Effect of cholesterol and its autooxidation derivatives on endocytosis and dipeptidyl peptidases of aortic endothelial cells

Abstract

The effects of cholesterol (CHO) and cholesterol autooxidation derivatives (CAD) on the endocytosis of cationized ferritin (CF) by endothelial cells have been investigated. The effect of both substances on the activity of lysosomal enzymes dipeptidyl peptidase 1 (DPP 1) and dipeptidyl peptidase 11 (DPP 11) was also studied. Treatment of rats with CAD induced striking alterations in the ultrastructure of endothelial cells and makes it impossible to analyze the effect of this toxin on endocytosis processes. In contrast, CHO-treated cells displayed a good ultrastructural preservation and showed an increased ability to endocyte ferritin, as compared with controls. Both DPPI and DPP 11 activities increased after 3 weeks of CAD or CHO treatment. Our results indicate that although CHO damage endothelial cells, the most important effects could be attributed to CAD which usually accompanies CHO-supplemented diets.