Figure 4

Exogenous addition of IL-1 β restores cytokine and MMP-1 levels. Conditioned medium (CM) with or without 3 μM PLX4032 (‘CM’ and ‘CM & PLX’, respectively) was isolated from Bowes cells (clones 7, 8, and 21). Next, 10 ng ml⁻¹ of IL-1β was added to the CM isolated from the Bowes cells and incubated on the HDFs for 24 h. As a negative control, serum-free medium with or without 3 μ M PLX4032 (‘SFM’ and ‘SFM & PLX’, respectively) was placed on the human dermal fibroblasts (‘Fibroblasts’) and incubated for 24 h. Total RNA was isolated from HDFs and real-time RT–PCR analysis was used to measure (A) IL-1β, (B) IL-8, (C) IL-6, and (D) MMP-1 mRNA levels. No significant difference in expression was observed in the HDFs with or without the presence of PLX4032. Data are shown on a log10 scale.