title: Modified plasma-derived lipoproteins in human atherosclerotic plaques.
abstract: 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.
authors.affiliation: Division of Chemical Pathology and Metabolic Disorders, United Medical School, St. Thomas' Hospital, London, U.K.
authors.forename: M
authors.initials: M
authors.lastname: Shaikh
authors.forename: S
authors.initials: S
authors.lastname: Martini
authors.forename: J R
authors.initials: JR
authors.lastname: Quiney
authors.forename: P
authors.initials: P
authors.lastname: Baskerville
authors.forename: A E
authors.initials: AE
authors.lastname: La Ville
authors.forename: N L
authors.initials: NL
authors.lastname: Browse
authors.forename: R
authors.initials: R
authors.lastname: Duffield
authors.forename: P R
authors.initials: PR
authors.lastname: Turner
authors.forename: B
authors.initials: B
authors.lastname: Lewis
mesh_terms: 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
chemical_list: D008074:Lipoproteins; D053419:Lipoproteins, IDL; D008077:Lipoproteins, LDL