Biomaterial Database

Receptor-dependent uptake of human chylomicron remnants by cultured skin fibroblasts. 1981

C H Florén, and J J Albers, and B J Kudchodkar, and E L Bierman

Human chylomicrons were isolated from plasma from a subject with familial hypertriglyceridemia and converted to chylomicron remnants by incubation with postheparin plasma. The interaction of these apolipoprotein E-containing, cholesterol-rich human chylomicron remnants with cultured skin fibroblasts was studied. Chylomicron remnants were internalized by skin fibroblasts as a unit, mainly via the low density lipoprotein (LDL)-receptor pathway, resulting in increased cell cholesterol content. After entering the fibroblast, chylomicron remnants stimulated cholesterol esterification, suppressed 3-hydroxy-3-methylglutaryl coenzyme A reductase activity, and down-regulated LDL receptor activity similar to the action of LDL. As a function of increasing lipolysis, remnant particles were progressively more effectively taken up by skin fibroblasts, despite a decrease in the apolipoprotein E content per lipoprotein particle. Remnant particles produced after hydrolysis of 70 to 80% of chylomicron triglyceride increased cell cholesterol content to an amount nearly identical to that observed with LDL when the two lipoproteins were incubated at an equal cholesterol concentration. However, when incubated on the basis of equal particle number, chylomicron remnants were 2 to 3 times more effective than LDL in delivering cholesterol to the cells. These results suggest that chylomicron remnants play a role in the regulation of postabsorptive cholesterol homeostasis in nonhepatic cells, and possibly in the pathogenesis of atherosclerosis.

UI	MeSH Term	Description	Entries
D006953	Hyperlipoproteinemia Type IV	A hypertriglyceridemia disorder, often with autosomal dominant inheritance. It is characterized by the persistent elevations of plasma TRIGLYCERIDES, endogenously synthesized and contained predominantly in VERY-LOW-DENSITY LIPOPROTEINS (pre-beta lipoproteins). In contrast, the plasma CHOLESTEROL and PHOSPHOLIPIDS usually remain within normal limits.	Hyperprebetalipoproteinemia,Hypertriglyceridemia, Familial,Carbohydrate Inducible Hyperlipemia,Carbohydrate-Inducible Hyperlipemia,Familial Hyperlipoproteinemia Type 4,Familial Type IV Hyperlipoproteinemia,Hyper prebeta lipoproteinemia,Hyperlipoproteinemia, Type IV,Carbohydrate Inducible Hyperlipemias,Carbohydrate-Inducible Hyperlipemias,Familial Hypertriglyceridemia,Hyperlipemia, Carbohydrate Inducible,Hyperlipemia, Carbohydrate-Inducible,Hyperlipemias, Carbohydrate Inducible,Hyperlipemias, Carbohydrate-Inducible,Hyperlipoproteinemias, Type IV,Inducible Hyperlipemia, Carbohydrate,Inducible Hyperlipemias, Carbohydrate,Type IV Hyperlipoproteinemia,Type IV Hyperlipoproteinemias,Type IV, Hyperlipoproteinemia
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D010743	Phospholipids	Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.	Phosphatides,Phospholipid
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D002784	Cholesterol	The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.	Epicholesterol
D002788	Cholesterol Esters	Fatty acid esters of cholesterol which constitute about two-thirds of the cholesterol in the plasma. The accumulation of cholesterol esters in the arterial intima is a characteristic feature of atherosclerosis.	Cholesterol Ester,Cholesteryl Ester,Cholesteryl Esters,Ester, Cholesterol,Ester, Cholesteryl,Esters, Cholesterol,Esters, Cholesteryl
D002914	Chylomicrons	A class of lipoproteins that carry dietary CHOLESTEROL and TRIGLYCERIDES from the SMALL INTESTINE to the tissues. Their density (0.93-1.006 g/ml) is the same as that of VERY-LOW-DENSITY LIPOPROTEINS.	Chylomicron
D005347	Fibroblasts	Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.	Fibroblast
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man