Caspases are activated through two main pathways: the intrinsic (mitochondrial) pathway and the extrinsic (death receptor) pathway. In the intrinsic pathway, internal cellular stresses like DNA damage lead to the release of cytochrome c from mitochondria, which then forms the apoptosome, activating initiator caspase-9. The extrinsic pathway is triggered by the binding of ligands to death receptors on the cell surface, leading to the formation of the death-inducing signaling complex (DISC) and activation of initiator caspase-8.
