Figure 6.

YP downregulates NF-kB expression and inhibits IkBα phosphorylation in IL-1β-stimulated primary articular chondrocytes. (a) Relative gene expression of NF-kB was determined by qPCR at 3 h and 6 h post 10 ng/mL IL-1β stimulation. Data is presented as mean of three independent experiments. (b) Total protein extracts of chondrocytes cultured in untreated conditions, stimulated with 10 ng/mL IL-1β for 30 min, and pre-treated with YP (μM) followed by 30 min of 10 ng/mL IL-1β treatment, were analyzed by Western blot to detect pIkBα. Position of relevant molecular mass marker (kDa) is indicated on the right side and GAPDH was used as loading control. (c) The pIkBα ratio (pIkBα/total IkBα) was determined in total protein extracts of chondrocytes cultured in control conditions (Ctr); 30 min of IL-1β (10 ng/mL) treatment; and pre-treated with YP for 24 h followed by 30 min of IL-1β stimulation (YP), by measuring the content of total and pIkBα with the specific InstantOne ELISA assay kit. Data is presented as mean of two out of four representative experiments. All graphs show mean ±SD. One-way ANOVA and multiple comparisons were achieved with the Dunnett’s test. Statistical significance was defined as p ≤ 0.05 (*), p ≤ 0.005 (**) and p ≤ 0.0005 (***).