Figure 1. Atherosclerotic plaque development.

Atherosclerotic plaques usually develop at the atheroprone regions of medium and large arteries. The process is initiated by endothelial dysfunction and the retention of LDL cholesterol. This causes monocyte transmigration into the intima and differentiation into macrophages. Continuous engulfment of LDL particles by macrophages causes foam cell formation. VSMCs proliferation is thought to initially stabilize the plaque, however VSMC apoptosis contributes to plaque destabilization and cause plaque rupture. Abbreviations: ECM, extracellular matrix; LDL, low-density lipoprotein.