Apoptosis of endothelial cells has been associated with inflammatory cytokines, oxidized low-density lipoprotein (oxLDL), and oxidative stress [2]. It has been shown that circulating levels of autoantibodies to oxLDL inversely correlate with endothelial function in resistance
Pemetrexed in men with coronary heart disease [5]. Oxysterols constitute the major toxic component in oxLDL and are present in human atheroma lesions [6] and [7]. 7β-Hydroxycholesterol (7βOH) in circulation has been related to the progression of atherosclerotic disease. Increased level of 7βOH has been associated with a high risk of cardiovascular disease [8] and coronary atherosclerotic patients [9]. 7βOH and 7-ketocholesterol (7keto) are cytotoxic to different types of arterial cells, such as smooth muscle cells, macrophages and endothelial
cells [10], [11] and [12]. Moreover, equivalent concentration of oxysterols as found in plasma of patients with vascular disease were toxic to cultured endothelial cells [13]. Activation of mitochondrial pathway in oxysterol-mediated apoptosis has been well documented, including endothelial cells [14]. Recently the lysosomal pathway and related cathepsins in the apoptosis machinery have been further recognized in a number of cell models [15]. However, whether lysosomal pathway and related cathepsins are involved in the 7-oxysterol induced apoptosis of endothelial cells and how 7-oxysterol influence cellular lipid metabolisms in the process remain unexplored.
