Glycoxidation of low-density lipoprotein increases TUNEL positivity and CPP32 activation in human coronary cells

Apoptosis of arterial cells induced by oxidized low-density lipoprotein (oxLDL) is thought to contribute to the progression of vascular dysfunction and atherogenesis. It is well established that diabetes mellitus is accompanied by both glycosylation and oxidation of LDL (glc-oxLDL), but the biological effects of these modified lipoproteins are poorly understood. We demonstrate here for the first time that glc-oxLDL increases TUNEL positivity and caspase-3 activation (by Western blot and immunocytochemistry) of human coronary smooth muscle cells. Overall, these effects induced by glc-oxLDL were greater than those achieved with oxLDL. Thus, glc-oxLDL activated downstream apoptotic signaling. This may influence the evolution of atherogenesis and vascular complications in diabetes.