Apoptosis and vascular remodelling

Cell death by apoptosis plays a major role in the homeostasis of the vascular system. Apoptosis of vascular cells, and of endothelial and smooth muscle cells, can be triggered by intrinsic signals related to the cell differentiation phenotype, or by extrinsic signals, including free radicals, inflammatory cytokines or oxidized LDL. Apoptosis contributes to normal physiological modelling of arteries after birth as well as to capillary rarefaction occurring during ontogenic development. Apoptotic processes have been found in several pathological conditions, including atherosclerosis, hypertension or restenosis following percutaneous transluminal angioplasty. However, a direct causal relationship between apoptosis and occurrence of these afflictions remains to be established.