Fig. 4

Comparison of the effects of PGE₂, PGF₂α, PGE₁, and misoprostol on expression of the Col1a1 proximal promoter and cAMP response. (A) BALBc/3T3 fibroblasts were transfected with the −222/+116 bp Col1a1-CAT construct and incubated in the absence (left panel) or presence (right panel) of hIL-1α (12.5 pM) with increasing concentrations (25, 125, and 250 nM) of PGE₂, PGF₂^α, PGE₁, and misoprostol, as indicated on the left. Indomethacin (Indo) was also added to all cultures, except to controls (solid bars), to inhibit endogenous prostaglandin synthesis. Values are means ± SEM from at least six independent transfections each performed in duplicate. (B) The cells were preincubated for 24 hr in the presence of indomethacin or left untreated (solid bar). The cell layers were then washed and challenged for 20 min with PGE₂, PGE₁, PGF₂^α, or misoprostol at 250 nM. cAMP content was measured in the cell lysates by radioimmunoassay. Values are means ± SEM of triplicate wells.