MMP-9 up-regulation by PGE2 is mediated through the EP2/EP4 receptors and the cAMP→PKA signaling pathway. (A) CD11c+ DCs were treated with butaprost (10−5 M) (an EP2 agonist), misoprostol (10−5 M) (an EP2/EP4/EP3 agonist), or sulprostone (10−5 M) (an EP1/EP3 agonist) for 24 hours in serum-free medium for membrane-bound MMP-9 and for 48 hours in complete medium for secreted MMP-9. Cells were stained with goat anti–mouse MMP-9 antibody for 40 minutes, followed by PE-donkey anti–goat IgG for 40 minutes. Membrane-associated MMP-9 was measured by FACS. The amounts of secreted pro–MMP-9 were measured in supernatants by using the pro–MMP-9 Quantikine assay. (B) CD11c+ DCs were treated with different concentrations of dbcAMP (10−4-10−7 M) for 24 hours (membrane MMP-9) or 48 hours for secreted MMP-9. Membrane-bound and secreted MMP-9 were determined as in panel A. (C) CD11c+ DCs were pretreated with H89 (10−5 M) for 30 minutes, followed by PGE2 (10−6 M) for 24 hours for membrane MMP-9 and 48 hours for secreted MMP-9. Membrane-bound and secreted MMP-9 were determined as in panel A. Data are representative of 2 independent experiments for membrane-bound MMP-9 and 3 independent experiments for secreted MMP-9.
