Figure 5. Miltirone induces ER stress in Jurkat and U937 cells.

(a) Shown are the effects of miltirone on the expression of ER stress-related proteins. Jurkat and U937 cells treated with miltirone at indicated concentrations for 12 h, whole-cell lysates were obtained and subjected to western blot analysis using antibodies against p-PERK, eIF2α, GRP78, GRP94, caspase-12 and β-actin; n = 3. The bands were excised from different gels which were run under the same electrophoresis condition. (b) Jurkat cells were treated with miltirone for 1.0 h, change of ER-Ca²⁺ levels (green) was observed using confocal microscopy. White arrows in 1.0 h panel indicate residual ER-Ca²⁺ are redistributed and trafficked into mitochondria.