Association of low-density lipoprotein with particulate connective tissue matrix components enhances cholesterol accumulation in cultured subendothelial cells of human aorta.
Low-density lipoproteins (LDL) were incubated with elastin particles, collagenase-resistant debris isolated from human aorta, and latex beads of 1.13 microns in diameter. As a result of incubation, insoluble LDL-associates were formed. These associates, as well as LDL-heparin-fibronectin-gelatin complexes described by other workers, were added to a 7-day primary culture of enzyme-isolated cells of human aortic subendothelial intima. The culture contained a mixed cell population made up mostly of typical and modified smooth muscle cells. 24 h later, total cholesterol, phospholipid, triacylglycerol, free cholesterol and cholesteryl ester levels were measured. Addition of insoluble LDL-complexes as well as LDL-associates to culture brought about a substantial accumulation of intracellular lipids; primarily, cholesteryl esters. The total cholesterol level in cultured cells was raised 3- to 8-fold. Addition of free LDL or LDL-free particles had no effect on the content of intracellular lipids. The results obtained allow the assumption that the occurrence of the LDL-mediated accumulation of intracellular lipids is due mainly to the LDL penetration inside the cell via 'nonspecific' phagocytosis and not through a regulated receptor-dependent pathway.
D000328:Adult; D001011:Aorta / Q000378:metabolism*; D002478:Cells, Cultured; D002784:Cholesterol / Q000378:metabolism*; D002788:Cholesterol Esters / Q000378:metabolism; D003238:Connective Tissue / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D004549:Elastin / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D005780:Gelatin / Q000378:metabolism; D006493:Heparin / Q000378:metabolism; D006801:Humans; D007840:Latex / Q000378:metabolism; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008297:Male; D003012:Microbial Collagenase / Q000378:metabolism; D008875:Middle Aged; D010587:Phagocytosis
D002788:Cholesterol Esters; D005353:Fibronectins; D007840:Latex; D008077:Lipoproteins, LDL; D005780:Gelatin; D006493:Heparin; D004549:Elastin; D002784:Cholesterol; D003012:Microbial Collagenase