文章基本信息

标题：Role of cholesteryl ester transfer protein in selective uptake of high density lipoprotein cholesteryl esters by adipocytes
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作者：Gerard Vassiliou ; Ruth McPherson
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2004
卷号：45
期号：9
页码：1683-1693
DOI：10.1194/jlr.M400051-JLR200
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：Previous reports attributed cholesteryl ester transfer protein (CETP)-mediated HDL cholesteryl ester (CE) selective uptake to the CETP-mediated transfer of CE from HDL to newly secreted apolipoprotein B-containing lipoproteins, which are then internalized by the LDL receptor (LDL-R). CETP has also been implicated in the remodeling of HDL, which renders it a better substrate for selective uptake by scavenger receptor class B type I (SR-BI). However, CETP-mediated selective uptake of HDL₃-derived CE was not diminished in LDL-R null adipocytes, SR-BI null adipocytes, or in the presence of the receptor-associated protein. We found that monensin treatment or energy depletion of the SW872 liposarcoma cells with 2-deoxyglucose and NaN₃ had no effect on CETP-mediated selective uptake, demonstrating that endocytosis is not required. This is supported by data indicating that CETP transfers CE into a compartment from which it can be extracted by unlabeled HDL. CETP could also mediate the selective uptake of HDL₃-derived triacylglycerol (TG) and phospholipid (PL). The CETP-specific kinetics for TG and CE uptake were similar, and both reached saturation at ∼5 μg/ml HDL. In contrast, CETP-specific PL uptake did not attain saturation at 5 μg/ml HDL and was ∼6-fold greater than the uptake of CE. We propose two possible mechanisms to account for the role of CETP in selective uptake.