Cell death pathway (apoptosis) (None)

Apoptosis is a form of programmed cell death that occurs in multicellular organisms. It is a tightly regulated, ATP-dependent process by which cells self-destruct when they are no longer needed or are damaged beyond repair. This mechanism maintains tissue homeostasis, shapes developing tissues, and eliminates potentially harmful cells. Key features include morphological changes (blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, DNA fragmentation), biochemical events (activation of caspases, mitochondrial outer membrane permeabilization), and formation of apoptotic bodies. The intrinsic pathway is triggered by internal stress signals, involving mitochondria and Bcl-2 family proteins. The extrinsic pathway is initiated by external death ligands binding to death receptors on the cell surface. Apoptosis is essential for embryonic development, immune system function, and removal of damaged or potentially cancerous cells. Defects in apoptosis contribute to diseases like atrophy/neurodegeneration and cancer/uncontrolled proliferation.

Modulation of apoptosis pathways via targeting caspases, Bcl-2 family proteins, or death receptors.