Figure 5
NF-κB inhibitor Bay 11-7085 blocks TNF-α antiapoptotic effect and induces chondrocyte apoptosis. A, Effect of Bay 11-7085 on basal and TNF-α–induced NF-κB-DNA binding activity in chondrocyte nuclear extracts, determined by EMSA. Chondrocytes were pretreated with Bay 11-7085 for 1 hour, at the indicated concentrations, in the absence of any stimulus or before 24 hours of TNF-α (10 ng/ml) treatment. The arrow indicates the p65/50 complex. B, Effect of Bay 11-7085 on TNF-α protection and chondrocyte survival. Chondrocytes were pretreated with Bay 11-7085 at the indicated concentrations for 1 hour and then treated with TNF-α (10 ng/ml) for 24 hours. SNP was then added for an additional 24 hours. Cell survival was determined by MTS test as explained in Figure 1A. *a, Statistically different from the nontreated control (p < 0.05); *b, statistically different from SNP-treated cells in the absence of TNF-α (p < 0.05); *c, statistically different from SNP-treated cells in the presence of TNF-α (p < 0.05). C, HMW DNA fragmentation test. After treatment with Bay 11-7085 (20 μm) or SNP (2 mm) for 24 hours, genomic DNA was isolated and labeled as explained in “Materials and Methods” and in Figure 2. Lane 1, control untreated cells; lane 2, BAY 11-7085; lane 3, SNP.
