Figure 3.

Inhibition of iPLA₂β induced the peroxidation of mitochondrial membranes. A, BEL-induced apoptosis at high concentrations. INS-1 and iPLA₂-INS cells were incubated with increasing concentrations of BEL in the presence of 11 mm glucose for 48 h. The cells were then stained with annexin-V and analyzed by flow cytometry. B, BEL-induced apoptosis was blocked by NAC. INS-1 cells were treated with 25 μm of BEL in the presence of 11 mm of glucose for 48 h. Apoptosis was analyzed by Annexin V-staining and fluorescence-activated cell sorter (*, compared with control). C, TBARS assay of mitochondrial membrane peroxidation in INS-1 cells. INS-1 cells were incubated with 25 μm BEL in the presence of 11 mm glucose for 48 h. Mitochondria (Mito) were isolated, and the Mito and non-Mito fractions were subjected to TBARS assay (*, compared with non-Mito). D, Cytochrome c release assay. P < 0.05 (n = 4); *, compared with control. Data are presented as the mean ± sem of three independent experiments.