Fig. 2

Pharmacological inhibition of VCP switched ACD to apoptosis in insulin-deprived HCN cells. a A VCP inhibitor, DBeQ (0.5 μM) markedly increased cell death following insulin withdrawal for 24 h, but without significant effect on I(+) HCN cells. Quantitative data were determined using One-way ANOVA followed by Tukey’s multiple comparison test. *p < 0.05, **p < 0.01, ***p < 0.001. n.s., not significant. b Z-VAD-FMK significantly prevented cell death induced by DBeQ in I(-). Staurosporine (STS, 1 μM for 12 h) was treated in I(+) HCN cells as a positive control for apoptosis induction. However, addition of necrostatin-1 (10 μM) up to 48 h did not decrease cell death in DBeQ-treated I(-) HCN cells. Quantitative data are represented as the mean ± SD by One-way ANOVA using Tukey’s multiple comparison test (n = 3). **p < 0.01, ***p < 0.001. n.s., not significant. c Caspase 3 was activated in DBeQ-treated I(-) HCN cells. d Nuclear condensation was observed by Hoechst staining, as indicated by arrow. Nuclear condensation was detected in DBeQ-treated I(-) HCN cells, but prevented by Z-VAD-FMK. Scale bar is 20 μm. e Apoptosis induction was confirmed by Annexin-V staining and FACS analysis for detection of the exposure of phosphatidylserine