GP1a treatment leads to decreased binding of c-Fos and c-Jun to the Mmp9 AP-1 sites. DCs were treated with PGE2 with or without GP1a for 1 hour. Cells were fixed, sonicated, and subjected to ChIP analysis using antibodies to c-Fos (A), c-Jun (B), or control IgG. Precipitated DNA was isolated and evaluated by PCR using specific primers for the AP-1 sites in the Mmp9 promoter. ***P < .001 compared with PGE2. Data are representative of 2 independent experiments.