Biomaterial Database

Histochemical characterization of low density lipoprotein receptors in internalization-defective familial hypercholesterolemia. 1985

S Takaichi, and S Tajima, and Y Miyake, and A Yamamoto

We studied the localization of low density lipoprotein (LDL) bound to the receptors on the cultured fibroblasts from a patient (MN) with homozygous familial hypercholesterolemia and a defect in internalization of LDL and compared the localization with normal fibroblasts and with those from another internalization-defective cell, GM2408A. Monolayers of cells were cultured with lipoprotein-deficient human serum, and the cells were incubated with 125I- or ferritin-labeled LDL. The LDL binding was observed by autoradiography or by an electron microscope. Autoradiographs of bound 125I-LDL confirmed that MN's cells could not internalize LDL inside the cell at 37 degrees C. In these cells, ferritin LDL was found mainly in noncoated regions at 4 degrees C; it was not found in endocytic vesicles after incubation at 37 degrees C. Ferritin cores that bound on the surface of the cells from the normal subject, from GM2408A, from MN, and from MN's parents, were counted and quantitatively analyzed at 4 degrees C. In normal cells, 62% of the ferritin cores were bound in the coated pits; in MN's cells, only 11% of the ferritin LDL was found in the coated pits; in the GM2408A cells, 12% of the ferritin LDL was found in the coated pits; in the cells from MN's parents, 40% of the ferritin LDL was found on the coated pits. The results indicate that the internalization defect in MN's cells is the same as that in the GM2408A cells; neither can localize the LDL and LDL receptor complex in coated pits.

UI	MeSH Term	Description	Entries
D008077	Lipoproteins, LDL	A class of lipoproteins of small size (18-25 nm) and light (1.019-1.063 g/ml) particles with a core composed mainly of CHOLESTEROL ESTERS and smaller amounts of TRIGLYCERIDES. The surface monolayer consists mostly of PHOSPHOLIPIDS, a single copy of APOLIPOPROTEIN B-100, and free cholesterol molecules. The main LDL function is to transport cholesterol and cholesterol esters to extrahepatic tissues.	Low-Density Lipoprotein,Low-Density Lipoproteins,beta-Lipoprotein,beta-Lipoproteins,LDL(1),LDL(2),LDL-1,LDL-2,LDL1,LDL2,Low-Density Lipoprotein 1,Low-Density Lipoprotein 2,LDL Lipoproteins,Lipoprotein, Low-Density,Lipoproteins, Low-Density,Low Density Lipoprotein,Low Density Lipoprotein 1,Low Density Lipoprotein 2,Low Density Lipoproteins,beta Lipoprotein,beta Lipoproteins
D011973	Receptors, LDL	Receptors on the plasma membrane of nonhepatic cells that specifically bind LDL. The receptors are localized in specialized regions called coated pits. Hypercholesteremia is caused by an allelic genetic defect of three types: 1, receptors do not bind to LDL; 2, there is reduced binding of LDL; and 3, there is normal binding but no internalization of LDL. In consequence, entry of cholesterol esters into the cell is impaired and the intracellular feedback by cholesterol on 3-hydroxy-3-methylglutaryl CoA reductase is lacking.	LDL Receptors,Lipoprotein LDL Receptors,Receptors, Low Density Lipoprotein,LDL Receptor,LDL Receptors, Lipoprotein,Low Density Lipoprotein Receptor,Low Density Lipoprotein Receptors,Receptors, Lipoprotein, LDL,Receptor, LDL,Receptors, Lipoprotein LDL
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
D003034	Coated Pits, Cell-Membrane	Specialized regions of the cell membrane composed of pits coated with a bristle covering made of the protein CLATHRIN. These pits are the entry route for macromolecules bound by cell surface receptors. The pits are then internalized into the cytoplasm to form the COATED VESICLES.	Bristle-Coated Pits,Cell-Membrane Coated Pits,Bristle Coated Pits,Bristle-Coated Pit,Cell Membrane Coated Pits,Cell-Membrane Coated Pit,Coated Pit, Cell-Membrane,Coated Pits, Cell Membrane,Pit, Bristle-Coated,Pit, Cell-Membrane Coated,Pits, Bristle-Coated,Pits, Cell-Membrane Coated
D004705	Endocytosis	Cellular uptake of extracellular materials within membrane-limited vacuoles or microvesicles. ENDOSOMES play a central role in endocytosis.	Endocytoses
D005347	Fibroblasts	Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.	Fibroblast
D006651	Histocytochemistry	Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.	Cytochemistry
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006938	Hyperlipoproteinemia Type II	A group of familial disorders characterized by elevated circulating cholesterol contained in either LOW-DENSITY LIPOPROTEINS alone or also in VERY-LOW-DENSITY LIPOPROTEINS (pre-beta lipoproteins).	Hyperbetalipoproteinemia,Hypercholesterolemia, Essential,Hypercholesterolemia, Familial,Apolipoprotein B-100, Familial Defective,Apolipoprotein B-100, Familial Ligand-Defective,Familial Combined Hyperlipoproteinemia,Hyper-Low Density Lipoproteinemia,Hyper-Low-Density-Lipoproteinemia,Hyper-beta-Lipoproteinemia,Hypercholesterolemia, Autosomal Dominant,Hypercholesterolemia, Autosomal Dominant, Type B,Hypercholesterolemic Xanthomatosis, Familial,Hyperlipoproteinemia Type 2,Hyperlipoproteinemia Type IIa,Hyperlipoproteinemia Type IIb,Hyperlipoproteinemia, Type II,Hyperlipoproteinemia, Type IIa,LDL Receptor Disorder,Apolipoprotein B 100, Familial Defective,Apolipoprotein B 100, Familial Ligand Defective,Autosomal Dominant Hypercholesterolemia,Autosomal Dominant Hypercholesterolemias,Combined Hyperlipoproteinemia, Familial,Combined Hyperlipoproteinemias, Familial,Density Lipoproteinemia, Hyper-Low,Density Lipoproteinemias, Hyper-Low,Disorder, LDL Receptor,Disorders, LDL Receptor,Dominant Hypercholesterolemia, Autosomal,Dominant Hypercholesterolemias, Autosomal,Essential Hypercholesterolemia,Essential Hypercholesterolemias,Familial Combined Hyperlipoproteinemias,Familial Hypercholesterolemia,Familial Hypercholesterolemias,Familial Hypercholesterolemic Xanthomatoses,Familial Hypercholesterolemic Xanthomatosis,Hyper Low Density Lipoproteinemia,Hyper beta Lipoproteinemia,Hyper-Low Density Lipoproteinemias,Hyper-Low-Density-Lipoproteinemias,Hyper-beta-Lipoproteinemias,Hyperbetalipoproteinemias,Hypercholesterolemias, Autosomal Dominant,Hypercholesterolemias, Essential,Hypercholesterolemias, Familial,Hypercholesterolemic Xanthomatoses, Familial,Hyperlipoproteinemia Type 2s,Hyperlipoproteinemia Type IIas,Hyperlipoproteinemia Type IIbs,Hyperlipoproteinemia Type IIs,Hyperlipoproteinemia, Familial Combined,Hyperlipoproteinemias, Familial Combined,Hyperlipoproteinemias, Type II,Hyperlipoproteinemias, Type IIa,LDL Receptor Disorders,Lipoproteinemia, Hyper-Low Density,Lipoproteinemias, Hyper-Low Density,Receptor Disorder, LDL,Receptor Disorders, LDL,Type 2, Hyperlipoproteinemia,Type II Hyperlipoproteinemia,Type II Hyperlipoproteinemias,Type IIa Hyperlipoproteinemia,Type IIa Hyperlipoproteinemias,Xanthomatoses, Familial Hypercholesterolemic,Xanthomatosis, Familial Hypercholesterolemic
D012867	Skin	The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.