Thapsigargin induces ER stress and apoptosis in hIAPP-INS1E cells.
A) INS1E control cells were cultured at 11 mM glucose and treated with 1 µM of thapsigargin for 8 and 24 hours. mRNA levels of ER stress markers ATF3, sXBP1 and CHOP were quantified by Real-Time PCR. *p<0.05, **p<0.01 and ***p<0.001 versus control cells at time 0. Results are expressed s mean ± S.E.M from five independent experiments. B) INS1E and hIAPP cells were exposed to 1 µM thapsigargin for 24 hours. Expression levels of CHOP, cleaved caspase 3, insulin, IAPP and β-actin were determined by Western blot. C) INS1E and hIAPP-INS1E control cells were exposed to 0.25, 0.5 and 1 µM of thapsigargin (Thp) for 8 and 24 hours. Protein levels of CHOP, cleaved caspase 3, IAPP and β-actin were determined by Western blot (n = 3). Representative Western blotting images are shown from 2 to 3 independent experiments.