The molecular pathways of keratinocyte apoptosis primarily include the intrinsic and extrinsic pathways. The intrinsic pathway is regulated by the Bcl-2 family of proteins, which control mitochondrial integrity. Upon receiving apoptotic signals, pro-apoptotic members such as Bax and Bak promote the release of cytochrome c, leading to caspase activation. The extrinsic pathway involves death receptors such as Fas and TNF receptor, which upon ligand binding, recruit adaptor proteins and form the death-inducing signaling complex (DISC), ultimately activating caspases. Caspases are proteolytic enzymes that dismantle the cell by cleaving cellular proteins.
