Fig. 3

The effect of BET protein inhibitor on regulation of protein expression and activity of matrix degradation enzyme genes in human chondrocytes (a). The protein expression of MMP1, MMP3, MMP13, MMP2, and MMP9 proteins (Western blot) in human chondrocytes after the cells were pre-treated with or without I-BET151 (10 μM) followed by addition of IL-1β (10 ng/ml) or TNF-α (10 ng/ml) for 24 h (n = 1). b For MMP enzyme activity assay, gelatin zymography was performed using the cell culture supernatants that were obtained from culture human chondrocytes treated as in a (n = 1). c For ADAMTS4/5 enzyme activity assay, ELISA was carried out using the cell culture supernatants that were obtained from culture human chondrocytes treated as in a and enzyme activity was calculated by setting vehicle control activity to 100% (n = 3)