Bcl-2 family members regulate anoxia-induced cell death.

The mechanisms underlying anoxia (0-0.5% oxygen)-induced cell death are not fully understood. Here we discuss the mechanisms by which cells undergo apoptosis in the absence of oxygen. Cell death during anoxia occurs via the intrinsic pathway of apoptosis. Key regulators of apoptosis during anoxia are the Bcl-2 family of proteins. The pathway is initiated by the loss of function of the prosurvival Bcl-2 family members Mcl-1 and Bcl-2/Bcl-XL, resulting in Bax- or Bak-dependent release of cytochrome c and subsequent caspase-9-dependent cell death.