinase activity.
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Affiliation(s)
- Maryam Goudarzi
- Lombardi Comprehensive Cancer Center, Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, DC, USA
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Martínez P, Gómez-López G, García F, Mercken E, Mitchell S, Flores JM, de Cabo R, Blasco MA. RAP1 protects from obesity through its extratelomeric role regulating gene expression. Cell Rep 2013; 3:2059-74. [PMID: 23791526 PMCID: PMC5889507 DOI: 10.1016/j.celrep.2013.05.030] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 03/30/2013] [Accepted: 05/20/2013] [Indexed: 11/17/2022] Open
Abstract
RAP1 is part of shelterin, the protective complex at telomeres. RAP1 also binds along chromosome arms, where it is proposed to regulate gene expression. To investigate the nontelomeric roles of RAP1 in vivo, we generated a RAP1 whole-body knockout mouse. These mice show early onset of obesity, which is more severe in females than in males. Rap1-deficient mice show accumulation of abdominal fat, hepatic steatosis, and high-fasting plasma levels of insulin, glucose, cholesterol, and alanine aminotransferase. Gene expression analyses of liver and visceral white fat from Rap1-deficient mice before the onset of obesity show deregulation of metabolic programs, including fatty acid, glucose metabolism, and PPARα signaling. We identify Pparα and Pgc1α as key factors affected by Rap1 deletion in the liver. We show that RAP1 binds to Pparα and Pgc1α loci and modulates their transcription. These findings reveal a role for a telomere-binding protein in the regulation of metabolism.
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Affiliation(s)
- Paula Martínez
- Telomeres and Telomerase Group, Molecular Oncology Program
| | | | - Fernando García
- Proteomics Core Unit, Biotechnology Program Spanish National Cancer
Research Centre (CNIO), Melchor Fernández Almagro 3, Madrid 28029,
Spain
| | - Evi Mercken
- Laboratory of Experimental Gerontology, National Institute of Aging,
National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD 21224, USA
| | - Sarah Mitchell
- Laboratory of Experimental Gerontology, National Institute of Aging,
National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD 21224, USA
| | - Juana M. Flores
- Animal Surgery and Medicine Department, Faculty of Veterinarian,
Complutense University of Madrid, Madrid 28029, Spain
| | - Rafael de Cabo
- Laboratory of Experimental Gerontology, National Institute of Aging,
National Institutes of Health, 251 Bayview Boulevard, Baltimore, MD 21224, USA
| | - Maria A. Blasco
- Telomeres and Telomerase Group, Molecular Oncology Program
- Correspondence:
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Brunton PJ, Sullivan KM, Kerrigan D, Russell JA, Seckl JR, Drake AJ. Sex-specific effects of prenatal stress on glucose homoeostasis and peripheral metabolism in rats. J Endocrinol 2013; 217:161-73. [PMID: 23428582 DOI: 10.1530/joe-12-0540] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Glucocorticoid overexposure during pregnancy programmes offspring physiology and predisposes to later disease. However, any impact of ethologically relevant maternal stress is less clear, yet of physiological importance. Here, we investigated in rats the short- and long-term effects in adult offspring of repeated social stress (exposure to an aggressive lactating female) during late pregnancy on glucose regulation following stress, glucose-insulin homoeostasis and peripheral expression of genes important in regulating glucose and lipid metabolism and glucocorticoid action. Prenatal stress (PNS) was associated with reduced birth weight in female, but not male, offspring. The increase in blood glucose with restraint was exaggerated in adult PNS males compared with controls, but not in females. Oral glucose tolerance testing showed no effects on plasma glucose or insulin concentrations in either sex at 3 months; however, at 6 months, PNS females were hyperinsulinaemic following an oral glucose load. In PNS males, plasma triglyceride concentrations were increased, with reduced hepatic mRNA expression of 5α-reductase and peroxisome proliferator-activated receptor α (Pparα (Ppara)) and a strong trend towards reduced peroxisome proliferator-activated receptor gamma coactivator 1α (Pgc1α (Ppargc1a)) and Pparγ (Pparg) expression, whereas only Pgc1α mRNA was affected in PNS females. Conversely, in subcutaneous fat, PNS reduced mRNA expression of 11β-hydroxysteroid dehydrogenase type 1 (11βhsd1), phosphoenolpyruvate carboxykinase (Pepck (Pck1)), adipose triglyceride lipase (Atgl) and diglyceride acyltransferase 2 (Dgat2) in females, but only Pepck mRNA expression was reduced in PNS males. Thus, prenatal social stress differentially programmes glucose homoeostasis and peripheral metabolism in male and female offspring. These long-term alterations in physiology may increase susceptibility to metabolic disease.
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Affiliation(s)
- Paula J Brunton
- Division of Neurobiology, The Roslin Institute and R(D)SVS, University of Edinburgh, Easter Bush Campus, Midlothian, EH25 9RG, UK.
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Znf202 affects high density lipoprotein cholesterol levels and promotes hepatosteatosis in hyperlipidemic mice. PLoS One 2013; 8:e57492. [PMID: 23469003 PMCID: PMC3585336 DOI: 10.1371/journal.pone.0057492] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 01/22/2013] [Indexed: 11/19/2022] Open
Abstract
Background The zinc finger protein Znf202 is a transcriptional suppressor of lipid related genes and has been linked to hypoalphalipoproteinemia. A functional role of Znf202 in lipid metabolism in vivo still remains to be established. Methodology and Principal Findings We generated mouse Znf202 expression vectors, the functionality of which was established in several in vitro systems. Next, effects of adenoviral znf202 overexpression in vivo were determined in normo- as well as hyperlipidemic mouse models. Znf202 overexpression in mouse hepatoma cells mhAT3F2 resulted in downregulation of members of the Apoe/c1/c2 and Apoa1/c3/a4 gene cluster. The repressive activity of Znf202 was firmly confirmed in an apoE reporter assay and Znf202 responsive elements within the ApoE promoter were identified. Adenoviral Znf202 transfer to Ldlr−/− mice resulted in downregulation of apoe, apoc1, apoa1, and apoc3 within 24 h after gene transfer. Interestingly, key genes in bile flux (abcg5/8 and bsep) and in bile acid synthesis (cyp7a1) were also downregulated. At 5 days post-infection, the expression of the aforementioned genes was normalized, but mice had developed severe hepatosteatosis accompanied by hypercholesterolemia and hypoalphalipoproteinemia. A much milder phenotype was observed in wildtype mice after 5 days of hepatic Znf202 overexpression. Interestingly and similar to Ldl−/− mice, HDL-cholesterol levels in wildtype mice were lowered after hepatic Znf202 overexpression. Conclusion/Significance Znf202 overexpression in vivo reveals an important role of this transcriptional regulator in liver lipid homeostasis, while firmly establishing the proposed key role in the control of HDL levels.
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Knoll N, Jarick I, Volckmar AL, Klingenspor M, Illig T, Grallert H, Gieger C, Wichmann HE, Peters A, Hebebrand J, Scherag A, Hinney A. Gene set of nuclear-encoded mitochondrial regulators is enriched for common inherited variation in obesity. PLoS One 2013; 8:e55884. [PMID: 23409076 PMCID: PMC3568071 DOI: 10.1371/journal.pone.0055884] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 01/03/2013] [Indexed: 01/13/2023] Open
Abstract
There are hints of an altered mitochondrial function in obesity. Nuclear-encoded genes are relevant for mitochondrial function (3 gene sets of known relevant pathways: (1) 16 nuclear regulators of mitochondrial genes, (2) 91 genes for oxidative phosphorylation and (3) 966 nuclear-encoded mitochondrial genes). Gene set enrichment analysis (GSEA) showed no association with type 2 diabetes mellitus in these gene sets. Here we performed a GSEA for the same gene sets for obesity. Genome wide association study (GWAS) data from a case-control approach on 453 extremely obese children and adolescents and 435 lean adult controls were used for GSEA. For independent confirmation, we analyzed 705 obesity GWAS trios (extremely obese child and both biological parents) and a population-based GWAS sample (KORA F4, n = 1,743). A meta-analysis was performed on all three samples. In each sample, the distribution of significance levels between the respective gene set and those of all genes was compared using the leading-edge-fraction-comparison test (cut-offs between the 50th and 95th percentile of the set of all gene-wise corrected p-values) as implemented in the MAGENTA software. In the case-control sample, significant enrichment of associations with obesity was observed above the 50th percentile for the set of the 16 nuclear regulators of mitochondrial genes (pGSEA,50 = 0.0103). This finding was not confirmed in the trios (pGSEA,50 = 0.5991), but in KORA (pGSEA,50 = 0.0398). The meta-analysis again indicated a trend for enrichment (pMAGENTA,50 = 0.1052, pMAGENTA,75 = 0.0251). The GSEA revealed that weak association signals for obesity might be enriched in the gene set of 16 nuclear regulators of mitochondrial genes.
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Affiliation(s)
- Nadja Knoll
- Department of Child and Adolescent Psychiatry, University of Duisburg-Essen, Essen, Germany
| | - Ivonne Jarick
- Institute of Medical Biometry and Epidemiology, Philipps-University of Marburg, Marburg, Germany
| | - Anna-Lena Volckmar
- Department of Child and Adolescent Psychiatry, University of Duisburg-Essen, Essen, Germany
| | - Martin Klingenspor
- Molecular Nutritional Medicine, Technical University of Munich, Else Kröner-Fresenius Center, Freising-Weihenstephan, Germany
| | - Thomas Illig
- Research Unit of Molecular Epidemiology, Helmholtz Center Munich – German Research Center for Environmental Health, Neuherberg, Germany
- Hannover Unified Biobank, Hannover Medical School, Hannover, Germany
| | - Harald Grallert
- Research Unit of Molecular Epidemiology, Helmholtz Center Munich – German Research Center for Environmental Health, Neuherberg, Germany
| | - Christian Gieger
- Institute of Genetic Epidemiology, Helmholtz Center Munich – German Research Center for Environmental Health, Neuherberg, Germany
| | - Heinz-Erich Wichmann
- Institute of Epidemiology I, Helmholtz Center Munich – German Research Center for Environmental Health, Neuherberg, Germany, Neuherberg, Germany
- Institute of Medical Informatics, Biometry, and Epidemiology, Chair of Epidemiology, Ludwig-Maximilians-Universität, Munich, Germany
- Munich University Hospital, Campus Grosshadern, Munich, Germany
| | - Annette Peters
- Institute of Epidemiology II, Helmholtz Center Munich – German Research Center for Environmental Health, Neuherberg, Germany
| | - Johannes Hebebrand
- Department of Child and Adolescent Psychiatry, University of Duisburg-Essen, Essen, Germany
| | - André Scherag
- Institute for Medical Informatics, Biometry and Epidemiology, University of Duisburg-Essen, Essen, Germany
| | - Anke Hinney
- Department of Child and Adolescent Psychiatry, University of Duisburg-Essen, Essen, Germany
- * E-mail:
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Zhang H, Shen WJ, Cortez Y, Kraemer FB, Azhar S. Nordihydroguaiaretic acid improves metabolic dysregulation and aberrant hepatic lipid metabolism in mice by both PPARα-dependent and -independent pathways. Am J Physiol Gastrointest Liver Physiol 2013; 304:G72-86. [PMID: 23104557 PMCID: PMC3543637 DOI: 10.1152/ajpgi.00328.2012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Creosote bush-derived nordihydroguaiaretic acid (NDGA), a lipoxygenase inhibitor, possesses antioxidant properties and functions as a potent antihyperlipidemic agent in rodent models. Here, we examined the effect of chronic NDGA treatment of ob/ob mice on plasma dyslipidemia, hepatic steatosis, and changes in hepatic gene expression. Feeding ob/ob mice a chow diet supplemented with either low (0.83 g/kg diet) or high-dose (2.5 g/kg diet) NDGA for 16 wk significantly improved plasma triglyceride (TG), inflammatory chemokine levels, hyperinsulinemia, insulin sensitivity, and glucose intolerance. NDGA treatment caused a marked reduction in liver weight and TG content, while enhancing rates of fatty acid oxidation. Microarray analysis of hepatic gene expression demonstrated that NDGA treatment altered genes for lipid metabolism, with genes involved in fatty acid catabolism most significantly increased. NDGA upregulated the mRNA and nuclear protein levels of peroxisome proliferator-activated receptor α (PPARα), and the activated (phosphorylated) form of AMP-activated kinase. NDGA increased PPARα promoter activity in AML12 hepatocytes and also prevented the fatty acid suppression of PPARα expression. In contrast, PPARα siRNA abrogated the stimulatory effect of NDGA on fatty acid catabolism. Likewise, no stimulatory effect of NDGA on hepatic fatty acid oxidation was observed in the livers of PPARα-deficient mice, but the ability of NDGA to reverse fatty liver conditions was unaffected. In conclusion, the beneficial actions of NDGA on dyslipidemia and hepatic steatosis in ob/ob mice are exerted primarily through enhanced fatty acid oxidation via PPARα-dependent pathways. However, PPARα-independent pathways also contribute to NDGA's action to ameliorate hepatic steatosis.
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Affiliation(s)
- Haiyan Zhang
- 1Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California; ,2Division of Endocrinology, Stanford University, Stanford, California; and
| | - Wen-Jun Shen
- 1Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California; ,2Division of Endocrinology, Stanford University, Stanford, California; and
| | - Yuan Cortez
- 1Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California;
| | - Fredric B. Kraemer
- 1Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California; ,2Division of Endocrinology, Stanford University, Stanford, California; and
| | - Salman Azhar
- 1Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California; ,3Gastroenterology and Hepatology, Stanford University, Stanford, California
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Montanez JE, Peters JM, Correll JB, Gonzalez FJ, Patterson AD. Metabolomics: an essential tool to understand the function of peroxisome proliferator-activated receptor alpha. Toxicol Pathol 2012. [PMID: 23197196 DOI: 10.1177/0192623312466960] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The peroxisome proliferator-activated receptor (PPAR) family of nuclear hormone transcription factors (PPARα, PPARβ/δ, and PPARγ) is regulated by a wide array of ligands including natural and synthetic chemicals. PPARs have important roles in control of energy metabolism and are known to influence inflammation, differentiation, carcinogenesis, and chemical toxicity. As such, PPARs have been targeted as therapy for common disorders such as cancer, metabolic syndrome, obesity, and diabetes. The recent application of metabolomics, or the global, unbiased measurement of small molecules found in biofluids, or extracts from cells, tissues, or organisms, has advanced our understanding of the varied and important roles that the PPARs have in normal physiology as well as in pathophysiological processes. Continued development and refinement of analytical platforms, and the application of new bioinformatics strategies, have accelerated the widespread use of metabolomics and have allowed further integration of small molecules into systems biology. Recent studies using metabolomics to understand PPARα function, as well as to identify PPARα biomarkers associated with drug efficacy/toxicity and drug-induced liver injury, will be discussed.
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Affiliation(s)
- Jessica E Montanez
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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Albrecht PP, Torsell NE, Krishnan P, Ehresman DJ, Frame SR, Chang SC, Butenhoff JL, Kennedy GL, Gonzalez FJ, Peters JM. A Species Difference in the Peroxisome Proliferator-Activated Receptor α-Dependent Response to the Developmental Effects of Perfluorooctanoic Acid. Toxicol Sci 2012; 131:568-82. [DOI: 10.1093/toxsci/kfs318] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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45
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Nakajima T, Kamijo Y, Yuzhe H, Kimura T, Tanaka N, Sugiyama E, Nakamura K, Kyogashima M, Hara A, Aoyama T. Peroxisome proliferator-activated receptor α mediates enhancement of gene expression of cerebroside sulfotransferase in several murine organs. Glycoconj J 2012; 30:553-60. [PMID: 23065187 DOI: 10.1007/s10719-012-9454-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 09/26/2012] [Accepted: 10/01/2012] [Indexed: 12/28/2022]
Abstract
Sulfatides, 3-O-sulfogalactosylceramides, are known to have multifunctional properties. These molecules are distributed in various tissues of mammals, where they are synthesized from galactosylceramides by sulfation at C3 of the galactosyl residue. Although this reaction is specifically catalyzed by cerebroside sulfotransferase (CST), the mechanisms underlying the transcriptional regulation of this enzyme are not understood. With respect to this issue, we previously found potential sequences of peroxisome proliferator-activated receptor (PPAR) response element on upstream regions of the mouse CST gene and presumed the possible regulation by the nuclear receptor PPARα. To confirm this hypothesis, we treated wild-type and Ppara-null mice with the specific PPARα agonist fenofibrate and examined the amounts of sulfatides and CST gene expression in various tissues. Fenofibrate treatment increased sulfatides and CST mRNA levels in the kidney, heart, liver, and small intestine in a PPARα-dependent manner. However, these effects of fenofibrate were absent in the brain or colon. Fenofibrate treatment did not affect the mRNA level of arylsulfatase A, which is the key enzyme for catalyzing desulfation of sulfatides, in any of these six tissues. Analyses of the DNA-binding activity and conventional gene expression targets of PPARα has demonstrated that fenofibrate treatment activated PPARα in the kidney, heart, liver, and small intestine but did not affect the brain or colon. These findings suggest that PPARα activation induces CST gene expression and enhances sulfatide synthesis in mice, which suggests that PPARα is a possible transcriptional regulator for the mouse CST gene.
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Affiliation(s)
- Takero Nakajima
- Department of Metabolic Regulation, Institute of Pathogenesis and Disease Prevention, Shinshu University Graduate School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano, 390-8621, Japan
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Caldwell JC. DEHP: Genotoxicity and potential carcinogenic mechanisms—A review. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2012; 751:82-157. [DOI: 10.1016/j.mrrev.2012.03.001] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 03/22/2012] [Accepted: 03/22/2012] [Indexed: 10/28/2022]
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Aleksunes LM, Klaassen CD. Coordinated regulation of hepatic phase I and II drug-metabolizing genes and transporters using AhR-, CAR-, PXR-, PPARα-, and Nrf2-null mice. Drug Metab Dispos 2012; 40:1366-79. [PMID: 22496397 DOI: 10.1124/dmd.112.045112] [Citation(s) in RCA: 199] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The transcription factors aryl hydrocarbon receptor (AhR), constitutive androstane receptor (CAR), pregnane X receptor (PXR), peroxisome proliferator-activated receptor α (PPARα), and nuclear factor erythroid 2-related factor 2 (Nrf2) regulate genes encoding drug-metabolizing enzymes and transporters in livers of mice after chemical activation. However, the specificity of their transcriptional regulation has not been determined systematically in vivo. The purpose of this study was to identify genes encoding drug-metabolizing enzymes and transporters altered by chemical activators in a transcription factor-dependent manner using wild-type and transcription factor-null mice. Chemical activators were administered intraperitoneally to mice once daily for 4 days. Livers were collected 24 h after the final dose, and total RNA was isolated for mRNA quantification of cytochromes P450, NAD(P)H quinone oxidoreductase 1 (Nqo1), aldehyde dehydrogenases (Aldhs), glutathione transferases (Gsts), sulfotransferases (Sults), UDP-glucuronosyltransferases (Ugts), organic anion-transporting polypeptides (Oatps), and multidrug resistance-associated proteins (Mrps). Pharmacological activation of each transcription factor leads to mRNA induction of drug metabolic and transport genes in livers of male and female wild-type mice, but no change in null mice: AhR (Cyp1a2, Nqo1, Aldh7a1, Ugt1a1, Ugt1a6, Ugt1a9, Ugt2b35, Sult5a1, Gstm3, and Mrp4), CAR (Cyp2b10, Aldh1a1, Aldh1a7, Ugt1a1, Ugt2b34, Sult1e1, Sult3a1, Sult5a1, Papps2, Gstt1, Gsta1, Gsta4, Gstm1-4, and Mrp2-4), PXR (Cyp3a11, Ugt1a1, Ugt1a5, Ugt1a9, Gsta1, Gstm1-m3, Oatp1a4, and Mrp3), PPARα (Cyp4a14, Aldh1a1, mGst3, Gstm4, and Mrp4), and Nrf2 (Nqo1, Aldh1a1, Gsta1, Gsta4, Gstm1-m4, mGst3, and Mrp3-4). Taken together, these data reveal transcription factor specificity and overlap in regulating hepatic drug disposition genes by chemical activators. Coordinated regulation of phase I, phase II, and transport genes by activators of transcription factors can have implications in development of pharmaceuticals as well as risk assessment of environmental contaminants.
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Affiliation(s)
- Lauren M Aleksunes
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160-7417, USA
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Zhang Y, Cheng X, Aleksunes L, Klaassen CD. Transcription factor-mediated regulation of carboxylesterase enzymes in livers of mice. Drug Metab Dispos 2012; 40:1191-7. [PMID: 22429928 DOI: 10.1124/dmd.111.043877] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The induction of drug-metabolizing enzymes by chemicals is one of the major reasons for drug-drug interactions. In the present study, the regulation of mRNA expression of one arylacetamide deacetylase (Aadac) and 11 carboxylesterases (Cess) by 15 microsomal enzyme inducers (MEIs) was examined in livers of male C57BL/6 mice. The data demonstrated that Aadac mRNA expression was suppressed by three aryl hydrocarbon receptor (AhR) ligands, two constitutive androstane receptor (CAR) activators, two pregnane X receptor (PXR) ligands, and one nuclear factor erythroid 2-related factor 2 (Nrf2) activator. Ces1 subfamily mRNA expression was not altered by most of the MEIs, whereas Ces2 subfamily mRNA was readily induced by the activators of CAR, PXR, and Nrf2 but not by peroxisome proliferator-activated receptor α activators. Studies using null mice demonstrated that 1) AhR was required for the 2,3,7,8-tetrachlorodibenzo-p-dioxin-mediated suppression of Aadac and Ces3a; 2) CAR was involved in the 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene-mediated induction of Aadac, Ces2c, Ces2a, and Ces3a; 3) PXR was required for the pregnenolone-16α-carbonitrile-mediated induction of Aadac, Ces2c, and Ces2a; 4) Nrf2 was required for the oltipraz-mediated induction of Ces1g and Ces2c; and 5) PXR was not required for the DEX-mediated suppression of Cess in livers of mice. In conclusion, the present study systematically investigated the regulation of Cess by MEIs in livers of mice and demonstrated that MEIs modulated mRNA expression of mouse hepatic Cess through the activation of AhR, CAR, PXR, and/or Nrf2 transcriptional pathways.
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Affiliation(s)
- Youcai Zhang
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
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Comprehensive analysis of PPARalpha-dependent regulation of hepatic lipid metabolism by expression profiling. PPAR Res 2011; 2007:26839. [PMID: 18288265 PMCID: PMC2233741 DOI: 10.1155/2007/26839] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Accepted: 07/25/2007] [Indexed: 01/30/2023] Open
Abstract
PPARα is a ligand-activated transcription factor involved in the regulation of nutrient metabolism and inflammation. Although much is already known about the function of PPARα in hepatic lipid metabolism, many PPARα-dependent pathways and genes have yet to be discovered. In order to obtain an overview of PPARα-regulated genes relevant to lipid metabolism, and to probe for novel candidate PPARα target genes, livers from several animal studies in which PPARα was activated and/or disabled were analyzed by Affymetrix GeneChips. Numerous novel PPARα-regulated genes relevant to lipid metabolism were identified. Out of this set of genes, eight genes were singled out for study of PPARα-dependent regulation in mouse liver and in mouse, rat, and human primary hepatocytes, including thioredoxin interacting protein (Txnip), electron-transferring-flavoprotein β polypeptide (Etfb), electron-transferring-flavoprotein dehydrogenase (Etfdh), phosphatidylcholine transfer protein (Pctp), endothelial lipase (EL, Lipg), adipose triglyceride lipase (Pnpla2), hormone-sensitive lipase (HSL, Lipe), and monoglyceride lipase (Mgll). Using an in silico screening approach, one or more PPAR response elements (PPREs) were identified in each of these genes. Regulation of Pnpla2, Lipe, and Mgll, which are involved in triglyceride hydrolysis, was studied under conditions of elevated hepatic lipids. In wild-type mice fed a high fat diet, the decrease in hepatic lipids following treatment with the PPARα agonist Wy14643 was paralleled by significant up-regulation of Pnpla2, Lipe, and Mgll, suggesting that induction of triglyceride hydrolysis may contribute to the anti-steatotic role of PPARα. Our study illustrates the power of transcriptional profiling to uncover novel PPARα-regulated genes and pathways in liver.
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50
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Hexarelin Signaling to PPARgamma in Metabolic Diseases. PPAR Res 2011; 2008:364784. [PMID: 18288286 PMCID: PMC2233980 DOI: 10.1155/2008/364784] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2007] [Accepted: 11/27/2007] [Indexed: 12/23/2022] Open
Abstract
Investigating the metabolic functions of the nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) has been extremely rewarding over the past years.
Uncovering the biologic roles of PPARγ and its mechanism of action has greatly advanced our understanding of the transcriptional control of lipid and glucose metabolism, and compounds such as thiazolidinediones which directly regulate PPARγ have proven to exhibit potent insulin-sensitizer effects in the treatment of diabetes. We review here recent advances on the emerging role of growth hormone releasing peptides in regulating PPARγ through interaction with scavenger receptor CD36 and ghrelin GHS-R1a receptor. With the impact that these peptides exert on the metabolic pathways involved in lipid metabolism and energy homeostasis, it is hoped that the development of novel approaches in the regulation of PPAR functions will bring additional therapeutic possibilities to face problems related to metabolic diseases.
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