Involvement of cholesterol-enriched microdomains in class A scavenger receptor-mediated responses in human macrophages
Involvement of cholesterol-enriched microdomains in class A scavenger receptor-mediated responses in human macrophages
复制标题
DOI：
10.1016/j.atherosclerosis.2010.10.019
复制
发表时间：
2011-03-01
期刊：
影响因子：
5.3
通讯作者：
Daida, Hiroyuki
中科院分区：
文献类型：
--
作者：
Kiyanagi, Takashi;Iwabuchi, Kazuhisa;Daida, Hiroyuki
目的：脂筏是细胞膜上富含胆固醇的微区。我们假设，这些微域可能涉及修改的低密度脂蛋白（LDL）uptake.Methods and Results：共定位的胆固醇富集的微域和CD 204在乙酰低密度脂蛋白（AcLDL）和氧化低密度脂蛋白的摄取过程中观察使用Alexa 488标记的聚乙二醇胆固醇酯，这是一种敏感的探针，用于分析在活细胞中的胆固醇丰富的脂质微域的动态。脂筏破坏剂，甲基-β环糊精和菲律宾，抑制AcLDL的摄取。CD 204 siRNA处理显著降低AcLDL摄取80%。我们还通过免疫印迹分析证明了CD 204在耐洗涤剂膜组分（DRM）中的存在。DRM中CD 204/flotillin-1的比率通过修饰的LDL施用增加11.5倍。PI 3激酶抑制剂LY 294002，而不是Src激酶抑制剂PP 1或G α i/o抑制剂百日咳毒素，抑制修饰的LDL摄取。AcLDL给药可增加白细胞介素（IL）-8的产生，但不增加CCL 2、CXCL 2、CXCL 3、IL-6或肿瘤坏死因子-α的产生。LY 294002和filipin均能抑制AcLDL诱导的IL-8的产生。结论：本研究首次证实PI 3激酶相关的胆固醇富集微区参与了CD 204介导的人巨噬细胞修饰LDL的摄取。富含胆固醇的微区可能在炎症过程中起关键作用。(C)2010爱思唯尔爱尔兰有限公司版权所有。
Objective: Lipid rafts are cholesterol-enriched microdomains on cell membranes. We hypothesized that these microdomains could involve modified low-density lipoprotein (LDL) uptake.Methods and results: Co-localizations of cholesterol-enriched microdomains and CD204 during the uptake of acetyl LDL (AcLDL) and oxidized LDL were observed using Alexa488-labeled polyethylene glycol cholesteryl ester, which is a sensitive probe used to analyze the dynamics of cholesterol-rich lipid microdomains in living cells. The lipid raft disruptors, methyl-beta cyclodextrin and filipin, inhibited the uptake of AcLDL. CD204 siRNA treatments significantly reduced AcLDL uptake by 80%. We also demonstrated the presence of CD204 in the detergent-resistant membrane fraction (DRM) by immunoblotting analysis. The ratio of CD204/flotillin-1 in DRM was increased 11.5-fold by modified LDL administration. The PI3 kinase inhibitor LY294002, but not the Src kinase inhibitor PP1 or the G alpha i/o inhibitor pertussis toxin, inhibited modified LDL uptake. The production of interleukin (IL)-8, but not CCL2, CXCL2, CXCL3, IL-6 or tumor necrosis factor-alpha was increased by AcLDL administration. The AcLDL-induced IL-8 production was inhibited by LY294002 and filipin.Conclusions: These data firstly demonstrated that PI3 kinase-associated cholesterol-enriched microdomains are involved in CD204-mediated modified LDL uptake in human macrophages. Cholesterol-enriched microdomains may play a critical role in inflammatory processes. (C) 2010 Elsevier Ireland Ltd. All rights reserved.