Fig. 3

Autophagy is dependent on ER stress. a Immunoblot for mTOR/p-mTOR and AKT/p-AKT with band densitometries; the total amount of both AKT and mTOR increases over polydatin treatment; however, the ratio between phosphorylated and non-phosphorylated forms does not change. b IF with ER-Tracker 24 h after polydatin treatment. ER Tracker stains the endoplasmic reticulum and its fluorescence is proportional to ER swelling. c IF and flow cytometry for lysotracker on cells treated with polydatin (20 μM) and either IRE1 inhibitor 4μ8c or PERK inhibitor GSK26064141. In the flow cytometry graphs, the medians of the fluorescence intensities are plotted. Both 4μ8c and GSK26064141 reduces the effect of polydatin on autophagy. *p < 0.05, N = 3 (biological replicates); error bars = SEM