title: The p65 subunit of NF-κB inhibits COL1A1 gene transcription in human dermal and scleroderma fibroblasts through its recruitment on promoter by protein interaction with transcriptional activators (c-Krox, Sp1, and Sp3).
abstract: Transcriptional mechanisms regulating type I collagen genes expression in physiopathological situations are not completely known. In this study, we have investigated the role of nuclear factor-κB (NF-κB) transcription factor on type I collagen expression in adult normal human (ANF) and scleroderma (SF) fibroblasts. We demonstrated that NF-κB, a master transcription factor playing a major role in immune response/apoptosis, down-regulates COL1A1 expression by a transcriptional control involving the -112/-61 bp sequence. This 51-bp region mediates the action of two zinc fingers, Sp1 (specific protein-1) and Sp3, acting as trans-activators of type I collagen expression in ANF and SF. Knockdown of each one of these trans factors by siRNA confirmed the trans-activating effect of Sp1/Sp3 and the p65 subunit of NF-κB trans-inhibiting effect on COL1A1 expression. Despite no existing κB consensus sequence in the COL1A1 promoter, we found that Sp1/Sp3/c-Krox and NF-κB bind and/or are recruited on the proximal promoter in chromatin immunoprecipitation (ChIP) assays. Attempts to elucidate whether interactions between Sp1/Sp3/c-Krox and p65 are necessary to mediate the NF-κB inhibitory effect on COL1A1 in ANF and SF were carried out; in this regard, immunoprecipitation assays revealed that they interact, and this was validated by re-ChIP. Finally, the knockdown of Sp1/Sp3/c-Krox prevents the p65 inhibitory effect on COL1A1 transcription in ANF, whereas only the siRNAs targeting Sp3 and c-Krox provoked the same effect in SF, suggesting that particular interactions are characteristic of the scleroderma phenotype. In conclusion, our findings highlight a new mechanism for COL1A1 transcriptional regulation by NF-κB, and these data could allow the development of new antifibrotic strategies.
authors.affiliation: Laboratoire Matrice Extracellulaire et Pathologie, IFR ICORE 146, Université de Caen/Basse-Normandie, UFR de Médecine, CHU niveau 3, Avenue de la Côte de Nacre, 14032 Caen Cedex, France.
authors.forename: Gallic
authors.initials: G
authors.lastname: Beauchef
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bigot
authors.forename: Magdalini
authors.initials: M
authors.lastname: Kypriotou
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Renard
authors.forename: Benoît
authors.initials: B
authors.lastname: Porée
authors.forename: Russell
authors.initials: R
authors.lastname: Widom
authors.forename: Anne
authors.initials: A
authors.lastname: Dompmartin-Blanchere
authors.forename: Thierry
authors.initials: T
authors.lastname: Oddos
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Maquart
authors.forename: Magali
authors.initials: M
authors.lastname: Demoor
authors.forename: Karim
authors.initials: K
authors.lastname: Boumediene
authors.forename: Philippe
authors.initials: P
authors.lastname: Galera
mesh_terms: D000328:Adult; D002648:Child; D002675:Child, Preschool; D024042:Collagen Type I / Q000096:biosynthesis* / Q000235:genetics; D000090602:Collagen Type I, alpha 1 Chain; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020405:Dermis / Q000378:metabolism* / Q000473:pathology; D005347:Fibroblasts / Q000378:metabolism* / Q000473:pathology; D005786:Gene Expression Regulation / Q000235:genetics; D006801:Humans; D008297:Male; D020218:Response Elements; D012594:Scleroderma, Localized / Q000378:metabolism* / Q000473:pathology; D016329:Sp1 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D051705:Sp3 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D004268:DNA-Binding Proteins; C498143:RELA protein, human; C497121:SP3 protein, human; D016329:Sp1 Transcription Factor; D051996:Transcription Factor RelA; D014157:Transcription Factors; C484225:ZBTB7B protein, human; D051705:Sp3 Transcription Factor