Figure 1.

Inhibition of MMP-1 by PD98059. PECs were cultured under control conditions, irradiated with 20 mJ/cm² UVB, or treated with either PD98059 (25 μmol/L) or SB203580 (10 μmol/L). Cell supernatants and total RNA were harvested after 48 hours (A and B) or 24 hours (C) and analyzed by enzyme-linked immunosorbent assay (A), gelatin zymography (B), or RT-PCR (C). The arrowhead in B points to the region of gelatinolytic activity expected for latent MMP-9. The bars in A represent the mean ± STD of triplicate experiments. **Significance set at P < 0.001.