Figure 7.

Effect of PGE₂ receptor agonist and/or antagonist treatment on gelatinase activity and expression of MMP-9 in peritoneal macrophages. A: A representative Western blot shows expression of MMP-9 protein in macrophages treated with PGE₂ receptor agonist and/or antagonist. Macrophages were treated with EP2 agonist (butaprost, buta), EP3 receptor agonist (sulprostone, Sul), or a combination of EP2/EP4 receptor agonist, PGE₁OH, and EP1/EP2 receptor antagonist, AH6809 (E₁OH+AH), and expression of MMP-9 protein was analyzed. The bottom panel shows means and standard errors obtained from four experiments in which different batches of cells were used. Asterisks denote significant difference from control group (P < 0.05). B: A representative gel picture shows RT-PCR results of levels of EP2, EP3, EP4, and GAPDH mRNA in peritoneal macrophages (labeled as 1 to 4). C: A representative Western blot result demonstrating the expression of MMP-9 protein in macrophages treated with different EP receptor agonists and/or antagonist. This experiment was repeated three times and the results were similar. D: Zymographic picture shows gelatinase activity of MMP-9 secreted by peritoneal macrophages. Pretreatment with H89 reversed PGE₂- and butaprost-suppressed MMP-9 gelatinase activity. This experiment was repeated three times and the results were similar.