FIGURE 6.

Cyathin-R-induced VDAC1 oligomerization and apoptosis are accompanied by an elevation of intercellular Ca²⁺ and are inhibited by BAPTA-AM. A, representative flow cytomery analysis of [Ca²⁺]_i levels, as monitored using Fluo-4. Bax^−/−/Bak^−/− MEF cells were incubated for 16 h with cyathin-R (8 μm) and harvested, and intracellular Ca²⁺ levels were assessed. The values shown indicate the increase in [Ca²⁺]_i. B, quantitative analysis of [Ca²⁺]_i levels (black circles) and apoptosis (white circles) assayed using annexin-V-FITC and PI staining, as analyzed by flow cytometry. C–E, Bax^−/−/Bak^−/− MEF cells were incubated with BAPTA-AM (5 μm, 1.5 h) and then with or without cyathin-R (5 or 8 μm, 16 h), and VDAC1 overexpression (C), VDAC1 oligomerization (D), and apoptosis (E) were assayed. Means ± S.E. (error bars) (n = 3) are presented.