Fig. 4.

Bak and Bax knockout block Bz-423 induced death. (A) Superoxide was measured using DHE in WT MEF (circles, solid line), Bax^−/− MEF (squares, long dashes), Bak^−/− MEF (diamonds, short dashes), and DKO MEF (“X”, dotted line) after treatment with Bz-423 (1 h). (B) Cytosolic fractions prepared from WT, Bax^−/−, Bak^−/−, and DKO MEF following treatment (12 h) with Bz-423 (12 μM) or control were analyzed for cytochrome c. (C) ΔΨ_m was measured using DIOC₆(3) in WT, Bax^−/−, Bak^−/−, and DKO MEF following Bz-423 (12 h). (D) Apoptosis was determined by hypodiploid DNA content in WT (circles, solid line), Bax^−/− (squares, long dashes), Bak^−/− (diamonds, short dashes), and DKO MEFs (“X”, dotted line) following Bz-423 treatment (48 h). P < 0.01 for WT vs Bak^−/−, Bax^−/−, or DKO MEFs at all [Bz-423] > 5 μM, P < 0.01 for Bak^−/− vs DKO MEFs at all [Bz-423] > 5 μM, P < 0.01 for Bax^−/− vs DKO MEFs at all [Bz-423] > 7.5 μM. (E) Cell viability was determined by PI exclusion in WT, Bax^−/−, Bak^−/−, and DKO MEF following Bz-423 treatment (48 h). P < 0.05 for WT vs Bak^−/− or Bax^−/− MEFs at all [Bz-423] > 5 μM, P < 0.02 for WT vs DKO MEFs at all [Bz-423] ≥ 2.5 μM, P < 0.02 for Bak^−/− vs DKO at [Bz-423] between 2.5 μM and 12.5 μM, P < 0.01 for Bax^−/− vs DKO at all [Bz-423] > 2.5 μM.