Caspase activation is a tightly regulated process that can occur via two main pathways: the intrinsic (mitochondrial) pathway and the extrinsic (death receptor) pathway. In the intrinsic pathway, cellular stress leads to mitochondrial outer membrane permeabilization and the release of cytochrome c, which forms a complex with Apaf-1 and procaspase-9 to create the apoptosome, activating caspase-9. The extrinsic pathway is initiated by the binding of death ligands to death receptors, leading to the formation of the death-inducing signaling complex (DISC) and the activation of caspase-8.
