| Autor: |
Gerard Vassiliou, Ruth McPherson |
| Jazyk: |
angličtina |
| Rok vydání: |
2004 |
| Předmět: |
|
| Zdroj: |
Journal of Lipid Research, Vol 45, Iss 9, Pp 1683-1693 (2004) |
| Druh dokumentu: |
article |
| ISSN: |
0022-2275 |
| DOI: |
10.1194/jlr.M400051-JLR200 |
| Popis: |
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. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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