title: Fibrogenic actions of acetaldehyde are β-catenin dependent but Wingless independent: a critical role of nucleoredoxin and reactive oxygen species in human hepatic stellate cells.
abstract: We investigated whether the fibrogenic actions of acetaldehyde, the immediate oxidation product of ethanol, are mediated via Wingless (WNT) and/or β-catenin pathways in human hepatic stellate cells (HSC). First, we show that both β-catenin small inhibitory RNA and a dominant negative-MYC expression vector markedly down-regulated the expressions of fibrogenic genes in freshly isolated HSC. We further show that acetaldehyde up-regulated platelet-derived growth factor receptor beta mRNA and protein expressions ranging from 4.0- to 7.2-fold (P<0.001). Acetaldehyde induced MYC and collagen type-1 alpha-2 mRNA and protein expressions were WNT independent because DKK1, an antagonist of the canonical WNT/β-catenin pathway, completely failed to block these inductions. Acetaldehyde increased phospho-glycogen synthase kinase-3 beta (GSK3B) protein by 31% (P<0.01), whereas phospho-β-catenin protein decreased by 50% (P ≤ 0.01). Significantly, in contrast to 43% (P<0.01) inhibition of β-catenin nuclear translocation in nucleoredoxin (NXN)-overexpressed HSC, acetaldehyde profoundly stimulated β-catenin nuclear translocation by 51%, (P<0.01). Acetaldehyde also increased the cellular reactive oxygen species level 2-fold (P<0.001) with a concomitant 2-fold (P<0.001) increase in 4-hydroxynonenal adducts. Conversely, there was a 44% decrease (P<0.001) in glutathione levels with a concomitant 76% (P<0.001) decrease in the level of NXN/ disheveled (DVL) complex. Based on these findings, we conclude that actions of acetaldehyde are mediated by a mechanism that inactivates NXN by releasing DVL, leading to the inactivation of GSK3B, and thereby blocks β-catenin phosphorylation and degradation. Thus, the stabilized β-catenin translocates to the nucleus where it up-regulates the fibrogenic pathway genes. This novel mechanism of action of acetaldehyde has the potential for therapeutic interventions in liver fibrosis induced by alcohol.
authors.affiliation: Lipid Research Laboratory, VA Medical Center, Washington, DC 20422, USA; Department of Biochemistry and Molecular Medicine, The George Washington University Medical Center, Washington, DC 20037, USA.
authors.forename: Jaime
authors.initials: J
authors.lastname: Arellanes-Robledo
authors.affiliation: Lipid Research Laboratory, VA Medical Center, Washington, DC 20422, USA; Department of Biochemistry and Molecular Medicine, The George Washington University Medical Center, Washington, DC 20037, USA.
authors.forename: Karina
authors.initials: K
authors.lastname: Reyes-Gordillo
authors.affiliation: Lipid Research Laboratory, VA Medical Center, Washington, DC 20422, USA; Department of Biochemistry and Molecular Medicine, The George Washington University Medical Center, Washington, DC 20037, USA.
authors.forename: Ruchi
authors.initials: R
authors.lastname: Shah
authors.affiliation: Department of Clinical Investigation, Institute of Chronic and Degenerative Diseases, CUCS, University of Guadalajara, Mexico.
authors.forename: José Alfredo
authors.initials: JA
authors.lastname: Domínguez-Rosales
authors.affiliation: Department of Clinical Investigation, Institute of Chronic and Degenerative Diseases, CUCS, University of Guadalajara, Mexico.
authors.forename: Zamira Helena
authors.initials: ZH
authors.lastname: Hernández-Nazara
authors.affiliation: Department of Pharmacology and Systems Therapeutics, P.O. Box 1603, Mount Sinai School of Medicine, New York, NY, USA.
authors.forename: Francesco
authors.initials: F
authors.lastname: Ramirez
authors.affiliation: Lipid Research Laboratory, VA Medical Center, Washington, DC 20422, USA; Department of Biochemistry and Molecular Medicine, The George Washington University Medical Center, Washington, DC 20037, USA.
authors.forename: Marcos
authors.initials: M
authors.lastname: Rojkind
authors.affiliation: Lipid Research Laboratory, VA Medical Center, Washington, DC 20422, USA; Department of Biochemistry and Molecular Medicine, The George Washington University Medical Center, Washington, DC 20037, USA; Department of Medicine, The George Washington University Medical Center, Washington, DC 20037, USA. Electronic address: M.R.Lakshman'@va.gov.
authors.forename: M Raj
authors.initials: MR
authors.lastname: Lakshman
mesh_terms: D000079:Acetaldehyde / Q000494:pharmacology*; D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D048868:Adaptor Proteins, Signal Transducing / Q000096:biosynthesis; D000447:Aldehydes / Q000378:metabolism; D002478:Cells, Cultured; D024042:Collagen Type I / Q000235:genetics; D000072261:Dishevelled Proteins; D000431:Ethanol / Q000737:chemistry / Q000378:metabolism; D016259:Genes, myc / Q000235:genetics; D005978:Glutathione / Q000096:biosynthesis; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D000071679:Glycogen Synthase Kinase 3 beta; D055166:Hepatic Stellate Cells / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D008104:Liver Cirrhosis, Alcoholic / Q000473:pathology*; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D018384:Oxidative Stress / Q000187:drug effects; D010088:Oxidoreductases / Q000037:antagonists & inhibitors* / Q000096:biosynthesis; D010750:Phosphoproteins / Q000096:biosynthesis; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species / Q000378:metabolism; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000096:biosynthesis / Q000235:genetics; D051153:Wnt Proteins / Q000378:metabolism; D051176:beta Catenin / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000447:Aldehydes; D024042:Collagen Type I; C501126:DKK1 protein, human; D000072261:Dishevelled Proteins; D036341:Intercellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D051153:Wnt Proteins; D051176:beta Catenin; D000431:Ethanol; D010088:Oxidoreductases; C105231:nucleoredoxin; D020797:Receptor, Platelet-Derived Growth Factor beta; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3; D005978:Glutathione; D000079:Acetaldehyde; C027576:4-hydroxy-2-nonenal
keywords: 2′,7′- dichorofluorescein diacetate; 4-HNE; 4-hydroxynonenal; 5,5′-dithiobis(2-nitrobenzoic acid); ACH; ACTA1; Acetaldehyde; COL1A2; DCFDA; DMEM; DTNB; DVL; Dulbecco's modified Eagle's medium; FBS; GAPDH; GSH; GSK3B; HSC; Hepatic stellate cells; NXN; Nucleoredoxin; Oxidative stress; PDGFRB; PVDF; ROS; SDS-PAGE; TCF/LEFT; WNT; Wingless; acetaldehyde; alpha-smooth muscle actin; cell factor/lymphocyte enhancer factor; collagen type-1 alpha-2; disheveled; fetal bovine serum; glutathione; glyceraldehyde-3-phosphate dehydrogenase; glycogen synthase kinase-3 beta; hepatic stellate cells; nucleoredoxin; platelet-derived growth factor receptor beta; polyvinylidene difluoride; reactive oxygen species; sodium dodecyl sulfate polyacrylamide gel electrophoresis; β-Catenin