title: Transforming Growth Factor-β (TGF-β) Inhibits the Expression of Factor VII-activating Protease (FSAP) in Hepatocytes.
abstract: Deletion of the Habp2 gene encoding Factor VII-activating protease (FSAP) increases liver fibrosis in mice. A single nucleotide polymorphism (G534E) in HABP2 leads to lower enzymatic activity and is associated with enhanced liver fibrosis in humans. Liver fibrosis is associated with a decrease in FSAP expression but, to date, nothing is known about how this might be regulated. Primary mouse hepatocytes or the hepatocyte cell line, AML12, were treated with different factors, and expression of FSAP was determined. Of the various regulatory factors tested, only transforming growth factor-β (TGF-β) demonstrated a concentration- and time-dependent inhibition of FSAP expression at the mRNA and protein level. The TGF-β-Type I receptor (ALK-5) antagonist SB431542 and Smad2 siRNA, but neither SIS3, which inhibits SMAD3, nor siRNA against Smad3 could block this effect. Various regions of the HABP2 promoter region were cloned into reporter constructs, and the promoter activity was determined. Accordingly, the promoter activity, which could phenocopy changes in Habp2 mRNA in response to TGF-β, was found to be located in the 177-bp region upstream of the transcription start site, and this region did not contain any SMAD binding sites. Mutation analysis of the promoter and chromatin immunoprecipitation assays were performed to identify an important role for the ATF3 binding element. Thus, TGF-β is the most likely mediator responsible for the decrease in FSAP expression in liver fibrosis.
authors.affiliation: From the Institute for Biochemistry, Justus-Liebig-University, 35392 Giessen, Germany.
authors.forename: Silke
authors.initials: S
authors.lastname: Leiting
authors.affiliation: Oslo University Hospital and.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Seidl
authors.affiliation: Institute for Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway, and.
authors.forename: Adoracion
authors.initials: A
authors.lastname: Martinez-Palacian
authors.affiliation: Department of Medical Biochemistry and Biophysics, Karolinska Institute, 17177 Stockholm, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Muhl
authors.affiliation: From the Institute for Biochemistry, Justus-Liebig-University, 35392 Giessen, Germany, Oslo University Hospital and Institute for Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway, and Sandip.Kanse@medisin.uio.no.
authors.forename: Sandip M
authors.identifier: http://orcid.org/0000-0003-0782-9957
authors.initials: SM
authors.lastname: Kanse
mesh_terms: D051700:Activating Transcription Factor 3 / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D015971:Gene Expression Regulation, Enzymologic; D022781:Hepatocytes / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008103:Liver Cirrhosis / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051379:Mice; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism; D020218:Response Elements; D012697:Serine Endopeptidases / Q000096:biosynthesis* / Q000235:genetics; D051785:Smad Proteins / Q000235:genetics / Q000378:metabolism; D051900:Smad3 Protein / Q000235:genetics / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*
chemical_list: C490449:ATF3 protein, human; D051700:Activating Transcription Factor 3; C103002:Atf3 protein, mouse; D018125:Receptors, Transforming Growth Factor beta; C497790:SMAD3 protein, human; D051785:Smad Proteins; D051900:Smad3 Protein; C497791:Smad3 protein, mouse; D016212:Transforming Growth Factor beta; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; C000625841:TGFBR1 protein, human; C000625842:Tgfbr1 protein, mouse; C520095:FSAP protein, mouse; C433550:HABP2 protein, human; D012697:Serine Endopeptidases
keywords: hepatocyte; liver injury; promoter; serine protease; transforming growth factor β (TGF-β)