Figure 7
The proteasome and NF-κB inhibitor MG-132 blocks the TNF-α antiapoptotic effect. A, Effect of MG-132 on basal and TNF-α–induced NF-κB-DNA binding activity in chondrocyte nuclear extracts, determined by EMSA. Chondrocytes were pretreated with MG-132 (20 mm) for 1 hour 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 MG-132 on TNF-α protection and chondrocyte survival. Chondrocytes were pretreated with MG-132 at the indicated concentrations for 1 hour and then treated with TNF-α (10 ng/ml) for 24 hours. SNP (2 mm) 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).
