C/EBP-b Regulates Cell Death Figure 2. LIP augments and LAP attenuates ER stress–triggered cell death. (A) F10.9-4 cells (26104/well) were cultured in 96-well plates in media without (Ctrl) or with (LIP) doxycycline. The cells were then treated with diluent (Ctrl), thapsigargin (Tg, 48 h) or tunicamycin (Tm, 24 h). The plates were stained with crystal violet and photographed (left panels, 1x; right panels, light microscopy). The photographs are representative of 5 replicates. Bar = 0.5 mm. (B) F10.9-3 cells (46105/well) were cultured in 6-well plates without (Ctrl) or with (LAP) doxycycline. Diluent (Ctrl), thapsigargin or tunicamycin were then added. The plates were then stained with crystal violet and photographed as in (A). The photographs are representative of 5 replicates. Bar = 0.5 mm. (C) F10.9-4 cells (1.56104/well) were cultured in 96-well plates without (Ctrl) or with (LIP) doxycycline. Diluent or tunicamycin were then added. After additional 24 h, the viable cell counts were determined by staining with Neutral Red and the percent survival was calculated. Percent survival was determined on averages of 9 pairs of replicates. (D) F10.9-3 cells (1.56104/well) were cultured in 96-well plates without (Ctrl) or with (LAP) doxycycline. Diluent or tunicamycin were then added. The cells were stained and percent survival was calculated as in (C). doi:10.1371/journal.pone.0009516.g002 PLoS ONE | www.plosone.org 4 March 2010 | Volume 5 | Issue 3 | e9516