Fig. 2

The pro-inflammatory cytokines IFNγ + IL-1β and IFNα induce apoptosis in iPSC-derived pancreatic endocrine cells. Control iPSCs (HEL115.6) were differentiated into endocrine pancreatic cells. The islet-like aggregates were exposed to IFNγ (1000 U/mL) + IL-1β (50 U/mL) or to IFNα (2000 U/mL) for 24 or 48 h. a, b Apoptosis was counted following Hoechst 33342 and propidium iodide staining (n = 12 independent experiments). c Representative pictures taken with an epifluorescence microscope with × 20 magnification (scale bar = 100 μm). d, e Aggregates were mixed with RealTime Glo solution and exposed to cytokines. Fluorescence and luminescence were recorded after 0, 4, 8, 16, 24, and 48 h. Results are expressed as arbitrary fluorescence units (AFU; necrosis/plasma membrane integrity) or arbitrary luminescence units (ALU; apoptosis), calculated as fold change of the value obtained at time 0 (control) (n = 6 independent experiments). f, g For each experiment, the area under the curve (AUC) was calculated. CTL denotes control. *p ≤ 0.05, ***p ≤ 0.001, ****p ≤ 0.0001 (paired Student’s t test)