Effect of specific cyclooxygenase-2 inhibitor celecoxib on podocyte apoptosis induced by puromycin aminonucleoside

Objective To determine the effect of specific cyclooxygenase (COX)-2 inhibitor celecoxib on podocyte apoptosis induced by puromycin aminonucleoside (PA) and to investigate the protective effect of specific COX-2 inhibitor on podocytes. Methods The conditionally immortalized mouse podocytes were divided into four groups: Control (CON), PA, celecoxib (CEL) and dexamethasone (DEX). The proliferation and apoptosis of podocytes were tested by MTT assay and Hoechst 33258 staining at 0, 8, 24 and 48 h after corresponding treatment, respectively. The activity of caspase-3 in apoptotic podocytes was detected with caspase-3 kit and the expressions of P53 and COX-2 in apoptotic podocytes were tested by Western blotting analysis. Results Compared with CON group, the apoptosis of podocytes induced by PA was increased in PA, CEL and DEX groups (P0.05). The most prominent apoptosis was found at 24 and 48 h (P0.05), but there was no difference among the latter 3 groups (P0.05); compared with PA group, those of CEL and DEX groups were obviously decreased (P0.05). The caspase-3 activity had no significant changes in each group in comparison with CON group (P0.05). The expressions of P53 and COX-2 were increased significantly after incubated with PA (P0.05), and the peak was found at 24 and 48 h (P53 at 24 h PA group 1.773±0.448 vs. CON group 0.288±0.057, at 48 h PA group 2.083±0.520 vs. CON group 0.283±0.090, P0.05; COX-2 at 24 h PA group 6.577±0.667 vs. CON group 0.065±0.027, at 48 h PA group 5.346±0.865 vs. CON group 0.096±0.092, P0.05 respectively). Their expressions were decreased in CEL and DEX groups after 24 and 48 h treatment when compared with those in PA group (P0.05). Conclusion Podocyte apoptosis shows a time-dependent manner after PA treatment. The expressions of P53 and COX-2 are increased during the process, while caspase-3 activity has no obvious change. Specific COX-2 inhibitor celecoxib exerts inhibitory effect on the apoptosis, and its effect is comparable to that of DEX.