Figure 1

LPS induces COX-2 protein expression and activity. A, B: bEnd.3 cells were incubated with various concentrations of LPS for the indicated time intervals. The expression of COX-2 was determined by western blot.*P < 0.05; ^#P < 0.01, as compared with the cells exposed to the vehicle. C, D: Cells were pretreated with either actinomycin D (Act.D) or cycloheximide (CHI) for 1 h, and then incubated with LPS for 24 h. The expression of COX-2 was determined by western blot. *P < 0.05; ^#P < 0.01, as compared with the cells incubated with LPS alone. E: Cells were incubated with 100 μg/ml LPS for 24 h. PGE₂ production was determined as the activity of COX-2. Data are summarized and expressed as mean ± SEM of four individual experiments. *P < 0.05, as compared with the cells exposed to the vehicle.