The p65 Subunit of NF-κB Inhibits <i>COL1A1</i> Gene Transcription in Human Dermal and Scleroderma Fibroblasts through Its Recruitment on Promoter by Protein Interaction with Transcriptional Activators (c-Krox, Sp1, and Sp3) - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Biological Chemistry Année : 2012

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)

Résumé

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-kappa B (NF-kappa B) transcription factor on type I collagen expression in adult normal human (ANF) and scleroderma (SF) fibroblasts. We demonstrated that NF-kappa B, 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-kappa B trans-inhibiting effect on COL1A1 expression. Despite no existing kappa B consensus sequence in the COL1A1 promoter, we found that Sp1/Sp3/c-Krox and NF-kappa B 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-kappa B 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-kappa B, and these data could allow the development of new antifibrotic strategies.

Dates et versions

hal-04289596 , version 1 (16-11-2023)

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Magali Demoor, Karim Boumediene, Philippe Galéra, Gallic Beauchef, Nicolas Bigot, et al.. 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). Journal of Biological Chemistry, 2012, 287 (5), pp.3462--3478. ⟨10.1074/jbc.M111.286443⟩. ⟨hal-04289596⟩
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