Effects of an MIF inhibitor (ISO-1) or MIF si RNA on the expression and production of MMP-9 and MMP-2 following UVB radiation.

<p>(A) The cells were treated with ISO-1 at 50 μM for 24 hours or MIF siRNA (30 pmol/ml) for 48 hours. Next, the expression of MIF mRNA and MIF protein was examined. (B) The expression levels of MMP-9 and MMP-2 mRNA were examined. Cells were pretreated with ISO-1 at 50 μM for 24 hours or MIF siRNA (30 pmol/ml) for 48 hours, and then were exposed to UVB light (30 mJ/cm²). Total RNA was isolated six hours after UVB exposure and analyzed by RT-PCR. (C) Cells were pretreated with ISO-1 at 50 μM for 24 hours or MIF siRNA (30 pmol/ml) for 48 hours, and were then exposed to UVB light (30 mJ/cm²). The Western blot analysis for the MMP-9 and MMP-2 proteins (30 μg of protein for each group) was performed 24 hours after UVB irradiation. The band of β-actin was used to normalize the expression level. A densitometric analysis was also performed to evaluate the intensity of each band. The data shown are representative of three independent experiments.