Fig. 3.

Modulation of EP2/EP-4 agonist, PGE₂, and TNFα induced COX-2 and mPGES-1 protein expression by native LDL in THP-1 macrophages. THP-1 monocytes were differentiated and cultured described in the legend of Fig. 1. THP-1 macrophages were then stimulated with either 1 µM EP-2 or 1 µM EP-4 agonist alone or in combination + 50 ng/ml TNFα or 1 µM PGE₂ + 50 ng/ml TNFα in the absence or presence of 500 µg/ml native LDL for 24 h. COX-2 (A) and mPGES-1 protein (B) was measured as described in the legend of Fig. 2. Data shown are means ± SEM of at least five independent experiments performed in triplicate. Statistics: two-way ANOVA with Tukey’s multicomparison test: a, significantly higher than control; b, significantly higher than without 500 µg/ml LDL; c, significantly lower than without 500 µg/ml LDL; d, significantly higher than EP4-agonist + TNFα + 500 µg/ml LDL (p < 0.05).