Page 551 - Veterinary Immunology, 10th Edition

stimuli that cause mitochondrial injury. The damaging stimuli (e.g.,
VetBooks.ir oxidants, radiation) activate pro-apoptotic proteins, which then

release cytochrome C from mitochondria (Fig. 18.3). The
cytochrome C triggers the formation of a large multiprotein

complex called an apoptosome. The apoptosome then activates
initiator caspase-9.

FIG. 18.3 The two pathways, intrinsic and extrinsic, by which
apoptosis may be triggered. Both lead to caspase activation, DNA
fragmentation, and cell death. The extrinsic pathway is activated by
ligation of death receptors such as CD95 and formation of the
death-inducing signaling complex (DISC). The intrinsic pathway is

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