Purified human paraoxonase-1 interacts with plasma membrane lipid rafts and mediates cholesterol efflux from macrophages
Purified human paraoxonase-1 interacts with plasma membrane lipid rafts and mediates cholesterol efflux from macrophages
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DOI：
10.1016/j.freeradbiomed.2012.01.019
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发表时间：
2012-04-15
影响因子：
7.4
通讯作者：
Khalil, Abdelouahed
中科院分区：
文献类型：
--
作者：
Berrougui, Hicham;Loued, Soumaya;Khalil, Abdelouahed
对氧磷酶-1（PON 1）是一种高密度脂蛋白（HDL）相关的血清酶，被认为对HDL的抗氧化和抗炎能力有重要贡献。然而，对PON 1在胆固醇流出调节中的作用知之甚少。本研究的目的是探讨PON 1参与胆固醇流出的调节，特别是它调节HDL介导的胆固醇转运的机制。用人PON 1富集HDL 3以剂量依赖性方式增强THP-1巨噬细胞样细胞和ABCA 1富集的J774巨噬细胞的胆固醇流出。此外，当ABCA 1富集的J774巨噬细胞与PON 1和apo-AI孵育时，观察到累加效应。有趣的是，单独的PON 1能够介导胆固醇从J774巨噬细胞流出并上调1774巨噬细胞上的ABCA 1表达。免疫荧光检测显示过表达ABCA 1的J774巨噬细胞胞质中PON 1水平增加。PON 1使用apo-AI样机制来调节来自质膜脂筏和非脂筏结构域的快速和缓慢流出池的胆固醇流出。这得到以下事实的支持：在与胆固醇负载的J774巨噬细胞孵育的最初几个小时内，ABCA 1蛋白由J774巨噬细胞递增地表达，并且环糊精显著抑制PON 1调节巨噬细胞胆固醇流出的能力。这一发现表明，PON 1在HDL的抗动脉粥样硬化特性中起着重要作用，并可能在脂蛋白环境外发挥其保护作用。(C)2012 Elsevier Inc. All rights reserved.
Paraoxonase-1 (PON1) is a high-density lipoprotein (HDL)-associated serum enzyme thought to make a major contribution to the antioxidant and anti-inflammatory capacities of HDLs. However, the role of PON1 in the modulation of cholesterol efflux is poorly understood. The aim of our study was to investigate the involvement of PON1 in the regulation of cholesterol efflux, especially the mechanism by which it modulates HDL-mediated cholesterol transport. The enrichment of HDL3 with human PON1 enhanced, in a dose-dependent manner, cholesterol efflux from THP-1 macrophage-like cells and ABCA1-enriched J774 macrophages. Moreover, an additive effect was observed when ABCA1-enriched J774 macrophages were incubated with both PON1 and apo-AI. Interestingly, PON1 alone was able to mediate cholesterol efflux from J774 macrophages and to upregulate ABCA1 expression on 1774 macrophages. Immunofluorescence measurement showed an increase in PON1 levels in the cytoplasm of J774 macrophages overexpressing ABCA1. PON1 used an apo-AI-like mechanism to modulate cholesterol efflux from rapid and slow efflux pools derived from the lipid raft and nonraft domains of the plasma membrane, respectively. This was supported by the fact that ABCA1 protein was incrementally expressed by J774 macrophages within the first few hours of incubation with cholesterol-loaded J774 macrophages and that cyclodextrin significantly inhibited the capacity of PON1 to modulate cholesterol efflux from macrophages. This finding suggested that PON1 plays an important role in the antiatherogenic properties of HDLs and may exert its protective function outside the lipoprotein environment. (C) 2012 Elsevier Inc. All rights reserved.