Figure 6. Regulation of S-phase entry in SMCs by mPGES-1 modulated prostanoids.

A: Both WT and KO VSMCs were serum starved for 48 h and stimulated with 2% FBS for 48 h in the absence or presence of PGE₂ (0.5 µM), the IP agonist, cicaprost (200 nM) or the IP antagonist, CAY10441 (50 nM). VSMCs were fixed and analyzed for BrdU incorporation by immunofluorescence. The data are presented as mean ± SD of three independent experiments. B: Dose-response curve of PGE₂ treatment (0.01–1µM) on cell proliferation in WT, mPGES-1 KO and IP KO SMCs. The data are presented as mean ± SD of four independent experiments. PGE₂ treatment is compared to baseline for each genotype. (ANOVA with Dunnett’s test. **: p < 0.01; ***: p < 0.001, n=4). At each dose, significant difference between WT and mPGES-1 KO and between WT and IP KO is indicated with † and ‡, respectively. (ANOVA with Bonferroni correction was applied. †† or ‡‡: p < 0.01; †††: p < 0.001, n=4).