Fig. 4.

IκBζ mediates regulation of ELF3 gene expression

(A) HEK293 cells were transfected with plasmid coding for IκBζ or with empty vector and after 48 h the cells were stimulated for 24 h with TNF (10 ng/ml) or left untreated. ELF3 mRNA expression was analysed by qRT-PCR. (B) HEK293 cells were transfected with plasmid coding for IκBζ or with empty vector in combination with ELF3 reporter plasmid. After 48 h the cells were stimulated for 24 h with TNF (10 ng/ml) or left untreated. ELF3 promoter activity was determined with dual-luciferase assay. (C and D) OA synovial fibroblasts were transfected with targeting siRNA or with negative control siRNA. After 48 h cells were stimulated for 24 h with IL-17A (50 ng/ml) and/or TNF (10 ng/ml). (C) The effect of IκBζ silencing on ELF3 mRNA expression. (D) The effect of C/EBPβ silencing on ELF3 mRNA expression. Data in (A, B) represent means ± SEM of five (A) and three (B) individual experiments. Data in (C, D) represent means ± SEM of four (C) and three (D) individual experiments with cells from different donors. *P < 0.05, **P < 0.01, ***P <  0.001. C/EBPβ: CCAAT/enhancer-binding protein β; ELF3: E74-like factor-3; IκBζ: NF-κB inhibitor-ζ; RLU: relative light units.