FOAM CELL APOPTOSIS AND THE DEVELOPMENT OF THE LIPID CORE OF HUMAN ATHEROSCLEROSIS

A characteristic feature of the advanced atherosclerotic lesion is the acellular lipid core, which appears to result at least partly from th e death of macrophage foam cells. This study shows that foam cell deat h at the edge of the lipid core includes both necrosis and apoptosis a nd that remnants of apoptotic nuclei are present within the lipid core . Apoptotic cells were identified by transmission electron microscopy and by nick end-labelling using terminal deoxynucleotidyl transferase (TUNEL). Some TUNEL-positive cells also expressed proliferating cell n uclear antigen (PCNA), The cause of foam cell death in atherogenesis i s unknown, but oxidized low-density lipoprotein (LDL) can cause macrop hage apoptosis in vitro and might therefore play a role in the formati on and enlargement of the lipid core.