Atherogenic levels of low-density lipoprotein increase endocytotic activity in cultured human endothelial cells. Am J Pathol 1992 Mar;140(3):551-8
Date
03/01/1992Pubmed ID
1546741Pubmed Central ID
PMC1886169Scopus ID
2-s2.0-0026551211 (requires institutional sign-in at Scopus site) 30 CitationsAbstract
Cultured human umbilical vein endothelial cells (EC) exposed to atherogenic low-density lipoprotein (LDL) levels for protracted periods demonstrated heightened endocytosis. Confluent EC were incubated with LDL 90 to 240 mg/dl cholesterol for 1 to 4 days and endocytosis was measured by 14C-sucrose uptake. Control EC and cells incubated with 90 mg/dl LDL cholesterol showed similar uptakes of 14C-sucrose during all measured time periods. In contrast, EC exposed to 240 mg/dl LDL cholesterol showed an increase in endocytosis beginning at 2 days, whereas 160 mg/dl LDL cholesterol promoted increased uptake by 4 days. The endocytotic activity of LDL-perturbed EC is reduced to levels seen in control cells by cytochalasin B, an actin polymerization inhibitor. This finding suggests a modulatory role for the cytoskeleton in endocytosis changes. Examination of LDL-perturbed EC cytoskeleton reveals structural remodeling resulting in a marked increase in stress fibers. Cytochalasin B exposure causes a loss of stress fibers with the formation of globular filamental aggregates. Such LDL-induced cellular functional changes may contribute mechanistically to endothelial dysfunction, which is widely held to be a major contributing factor in the pathogenesis of atherosclerosis.
Author List
Holland JA, Pritchard KA, Rogers NJ, Stemerman MBAuthor
Kirkwood A. Pritchard PhD Professor in the Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
ArteriosclerosisCells, Cultured
Cytochalasin B
Cytoskeleton
Endocytosis
Endothelium, Vascular
Humans
Lipoproteins, LDL
Osmolar Concentration
Thymidine