Mechanisms of oxysterol-induced apoptosis.

The rationale for the present review is that oxysterols found in oxidized LDL (oxLDL) play a role in atherogenesis. This perspective is based on studies that show that induction of apoptosis in vascular cells is an important process in atherogenesis, that apoptosis can be induced by oxLDL, and that the oxysterol component of oxLDL is responsible for its proapoptotic activity. The evidence for these concepts is reviewed, as are studies on the mechanisms by which oxysterols can induce apoptosis. An elevation in intracellular calcium appears to be an early signal transduction event that leads to apoptosis through both the extrinsic and intrinsic apoptotic pathways.