The Apoptosis of Bovine Lens Epithelial Cells Induced by Proteasome Inhibitor MG132

To investigate the effect of proteasome inhibitor MG132 on the apoptosis of bovine lens epithelial cells (BLECs), the cells were treated with MG132 at different concentrations for 12, 24 and 36 h. The cell viability was analyzed by MTT assay and the effect of MG132 on the apoptosis of BLECs was assessed by flow cytometry (FCM). The results showed that after treatment for the same period, the inhibitory effect of MG132 on BLECs proliferation was enhanced with the increment of the concentration of MG132 (0, 2, 5, 10, mu mol/L) (P<0.05). The 50% inhibiting concentration (IC50) was 2.03 mu mol/L when the BLECs were treated with MG132 for 36 h. MG132 also induced the apoptosis of BLECs obviously. FCM showed that the apoptosis index of the cells treated by MG132 at 2 mu mol/L for 12 h was (20.24 +/- 1.51)%, and that of the control was (0.98 +/- 0.20)% respectively (P<0.01, n=3). It was concluded that MG132 could lead to apoptosis of BLECs. The decrease of proteasome activity may play an important role in the formation and development of cataract.