Endothelial Glycocalyx and Apoptosis in Atherosclerosis

Elevated permeability of vascular endothelium to low density lipoprotein (LDL) is characteristic of focal sites within the vasculature that are prone to the development of atherosclerosis. Previous experiments have suggested that both increased endothelial cell (EC) apoptosis and endothelial surface glycocalyx (GCX) shedding could play a role in the elevated LDL permeability of athero-prone regions. In this work, we sought to confirm that GCX shedding and increased EC apoptosis do occur in lipid plaque filled vessel areas. Six 4- to 6-week old male C57Bl/6 apolipoprotein E knockout (ApoE) mice were fed a Western diet for 10 weeks and developed raised plaques in their brachiocephalic arteries (BCA). Our results show that EC apoptosis is significantly increased throughout the vasculature of ApoE mice compared with wild type mice fed a normal diet. More importantly, we demonstrate that the number of apoptotic ECs per unit length is 3 times higher in the plaque region of the BCA of ApoE mice than in the non-p...