Following treatment with the mPGES-1 inhibitor 15d-PGJ2 or the COX-2 inhibitor celecoxib (Cel, 2 µM) for 1 day in de-differentiation conditions, hASMCs were analyzed for (A) PGE2 in the culture media, or (B) α-actin protein expression by immunohistochemistry. (C) hASMCs were also treated with 15d-PGJ2 in serum-free conditions and analyzed for α-actin protein expression by immunohistochemistry. (D) hASMCs were treated with rosiglitazone under de-differentiation (d-DC) and serum-free conditions (SFC) and analyzed for α-actin protein expression by immunohistochemistry. (E) hASMCs were treated for 1 day with 15d-PGJ2 or celecoxib (Cel, 2 µM) under de-differentiation conditions and analyzed for the stable PGI2 product 6-keto PG F1α in the culture media. (F) hASMCs were treated with 15d-PGJ2 or celecoxib (Cel, 2 µM) under de-differentiation conditions and analyzed for the stable TXA2 product TXB2. The data represent mean + SEM (n=4), * = p < 0.05, *** = p < 0.001, and **** = p < 0.0001; one-way ANOVA.