Fig. 4: ER membrane reorganisation inhibits BH3 mimetic-mediated mitochondrial outer membrane permeabilisation and apoptosis.

a H1299 cells exposed to apogossypol (20 μΜ) for 1 h and then exposed to a combination of BH3 mimetics, A-1331852 (0.1 μΜ) and A-1210477 (10 μΜ) for a further 4 h and assessed for cytochrome c release and ER morphology by immunocytochemistry. Scale bar: 10 μm. Quantification of the extent of cytochrome c release was performed by counting ~100 cells from 3 independent experiments. Error bars = Mean ± SEM. ***p ≤ 0.001. b Western blot analysis of cytosolic and mitochondrial fraction of H1299 cells exposed to BH3-mimetics and apogossypol. Tubulin and TIM22 were used as controls for assessing the purity of the cytosolic and mitochondrial fractions. c The indicated cell lines were exposed to apogossypol (20 µM) for 1 h, followed by the indicated specific BH3 mimetics for 4 h and then assessed for apoptosis by PS externalisation. d HeLa cells exposed to either NDGA (50 µM), Ivermectin (20 µM), Terfenadine (5 µM), or Suloctidil (5 µM) for 1 h, followed by a combination of A-1210477 (10 µM) and A-1331852 (0.1 μΜ) for 4 h were assessed for apoptosis. Error bars = Mean ± SEM. ***p ≤ 0.001 and **p ≤ 0.005