Abnormal suppression of 3-hydroxy-3-methylglutaryl-CoA reductase activity in cultured human fibroblasts by hypertriglyceridemic very low density lipoprotein subclasses

Lipids ◽  
1980 ◽  
Vol 15 (6) ◽  
pp. 456-463 ◽  
Author(s):  
Sandra H. Gianturco ◽  
Christopher J. Packard ◽  
James Shepherd ◽  
Louis C. Smith ◽  
Alberico L. Catapano ◽  
...  
Keyword(s):  
Reductase Activity ◽  
Low Density Lipoprotein ◽  
Human Fibroblasts ◽  
Density Lipoprotein ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Lipoprotein Subclasses ◽  
Cultured Human Fibroblasts ◽  
Coa Reductase

scholarly journals Fluorescent low density lipoprotein for observation of dynamics of individual receptor complexes on cultured human fibroblasts.

1981 ◽  
Vol 90 (3) ◽  
pp. 595-604 ◽  
Author(s):  
L S Barak ◽  
W W Webb
Keyword(s):  
Low Density Lipoprotein ◽  
Human Fibroblasts ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Receptor Internalization ◽  
Low Density ◽  
Receptor Complexes ◽  
Heparin Sulfate ◽  
Cultured Human Fibroblasts ◽  
Coa Reductase

The visible wavelength excited fluorophore 3,3'-dioctadecylindocarbocyanine iodide (Dil[3]) was incorporated into human low density lipoprotein (LDL) to form the highly fluorescent LDL derivative dil(3)-LDL. Dil(3)-LDL binds to normal human fibroblasts and to human fibroblasts defective in LDL receptor internalization but does not bind to LDL receptor-negative human fibroblasts at 4 degrees C or 37 degrees C. It is internalized rapidly at 37 degrees C by normal fibroblasts and depresses the activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) in a manner similar to that of LDL. It is prevented from binding to the LDL receptor by an excess of unlabeled LDL or by heparin sulfate. Identical distributions of dil(3)-LDL are observed on cells by either indirect immunofluorescence with fluorescein-labeled antibody or directly by dil(3) fluorescence. Upwards of 45 molecules of dil(3) are incorporated per molecule of LDL without affecting binding to the receptor. This labeling renders individual molecules visible by their fluorescence and enables the derivative to be used in dynamic studies of LDL-receptor motion on living fibroblasts by standard fluorescence techniques at low LDL receptor density. Observations with this derivative indicate that the LDL-receptor complex is immobilized on the surface of human fibroblasts but, when free of this linkage, undergoes a Brownian motion consistent with theory.

scholarly journals Phorbol esters inhibit low density lipoprotein processing by cultured human fibroblasts

FEBS Letters ◽  
1986 ◽  
Vol 195 (1-2) ◽  
pp. 135-139 ◽  
Author(s):  
J.C. Mazière ◽  
C. Mazière ◽  
L. Mora ◽  
M. Auclair ◽  
S. Goldstein ◽  
...  
Keyword(s):  
Phorbol Esters ◽  
Low Density Lipoprotein ◽  
Human Fibroblasts ◽  
Density Lipoprotein ◽  
Low Density ◽  
Cultured Human Fibroblasts
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