Effect of IRE1 inhibition on apoptosis induced by misfolded proinsulin expression. A. Insulin 2 C96Y-GFP cells were treated with or without IRE1 inhibitor 4μ8c (5 μM) in the presence or absence of doxycycline (2 μg/ml). After 48 h the cells were subjected to an MTS assay and % cell viability normalized to control cells. Result is from three independent experiments. (Cont: Control), (D: Doxycycline), (D + i: Doxycycline + 4μ8c inhibitor), (i: 4μ8c inhibitor alone). B. Cells were treated as in (A) and apoptotic cells were detected using a Roche Cell Death Detection ELISA assay kit as outlined in the Methods. Results shown represent the mean ± SE of 5 independent experiments. C. Insulin 2 C96Y-GFP cells were treated as indicated in the figure and cleaved caspase 3 levels were monitored by western blot analysis. Tg, thapsigargin 1 μM 6 h; Tm, tunicamycin 2 μg/ml 16 h; Stau, staurosporine 1 μM 2 h. D. Insulin 2 C96Y-GFP cells were treated as indicated in the figure and cleaved caspase 3 levels were monitored by western blot analysis.
Zhang et al. BMC Cell Biology 2014 15:29 doi:10.1186/1471-2121-15-29