Figure 1

NBD peptide blocks interleukin (IL)-1-β-induced IκBα phosphorylation and IL-6 production in fibroblast-like synoviocytes (FLS). (a) FLS were pre-incubated with either NBD or mutant NBD (MUT) peptide at a concentration of 50 μM for 2 hours. Subsequently, cells were stimulated with IL-1-β (2.5 ng/ml) for 30 minutes, extensively washed, and lysed in sample buffer. Cell lysates were analyzed by Western blotting. One representative blot out of three is shown. Densitometry includes all three experiments, and data are expressed as mean ± standard error of the mean (*p < 0.01). (b) NBD peptide blocks IL-1-β-induced IL-6 production by FLS in vitro. FLS were pre-incubated with either NBD or MUT peptide at a concentration of 50 μM for 2 hours. Subsequently, cells were stimulated with IL-1-β (2.5 ng/ml). After 24 hours, supernatants were collected and IL-6 levels were measured by sandwich enzyme-linked immunosorbent assay. Data are representative of three independent experiments performed in triplicates (*p < 0.01).