Figure 4. Inhibitory effect of PDTC on NF-B activity and COX-2 protein expression induced by TNF- in synovial fibroblasts from the TMJ. (A) NF- B binding activity in the nuclear extracts from cells pre-treated with PDTC (50 µmol/L) 1 hr before 20 ng/mL of TNF- stimulation for 40 min was determined by EMSA. (B) COX-2 protein expression in the whole-cell lysates from cells pre-treated with PDTC (50 µmol/L) 1 hr before 20 ng/mL of TNF- stimulation for 6 hrs was assayed by Western blotting. The data represent 1 of 3 separate experiments with similar results.