Fig. 6. Kinetics of caspase-8 activation, Bid cleavage, cytochrome
c release, and caspase-3 activation in response to CDDO.
U-937 cells were treated with 5 µM CDDO and harvested at
the indicated times. A, cell lysates were assayed for
caspase-8 activity. Results are expressed as the fold increase (means;
bars, SD) for two independent experiments each performed
in duplicate. B, cell lysates were subjected to
immunoblot analysis with anti-Bid (upper panel),
anti-cytochrome c (middle panel), or
anti-caspase-3 (lower panel).