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Non-oxidative ethanol metabolism in human hepatic cells in vitro: Involvement of uridine diphospho-glucuronosyltransferase 1A9 in ethylglucuronide production. Toxicol In Vitro 2020; 66:104842. [PMID: 32283135 DOI: 10.1016/j.tiv.2020.104842] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 03/27/2020] [Accepted: 04/02/2020] [Indexed: 12/12/2022]
Abstract
Ethanol is the most frequently psychoactive substance used in the world, leading to major public health problems with several millions of deaths attributed to alcohol consumption each year. Metabolism of ethanol occurs mainly in the liver via the predominant oxidative metabolism pathway involving phase I enzymes including alcohol dehydrogenases (ADH), cytochrome P450 (CYP) 2E1 and catalase. In a lesser extent, an alternative non-oxidative pathway also contributes to the metabolism of ethanol, which involves the uridine diphospho-glucuronosyltransferase (UGT) and sulfotransferase (SULT) phase II enzymes. Using liquid chromatography-high resolution mass spectrometry, ethylglucuronide (EtG) and ethylsulfate (EtS) produced respectively by UGT and SULT conjugation and detected in various biological samples are direct markers of alcohol consumption. We report herein the efficient non-oxidative metabolic pathway of ethanol in human differentiated HepaRG cells compared to primary human hepatocytes (HH). We showed dose- and time-dependent production of EtS and EtG after ethanol (25 or 50 mM) treatment in culture media of differentiated HepaRG cells and HH and a significant induction of CYP2E1 mRNA expression upon acute ethanol exposure in HepaRG cells. These differentiated hepatoma cells thus represent a suitable in vitro human liver cell model to explore ethanol metabolism and more particularly EtG and EtS production. In addition, using recombinant HepG2 cells expressing different UGT1A genes, we found that UGT1A9 was the major UGT involved in ethanol glucuronidation.
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Mahli A, Seitz T, Beckröge T, Freese K, Thasler WE, Benkert M, Dietrich P, Weiskirchen R, Bosserhoff A, Hellerbrand C. Bone Morphogenetic Protein-8B Expression is Induced in Steatotic Hepatocytes and Promotes Hepatic Steatosis and Inflammation In Vitro. Cells 2019; 8:cells8050457. [PMID: 31096638 PMCID: PMC6562647 DOI: 10.3390/cells8050457] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/09/2019] [Accepted: 05/14/2019] [Indexed: 02/07/2023] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is considered to be the hepatic manifestation of the metabolic syndrome. The bone morphogenetic protein-8B (BMP8B) has been shown to be expressed in brown adipose tissues and the hypothalamus and to affect thermogenesis and susceptibility to diet-induced obesity. Here, we aimed to analyze BMP8B expression in NAFLD and to gain insight into BMP8B effects on pathophysiological steps of NAFLD progression. BMP8B mRNA and protein expression were dose-dependently induced in primary human hepatocytes in vitro upon incubation with fatty acids. Furthermore, hepatic BMP8B expression was significantly increased in a murine NAFLD model and in NAFLD patients compared with controls. Incubation with recombinant BMP8B further enhanced the fatty acid-induced cellular lipid accumulation as well as NFκB activation and pro-inflammatory gene expression in hepatocytes, while siRNA-mediated BMP8B depletion ameliorated these fatty acid-induced effects. Analysis of the expression of key factors of hepatocellular lipid transport and metabolisms indicated that BMP8B effects on fatty acid uptake as well as de novo lipogenesis contributed to hepatocellular accumulation of fatty acids leading to increased storage in the form of triglycerides and enhanced combustion by beta oxidation. In conclusion, our data indicate that BMP8B enhances different pathophysiological steps of NAFLD progression and suggest BMP8B as a promising prognostic marker and therapeutic target for NAFLD and, potentially, also for other chronic liver diseases.
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Affiliation(s)
- Abdo Mahli
- Institute of Biochemistry (Emil-Fischer Zentrum), Friedrich-Alexander University Erlangen-Nürnberg, Fahrstr. 17, D-91054 Erlangen, Germany.
| | - Tatjana Seitz
- Institute of Biochemistry (Emil-Fischer Zentrum), Friedrich-Alexander University Erlangen-Nürnberg, Fahrstr. 17, D-91054 Erlangen, Germany.
| | - Tobias Beckröge
- Institute of Biochemistry (Emil-Fischer Zentrum), Friedrich-Alexander University Erlangen-Nürnberg, Fahrstr. 17, D-91054 Erlangen, Germany.
| | - Kim Freese
- Institute of Biochemistry (Emil-Fischer Zentrum), Friedrich-Alexander University Erlangen-Nürnberg, Fahrstr. 17, D-91054 Erlangen, Germany.
| | | | - Matthias Benkert
- Institute of Biochemistry (Emil-Fischer Zentrum), Friedrich-Alexander University Erlangen-Nürnberg, Fahrstr. 17, D-91054 Erlangen, Germany.
| | - Peter Dietrich
- Institute of Biochemistry (Emil-Fischer Zentrum), Friedrich-Alexander University Erlangen-Nürnberg, Fahrstr. 17, D-91054 Erlangen, Germany.
| | - Ralf Weiskirchen
- Institute of Molecular Pathobiochemistry, Experimental Gene Therapy and Clinical Chemistry (IFMPEGKC), RWTH University Hospital Aachen, D-52074 Aachen, Germany.
| | - Anja Bosserhoff
- Institute of Biochemistry (Emil-Fischer Zentrum), Friedrich-Alexander University Erlangen-Nürnberg, Fahrstr. 17, D-91054 Erlangen, Germany.
| | - Claus Hellerbrand
- Institute of Biochemistry (Emil-Fischer Zentrum), Friedrich-Alexander University Erlangen-Nürnberg, Fahrstr. 17, D-91054 Erlangen, Germany.
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