Fig. 5

Knockout of Vdac1 maintains a basal level of apoptosis. a Wt and Vdac1 ^−/− MEF were cultured for 3 days in normoxia (Nx) or hypoxia 1 % O₂ (Hx). The percentage cell mortality was measured by trypan blue exclusion. A p < 0.05 shows a tendency from the basal apoptosis of Wt MEF. b Cells were stained with DAPI (blue) to highlight the nucleus and its morphology. Quantification of the percentage of blebbing in Wt and Vdac1 ^−/− MEF. At least 200 nuclei were counted blindly. c Wt (+) and Vdac1 ^−/− (−) MEF were incubated in Nx or Hx for 72 h and cell lysates were analyzed by immunoblotting for Bak, Bax, Mcl-1, Bcl-X_L, Bcl-2, VDAC, and HKII. β-actin was used as a loading control. d Wt and Vdac1 ^−/− MEF were incubated in Nx or Hx for 72 h and challenged with staurosporin (STS) (1 μM) for 4 h. Apoptosis was evaluated from the level of caspase 3/7. A p < 0.001 and p < 0.0001 show significant differences. e Wt and Vdac1 ^−/− MEF were cultured for 2 days and then treated for 3 days with staurosporine (STS) (1 μM), cisplatin (CIS) (2 μg/ml), doxorubicin (DOXO) (4 μg/ml), or bleomycin (Bleo) (10 μg/ml). Cell viability was measured using an ADAM cell counter. A p < 0.02, p < 0.002, and p < 0.005 show significant differences. f Radioresistance of Wt and Vdac1 ^−/− MEF cultured for 24 h in Nx or Hx and treated with the indicated dose of radiation. Cell growth was then evaluated with a clonogenic cell survival assay. X-axis: dose of X-radiation (Gy). Y-axis: surviving fraction. The mean ± SEM is representative of two independent experiments carried out in duplicate. A p < 0.01 and p < 0.005 show significant differences