Apolipoproteins C-II and C-III inhibit selective uptake of low- and high-density lipoprotein cholesteryl esters in HepG2 cells
Apolipoproteins C-II and C-III inhibit selective uptake of low- and high-density lipoprotein cholesteryl esters in HepG2 cells
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DOI：
10.1016/j.biocel.2005.01.005
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发表时间：
2005-06-01
影响因子：
4
通讯作者：
Brissette, L
中科院分区：
文献类型：
--
作者：
Huard, K;Bourgeois, P;Brissette, L
血浆低密度脂蛋白和高密度脂蛋白（LDL 和 HDL）被特定受体从循环中清除，或者被完全降解，或者它们的胆固醇酯 (CE) 通过受体（例如 I 类清道夫受体 B 型 (SR-BI)）选择性递送至细胞。本研究的目的是确定 apoC-II 和 apoC-III 对 HepG2 细胞摄取 LDL 和 HDL 的影响。通过有义或反义策略获得稳定的转化体，其分泌apoC-II正常水平的47-294%或apoC-III正常水平的60-200%。不同水平分泌的apoC-II或apoC-III对HepG2细胞降解LDL和HDL蛋白影响不大。然而，与对照相比。低表达 apoC-II 的细胞选择性摄取 HDL-CE 的能力高出 160%。而低表达 apoC-III 的细胞从 LDL 和 HDL 中摄取 CE 的能力分别高出 70% 和 160%。然而，在使用外源添加的apoC-II或apoC-III进行的实验中，没有观察到对脂蛋白-蛋白质结合/去辐射的显着影响。 LDL-CE和HDL-CE选择性摄取以剂量依赖性方式显着降低。这些结果表明apoC-II和apoC-III抑制CE选择性摄取。 (c) 2005 Elsevier Ltd. 保留所有权利。
Plasma low- and high-density lipoproteins (LDL and HDL) are cleared from the circulation by specific receptors and are either totally degraded or their cholesteryl esters (CE) are selectively delivered to cells by receptors such as the scavenger receptor class B type I (SR-BI). The aim of the present study was to define the effect of apoC-II and apoC-III on the uptake of LDL and HDL by HepG2 cells. Stable transformants were obtained with sense or antisense strategies that secrete 47-294% the normal level of apoC-II or 60-200% that of apoC-III. Different levels of secreted apoC-II or apoC-III had little effect on LDL and HDL protein degradation by HepG2 cells. However, compared to controls. cells under-expressing apoC-II showed a 160% higher capacity to selectively take up HDL-CE. while cells under-expressing apoC-III demonstrated 70 and 160% higher capacity to take up CE from LDL and HDL, respectively. In experiments conducted with exogenously added apoC-II or apoC-III, no significant effect was observed on lipoprotein-protein association/de.-radation however. LDL-CE and HDL-CE selective uptake was significantly reduced in a dose-dependent manner. These results indicate that apoC-II and apoC-III inhibit CE-selective uptake. (c) 2005 Elsevier Ltd. All rights reserved.