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Lu Y, George J. Interaction between fatty acid oxidation and ethanol metabolism in liver. Am J Physiol Gastrointest Liver Physiol 2024; 326:G483-G494. [PMID: 38573193 DOI: 10.1152/ajpgi.00281.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 02/13/2024] [Accepted: 02/26/2024] [Indexed: 04/05/2024]
Abstract
Fatty acid oxidation (FAO) releases the energy stored in fat to maintain basic biological processes. Dehydrogenation is a major way to oxidize fatty acids, which needs NAD+ to accept the released H+ from fatty acids and form NADH, which increases the ratio of NADH/NAD+ and consequently inhibits FAO leading to the deposition of fat in the liver, which is termed fatty liver or steatosis. Consumption of alcohol (ethanol) initiates simple steatosis that progresses to alcoholic steatohepatitis, which constitutes a spectrum of liver disorders called alcohol-associated liver disease (ALD). ALD is linked to ethanol metabolism. Ethanol is metabolized by alcohol dehydrogenase (ADH), microsomal ethanol oxidation system (MEOS), mainly cytochrome P450 2E1 (CYP2E1), and catalase. ADH also requires NAD+ to accept the released H+ from ethanol. Thus, ethanol metabolism by ADH leads to increased ratio of NADH/NAD+, which inhibits FAO and induces steatosis. CYP2E1 directly consumes reducing equivalent NADPH to oxidize ethanol, which generates reactive oxygen species (ROS) that lead to cellular injury. Catalase is mainly present in peroxisomes, where very long-chain fatty acids and branched-chain fatty acids are oxidized, and the resultant short-chain fatty acids will be further oxidized in mitochondria. Peroxisomal FAO generates hydrogen peroxide (H2O2), which is locally decomposed by catalase. When ethanol is present, catalase uses H2O2 to oxidize ethanol. In this review, we introduce FAO (including α-, β-, and ω-oxidation) and ethanol metabolism (by ADH, CYP2E1, and catalase) followed by the interaction between FAO and ethanol metabolism in the liver and its pathophysiological significance.
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Affiliation(s)
- Yongke Lu
- Department of Biomedical Sciences, Joan C. Edwards College of Medicine, Marshall University, Huntington, West Virginia, United States
| | - Joseph George
- Department of Hepatology, Kanazawa Medical University, Uchinada, Ishikawa, Japan
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2
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Chen X, Wang L, Denning KL, Mazur A, Xu Y, Wang K, Lawrence LM, Wang X, Lu Y. Hepatocyte-Specific PEX16 Abrogation in Mice Leads to Hepatocyte Proliferation, Alteration of Hepatic Lipid Metabolism, and Resistance to High-Fat Diet (HFD)-Induced Hepatic Steatosis and Obesity. Biomedicines 2024; 12:988. [PMID: 38790950 PMCID: PMC11117803 DOI: 10.3390/biomedicines12050988] [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: 03/09/2024] [Revised: 04/15/2024] [Accepted: 04/25/2024] [Indexed: 05/26/2024] Open
Abstract
Obesity results in hepatic fat accumulation, i.e., steatosis. In addition to fat overload, impaired fatty acid β-oxidation also promotes steatosis. Fatty acid β-oxidation takes place in the mitochondria and peroxisomes. Usually, very long-chain and branched-chain fatty acids are the first to be oxidized in peroxisomes, and the resultant short chain fatty acids are further oxidized in the mitochondria. Peroxisome biogenesis is regulated by peroxin 16 (PEX16). In liver-specific PEX16 knockout (Pex16Alb-Cre) mice, hepatocyte peroxisomes were absent, but hepatocytes proliferated, and liver mass was enlarged. These results suggest that normal liver peroxisomes restrain hepatocyte proliferation and liver sizes. After high-fat diet (HFD) feeding, body weights were increased in PEX16 floxed (Pex16fl/fl) mice and adipose-specific PEX16 knockout (Pex16AdipoQ-Cre) mice, but not in the Pex16Alb-Cre mice, suggesting that the development of obesity is regulated by liver PEX16 but not by adipose PEX16. HFD increased liver mass in the Pex16fl/fl mice but somehow reduced the already enlarged liver mass in the Pex16Alb-Cre mice. The basal levels of serum triglyceride, free fatty acids, and cholesterol were decreased, whereas serum bile acids were increased in the Pex16Alb-Cre mice, and HFD-induced steatosis was not observed in the Pex16Alb-Cre mice. These results suggest that normal liver peroxisomes contribute to the development of liver steatosis and obesity.
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Affiliation(s)
- Xue Chen
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, 1700 3rd Avenue, Huntington, WV 25755, USA; (X.C.); (A.M.)
| | - Long Wang
- Department of Pathology, Guiqian International General Hospital, 1 Dongfeng Ave., Wudang, Guiyang 550018, China (Y.X.)
| | - Krista L. Denning
- Department of Pathology, Joan C. Edwards School of Medicine, Marshall University, 1 John Marshall Drive, Huntington, WV 25755, USA; (K.L.D.)
| | - Anna Mazur
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, 1700 3rd Avenue, Huntington, WV 25755, USA; (X.C.); (A.M.)
| | - Yujuan Xu
- Department of Pathology, Guiqian International General Hospital, 1 Dongfeng Ave., Wudang, Guiyang 550018, China (Y.X.)
| | - Kesheng Wang
- Department of Family and Community Health, School of Nursing, Health Sciences Center, West Virginia University, Morgantown, WV 26506, USA;
| | - Logan M. Lawrence
- Department of Pathology, Joan C. Edwards School of Medicine, Marshall University, 1 John Marshall Drive, Huntington, WV 25755, USA; (K.L.D.)
| | - Xiaodong Wang
- Department of Pathology, Guiqian International General Hospital, 1 Dongfeng Ave., Wudang, Guiyang 550018, China (Y.X.)
| | - Yongke Lu
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, 1700 3rd Avenue, Huntington, WV 25755, USA; (X.C.); (A.M.)
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Chen X, Denning KL, Mazur A, Lawrence LM, Wang X, Lu Y. Under peroxisome proliferation acyl-CoA oxidase coordinates with catalase to enhance ethanol metabolism. Free Radic Biol Med 2023; 208:221-228. [PMID: 37567517 PMCID: PMC10592128 DOI: 10.1016/j.freeradbiomed.2023.08.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/06/2023] [Accepted: 08/08/2023] [Indexed: 08/13/2023]
Abstract
In peroxisomes, acyl-CoA oxidase (ACOX) oxidizes fatty acids and produces H2O2, and the latter is decomposed by catalase. If ethanol is present, ethanol will be oxidized by catalase coupling with decomposition of H2O2. Peroxisome proliferator-activated receptor α (PPARα) agonist WY-14,643 escalated ethanol clearance, which was not observed in catalase knockout (Cat-/-) mice or partially blocked by an ACOX1 inhibitor. WY-14,643 induced peroxisome proliferation via peroxin 16 (PEX16). PEX16 liver-specific knockout (Pex16Alb-Cre) mice lack intact peroxisomes in liver, but catalase and ACOX1 were upregulated. Due to lacking intact peroxisomes, the upregulated catalase and ACOX1 in the Pex16Alb-Cre mice were mislocated in cytosol and microsomes, and the escalated ethanol clearance was not observed in the Pex16Alb-Cre mice, implicating that the intact functional peroxisomes are essential for ACOX1/catalase to metabolize ethanol. Alcohol-associated liver disease (ALD) is a spectrum of liver disorders ranging from alcoholic steatosis to steatohepatitis. WY-14,643 ameliorated alcoholic steatosis but tended to enhance alcoholic steatohepatitis. In mice lacking nuclear factor erythroid 2-related factor 2 (Nrf2-/-), WY-14,643 still induced PEX16, ACOX1 and catalase to escalate ethanol clearance and blunt alcoholic steatosis, which was not observed in the PPARα-absent Nrf2-/- mice (Pparα-/-/Nrf2-/-) mice, suggesting that WY-14,643 escalates ethanol clearance through PPARα but not through Nrf2.
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Affiliation(s)
- Xue Chen
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, 1700 3rd Avenue, Huntington, WV, 25755, USA
| | - Krista L Denning
- Department of Pathology, Joan C. Edwards School of Medicine, Marshall University, 1 John Marshall Drive, WV, 25755, United States
| | - Anna Mazur
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, 1700 3rd Avenue, Huntington, WV, 25755, USA
| | - Logan M Lawrence
- Department of Pathology, Joan C. Edwards School of Medicine, Marshall University, 1 John Marshall Drive, WV, 25755, United States
| | - Xiaodong Wang
- Department of Pathology, Guiqian International General Hospital, 1 Dongfeng Ave., Wudang Guiyang, Guizhou, 550018, PR China
| | - Yongke Lu
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, 1700 3rd Avenue, Huntington, WV, 25755, USA.
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Qiu YY, Zhang J, Zeng FY, Zhu YZ. Roles of the peroxisome proliferator-activated receptors (PPARs) in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Pharmacol Res 2023; 192:106786. [PMID: 37146924 DOI: 10.1016/j.phrs.2023.106786] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 04/28/2023] [Accepted: 05/02/2023] [Indexed: 05/07/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of disease phenotypes which start with simple steatosis and lipid accumulation in the hepatocytes - a typical histological lesions characteristic. It may progress to non-alcoholic steatohepatitis (NASH) that is characterized by hepatic inflammation and/or fibrosis and subsequent onset of NAFLD-related cirrhosis and hepatocellular carcinoma (HCC). Due to the central role of the liver in metabolism, NAFLD is regarded as a result of and contribution to the metabolic abnormalities seen in the metabolic syndrome. Peroxisome proliferator-activated receptors (PPARs) has three subtypes, which govern the expression of genes responsible for energy metabolism, cellular development, inflammation, and differentiation. The agonists of PPARα, such as fenofibrate and clofibrate, have been used as lipid-lowering drugs in clinical practice. Thiazolidinediones (TZDs) - ligands of PPARγ, such as rosiglitazone and pioglitazone, are also used in the treatment of type 2 diabetes (T2D) with insulin resistance (IR). Increasing evidence suggests that PPARβ/δ agonists have potential therapeutic effects in improving insulin sensitivity and lipid metabolism disorders. In addition, PPARs ligands have been considered as potential therapeutic drugs for hypertension, atherosclerosis (AS) or diabetic nephropathy. Their crucial biological roles dictate the significance of PPARs-targeting in medical research and drug discovery. Here, it reviews the biological activities, ligand selectivity and biological functions of the PPARs family, and discusses the relationship between PPARs and the pathogenesis of NAFLD and metabolic syndrome. This will open new possibilities for PPARs application in medicine, and provide a new idea for the treatment of fatty liver and related diseases.
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Affiliation(s)
- Yuan-Ye Qiu
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; Faculty of Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China.
| | - Jing Zhang
- University International College, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China.
| | - Fan-Yi Zeng
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; School of Pharmacy, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; Shanghai Institute of Medical Genetics, Shanghai Children's Hospital, Shanghai Jiao Tong University, 24/1400 West Beijing Road, Shanghai, 200040, China.
| | - Yi Zhun Zhu
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; Faculty of Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; School of Pharmacy, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China.
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Singdam P, Naowaboot J, Senggunprai L, Boonloh K, Pannangpetch P. Pluchea indica Leaf Extract Alleviates Dyslipidemia and Hepatic Steatosis by Modifying the Expression of Lipid Metabolism-Related Genes in Rats Fed a High Fat-High Fructose Diet. Prev Nutr Food Sci 2022; 27:384-398. [PMID: 36721751 PMCID: PMC9843721 DOI: 10.3746/pnf.2022.27.4.384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 08/23/2022] [Accepted: 09/26/2022] [Indexed: 01/03/2023] Open
Abstract
This study evaluated the effect of Pluchea indica leaf extract (PIE) on dyslipidemia and lipid accumulation in the liver, emphasizing its molecular mechanisms in regulating lipid metabolism in rats fed a high fat-high fructose diet (HFFD). Male rats were fed HFFD (40% lard and 20% fructose) for ten weeks. They were then divided into four groups receiving distilled water, PIE (100 or 300 mg/kg/d), and pioglitazone (10 mg/kg/d) for a further six weeks, during which the HFFD was continued. After the experiment, fasting blood glucose (FBG), oral glucose tolerance (OGT), serum insulin and leptin levels, lipid profiles, and hepatic triglyceride content were measured. Histological examination and expression levels of lipid metabolism-related genes in the liver were measured. HFFD-fed rats indicated a significantly increased FBG, serum leptin, and homeostasis model assessment of insulin resistance (HOMA-IR) scores with impaired OGT and dyslipidemia compared to rats fed a normal diet. PIE significantly reduced FBG, serum leptin, and HOMA-IR scores and improved OGT. Additionally, PIE significantly improved dyslipidemia and decreased serum-free fatty acids and liver triglyceride content. Hepatic histological examination showed a marked reduction lipid accumulation in relation to HFFD controls. Interestingly, PIE significantly downregulated the expression of lipid synthesis-related genes and upregulated the expression of fatty-acid oxidation-related genes. In conclusion, PIE alleviates dyslipidemia and hepatic steatosis in HFFD rats plausibly by increasing insulin resistance and modifying the gene expression associated with lipid metabolism. PIE may be used as preventive nutrition for dyslipidemia and hepatic steatosis.
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Affiliation(s)
- Patcharin Singdam
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Jarinyaporn Naowaboot
- Division of Pharmacology, Department of Preclinical Science, Faculty of Medicine, Thammasat University, Pathum Thani 12120, Thailand
| | - Laddawan Senggunprai
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Kampeebhorn Boonloh
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Patchareewan Pannangpetch
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand,
Correspondence to Patchareewan Pannangpetch, E-mail:
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PPARα agonist WY-14,643 induces the PLA2/COX-2/ACOX1 pathway to enhance peroxisomal lipid metabolism and ameliorate alcoholic fatty liver in mice. Biochem Biophys Res Commun 2022; 613:47-52. [DOI: 10.1016/j.bbrc.2022.04.132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 04/27/2022] [Accepted: 04/27/2022] [Indexed: 12/11/2022]
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Chen J, Liu Y, Huang Y, Tong A, Liu B, Zeng F. Schizochytrium
oil and its Mixture with Fish Oil and
Sacha inchi
Oil Ameliorate Gut Microbiota Composition and Lipid Metabolism via the FAS/HMGCR/SREBP Signaling Pathway. EUR J LIPID SCI TECH 2021. [DOI: 10.1002/ejlt.202100108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jie Chen
- College of Food Science Fujian Agriculture and Forestry University Fuzhou 350002 China
| | - Yilin Liu
- College of Food Science Fujian Agriculture and Forestry University Fuzhou 350002 China
| | - Ying Huang
- College of Food Science Fujian Agriculture and Forestry University Fuzhou 350002 China
| | - Aijun Tong
- College of Food Science Fujian Agriculture and Forestry University Fuzhou 350002 China
| | - Bin Liu
- College of Food Science Fujian Agriculture and Forestry University Fuzhou 350002 China
- National Engineering Research Center of JUNCAO Technology Fujian Agriculture and Forestry University Fuzhou 350002 China
| | - Feng Zeng
- College of Food Science Fujian Agriculture and Forestry University Fuzhou 350002 China
- National Engineering Research Center of JUNCAO Technology Fujian Agriculture and Forestry University Fuzhou 350002 China
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Tahri-Joutey M, Andreoletti P, Surapureddi S, Nasser B, Cherkaoui-Malki M, Latruffe N. Mechanisms Mediating the Regulation of Peroxisomal Fatty Acid Beta-Oxidation by PPARα. Int J Mol Sci 2021; 22:ijms22168969. [PMID: 34445672 PMCID: PMC8396561 DOI: 10.3390/ijms22168969] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/14/2021] [Accepted: 08/15/2021] [Indexed: 12/12/2022] Open
Abstract
In mammalian cells, two cellular organelles, mitochondria and peroxisomes, share the ability to degrade fatty acid chains. Although each organelle harbors its own fatty acid β-oxidation pathway, a distinct mitochondrial system feeds the oxidative phosphorylation pathway for ATP synthesis. At the same time, the peroxisomal β-oxidation pathway participates in cellular thermogenesis. A scientific milestone in 1965 helped discover the hepatomegaly effect in rat liver by clofibrate, subsequently identified as a peroxisome proliferator in rodents and an activator of the peroxisomal fatty acid β-oxidation pathway. These peroxisome proliferators were later identified as activating ligands of Peroxisome Proliferator-Activated Receptor α (PPARα), cloned in 1990. The ligand-activated heterodimer PPARα/RXRα recognizes a DNA sequence, called PPRE (Peroxisome Proliferator Response Element), corresponding to two half-consensus hexanucleotide motifs, AGGTCA, separated by one nucleotide. Accordingly, the assembled complex containing PPRE/PPARα/RXRα/ligands/Coregulators controls the expression of the genes involved in liver peroxisomal fatty acid β-oxidation. This review mobilizes a considerable number of findings that discuss miscellaneous axes, covering the detailed expression pattern of PPARα in species and tissues, the lessons from several PPARα KO mouse models and the modulation of PPARα function by dietary micronutrients.
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Affiliation(s)
- Mounia Tahri-Joutey
- Bio-PeroxIL Laboratory, University of Bourgogne Franche-Comté, 21000 Dijon, France; (M.T.-J.); (P.A.); (M.C.-M.)
- Laboratory of Biochemistry, Neurosciences, Natural Resources and Environment, Faculty of Sciences & Techniques, University Hassan I, BP 577, 26000 Settat, Morocco;
| | - Pierre Andreoletti
- Bio-PeroxIL Laboratory, University of Bourgogne Franche-Comté, 21000 Dijon, France; (M.T.-J.); (P.A.); (M.C.-M.)
| | - Sailesh Surapureddi
- Office of Pollution Prevention and Toxics, United States Environmental Protection Agency, Washington, DC 20460, USA;
| | - Boubker Nasser
- Laboratory of Biochemistry, Neurosciences, Natural Resources and Environment, Faculty of Sciences & Techniques, University Hassan I, BP 577, 26000 Settat, Morocco;
| | - Mustapha Cherkaoui-Malki
- Bio-PeroxIL Laboratory, University of Bourgogne Franche-Comté, 21000 Dijon, France; (M.T.-J.); (P.A.); (M.C.-M.)
| | - Norbert Latruffe
- Bio-PeroxIL Laboratory, University of Bourgogne Franche-Comté, 21000 Dijon, France; (M.T.-J.); (P.A.); (M.C.-M.)
- Correspondence:
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PPARα agonist WY-14,643 induces adipose atrophy and fails to blunt chronic ethanol-induced hepatic fat accumulation in mice lacking adipose FGFR1. Biochem Pharmacol 2021; 192:114678. [PMID: 34265279 DOI: 10.1016/j.bcp.2021.114678] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/08/2021] [Accepted: 07/09/2021] [Indexed: 01/05/2023]
Abstract
Fibroblast growth factor 21 (FGF21) is mainly regulated by peroxisome proliferator-activated receptor α (PPARα) in liver. The PPARα-FGF21 axis protects against alcohol-related liver disease (ALD). FGF21 exerts its effect via FGF receptor 1 (FGFR1). However, liver specific FGFR1 abrogation had no effect on ALD. Adipose tissues highly express FGFR1. When adipocyte specific FGFR1 knockout (fgfr1adipoQ-cre) mice and corresponding normal control (fgfr1fl/fl) mice were fed with Lieber-DeCarli ethanol liquid diet for 3 weeks, liver triglyceride (TG) accumulation was increased in the fgfr1fl/fl mice to a greater extent than in the fgfr1adipoQ-cre mice. When PPARα agonist WY-14,643 was added in the liquid ethanol diet at 10 mg/L, the ethanol-induced liver TG accumulation was blunted in the fgfr1fl/fl mice but not in the fgfr1adipoQ-cre mice. There was no significant difference in WY-14,643-induced fatty acid oxidation, ethanol metabolism, and oxidative stress between the fgfr1fl/fl and fgfr1adipoQ-cre mice. Interestingly, adipose atrophy was induced by WY-14,643 in the fgfr1adipoQ-cre mice but not in the fgfr1fl/fl mice. Serum free fatty acid was also decreased by WY-14,643 in the fgfr1adipoQ-cre mice but not in the fgfr1fl/fl mice. These results suggest that WY-14,643 inhibits alcoholic fatty liver and regulates adipose tissue mass and fat mobilization from adipose tissues to liver in an adipocyte FGFR1-dependent manner.
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Chen X, Xu Y, Denning KL, Grigore A, Lu Y. PPARα agonist WY-14,643 enhances ethanol metabolism in mice: Role of catalase. Free Radic Biol Med 2021; 169:283-293. [PMID: 33892114 PMCID: PMC8504580 DOI: 10.1016/j.freeradbiomed.2021.04.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 04/06/2021] [Accepted: 04/13/2021] [Indexed: 02/06/2023]
Abstract
Peroxisome proliferator-activated receptor α (PPARα), a fatty acid oxidation regulator, inhibits alcohol-induced fatty liver (AFL). PPARα agonist WY-14,643 ameliorates AFL. Nicotine enhances AFL. In this study, we investigated whether PPARα activation also blocks nicotine-enhanced AFL. Mice were fed liquid diets containing ethanol in the presence or absence of nicotine, WY-14,643 was added to the above diets at 10 mg/L. The results showed that WY-14,643 blunted AFL and nicotine-enhanced AFL, which was paralleled with striking induction of PPARα target genes. However, serum ALT was dramatically increased by the ethanol/WY-14,643 feeding and was further increased by nicotine/ethanol/WY-14,643 feeding, which was confirmed by necro-inflammation and elevated oxidative stress. Interestingly, serum alcohol levels were dramatically decreased by WY-14,643. Ethanol is mainly metabolized by alcohol dehydrogenase (ADH), cytochrome P450 2E1 (CYP2E1) and catalase. ADH and CYP2E1 were not increased by WY-14,643, but catalase was induced. What is more, injection of catalase inhibitor increased serum ethanol. Decreased serum alcohol, attenuated fatty liver, and enhanced liver injury were not induced by WY-14,643 in mice lacking PPARα. In conclusion, PPARα activation by WY-14,643 attenuates alcohol/nicotine-induced fatty liver but deteriorates ethanol/nicotine-induced liver injury; WY-14,643 enhances ethanol metabolism via induction of catalase.
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Affiliation(s)
- Xue Chen
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, 1700 3rd Avenue, Huntington, WV, 25755, USA
| | - Yunhui Xu
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, 1700 3rd Avenue, Huntington, WV, 25755, USA
| | - Krista L Denning
- Department of Pathology, Joan C. Edwards School of Medicine, Marshall University, 1 John Marshall Drive, WV, 25755, United States
| | - Audrey Grigore
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, 1700 3rd Avenue, Huntington, WV, 25755, USA
| | - Yongke Lu
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, 1700 3rd Avenue, Huntington, WV, 25755, USA; Department of Clinical and Translational Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, 25755, USA.
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11
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Hakkola J, Bernasconi C, Coecke S, Richert L, Andersson TB, Pelkonen O. Cytochrome P450 Induction and Xeno-Sensing Receptors Pregnane X Receptor, Constitutive Androstane Receptor, Aryl Hydrocarbon Receptor and Peroxisome Proliferator-Activated Receptor α at the Crossroads of Toxicokinetics and Toxicodynamics. Basic Clin Pharmacol Toxicol 2018. [DOI: 10.1111/bcpt.13004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Jukka Hakkola
- Research Unit of Biomedicine, Pharmacology and Toxicology; Faculty of Medicine; University of Oulu; Oulu Finland
- Medical Research Center Oulu; University of Oulu; Oulu Finland
| | | | - Sandra Coecke
- European Commission Joint Research Centre; EURL ECVAM; Ispra Italy
| | | | - Tommy B. Andersson
- Drug Metabolism and Pharmacokinetics; Cardiovascular and Metabolic Diseases; IMED Biotech Unit; AstraZeneca; Gothenburg Sweden
- Department of Physiology and Pharmacology; Section of Pharmacogenetics; Karolinska Institutet; Stockholm Sweden
| | - Olavi Pelkonen
- Research Unit of Biomedicine, Pharmacology and Toxicology; Faculty of Medicine; University of Oulu; Oulu Finland
- Medical Research Center Oulu; University of Oulu; Oulu Finland
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12
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Walker CL, Pomatto LCD, Tripathi DN, Davies KJA. Redox Regulation of Homeostasis and Proteostasis in Peroxisomes. Physiol Rev 2018; 98:89-115. [PMID: 29167332 PMCID: PMC6335096 DOI: 10.1152/physrev.00033.2016] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 06/19/2017] [Accepted: 06/21/2017] [Indexed: 02/08/2023] Open
Abstract
Peroxisomes are highly dynamic intracellular organelles involved in a variety of metabolic functions essential for the metabolism of long-chain fatty acids, d-amino acids, and many polyamines. A byproduct of peroxisomal metabolism is the generation, and subsequent detoxification, of reactive oxygen and nitrogen species, particularly hydrogen peroxide (H2O2). Because of its relatively low reactivity (as a mild oxidant), H2O2 has a comparatively long intracellular half-life and a high diffusion rate, all of which makes H2O2 an efficient signaling molecule. Peroxisomes also have intricate connections to mitochondria, and both organelles appear to play important roles in regulating redox signaling pathways. Peroxisomal proteins are also subject to oxidative modification and inactivation by the reactive oxygen and nitrogen species they generate, but the peroxisomal LonP2 protease can selectively remove such oxidatively damaged proteins, thus prolonging the useful lifespan of the organelle. Peroxisomal homeostasis must adapt to the metabolic state of the cell, by a combination of peroxisome proliferation, the removal of excess or badly damaged organelles by autophagy (pexophagy), as well as by processes of peroxisome inheritance and motility. More recently the tumor suppressors ataxia telangiectasia mutate (ATM) and tuberous sclerosis complex (TSC), which regulate mTORC1 signaling, have been found to regulate pexophagy in response to variable levels of certain reactive oxygen and nitrogen species. It is now clear that any significant loss of peroxisome homeostasis can have devastating physiological consequences. Peroxisome dysregulation has been implicated in several metabolic diseases, and increasing evidence highlights the important role of diminished peroxisomal functions in aging processes.
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Affiliation(s)
- Cheryl L Walker
- Center for Precision Environmental Health and Departments of Molecular & Cellular Biology and Medicine, Baylor College of Medicine, Houston, Texas; and Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center and Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts, and Sciences, The University of Southern California, Los Angeles, California
| | - Laura C D Pomatto
- Center for Precision Environmental Health and Departments of Molecular & Cellular Biology and Medicine, Baylor College of Medicine, Houston, Texas; and Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center and Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts, and Sciences, The University of Southern California, Los Angeles, California
| | - Durga Nand Tripathi
- Center for Precision Environmental Health and Departments of Molecular & Cellular Biology and Medicine, Baylor College of Medicine, Houston, Texas; and Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center and Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts, and Sciences, The University of Southern California, Los Angeles, California
| | - Kelvin J A Davies
- Center for Precision Environmental Health and Departments of Molecular & Cellular Biology and Medicine, Baylor College of Medicine, Houston, Texas; and Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center and Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts, and Sciences, The University of Southern California, Los Angeles, California
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Mudumbi JBN, Ntwampe SKO, Matsha T, Mekuto L, Itoba-Tombo EF. Recent developments in polyfluoroalkyl compounds research: a focus on human/environmental health impact, suggested substitutes and removal strategies. ENVIRONMENTAL MONITORING AND ASSESSMENT 2017; 189:402. [PMID: 28721589 DOI: 10.1007/s10661-017-6084-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 06/20/2017] [Indexed: 06/07/2023]
Abstract
Between the late 1940s and early 1950s, humans manufactured polyfluoroalkyl compounds (PFCs) using electrochemical fluorination and telomerisation technologies, whereby hydrogen atoms are substituted by fluorine atoms, thus conferring unnatural and unique physicochemical properties to these compounds. Presently, there are wide ranges of PFCs, and owing to their bioaccumulative properties, they have been detected in various environmental matrices and in human sera. It has thus been suggested that they are hazardous. Hence, this review aims at highlighting the recent development in PFC research, with a particular focus on perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS), the most studied and predominantly found PFCs in various environmental matrices, although recent reports have included perfluorobutane sulfonate (PFBS), which was previously regarded as innocuously harmless, when compared to its counterparts, PFOA and PFOS. As such, proper investigations are thus required for a better understanding of short-chain PFC substitutes, which have been suggested as suitable replacements to long-chained PFCs, although these substitutes have also been suggested to pose various health risks comparable to those associated with long-chain PFCs. Similarly, several novel technologies, such as PFC reduction using zero-valent iron, including removal at point of use, adsorption and coagulation, have been proposed. However, regardless of how efficient removers some of these techniques have proven to be, short-chain PFCs remain a challenge to overcome for scientists, in this regard.
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Affiliation(s)
- John Baptist Nzukizi Mudumbi
- Bioresource Engineering Research Group (BioERG), Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000, South Africa.
| | - Seteno Karabo Obed Ntwampe
- Bioresource Engineering Research Group (BioERG), Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000, South Africa
| | - Tandi Matsha
- Department of Bio-Medical Sciences, Faculty of Health and Wellness Science, Cape Peninsula University of Technology, PO Box 1906, Bellville, 7535, South Africa
| | - Lukhanyo Mekuto
- Bioresource Engineering Research Group (BioERG), Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000, South Africa
| | - Elie Fereche Itoba-Tombo
- Bioresource Engineering Research Group (BioERG), Department of Biotechnology, Cape Peninsula University of Technology, PO Box 652, Cape Town, 8000, South Africa
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Hua R, Kim PK. Multiple paths to peroxisomes: Mechanism of peroxisome maintenance in mammals. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:881-91. [DOI: 10.1016/j.bbamcr.2015.09.026] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 09/18/2015] [Accepted: 09/21/2015] [Indexed: 12/19/2022]
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15
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An integrative data mining approach to identifying adverse outcome pathway signatures. Toxicology 2016; 350-352:49-61. [DOI: 10.1016/j.tox.2016.04.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 03/10/2016] [Accepted: 04/18/2016] [Indexed: 01/27/2023]
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Oxidative Stress in the Healthy and Wounded Hepatocyte: A Cellular Organelles Perspective. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2016:8327410. [PMID: 26788252 PMCID: PMC4691634 DOI: 10.1155/2016/8327410] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 09/10/2015] [Indexed: 02/06/2023]
Abstract
Accurate control of the cell redox state is mandatory for maintaining the structural integrity and physiological functions. This control is achieved both by a fine-tuned balance between prooxidant and anti-oxidant molecules and by spatial and temporal confinement of the oxidative species. The diverse cellular compartments each, although structurally and functionally related, actively maintain their own redox balance, which is necessary to fulfill specialized tasks. Many fundamental cellular processes such as insulin signaling, cell proliferation and differentiation and cell migration and adhesion, rely on localized changes in the redox state of signal transducers, which is mainly mediated by hydrogen peroxide (H2O2). Therefore, oxidative stress can also occur long before direct structural damage to cellular components, by disruption of the redox circuits that regulate the cellular organelles homeostasis. The hepatocyte is a systemic hub integrating the whole body metabolic demand, iron homeostasis and detoxification processes, all of which are redox-regulated processes. Imbalance of the hepatocyte's organelles redox homeostasis underlies virtually any liver disease and is a field of intense research activity. This review recapitulates the evolving concept of oxidative stress in the diverse cellular compartments, highlighting the principle mechanisms of oxidative stress occurring in the healthy and wounded hepatocyte.
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Rocha E, Resende AD, Rocha MJ, Malhão F, Monteiro RAF, Lobo-da-Cunha A. Stereology of Brown Trout Liver Peroxisomes at Vitellogenesis and Pre-spawning Strengthens the Hypothesis of Their Regulation by Sex Steroids. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2015; 21 Suppl 5:87-88. [PMID: 26227724 DOI: 10.1017/s1431927615014245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Affiliation(s)
- Eduardo Rocha
- 1Microscopy Department,Institute of Biomedical Sciences Abel Salazar (ICBAS),U.Porto, Rua de Jorge Viterbo Ferreira n.º 228,Porto,Portugal
| | - Albina D Resende
- 2Interdisciplinary Center of Marine and Environmental Research (CIIMAR/CIMAR),U.Porto,Rua dos Bragas 289,Porto,Portugal
| | - Maria J Rocha
- 1Microscopy Department,Institute of Biomedical Sciences Abel Salazar (ICBAS),U.Porto, Rua de Jorge Viterbo Ferreira n.º 228,Porto,Portugal
| | - Fernanda Malhão
- 1Microscopy Department,Institute of Biomedical Sciences Abel Salazar (ICBAS),U.Porto, Rua de Jorge Viterbo Ferreira n.º 228,Porto,Portugal
| | - Rogério A F Monteiro
- 1Microscopy Department,Institute of Biomedical Sciences Abel Salazar (ICBAS),U.Porto, Rua de Jorge Viterbo Ferreira n.º 228,Porto,Portugal
| | - Alexandre Lobo-da-Cunha
- 1Microscopy Department,Institute of Biomedical Sciences Abel Salazar (ICBAS),U.Porto, Rua de Jorge Viterbo Ferreira n.º 228,Porto,Portugal
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Aranovich A, Hua R, Rutenberg AD, Kim PK. PEX16 contributes to peroxisome maintenance by constantly trafficking PEX3 via the ER. J Cell Sci 2014; 127:3675-86. [PMID: 25002403 PMCID: PMC4172262 DOI: 10.1242/jcs.146282] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The endoplasmic reticulum (ER) is required for the de novo biogenesis of peroxisomes in mammalian cells. However, its role in peroxisome maintenance is unclear. To explore ER involvement in the maintenance of peroxisomes, we redirect a peroxisomal membrane protein (PMP), PEX3, to directly target to the ER using the N-terminal ER signal sequence from preprolactin. Using biochemical techniques and fluorescent imaging, we find that ER-targeting PEX3 (ssPEX3) is continuously imported into pre-existing peroxisomes. This suggests that the ER constitutively provides membrane proteins and associated lipids to pre-existing peroxisomes. Using quantitative time-lapse live-cell fluorescence microscopy applied to cells that were either depleted of or exogenously expressing PEX16, we find that PEX16 mediates the peroxisomal trafficking of two distinct peroxisomal membrane proteins, PEX3 and PMP34, via the ER. These results not only provide insight into peroxisome maintenance and PMP trafficking in mammalian cells but also highlight important similarities and differences in the mechanisms of PMP import between the mammalian and yeast systems.
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Affiliation(s)
- Alexander Aranovich
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Rong Hua
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Andrew D Rutenberg
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS B3H 1Z9, Canada
| | - Peter K Kim
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON M5G 0A4, Canada Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada
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Misra P, Reddy JK. Peroxisome proliferator-activated receptor-α activation and excess energy burning in hepatocarcinogenesis. Biochimie 2014; 98:63-74. [DOI: 10.1016/j.biochi.2013.11.011] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 11/14/2013] [Indexed: 01/23/2023]
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Venkatachalam AB, Sawler DL, Wright JM. Tissue-specific transcriptional modulation of fatty acid-binding protein genes, fabp2, fabp3 and fabp6, by fatty acids and the peroxisome proliferator, clofibrate, in zebrafish (Danio rerio). Gene 2013; 520:14-21. [PMID: 23466978 DOI: 10.1016/j.gene.2013.02.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 02/19/2013] [Accepted: 02/21/2013] [Indexed: 12/28/2022]
Abstract
All fabp genes, except fabp2, fabp3 and fabp6, exist as duplicates in the zebrafish genome owing to a whole genome duplication event ~230-400 million years ago. Transcription of some duplicated fabp genes is modulated by fatty acids (FAs) and/or clofibrate, a peroxisome proliferator-activated receptor (PPAR) agonist. We had also shown previously that the steady-state level of acyl-CoA oxidase 1 (acox1) mRNA, a marker of PPARα activation, was elevated in liver, intestine, heart and muscle of fish fed clofibrate demonstrating that zebrafish, unlike some fishes, is responsive to this drug. acox1 transcripts were not induced in the brain of fish fed clofibrate, which suggests this drug may not cross the blood brain barrier. Here, we investigated the effect of dietary FAs and clofibrate on the transcription of single copy fabp genes, fabp2, fabp3 and fabp6, in five tissues of inbred zebrafish. The steady-state level of fabp2 transcripts increased in intestine, while fabp3 mRNA increased in liver of fish fed diets differing in FA content. In fish fed clofibrate, fabp3 mRNA in intestine, and fabp6 mRNA in intestine and heart, were elevated. Based on these findings, modulation of fabp2, fabp3 and fabp6 transcription by FAs and/or clofibrate in zebrafish implicates control of these genes by PPAR interaction with peroxisome proliferator response elements (PPRE) most likely in fabp promoters. Moreover, transcriptional induction of these fabp genes by dietary FAs and/or clofibrate is over-ridden by a tissue-specific mechanism(s), e.g., transcriptional activator or repressor proteins.
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Misra P, Viswakarma N, Reddy JK. Peroxisome proliferator-activated receptor-α signaling in hepatocarcinogenesis. Subcell Biochem 2013; 69:77-99. [PMID: 23821144 DOI: 10.1007/978-94-007-6889-5_5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Peroxisomes are subcellular organelles that are found in the cytoplasm of most animal cells. They perform diverse metabolic functions, including H2O2-derived respiration, β-oxidation of fatty acids, and cholesterol metabolism. Peroxisome proliferators are a large class of structurally dissimilar industrial and pharmaceutical chemicals that were originally identified as inducers of both the size and the number of peroxisomes in rat and mouse livers or hepatocytes in vitro. Exposure to peroxisome proliferators leads to a stereotypical orchestration of adaptations consisting of hepatocellular hypertrophy and hyperplasia, and transcriptional induction of fatty acid metabolizing enzymes regulated in parallel with peroxisome proliferation. Chronic exposure to peroxisome proliferators causes liver tumors in both male and female mice and rats. Evidence indicates a pivotal role for a subset of nuclear receptor superfamily members, called peroxisome proliferator-activated receptors (PPARs), in mediating energy metabolism. Upon activation, PPARs regulate the expression of genes involved in lipid metabolism and peroxisome proliferation, as well as genes involved in cell growth. In this review, we describe the molecular mode of action of PPAR transcription factors, including ligand binding, interaction with specific DNA response elements, transcriptional activation, and cross talk with other signaling pathways. We discuss the evidence that suggests that PPARα and transcriptional coactivator Med1/PBP, a key subunit of the Mediator complex play a central role in mediating hepatic steatosis to hepatocarcinogenesis. Disproportionate increases in H2O2-generating enzymes generates excess reactive oxygen species resulting in sustained oxidative stress and progressive endoplasmic reticulum (ER) stress with activation of unfolded protein response signaling. Thus, these major contributors coupled with hepatocellular proliferation are the key players of peroxisome proliferators-induced hepatocarcinogenesis.
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Affiliation(s)
- Parimal Misra
- Department of Biology, Dr. Reddy's Institute of Life Sciences, An Associate Institute of University of Hyderabad, Gachibowli, Hyderabad, 500046, India,
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Benz V, Kintscher U, Foryst-Ludwig A. Sex-specific differences in Type 2 Diabetes Mellitus and dyslipidemia therapy: PPAR agonists. Handb Exp Pharmacol 2013:387-410. [PMID: 23027460 DOI: 10.1007/978-3-642-30726-3_18] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The influence of sex on the development of obesity, Type 2 Diabetes Mellitus (T2DM), and dyslipidemia is well documented, although the molecular mechanism underlying those differences reminds elusive. Ligands of peroxisome proliferator-activated receptors (PPARs) are used as oral antidiabetics (PPARgamma agonists: thiazolidinediones, TZDs), or for the treatment of dyslipidemia and cardiovascular diseases, due to their lipid-lowering properties (PPARalpha agonists: fibrates), as PPARs control transcription of a set of genes involved in the regulation of lipid and carbohydrate metabolism. Given a high prevalence of those metabolic disorders, and thus a broad use of PPAR agonists, the present review will discuss distinct aspects of sex-specific differences in antiobesity treatment using those groups of PPAR ligands.
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Affiliation(s)
- Verena Benz
- Charité-Universitätsmedizin Berlin, Berlin, Germany.
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Venkatachalam AB, Lall SP, Denovan-Wright EM, Wright JM. Tissue-specific differential induction of duplicated fatty acid-binding protein genes by the peroxisome proliferator, clofibrate, in zebrafish (Danio rerio). BMC Evol Biol 2012; 12:112. [PMID: 22776158 PMCID: PMC3483278 DOI: 10.1186/1471-2148-12-112] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 05/31/2012] [Indexed: 01/03/2023] Open
Abstract
Background Force, Lynch and Conery proposed the duplication-degeneration-complementation (DDC) model in which partitioning of ancestral functions (subfunctionalization) and acquisition of novel functions (neofunctionalization) were the two primary mechanisms for the retention of duplicated genes. The DDC model was tested by analyzing the transcriptional induction of the duplicated fatty acid-binding protein (fabp) genes by clofibrate in zebrafish. Clofibrate is a specific ligand of the peroxisome proliferator-activated receptor (PPAR); it activates PPAR which then binds to a peroxisome proliferator response element (PPRE) to induce the transcriptional initiation of genes primarily involved in lipid homeostasis. Zebrafish was chosen as our model organism as it has many duplicated genes owing to a whole genome duplication (WGD) event that occurred ~230-400 million years ago in the teleost fish lineage. We assayed the steady-state levels of fabp mRNA and heterogeneous nuclear RNA (hnRNA) transcripts in liver, intestine, muscle, brain and heart for four sets of duplicated fabp genes, fabp1a/fabp1b.1/fabp1b.2, fabp7a/fabp7b, fabp10a/fabp10b and fabp11a/fabp11b in zebrafish fed different concentrations of clofibrate. Result Electron microscopy showed an increase in the number of peroxisomes and mitochondria in liver and heart, respectively, in zebrafish fed clofibrate. Clofibrate also increased the steady-state level of acox1 mRNA and hnRNA transcripts in different tissues, a gene with a functional PPRE. These results demonstrate that zebrafish is responsive to clofibrate, unlike some other fishes. The levels of fabp mRNA and hnRNA transcripts for the four sets of duplicated fabp genes was determined by reverse transcription, quantitative polymerase chain reaction (RT-qPCR). The level of hnRNA coded by a gene is an indirect estimate of the rate of transcriptional initiation of that gene. Clofibrate increased the steady-state level of fabp mRNAs and hnRNAs for both the duplicated copies of fabp1a/fabp1b.1, and fabp7a/fabp7b, but in different tissues. Clofibrate also increased the steady-state level of fabp10a and fabp11a mRNAs and hnRNAs in liver, but not for fabp10b and fabp11b. Conclusion Some duplicated fabp genes have, most likely, retained PPREs, but induction by clofibrate is over-ridden by an, as yet, unknown tissue-specific mechanism(s). Regardless of the tissue-specific mechanism(s), transcriptional control of duplicated zebrafish fabp genes by clofibrate has markedly diverged since the WGD event.
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Rose RJ, Priston MJ, Rigby‐Jones AE, Sneyd JR. The effect of temperature on di(2‐ethylhexyl) phthalate leaching from PVC infusion sets exposed to lipid emulsions. Anaesthesia 2012; 67:514-520. [DOI: 10.1111/j.1365-2044.2011.07006.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - M. J. Priston
- Principle Healthcare Scientist, Department of Pharmacy, Derriford Hospital, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - A. E. Rigby‐Jones
- Research Fellow, Anaesthesia Research Group, Peninsula College of Medicine & Dentistry, University of Plymouth, Plymouth, UK
| | - J. R. Sneyd
- Vice Dean and Professor of Anaesthesia, Peninsula College of Medicine & Dentistry, University of Plymouth, Plymouth, UK
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Huang J, Viswakarma N, Yu S, Jia Y, Bai L, Vluggens A, Cherkaoui-Malki M, Khan M, Singh I, Yang G, Rao MS, Borensztajn J, Reddy JK. Progressive endoplasmic reticulum stress contributes to hepatocarcinogenesis in fatty acyl-CoA oxidase 1-deficient mice. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:703-13. [PMID: 21801867 DOI: 10.1016/j.ajpath.2011.04.030] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2010] [Revised: 04/20/2011] [Accepted: 04/25/2011] [Indexed: 02/08/2023]
Abstract
Fatty acyl-coenzyme A oxidase 1 (ACOX1) knockout (ACOX1(-/-)) mice manifest hepatic metabolic derangements that lead to the development of steatohepatitis, hepatocellular regeneration, spontaneous peroxisome proliferation, and hepatocellular carcinomas. Deficiency of ACOX1 results in unmetabolized substrates of this enzyme that function as biological ligands for peroxisome proliferator-activated receptor-α (PPARα) in liver. Here we demonstrate that sustained activation of PPARα in ACOX1(-/-) mouse liver by these ACOX1 substrates results in endoplasmic reticulum (ER) stress. Overexpression of transcriptional regulator p8 and its ER stress-related effectors such as the pseudokinase tribbles homolog 3, activating transcription factor 4, and transcription factor CCAAT/-enhancer-binding protein homologous protein as well as phosphorylation of eukaryotic translation initiation factor 2α, indicate the induction of unfolded protein response signaling in the ACOX1(-/-) mouse liver. We also show here that, in the liver, p8 is a target for all three PPAR isoforms (-α, -β, and -γ), which interact with peroxisome proliferator response elements in p8 promoter. Sustained activation of p8 and unfolded protein response-associated ER stress in ACOX1(-/-) mouse liver contributes to hepatocyte apoptosis and liver cell proliferation culminating in the development of hepatocarcinogenesis. We also demonstrate that human ACOX1 transgene is functional in ACOX1(-/-) mice and effectively prevents metabolic dysfunctions that lead to ER stress and carcinogenic effects. Taken together, our data indicate that progressive PPARα- and p8-mediated ER stress contribute to the hepatocarcinogenesis in ACOX1(-/-) mice.
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Affiliation(s)
- Jiansheng Huang
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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Locker J. Transcriptional Control of Hepatocyte Differentiation. MOLECULAR PATHOLOGY LIBRARY 2011. [DOI: 10.1007/978-1-4419-7107-4_14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Peroxisomes and peroxisomal disorders: The main facts. ACTA ACUST UNITED AC 2010; 62:615-25. [DOI: 10.1016/j.etp.2009.08.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2009] [Revised: 08/12/2009] [Accepted: 08/16/2009] [Indexed: 11/23/2022]
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PRIC295, a Nuclear Receptor Coactivator, Identified from PPARα-Interacting Cofactor Complex. PPAR Res 2010; 2010. [PMID: 20885938 PMCID: PMC2946606 DOI: 10.1155/2010/173907] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Accepted: 07/22/2010] [Indexed: 01/22/2023] Open
Abstract
The peroxisome proliferator-activated receptor-α (PPARα) plays a key role in lipid metabolism and energy combustion. Chronic activation of PPARα in rodents leads to the development of hepatocellular carcinomas. The ability of PPARα to induce expression of its target genes depends on Mediator, an evolutionarily conserved complex of cofactors and, in particular, the subunit 1 (Med1) of this complex. Here, we report the identification and characterization of PPARα-interacting cofactor (PRIC)-295 (PRIC295), a novel coactivator protein, and show that it interacts with the Med1 and Med24 subunits of the Mediator complex. PRIC295 contains 10 LXXLL signature motifs that facilitate nuclear receptor binding and interacts with PPARα and five other members of the nuclear receptor superfamily in a ligand-dependent manner. PRIC295 enhances the transactivation function of PPARα, PPARγ, and ERα. These data demonstrate that PRIC295 interacts with nuclear receptors such as PPARα and functions as a transcription coactivator under in vitro conditions and may play an important role in mediating the effects in vivo as a member of the PRIC complex with Med1 and Med24.
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Vluggens A, Andreoletti P, Viswakarma N, Jia Y, Matsumoto K, Kulik W, Khan M, Huang J, Guo D, Yu S, Sarkar J, Singh I, Rao MS, Wanders RJ, Reddy JK, Cherkaoui-Malki M. Reversal of mouse Acyl-CoA oxidase 1 (ACOX1) null phenotype by human ACOX1b isoform [corrected]. J Transl Med 2010; 90:696-708. [PMID: 20195242 DOI: 10.1038/labinvest.2010.46] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Disruption of the peroxisomal acyl-CoA oxidase 1 (Acox1) gene in the mouse results in the development of severe microvesicular hepatic steatosis and sustained activation of peroxisome proliferator-activated receptor-alpha (PPARalpha). These mice manifest spontaneous massive peroxisome proliferation in regenerating hepatocytes and eventually develop hepatocellular carcinomas. Human ACOX1, the first and rate-limiting enzyme of the peroxisomal beta-oxidation pathway, has two isoforms including ACOX1a and ACOX1b, transcribed from a single gene. As ACOX1a shows reduced activity toward palmitoyl-CoA as compared with ACOX1b, we used adenovirally driven ACOX1a and ACOX1b to investigate their efficacy in the reversal of hepatic phenotype in Acox1(-/-) mice. In this study, we show that human ACOX1b is markedly effective in reversing the ACOX1 null phenotype in the mouse. In addition, expression of human ACOX1b was found to restore the production of nervonic (24:1) acid and had a negative impact on the recruitment of coactivators to the PPARalpha-response unit, which suggests that nervonic acid might well be an endogenous PPARalpha antagonist, with nervonoyl-CoA probably being the active form of nervonic acid. In contrast, restoration of docosahexaenoic (22:6) acid level, a retinoid-X-receptor (RXRalpha) agonist, was dependent on the concomitant hepatic expression of both ACOX1a and ACOX1b isoforms. This is accompanied by a specific recruitment of RXRalpha and coactivators to the PPARalpha-response unit. The human ACOX1b isoform is more effective than the ACOX1a isoform in reversing the Acox1 null phenotype in the mouse. Substrate utilization differences between the two ACOX1 isoforms may explain the reason why ACOX1b is more effective in metabolizing PPARalpha ligands.
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Shimizu T, Fan Y, Yamana D, Miura T, Nanashima N, Yamada T, Tsuchida S. Glutathione S-transferase A4 is a positive marker for rat hepatic foci induced by clofibrate and genotoxic carcinogens. Cancer Sci 2010; 101:1093-8. [PMID: 20180811 PMCID: PMC11158787 DOI: 10.1111/j.1349-7006.2010.01508.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Peroxisome proliferators (PP), including clofibrate (CF), are non-genotoxic rodent carcinogens, and oxidative DNA damages are suggested as a causative event for carcinogenesis. Gene expression profiles differ between hepatic lesions induced by PP and genotoxic carcinogens. Our previous study revealed that expression of L-bifunctional enzyme (enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase, BE) was repressed in preneoplastic lesions induced by PP, whereas it was enhanced in the surrounding tissues. In the present study, we immunohistochemically examined expression of the specific glutathione S-transferase (GST) form, GST-A4, which detoxifies 4-hydroxy-alkenal, the end-product of lipid peroxides, and nuclear factor-erythroid 2-related factor 2 (Nrf2), a transcription factor for many genes encoding drug-metabolizing enzymes and defending enzymes against oxidative stress, during rat hepatocarcinogenesis induced by CF and genotoxic carcinogens. GST-A4 and Nrf2 were not expressed in BE-negative foci at 8 weeks of CF administration, but were expressed in the foci at 60 weeks. GST-A4-positive foci appeared at later stages than BE-negative foci, but its localization was coincidental with that of the latter foci. The areas of GST-A4-positive foci were larger than those of BE-negative foci without GST-A4 expression. Most GST-A4-positive foci were also positive for Nrf2. In rat livers induced by genotoxic carcinogens, GST-P-negative foci as well as GST-P-positive foci were demonstrated. GST-A4 and Nrf2 were expressed in GST-P-negative foci, whereas they were not expressed in most GST-P-positive foci. Thus, GST-A4-positive foci developed in rat livers by CF and genotoxic carcinogen administration, indicating that the enzyme is a positive marker for hepatic foci induced by these different carcinogens.
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Affiliation(s)
- Takeshi Shimizu
- Department of Biochemistry and Genome Biology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
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31
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Pyper SR, Viswakarma N, Yu S, Reddy JK. PPARalpha: energy combustion, hypolipidemia, inflammation and cancer. NUCLEAR RECEPTOR SIGNALING 2010; 8:e002. [PMID: 20414453 PMCID: PMC2858266 DOI: 10.1621/nrs.08002] [Citation(s) in RCA: 293] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Accepted: 03/04/2010] [Indexed: 12/11/2022]
Abstract
The peroxisome proliferator-activated receptor alpha (PPARalpha, or NR1C1) is a nuclear hormone receptor activated by a structurally diverse array of synthetic chemicals known as peroxisome proliferators. Endogenous activation of PPARalpha in liver has also been observed in certain gene knockout mouse models of lipid metabolism, implying the existence of enzymes that either generate (synthesize) or degrade endogenous PPARalpha agonists. For example, substrates involved in fatty acid oxidation can function as PPARalpha ligands. PPARalpha serves as a xenobiotic and lipid sensor to regulate energy combustion, hepatic steatosis, lipoprotein synthesis, inflammation and liver cancer. Mainly, PPARalpha modulates the activities of all three fatty acid oxidation systems, namely mitochondrial and peroxisomal beta-oxidation and microsomal omega-oxidation, and thus plays a key role in energy expenditure. Sustained activation of PPARalpha by either exogenous or endogenous agonists leads to the development of hepatocellular carcinoma resulting from sustained oxidative and possibly endoplasmic reticulum stress and liver cell proliferation. PPARalpha requires transcription coactivator PPAR-binding protein (PBP)/mediator subunit 1(MED1) for its transcriptional activity.
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Affiliation(s)
| | | | | | - Janardan K. Reddy
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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32
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Pettinelli P, Del Pozo T, Araya J, Rodrigo R, Araya AV, Smok G, Csendes A, Gutierrez L, Rojas J, Korn O, Maluenda F, Diaz JC, Rencoret G, Braghetto I, Castillo J, Poniachik J, Videla LA. Enhancement in liver SREBP-1c/PPAR-alpha ratio and steatosis in obese patients: correlations with insulin resistance and n-3 long-chain polyunsaturated fatty acid depletion. Biochim Biophys Acta Mol Basis Dis 2009; 1792:1080-6. [PMID: 19733654 DOI: 10.1016/j.bbadis.2009.08.015] [Citation(s) in RCA: 170] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2009] [Revised: 08/26/2009] [Accepted: 08/31/2009] [Indexed: 12/13/2022]
Abstract
Sterol receptor element-binding protein-1c (SREBP-1c) and peroxisome proliferator-activated receptor-alpha (PPAR-alpha) mRNA expression was assessed in liver as signaling mechanisms associated with steatosis in obese patients. Liver SREBP-1c and PPAR-alpha mRNA (RT-PCR), fatty acid synthase (FAS) and carnitine palmitoyltransferase-1a (CPT-1a) mRNA (real-time RT-PCR), and n-3 long-chain polyunsaturated fatty acid (LCPUFA)(GLC) contents, plasma adiponectin levels (RIA), and insulin resistance (IR) evolution (HOMA) were evaluated in 11 obese patients who underwent subtotal gastrectomy with gastro-jejunal anastomosis in Roux-en-Y and 8 non-obese subjects who underwent laparoscopic cholecystectomy (controls). Liver SREBP-1c and FAS mRNA levels were 33% and 70% higher than control values (P<0.05), respectively, whereas those of PPAR-alpha and CPT-1a were 16% and 65% lower (P<0.05), respectively, with a significant 62% enhancement in the SREBP-1c/PPAR-alpha ratio. Liver n-3 LCPUFA levels were 53% lower in obese patients who also showed IR and hipoadiponectinemia over controls (P<0.05). IR negatively correlated with both the hepatic content of n-3 LCPUFA (r=-0.55; P<0.01) and the plasma levels of adiponectin (r=-0.62; P<0.005). Liver SREBP-1c/PPAR-alpha ratio and n-3 LCPUFA showed a negative correlation (r=-0.48; P<0.02) and positive associations with either HOMA (r=0.75; P<0.0001) or serum insulin levels (r=0.69; P<0.001). In conclusion, liver up-regulation of SREBP-1c and down-regulation of PPAR-alpha occur in obese patients, with enhancement in the SREBP-1c/PPAR-alpha ratio associated with n-3 LCPUFA depletion and IR, a condition that may favor lipogenesis over FA oxidation thereby leading to steatosis.
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Affiliation(s)
- Paulina Pettinelli
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile
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33
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Bonekamp NA, Völkl A, Fahimi HD, Schrader M. Reactive oxygen species and peroxisomes: struggling for balance. Biofactors 2009; 35:346-55. [PMID: 19459143 DOI: 10.1002/biof.48] [Citation(s) in RCA: 186] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Reactive oxygen species (ROS) can surely be considered as multifunctional biofactors within the cell. They are known to participate in regular cell functions, for example, as signal mediators, but overproduction under oxidative stress conditions leads to deleterious cellular effects, cell death and diverse pathological conditions. Peroxisomal function has long been linked to oxygen metabolism due to the high concentration of H(2)O(2)-generating oxidases in peroxisomes and their set of antioxidant enzymes, especially catalase. Still, mitochondria have been very much placed in the centre of ROS metabolism and oxidative stress. This review discusses novel findings concerning the relationship between ROS and peroxisomes, as they revealed to be a key player in the dynamic spin of ROS metabolism and oxidative injury. An overview of ROS generating enzymes as well as their antioxidant counterparts will be given, exemplifying the precise fine-tuning between the opposing systems. Various conditions in which the balance between generation and scavenging of ROS in peroxisomes is perturbed, for example, exogenous manipulation, ageing and peroxisomal disorders, are addressed. Furthermore, peroxisome-derived oxidative stress and its effect on mitochondria (and vice versa) are discussed, highlighting the close interrelationship of both organelles.
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Affiliation(s)
- Nina A Bonekamp
- Centre for Cell Biology and Department of Biology, University of Aveiro, Aveiro, Portugal
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34
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Human health risk assessment for peroxisome proliferators: More than 30 years of research. ACTA ACUST UNITED AC 2009; 61:215-21. [DOI: 10.1016/j.etp.2008.09.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Revised: 09/04/2008] [Accepted: 09/08/2008] [Indexed: 11/24/2022]
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35
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El Kebbaj Z, Andreoletti P, Mountassif D, Kabine M, Schohn H, Dauça M, Latruffe N, El Kebbaj MS, Cherkaoui-Malki M. Differential regulation of peroxisome proliferator-activated receptor (PPAR)-alpha1 and truncated PPARalpha2 as an adaptive response to fasting in the control of hepatic peroxisomal fatty acid beta-oxidation in the hibernating mammal. Endocrinology 2009; 150:1192-201. [PMID: 18948393 DOI: 10.1210/en.2008-1394] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Seasonal obesity and fasting-associated hibernation are the two major metabolic events governing hepatic lipid metabolism in hibernating mammals. In this process, however, the role of the nuclear receptor known as peroxisome proliferator-activated receptor (PPAR)-alpha has not been elucidated yet. Here we show, as in human, that jerboa (Jaculus orientalis) liver expresses both active wild-type PPARalpha (PPARalpha1wt) and truncated PPARalpha forms and that the PPARalpha1wt to truncated PPARalpha2 ratio, which indicates the availability of active PPARalpha1wt, is differentially regulated during fasting-associated hibernation. Functional activation of hepatic jerboa PPARalpha, during prehibernating and hibernating states, was demonstrated by the induction of its target genes, which encode peroxisomal proteins such as acyl-CoA oxidase 1, peroxisomal membrane protein 70, and catalase, accompanied by a concomitant induction of PPARalpha thermogenic coactivator PPARgamma coactivator-1alpha. Interestingly, sustained activation of PPARalpha by its hypolipidemic ligand, ciprofibrate, abrogates the adaptive fasting response of PPARalpha during prehibernation and overinduces its target genes, disrupting the prehibernation fattening process. In striking contrast, during fasting-associated hibernation, jerboas exhibit preferential up-regulation of hepatic peroxisomal fatty acid oxidation instead of the mitochondrial pathway, which is down-regulated. Taken together, our results strongly suggest that PPARalpha is subject to a hibernation-dependent splicing regulation in response to feeding-fasting conditions, which defines the activity of PPARalpha and the activation of its target genes during hibernation bouts of jerboas.
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Affiliation(s)
- Zakaria El Kebbaj
- Faculté des Sciences Gabriel, Unité Mixté de Recherche 866, Institut National de la Santé et de la Recherche Médicale, Centre de Recherche-Biochimie Métabolique et Nutritionnelle, Université de Bourgogne, Dijon, France
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36
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Chung C, Doll JA, Stellmach VM, Gonzales J, Surapureddi S, Cornwell M, Reddy JK, Crawford SE. Pigment epithelium-derived factor is an angiogenesis and lipid regulator that activates peroxisome proliferator-activated receptor alpha. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2008; 617:591-7. [PMID: 18497086 DOI: 10.1007/978-0-387-69080-3_61] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Pigment epithelium-derived factor (PEDF) is an endogenous antiangiogenic protein that also possesses antitumor activity. The mechanisms by which PEDF exerts its actions remains poorly understood. We sought to understand the role of PEDF in hepatocellular carcinoma (HCC), a hypervascular malignancy that has been shown to upregulate enzymes involved in fatty acid synthesis. PEDF expression occurs in two HCC cell lines and is oxygen dependent. Migration studies confirm PEDF's role as an endogenous inhibitor of angiogenesis in HCC cells. Loss of PEDF in an animal model leads to hepatocyte lipid accumulation, proliferation, and cellular atypia. To investigate potential interactions with transcription factors that are involved in fatty acid metabolism and cellular proliferation, we examined PEDF's interaction with PPARalpha in vitro and its functional activity through transactivation assays. We show that PEDF binds to PPARalpha but minimally to PPARgamma. In the presence of the ligand, ciprofibrate, PEDF binding to PPARalpha decreases whereas the presence of troglitazone does not alter PEDF interactions with PPARgamma. Transfection of the PEDF gene in the presence of the PPARalpha/RXR heterodimer demonstrates transcriptional activation of PPARalpha by PEDF. These data show that PEDF regulates lipid metabolism through activation of the transcription factor PPARalpha.
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Affiliation(s)
- Chuhan Chung
- Section of Digestive Disease, Yale University School of Medicine, West Haven, CT, USA
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37
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Guo D, Sarkar J, Suino-Powell K, Xu Y, Matsumoto K, Jia Y, Yu S, Khare S, Haldar K, Rao MS, Foreman JE, Monga SPS, Peters JM, Xu HE, Reddy JK. Induction of nuclear translocation of constitutive androstane receptor by peroxisome proliferator-activated receptor alpha synthetic ligands in mouse liver. J Biol Chem 2007; 282:36766-76. [PMID: 17962186 DOI: 10.1074/jbc.m707183200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Peroxisome proliferators activate nuclear receptor peroxisome proliferator-activated receptor alpha (PPARalpha) and enhance the transcription of several genes in liver. We report here that synthetic PPARalpha ligands Wy-14,643, ciprofibrate, clofibrate, and others induce the nuclear translocation of constitutive androstane receptor (CAR) in mouse liver cells in vivo. Adenoviral-enhanced green fluorescent protein-CAR expression demonstrated that PPARalpha synthetic ligands drive CAR into the hepatocyte nucleus in a PPARalpha- and PPARbeta-independent manner. This translocation is dependent on the transcription coactivator PPAR-binding protein but independent of coactivators PRIP and SRC-1. PPARalpha ligand-induced nuclear translocation of CAR is not associated with induction of Cyp2b10 mRNA in mouse liver. PPARalpha ligands interfered with coactivator recruitment to the CAR ligand binding domain and reduced the constitutive transactivation of CAR. Both Wy-14,643 and ciprofibrate occupied the ligand binding pocket of CAR and adapted a binding mode similar to that of the CAR inverse agonist androstenol. These observations, therefore, provide information for the first time to indicate that PPARalpha ligands not only serve as PPARalpha agonists but possibly act as CAR antagonists.
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Affiliation(s)
- Dongsheng Guo
- Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611-3008, USA
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38
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Druckova A, Mernaugh RL, Ham AJL, Marnett LJ. Identification of the Protein Targets of the Reactive Metabolite of Teucrin A in Vivo in the Rat. Chem Res Toxicol 2007; 20:1393-408. [PMID: 17892266 DOI: 10.1021/tx7001405] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Covalent modification of proteins is associated with the toxicity of many electrophiles, and the identification of relevant in vivo protein targets is a desirable but challenging goal. Here, we describe a strategy for the enrichment of adducted proteins utilizing single-chain fragment variable (ScFv) antibodies selected using phage-display technology. Teucrin A is a furan-containing diterpenoid found in the herb germander that is primarily responsible for the herb's hepatotoxicity in rodents and humans following metabolic activation by cytochrome P450 enzymes. Conjugates of the 1,4-enedial derivative of teucrin A, its presumed toxic metabolite, with lysine- and cysteine-containing peptides were synthesized and used to select ScFvs from a rodent phage-displayed library, which recognized the terpenoid moiety of the teucrin-derived adducts. Immunoaffinity isolation of adducted proteins from rat liver homogenates following administration of a toxic dose of teucrin A afforded a family of proteins that were identified by liquid chromatography/tandem mass spectrometry. Of the 46 proteins identified in this study, most were of mitochondrial and endoplasmic reticulum origin. Several cytosolic proteins were found, as well as four peroxisomal and two secreted proteins. Using Ingenuity Pathway Analysis software, two significant networks involving the target genes were identified that had major functions in gene expression, small molecule biochemistry, and cellular function and maintenance. These included proteins involved in lipid, amino acid, and drug metabolism. This study illustrates the utility of chemically synthesized biological conjugates of reactive intermediates and the potential of the phage display technology for the generation of affinity reagents for the isolation of adducted proteins.
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Affiliation(s)
- Alexandra Druckova
- Department of Biochemistry, A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
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39
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Wheelock CE, Goto S, Hammock BD, Newman JW. Clofibrate-induced changes in the liver, heart, brain and white adipose lipid metabolome of Swiss-Webster mice. Metabolomics 2007; 3:137-145. [PMID: 19079556 PMCID: PMC2597807 DOI: 10.1007/s11306-007-0052-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Peroxisome proliferator activated receptor alpha (PPARα) agonists are anti-hyperlipidemic drugs that influence fatty acid combustion, phospholipid biosynthesis and lipoprotein metabolism. To evaluate impacts on other aspects of lipid metabolism, we applied targeted metabolomics to liver, heart, brain and white adipose tissue samples from male Swiss-Webster mice exposed to a 5 day, 500 mg/kg/day regimen of i.p. clofibrate. Tissue concentrations of free fatty acids and the fatty acid content of sphingomyelin, cardiolipin, cholesterol esters, triglycerides and phospholipids were quantified. Responses were tissue-specific, with changes observed in the liver > heart ≫ brain > adipose. These results indicate that liver saturated fatty acid-rich triglycerides feeds clofibrate-induced monounsaturated fatty acid (MUFA) synthesis, which were incorporated into hepatic phospholipids and sphingomyelin. In addition, selective enrichment of docosahexeneoic acid in the phosphatidylserine of liver (1.7-fold), heart (1.6-fold) and brain (1.5-fold) suggests a clofibrate-dependent systemic activation of phosphatidylserine synthetase 2. Furthermore, the observed ~20% decline in cardiac sphingomyelin is consistent with activation of a sphingomeylinase with a substrate preference for polyunsaturate-containing sphingomyelin. Finally, perturbations in the liver, brain, and adipose cholesterol esters were observed, with clofibrate exposure elevating brain cholesterol arachidonyl-esters ~20-fold. Thus, while supporting previous findings, this study has identified novel impacts of PPARα agonist exposure on lipid metabolism that should be further explored.
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Affiliation(s)
- Craig E. Wheelock
- Department of Entomology and Cancer Research Center, University of California, Davis, CA 95616
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Kyoto, Japan 611-0011
| | - Susumu Goto
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Kyoto, Japan 611-0011
| | - Bruce D. Hammock
- Department of Entomology and Cancer Research Center, University of California, Davis, CA 95616
- Corresponding Author: Dr. Bruce D. Hammock, Department of Entomology, University of California, Davis, CA 95616, Tel: (530) 752-8465, Fax: (530) 752-1537, E-mail:
| | - John W. Newman
- Department of Entomology and Cancer Research Center, University of California, Davis, CA 95616
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40
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Negishi K, Noiri E, Sugaya T, Li S, Megyesi J, Nagothu K, Portilla D. A role of liver fatty acid-binding protein in cisplatin-induced acute renal failure. Kidney Int 2007; 72:348-58. [PMID: 17495861 DOI: 10.1038/sj.ki.5002304] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Previous studies from our laboratory showed that increased fatty acid oxidation by the kidney is cytoprotective during cisplatin (CP)-mediated nephrotoxicity. In this study, we determined the effects of CP and fibrates on peroxisome proliferation and the expression of liver fatty acid-binding protein (L-FABP) in normal mice, and in mice transgenically overexpressing human L-FABP (h-L-FABP). Labeling of peroxisomes demonstrated reduced peroxisomal staining in the proximal tubule of CP-treated mice compared with control mice. There was increased peroxisomal labeling in the proximal tubules of both control and CP-treated mice when either was treated with fibrate; a known peroxisome proliferator-activated receptor-alpha ligand. L-FABP protein expression, not detected in control or CP-treated mice, was significantly increased in the proximal tubules of fibrate-treated mice of either group. In the transgenic mice, CP increased the shedding of h-L-FABP in the urine, which was decreased by fibrate as was the acute renal failure. A cytosolic pattern of h-L-FABP expression was found in the proximal tubules of untreated transgenic mice with a nuclear presence in CP-treated mice. Fibrate pretreatment restored the cytosolic expression pattern in CP-treated mice. Our study shows that fibrate may improve CP-induced acute renal failure due to both peroxisome proliferation and increased L-FABP in the cytosol of the proximal tubule.
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Affiliation(s)
- K Negishi
- Department of Nephrology and Endocrinology, University of Tokyo, Tokyo, Japan
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41
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Antonenkov VD, Ohlmeier S, Sormunen RT, Hiltunen JK. UK114, a YjgF/Yer057p/UK114 family protein highly conserved from bacteria to mammals, is localized in rat liver peroxisomes. Biochem Biophys Res Commun 2007; 357:252-7. [PMID: 17416349 DOI: 10.1016/j.bbrc.2007.03.136] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Accepted: 03/22/2007] [Indexed: 11/25/2022]
Abstract
Mammalian UK114 belongs to a highly conserved family of proteins with unknown functions. Although it is believed that UK114 is a cytosolic or mitochondrial protein there is no detailed study of its intracellular localization. Using analytical subcellular fractionation, electron microscopic colloidal gold technique, and two-dimensional gel electrophoresis of peroxisomal matrix proteins combined with mass spectrometric analysis we show here that a large portion of UK114 is present in rat liver peroxisomes. The peroxisomal UK114 is a soluble matrix protein and it is not inducible by the peroxisomal proliferator clofibrate. The data predict involvement of UK114 in peroxisomal metabolism.
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Affiliation(s)
- Vasily D Antonenkov
- Department of Biochemistry, Biocenter Oulu, University of Oulu, Linnanmaa, P.O. Box 3000, FIN-90014 Oulu, Finland.
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42
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Viswakarma N, Yu S, Naik S, Kashireddy P, Matsumoto K, Sarkar J, Surapureddi S, Jia Y, Rao MS, Reddy JK. Transcriptional regulation of Cidea, mitochondrial cell death-inducing DNA fragmentation factor alpha-like effector A, in mouse liver by peroxisome proliferator-activated receptor alpha and gamma. J Biol Chem 2007; 282:18613-18624. [PMID: 17462989 DOI: 10.1074/jbc.m701983200] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cidea (cell death-inducing DNA fragmentation factor alpha-like effector A), a member of a novel family of proapoptotic proteins, is expressed abundantly in the brown adipose tissue of the mouse. Although Cidea mRNA is not detectable in the mouse liver, we now show that peroxisome proliferator-activated receptor (PPAR) alpha ligands Wy-14,643 and ciprofibrate increase the Cidea mRNA level in a PPARalpha-dependent manner, whereas Cidea induction in liver by PPARgamma overexpression is PPARalpha independent. Increase in Cidea mRNA content in liver did not alter the expression of uncoupling protein 1 (Ucp1) gene, which regulates thermogenesis, lipolysis, and conservation of energy. Although Cidea is considered to be a proapoptotic factor, Cidea induction in liver did not result in increased apoptosis. To elucidate the mechanism by which PPARalpha and PPARgamma regulate Cidea gene expression in the liver, we analyzed the promoter region of the Cidea gene. Three putative peroxisome proliferator response elements (PPREs) are found in the Cidea gene promoter. Transactivation, gel-shift, and chromatin immunoprecipitation assays indicated that the proximal PPRE in Cidea gene (Cidea-PPRE1 at -680/-668) is functional for both PPARalpha and -gamma. We conclude that Cidea is a novel target gene for both PPARalpha and -gamma in the liver where these two transcription factors utilize the same PPRE region for dual regulation. The induction of Cidea in liver with these PPARalpha and -gamma agonists suggests a possible role for Cidea in energy metabolism and a less likely role in hepatocyte apoptosis.
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Affiliation(s)
- Navin Viswakarma
- Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611-3008
| | - Songtao Yu
- Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611-3008
| | - Swati Naik
- Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611-3008
| | - Papreddy Kashireddy
- Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611-3008
| | - Kojiro Matsumoto
- Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611-3008
| | - Joy Sarkar
- Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611-3008
| | - Sailesh Surapureddi
- Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611-3008
| | - Yuzhi Jia
- Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611-3008
| | - M Sambasiva Rao
- Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611-3008
| | - Janardan K Reddy
- Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611-3008.
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Matsumoto K, Yu S, Jia Y, Ahmed MR, Viswakarma N, Sarkar J, Kashireddy PV, Rao MS, Karpus W, Gonzalez FJ, Reddy JK. Critical role for transcription coactivator peroxisome proliferator-activated receptor (PPAR)-binding protein/TRAP220 in liver regeneration and PPARalpha ligand-induced liver tumor development. J Biol Chem 2007; 282:17053-60. [PMID: 17438330 DOI: 10.1074/jbc.m701956200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Disruption of the gene encoding for the transcription coactivator peroxisome proliferator-activated receptor (PPAR)-binding protein (PBP/TRAP220/DRIP205/Med1) in the mouse results in embryonic lethality. Here, we have reported that targeted disruption of the Pbp/Pparbp gene in hepatocytes (Pbp(DeltaLiv)) impairs liver regeneration with low survival after partial hepatectomy. Analysis of cell cycle progression suggests a defective exit from quiescence, reduced BrdUrd incorporation, and diminished entry into G(2)/M phase in Pbp(DeltaLiv) hepatocytes after partial hepatectomy. Pbp(DeltaLiv) hepatocytes failed to respond to hepatocyte growth factor/scatter factor, implying that hepatic PBP deficiency affects c-met signaling. Pbp gene disruption also abolishes primary mitogen-induced liver cell proliferative response. Striking abrogation of CCl(4)-induced hepatocellular proliferation and hepatotoxicity occurred in Pbp(DeltaLiv) mice pretreated with phenobarbital due to lack of expression of xenobiotic metabolizing enzymes necessary for CCl(4) activation. Pbp(DeltaLiv) mice, chronically exposed to Wy-14,643, a PPARalpha ligand, revealed a striking proliferative response and clonal expansion of a few Pbp(fl/fl) hepatocytes that escaped Cre-mediated gene deletion in Pbp(DeltaLiv) livers, but no proliferative expansion of PBP null hepatocytes was observed. In these Pbp(DeltaLiv) mice, none of the Wy-14,643-induced hepatic adenomas and hepatocellular carcinomas was derived from PBP(DeltaLiv) hepatocytes; all liver tumors developing in Pbp(DeltaLiv) mice maintained non-recombinant Pbp alleles and retained PBP expression. These studies provide direct evidence in support of a critical role of PBP/TRAP220 in liver regeneration, induction of hepatotoxicity, and hepatocarcinogenesis.
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Affiliation(s)
- Kojiro Matsumoto
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611-3008, USA
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McGrane MM. Vitamin A regulation of gene expression: molecular mechanism of a prototype gene. J Nutr Biochem 2007; 18:497-508. [PMID: 17320364 DOI: 10.1016/j.jnutbio.2006.10.006] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Revised: 09/23/2006] [Accepted: 10/16/2006] [Indexed: 10/23/2022]
Abstract
Vitamin A regulation of gene expression is a well-characterized example of direct nutrient regulation of gene expression. The downstream metabolites of retinol, all-trans and 9-cis retinoic acids are the bioactive components that bind and activate their cognate nuclear receptors to regulate target genes. There are multiple retinoid receptor subtypes that are encoded by separate genes and each subtype has different isoforms. These receptors are Class II members of the thyroid/retinoid/vitamin D superfamily of nuclear receptors. The characterization of the retinoid receptors and the DNA response elements of target genes that bind these receptors have vastly expanded our knowledge of the mechanism of retinoid regulation of target genes. The basic regulatory mechanism of retinoids interacting with their cognate receptors is further complicated by the interaction of coactivators and corepressors, nuclear proteins that are involved in activation or repression of transcription, respectively. Most of these coregulators are involved in modifying chromatin and nucleosome structure such that chromatin is relaxed or condensed, and in bridging between the upstream enhancer domains and the transcription preinitiation complex. Retinoid regulation of the rate of transcription of target genes and the duration of the retinoid response is further complicated by covalent modification of the retinoid receptors by phosphorylation involved in coactivator association and ubiquitinylation involved in the degradation of retinoid receptors. This review presents a prototype retinoid responsive gene that encodes the phosphoenolpyruate carboxykinase (PEPCK) gene as an example of a specific mechanism of retinoid regulation of a metabolic gene. The retinoid response elements and overall mechanism of retinoid regulation of the PEPCK gene have been well documented by both in vitro and in vivo methods. We provide detailed information on the specific nuclear receptors, coactivators and chromatin modification events that occur when vitamin A is deficient and, therefore, retinoids are not available to activate the nuclear retinoid-signaling cascade.
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Affiliation(s)
- Mary M McGrane
- Department of Nutritional Sciences, The University of Connecticut, Storrs, CT 06269, USA.
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Kurochkin IV, Mizuno Y, Konagaya A, Sakaki Y, Schönbach C, Okazaki Y. Novel peroxisomal protease Tysnd1 processes PTS1- and PTS2-containing enzymes involved in beta-oxidation of fatty acids. EMBO J 2007; 26:835-45. [PMID: 17255948 PMCID: PMC1794383 DOI: 10.1038/sj.emboj.7601525] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2006] [Accepted: 12/05/2006] [Indexed: 12/21/2022] Open
Abstract
Peroxisomes play an important role in beta-oxidation of fatty acids. All peroxisomal matrix proteins are synthesized in the cytosol and post-translationally sorted to the organelle. Two distinct peroxisomal signal targeting sequences (PTSs), the C-terminal PTS1 and the N-terminal PTS2, have been defined. Import of precursor PTS2 proteins into the peroxisomes is accompanied by a proteolytic removal of the N-terminal targeting sequence. Although the PTS1 signal is preserved upon translocation, many PTS1 proteins undergo a highly selective and limited cleavage. Here, we demonstrate that Tysnd1, a previously uncharacterized protein, is responsible both for the removal of the leader peptide from PTS2 proteins and for the specific processing of PTS1 proteins. All of the identified Tysnd1 substrates catalyze peroxisomal beta-oxidation. Tysnd1 itself undergoes processing through the removal of the presumably inhibitory N-terminal fragment. Tysnd1 expression is induced by the proliferator-activated receptor alpha agonist bezafibrate, along with the increase in its substrates. A model is proposed where the Tysnd1-mediated processing of the peroxisomal enzymes promotes their assembly into a supramolecular complex to enhance the rate of beta-oxidation.
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Affiliation(s)
- Igor V Kurochkin
- Immunoinformatics Team, Advanced Genome Information Group, RIKEN Genomic Sciences Center, Yokohama, Japan
- Present address: Genome Annotation and Comparative Analysis Team, Computational and Experimental Systems Biology Group, RIKEN Genomic Sciences Center, Yokohama 230-0045, Japan
- IV Kurochkin, Genome Annotation and Comparative Analysis Team, Computational and Experimental Systems Biology Group, RIKEN Genomic Sciences Center, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan. Tel.: +81 45 503 9111 (ext 8106); Fax: +81 45 503 9176; E-mail:
| | - Yumi Mizuno
- Division of Functional Genomics and Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Hidaka-shi, Saitama, Japan
| | | | - Yoshiyuki Sakaki
- Computational and Experimental Systems Biology Group, RIKEN Genomic Sciences Center, Yokohama, Japan
| | - Christian Schönbach
- Immunoinformatics Team, Advanced Genome Information Group, RIKEN Genomic Sciences Center, Yokohama, Japan
| | - Yasushi Okazaki
- Division of Functional Genomics and Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Hidaka-shi, Saitama, Japan
- Division of Functional Genomics and Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka-city, Saitama 350-1241, Japan. Tel.: +81 42 985 7319; Fax: +81 42 985 7329; E-mail:
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Sarkar J, Qi C, Guo D, Ahmed MR, Jia Y, Usuda N, Viswakarma N, Rao MS, Reddy JK. Transcription coactivator PRIP, the peroxisome proliferator-activated receptor (PPAR)-interacting protein, is redundant for the function of nuclear receptors PParalpha and CAR, the constitutive androstane receptor, in mouse liver. Gene Expr 2007; 13:255-69. [PMID: 17605299 PMCID: PMC6032459 DOI: 10.3727/000000006780666948] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Disruption of the genes encoding for the transcription coactivators, peroxisome proliferator-activated receptor (PPAR)-interacting protein (PRIP/ASC-2/RAP250/TRBP/NRC) and PPAR-binding protein (PBP/TRAP220/DRIP205/MED1), results in embryonic lethality by affecting placental and multiorgan development. Targeted deletion of coactivator PBP gene in liver parenchymal cells (PBP(LIV-/-)) results in the near abrogation of the induction of PPARalpha and CAR (constitutive androstane receptor)-regulated genes in liver. Here, we show that targeted deletion of coactivator PRIP gene in liver (PRIP(LIV-/-)) does not affect the induction of PPARalpha-regulated pleiotropic responses, including hepatomegaly, hepatic peroxisome proliferation, and induction of mRNAs of genes involved in fatty acid oxidation system, indicating that PRIP is not essential for PPARalpha-mediated transcriptional activity. We also provide additional data to show that liver-specific deletion of PRIP gene does not interfere with the induction of genes regulated by nuclear receptor CAR. Furthermore, disruption of PRIP gene in liver did not alter zoxazolamine-induced paralysis, and acetaminophen-induced hepatotoxicity. Studies with adenovirally driven EGFP-CAR expression in liver demonstrated that, unlike PBP, the absence of PRIP does not prevent phenobarbital-mediated nuclear translocation/retention of the receptor CAR in liver in vivo and cultured hepatocytes in vitro. These results show that PRIP deficiency in liver does not interfere with the function of nuclear receptors PPARalpha and CAR. The dependence of PPARalpha- and CAR-regulated gene transcription on coactivator PBP but not on PRIP attests to the existence of coactivator selectivity in nuclear receptor function.
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Affiliation(s)
- Joy Sarkar
- Department of Pathology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
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Schrader M, Fahimi HD. Peroxisomes and oxidative stress. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1755-66. [PMID: 17034877 DOI: 10.1016/j.bbamcr.2006.09.006] [Citation(s) in RCA: 516] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Revised: 09/05/2006] [Accepted: 09/06/2006] [Indexed: 12/28/2022]
Abstract
The discovery of the colocalization of catalase with H2O2-generating oxidases in peroxisomes was the first indication of their involvement in the metabolism of oxygen metabolites. In past decades it has been revealed that peroxisomes participate not only in the generation of reactive oxygen species (ROS) with grave consequences for cell fate such as malignant degeneration but also in cell rescue from the damaging effects of such radicals. In this review the role of peroxisomes in a variety of physiological and pathological processes involving ROS mainly in animal cells is presented. At the outset the enzymes generating and scavenging H2O2 and other oxygen metabolites are reviewed. The exposure of cultured cells to UV light and different oxidizing agents induces peroxisome proliferation with formation of tubular peroxisomes and apparent upregulation of PEX genes. Significant reduction of peroxisomal volume density and several of their enzymes is observed in inflammatory processes such as infections, ischemia-reperfusion injury and hepatic allograft rejection. The latter response is related to the suppressive effects of TNFalpha on peroxisomal function and on PPARalpha. Their massive proliferation induced by a variety of xenobiotics and the subsequent tumor formation in rodents is evidently due to an imbalance in the formation and scavenging of ROS, and is mediated by PPARalpha. In PEX5-/- mice with the absence of functional peroxisomes severe abnormalities of mitochondria in different organs are observed which resemble closely those in respiratory chain disorders associated with oxidative stress. Interestingly, no evidence of oxidative damage to proteins or lipids, nor of increased peroxide production has been found in that mouse model. In this respect the role of PPARalpha, which is highly activated in those mice, in prevention of oxidative stress deserves further investigation.
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Affiliation(s)
- Michael Schrader
- Department of Cell Biology and Cell Pathology, University of Marburg, Robert Koch Str. 6, 35037 Marburg, Germany.
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Tien Kuo M, Savaraj N. Roles of reactive oxygen species in hepatocarcinogenesis and drug resistance gene expression in liver cancers. Mol Carcinog 2006; 45:701-9. [PMID: 16652372 DOI: 10.1002/mc.20240] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Hepatocellular carcinoma (HCC) has traditionally been an attractive system for cancer research because many animal HCC models are available. It is well known that liver tumors in animals can be induced by many different protocols, such as chronic hepatitis viral infections, carcinogens, toxins, steroid hormones, and dietary intervention. Although these different inducers have different cellular targets and modes of cytotoxic effects, their common denominator is the formation of reactive oxygen species (ROS). In this review, we present compelling evidence to support the hypothesis that ROS play important roles in hepatocarcinogenesis and the associated upregulation of drug resistance gene expression.
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Affiliation(s)
- M Tien Kuo
- Department of Molecular Pathology, The University of Texas M. D. Anderson Cancer Center, Houston, 77030, USA
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50
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Martinelli MI, Mocchiutti NO, Bernal CA. Dietary di(2-ethylhexyl)phthalate-impaired glucose metabolism in experimental animals. Hum Exp Toxicol 2006; 25:531-8. [PMID: 17017006 DOI: 10.1191/0960327106het651oa] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The effects of chronic intake of di(2-ethylhexyl)phthalate (DEHP) on the main intermediate glycolytic metabolites in liver and gastrocnemius muscle were investigated in experimental animals. Male Wistar rats (90-100 g) were fed for 21 days either with a standard chow or the same diet supplemented with 2% (w/w) of DEHP. The DEHP-fed rats had an altered in vivo glucose tolerance associated with abnormal glucose intermediate metabolite contents in liver and skeletal muscle. In these rats, the hepatic content of glucose-6-phosphate (G-6-P), fructose-6-phosphate, pyruvate, lactate, glucose-1-phosphate and glycogen decreased. At the same time, the G-6-P content decreased while the pyruvate and lactate levels increased in skeletal muscle. These data, along with the high plasma glucose concentration and the normal lactate blood levels of this group, could indicate that DEHP-fed rats could present a deficiency in muscle glucose and lactate transport, a reduction of the flux through muscle hexokinase and hepatic glucokinase, and a reduction in glycogen synth-
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Affiliation(s)
- Marcela I Martinelli
- Departamento de Ciencias Biológicas, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina
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