Endothelial cell apoptosis: Biochemical characteristics and potential implications for atherosclerosis

The high turnover of endothelial cells (EC) in atherosclerosis suggests tha t an increase in the frequency of both cell proliferation and cell death is important in the pathogenesis of this common disorder. Further, increased apoptosis of EC, smooth muscle cells (SMC) and immune cells has been observ ed in atheromatous plaques. Many pro-atherogenic factors, including oxidize d low-density lipoproteins, angiotensin II and oxidative stress, can induce EC apoptosis. Such damage to the endothelium may be an initiating event in atherogenesis since EC apoptosis may compromise vasoregulation, increase S MC proliferation, SMC migration and blood coagulation. In addition, EC over lying vascular lesions have been shown to increase their expression of pro- apoptotic proteins. such as Fas and Bax, while decreasing levels of anti-ap optotic factors. Therefore, understanding EC apoptotic pathways that are al tered in atherosclerosis may enable a greater understanding of disease path ogenesis and foster the development of new therapies. The present discussio n outlines the biochemical characteristics of EC apoptosis and the role tha t altered regulation of apoptosis plays in vasculopathy. (C) 2001 Academic Press.