J Clin Invest.
ER stress precedes autophagy in cannabinoid action.
(A) Effect of THC on U87MG cell morphology. Note the presence of the
dilated ER in THC- but not vehicle-treated cells (6 h). Arrows point to the ER.
Scale bars: 500 nm. (B) Effect of SR1 (1 μM) and THC on
PDI immunostaining (red) in U87MG cells (8 h; n = 3). The
percentage of cells with PDI dots relative to the total cell number is shown in
the corner of each panel (mean ± SD). Scale bar: 20 μm.
(C) Effect of SR1 (1 μM) on THC-induced
eIF2α phosphorylation of U87MG cells (3 h; OD relative to
vehicle-treated cells, mean ± SD; n = 3).
(D) Effect of THC on PDI (red) and LC3 (green) immunostaining in
U87MG cells (n = 3). The percentage of cells with PDI or LC3 dots
relative to total cell number at each time point (mean ± SD) is shown.
Scale bar: 20 μm. (E) Effect of THC on eIF2α
phosphorylation and LC3 lipidation in U87MG cells (n = 3).
**P < 0.01 compared with THC-treated (B)
or vehicle-treated (C and D) cells.