Fig. 5

Inhibition of autophagy promoted apoptosis induced by celastrol and repressed caspase-dependent apoptosis increased the expression of autophagy-related proteins. a Cells were preincubated with z-VAD or 3-MA, and then treated with celastrol for 24 h. Early and late apoptotic cells were analyzed using Annexin V-FITC/PI flow cytometry. The histograms indicate the proportion of cells undergoing apoptosis from three separate experiments. b U251 cells were preincubated with CQ for 2 h, and then treated with celastrol for 24 h. Early and late apoptotic cells were analyzed using Annexin V-FITC/PI flow cytometry. The histograms indicate the proportion of cells undergoing apoptosis from three separate experiments. c U251 cells were preincubated with z-VAD or 3-MA or CQ, and then treated with celastrol for 24 h. The expression levels of LC3, P62, cleaved PARP and Caspase-3, -8, -9 were detected by western blotting. β-actin was used as an internal control. Data are presented as the Mean ± SD (n = 3). **P < 0.01, ***P < 0.001, significantly different compared with the untreated control group. ^#P < 0.05, ^###P < 0.001, significantly different compared with the celastrol treatment group