title: Interferon-gamma down-regulates expression of tumor necrosis factor-alpha converting enzyme/a disintegrin and metalloproteinase 17 in activated hepatic stellate cells of rats.
abstract: Interferon-gamma (IFN-gamma) is a potent cytokine that exerts antiproliferative and antifibrogenic effects on hepatic stellate cells (HSCs). Although therapeutic application of IFN-gamma for chronic liver diseases is anticipated, the responses of activated HSCs to IFN-gamma have not been fully elucidated. To seek unknown molecules and pathways that might be responsive to IFN-gamma treatment in activated HSCs, we examined global protein expression profiles using two-dimensional gel electrophoresis combined with peptide mass fingerprint. We identified 76 increased and 59 decreased spots (>3-fold increase or decrease, total 135 spots). Database analysis suggested that the following four pathways were involved in alteration of HSCs toward a quiescent phenotype in response to IFN-gamma: i) down-regulation of the TGF-beta and PDGF signaling pathways; ii) reorganization of intermediate filaments; iii) up-regulation of fatty acid metabolism; iv) decreased expression of TNF-alpha converting enzyme (TACE)/a disintegrin and metalloproteinase 17 (ADAM17), which is responsible for shedding of the proinflammatory cytokine TNF-alpha. We confirmed down-regulation of both ADAM17 expression and soluble TNF-alpha secretion by Western blotting and real-time PCR. TNF-alpha mRNA/protein expression was not altered by IFN-gamma treatment. Our data suggest that IFN-gamma stimulation suppresses the activated phenotype of HSCs in vitro through multiple pathways. Of these pathways, down-regulation of ADAM17 expression may play a role in blocking the auto-activation mechanism of cultured HSCs through activation of the TNF-alpha signaling and shedding pathways.
authors.affiliation: Departments of Pathology and Surgery I, Iwate Medical University School of Medicine, Uchimaru, Morioka 020-8505, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Fujita
authors.forename: Chihaya
authors.initials: C
authors.lastname: Maesawa
authors.forename: Kanta
authors.initials: K
authors.lastname: Oikawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nitta
authors.forename: Go
authors.initials: G
authors.lastname: Wakabayashi
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Masuda
mesh_terms: D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism*; D000072198:ADAM17 Protein; D000199:Actins / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D015536:Down-Regulation; D015180:Electrophoresis, Gel, Two-Dimensional; D015870:Gene Expression / Q000187:drug effects; D017228:Hepatocyte Growth Factor / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology*; D008099:Liver / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D009130:Muscle, Smooth / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000378:metabolism; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000378:metabolism; D011994:Recombinant Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016212:Transforming Growth Factor beta / Q000378:metabolism; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
chemical_list: D000199:Actins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C508962:Tgfb1 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D014409:Tumor Necrosis Factor-alpha; D017228:Hepatocyte Growth Factor; D007371:Interferon-gamma; C496350:Fgfr1 protein, rat; D051496:Receptor, Fibroblast Growth Factor, Type 1; D020797:Receptor, Platelet-Derived Growth Factor beta; D051722:ADAM Proteins; D000072198:ADAM17 Protein; C000606464:Adam17 protein, rat