Dynamic compression inhibits IL-1β induced COX-2 expression and production of PGE
release. Effects of 15% dynamic compressive strain on (a,b,c) COX-2 expression and (d) PGE2 production in unstrained and strained constructs cultured under no treatment conditions or with 10 ng/ml IL-1β and/or 10 μmol/l SB203580 for 6, 12 and 48 hours. The ratio of the relative expression level of COX-2 was calibrated to the mean value for the unstrained (untreated) control and normalized to GAPDH. Ratios were expressed on a logarithmic scale. Bars represent the mean and standard error of the mean of 16 to 18 replicates from four separate experiments. Two-way analysis of variance with post hoc Bonferroni-corrected t-tests was used to compare data: **P < 0.01 and ***P < 0.001. COX, cyclo-oxygenase; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; PG, prostaglandin.