Lipoprotein metabolism of human and rabbit arterial cells in primary culture

• Published in: European heart journal 1990-08, Vol.11 (suppl-E), p.128-133
• Main Authors: Jaakkola, O., Kallioniemi, O.-P., Nikkari, T.
• Format: Article
• Language: English
• Subjects: Animals; Aorta - metabolism; Arteries - metabolism; Atherosclerosis; Cells, Cultured; Endothelium, Vascular - metabolism; Humans; lipoproteins; Lipoproteins - metabolism; low density lipoprotein; macrophages; Rabbits; smooth muscle cells; β-low density lipoprotein
• ISSN: 0195-668X; 1522-9645
• DOI: 10.1093/eurheartj/11.suppl_E.128

The early atherosclerotic lesion, the fatty streak, consists of cholesteryl ester-containing foam cells originating mainly from monocyte-macrophages and to a lesser extent from smooth muscle cells. In this study, we describe lipoprotein uptake and cholesterol accumulation into enzyme-dispersed primary cell cultures from cholesterolfed rabbit aortas and human aortic fatty streaks. Uptake of fluorescently labelled acetylated low density lipoprotein (acetyl-LDL) was demonstrable in macrophage-derived foam cells and in many smooth muscle cells in early primary cultures. The uptake of acetyl-LDL led to significantly enhanced cellular esterification of cholesterol. Fluorescent β-migrating very low density lipoprotein (β-VLDL) was internalized by a considerable number of lesion macrophages and also by smooth muscle cells. Also β-VLDL uptake stimulated cholesterol esterification, although the effect was milder than that of acetyl-LDL. These findings lend support to the assumption that, during atherogenesis, arterial macrophages are capable of accumulating cholesteryl esters by receptor-mediated uptake of β-VLDL and modified LDL. The internalization of modified LDL by smooth muscle cells represents a mechanism potentially contributing to the formation of foam cells in the atherosclerotic lesion.