FIGURE 1.

BAK/BAX and ceramide are important mediators of UV-C irradiation-induced apoptosis. Wild-type (WT) and BAK and BAX double knock-out (DKO) BMK cells were untreated or UV-C irradiated (10 mJ/cm²). Where indicated, WT cells were pretreated with vehicle (MeOH), myriocin (myr, 100 nm, 2 h), or FB1 (25 μm, 2 h) and then left untreated or UV-C irradiated (10 mJ/cm²). a, cells negative for annexin V-FITC and PI by flow cytometry were deemed viable. b, caspase 3/7 activity was measured and expressed relative to control, non-irradiated cells. c, total ceramides; d, long-chain ceramides; and e, very long-chain ceramides were measured in WT BMK cells, normalized to total lipid phosphate, and expressed relative to untreated controls. a–e, data are the mean of three independent experiments. Error bars, ±S.D. For statistical analyses a two-way ANOVA was performed with a Bonferroni post-test. *, p ≤ 0.05 statistically significant difference between treatment and its corresponding control and #, p ≤ 0.05 statistically significant difference between myr or DKO and the corresponding time-matched WT value.