RESUMEN
Objective To initially investigate the mechanism of COX-2 inhibitor inducing cell apoptosis through the observation of celecoxib (CXB),a specific COX-2 inhibitor,inducing apoptosis of cyst lining epithelial cells of human polycystic kidney.Methods (1)Primarily cultured cell was divided into control group and CXB group to evaluate the proliferative state by Brdu assay.(2)The cell apoptosis was observed by transmitted electronic microscope after being cultured in CXB 2?10~(-5) mol/L for 24,48 hours.(3)The cell apoptosis and apoptotic rate were detected by TUNEL assay.(4) The cell apoptotic rate were measured by AnnexinV,PI-labeled flow cytometry after being cultured in CXB 2?10~(-5) mol/L for 0,24,48 hours.(5)Protein expression of Bax,Bcl-2,caspase 3 was examined by Western blotting.Results (1)The Brdu assay revealed that CXB inhibited cell growth in a concentration-dependent manner,with the maximum growth inhibition ratio of 63.9% when treated by CXB 2?10~(-5) mol/L for 24 h.(2)Typical morphological changes of apoptotic cell were apoptotic body, nuclear concentration,chromatin aggregation,endochylema vacuolization and ravinement under eletrou microscope.(3)TUNEL assay showed that the apoptotic rate was (2.8?0.2)% in control group,and (28.5?1.6)%,(48.5?1.2)% in CXB group for 24,48 hours respectively,with significant differences to control group(P＜0.05).(4) AnnexinV,PI-labeled flow cytometry showed that,in 0,0.5,1,2?10~(-5) mol/L CXB group,the apoptotic rates were (3.15?0.05)%,(7.15?0.11)%,(7.76?0.08)%, (12.15?0.07)% for 24 hours respectively,and (13.53?0.21)%,(18.36?0.17)%,(24.87?0.25)%, (53.66?0.32)% for 48 hours respectively.Significant differences were found among corresponding groups(all P＜0.01 ).(5) Extracted total cell protein in every group and more protein of Bax,Bcl-2 expressed in CXB-treated group was detected by Western blotting than that in control group. Conclusions CXB can inhibit the proliferation of cyst liner epithelial cells in a time- and concentration- dependent manner,and induce cell apoptosis through increasing the ratio of Bax/Bcl-2.CXB is hopeful to become an effective drug to treat ADPKD.