Modified plasma-derived lipoproteins in human atherosclerotic plaques.
Low density lipoproteins extracted from surgical specimens of human atherosclerotic plaques (A-LDL) showed altered electrophoretic mobility indicating a greater negative charge than that of plasma LDL (P-LDL). A-LDL but not P-LDL showed high affinity binding/degradation by human monocyte-derived macrophages; this was inhibited by acetylated LDL but not by native P-LDL. Following injection of 125I-labelled autologous P-LDL prior to reconstructive arterial surgery, polyacrylamide and agarose gel electrophoresis of A-LDL extracted from arterial intima showed that the A-LDL and its apolipoprotein B moiety were derived from P-LDL; the electrophoretic mobility of the product A-LDL was greater than that of native P-LDL. The compositions of arterial intermediate density lipoprotein (A-IDL) and A-LDL differed from those obtained from human plasma intermediate density lipoprotein (P-IDL) and P-LDL. A-IDL showed a reduced triglyceride content and increased esterified and unesterified cholesterol. Although the total cholesterol content of A-LDL was similar to that of P-LDL, there was an increase in unesterified cholesterol and a decrease of cholesteryl ester. These studies indicate that LDL extracted from human atherosclerotic plaque is derived from and modified from P-LDL in vivo. Compared with native P-LDL, A-LDL showed differences in charge and composition, associated with its high affinity binding by the acetyl LDL receptor of human macrophages.
Shaikh
M
M
Division of Chemical Pathology and Metabolic Disorders, United Medical School, St. Thomas' Hospital, London, U.K.
Martini
S
S
Quiney
J R
JR
Baskerville
P
P
La Ville
A E
AE
Browse
N L
NL
Duffield
R
R
Turner
P R
PR
Lewis
B
B
D001161:Arteriosclerosis / Q000378:metabolism*; D001797:Blood Protein Electrophoresis; D006801:Humans; D007525:Isoelectric Focusing; D008074:Lipoproteins / Q000032:analysis; D053419:Lipoproteins, IDL; D008077:Lipoproteins, LDL / Q000032:analysis*; D008264:Macrophages / Q000378:metabolism
D008074:Lipoproteins; D053419:Lipoproteins, IDL; D008077:Lipoproteins, LDL