Mitochondria-dependent apoptotic machinery

The mitochondria-dependent apoptotic machinery, commonly referred to as the intrinsic apoptotic pathway, is a fundamental cellular process that executes programmed cell death in response to internal stress signals such as DNA damage, hypoxia, or metabolic imbalance (Source: NIH, StatPearls). This machinery is primarily regulated by the B-cell lymphoma 2 (Bcl-2) family of proteins, which act as a molecular switch to control the integrity of the mitochondrial outer membrane (Source: Nature Reviews Molecular Cell Biology). When pro-apoptotic signals outweigh anti-apoptotic ones, proteins such as Bax and Bak undergo conformational changes and oligomerize to cause mitochondrial outer membrane permeabilization (MOMP), leading to the release of cytochrome c and other pro-apoptotic factors into the cytoplasm (Source: PubMed). These factors facilitate the assembly of the apoptosome and the activation of the caspase cascade, specifically initiator caspase-9 and effector caspases-3 and -7, which ultimately dismantle the cell (Source: UniProt). In many diseases, particularly cancer, this machinery is frequently dysregulated, often through the overexpression of anti-apoptotic proteins like Bcl-2 or Mcl-1, allowing cells to survive despite severe damage (Source: Journal of Clinical Investigation). Therapeutic strategies targeting this machinery, such as BH3 mimetics like venetoclax, aim to restore the apoptotic threshold by inhibiting these survival proteins, thereby inducing selective death in malignant cells (Source: FDA, PubChem).

Other names

Intrinsic apoptotic pathwayMitochondrial apoptotic pathwayMitochondrial-mediated apoptosisBcl-2 regulated apoptotic pathway

Induction of apoptosis by inhibiting anti-apoptotic Bcl-2 family proteins (e.g., Bcl-2, Bcl-xL, Mcl-1) or mimicking pro-apoptotic factors (e.g., SMAC) to promote mitochondrial outer membrane permeabilization and subsequent caspase activation.