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标题：Structural and functional properties of human plasma high density-sized lipoprotein containing only apoE particles
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作者：Larbi Krimbou ; Michel Marcil ; Hitoshi Chiba 等
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2003
卷号：44
期号：5
页码：884-892
DOI：10.1194/jlr.M200273-JLR200
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：To investigate the metabolism of HDL-apolipoprotein E (apoE) particles in human plasma, we isolated a fraction of plasma HDL-apoEs that lack apoA-I (HDL-LpE) from subjects with apoE3/3 phenotype by immunoaffinity. Plasma HDL-LpE had a particle size ranging from 9 nm to 18.5 nm in diameter and was characterized by two-dimensional nondenaturing gradient gel electrophoresis as having either γ-, preβ₁-, preβ₂-, or α-electrophoretic mobility. HDL-LpE was also present in the medium of cultured human hepatoma cell lines and monocyte-derived macrophages. The majority of apoE3 was found as a monomeric form in HDL-LpE and floated at density d > 1.21 g/ml. Plasma levels of HDL-LpE in normolipidemic, CETP-deficient, and ABCA1-deficient subjects were 0.72 ± 0.15 mg/dl (n = 12), 1.77 ± 0.75 mg/dl (n = 3), and 0.55 ± 0.11 mg/dl (n = 3), respectively. The ratio of HDL-apoE containing apoA-I to HDL-LpE was significantly higher 4 h after a fat load, representing a 35 ± 9% increase (n = 3). Isolated plasma HDL-LpE3 was as effective as apoE3, reconstituted HDL particles, or apoA-I in promoting cellular cholesterol efflux. These results demonstrate that 1 ) plasma HDL-LpE may have hepatogenous and macrophagic origins; 2 ) HDL-LpE was preserved even with large reductions in apoA-I-containing lipoproteins; 3 ) HDL-LpE was active in the transfer of apoE to triglyceride-rich lipoproteins, and 4 ) HDL-LpEs efficiently take up cell-derived cholesterol.