Fig. 4.
A downstream target of caspase-2. (A) In vitro processing of brain extract by recombinant activated caspase-2 using whole-cell extracts from fresh hippocampal CA1 subregions. The products were analyzed by SDS/PAGE. Bid cleavage was observed in a dose-dependent manner after incubation with caspase-2 (n = 4; ‡, P < 0.005; §, P < 0.001). Bax or Bcl-XL expression showed no significant difference. β-actin was used as an internal control. V, vehicle-treated sample (i.e., caspase-2 buffer); OD, optical density. (B) Mitochondrial up-regulation of tBid after tGCI. tBid expression significantly increased in the mitochondrial fraction of the hippocampal CA1 subregion 4, 8, 24, and 72 h after tGCI (n = 4; *, P < 0.05; †, P < 0.01; §, P < 0.001). Cytochrome oxidase subunit IV (COX IV) was used as an internal control. s, shams.