Mutations in the distal AP-1 (−3471)/Ets (−3836) (a) and proximal AP-1 (−72)/Ets (−88) motifs (b) inhibit LDL-IC-stimulated MMP-1 promoter activity. (a). U937 cells were transiently transfected with Construct 1 (wild-type construct), Construct 9 (−3471 AP-1 mutant), Construct 10 (−3836 Ets mutant), or Construct 11 (−3187 CREB mutant) and then treated with 150 µg/ml of LDL-ICs for 24 hr. The cellular luciferase activity was measured and corrected for transfection efficiency. (b). U937 cells were transiently transfected with Construct 1 (wild-type), Construct 12 (−72 AP-1 mutant), and Construct 13 (−88 Ets mutant), and then treated with 150 µg/ml of LDL-ICs for 24 hr. The cellular luciferase activity was measured and corrected for transfection efficiency. Data presented are mean ± SEM of three experiments run in triplicate. The luciferase activity in cells transfected with wild-type Construct 1 and that had no exposure to LDL-IC was designated as 100%.