FIGURE 1.

IL-1-induced MMP3 expression depends on the ERK-mediated pathway. A, human gingival fibroblasts were plated on fibronectin (FN) or poly-l-lysine (PL) and treated with vehicle or IL-1 (40 ng/ml) overnight. Cell lysates were immunoblotted (WB) for MEK or phospho-MEK. B–E, human gingival fibroblasts grown on fibronectin were pretreated with vehicle (B and C) or MEK inhibitor, U0126 (30 μm; 30 min; D and E), which blocks ERK activation, and were stimulated with vehicle (B and D) or with IL-1 (40 ng/ml; C and E) overnight. Conditioned media were screened with human MMP/TIMP antibody arrays. Negative (Neg) and positive (Pos) controls were also screened.