Overexpression of apolipoprotein A-I promotes reverse transport of cholesterol from macrophages to feces in vivo
Overexpression of apolipoprotein A-I promotes reverse transport of cholesterol from macrophages to feces in vivo
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DOI：
10.1161/01.cir.0000086981.09834.e0
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发表时间：
2003-08-12
期刊：
影响因子：
37.8
通讯作者：
Rader, DJ
中科院分区：
文献类型：
--
作者：
Zhang, YZ;Zanotti, I;Rader, DJ
背景-大量数据表明，小鼠过表达载脂蛋白A-I(apoA-I)可抑制动脉粥样硬化。一种机制被认为是促进胆固醇反向运输，但没有直接证据表明这一概念存在。我们开发了一种新的方法来追踪标记的胆固醇在体内从巨噬细胞到肝脏和粪便的反向运输，并应用该方法研究了apoA-I过表达促进巨噬细胞特异性反向胆固醇运输的能力。方法和结果-J774巨噬细胞通过与乙酰化的低密度脂蛋白孵育负载胆固醇，标记H-3-胆固醇，然后注射到小鼠体内。分别在24小时和48小时采集小鼠的血浆和粪便，并采集组织，分析示踪剂计数。在血浆、肝脏和粪便中发现H-3-胆固醇。对于apoA-I过表达的小鼠，在注射标记的巨噬细胞前3天静脉注射apoA-I腺病毒(每只动物10(11)个颗粒)。ApoA-I过表达导致血浆、肝脏和粪便中H-3-胆固醇显著升高。与对照组相比，表达apoA-I的小鼠肝脏中H-3示踪剂的量增加了35%(P<；0.05)，48小时后排入粪便的H-3示踪剂增加了63%(P<；0.05)。结论注射H-3-胆固醇标记的巨噬细胞泡沫细胞是一种检测体内胆固醇从巨噬细胞到粪便的反向转运的方法，apoA-I的过表达促进了巨噬细胞特异性的胆固醇反向转运。
Background-Abundant data indicate that overexpression of apolipoprotein A-I (apoA-I) in mice inhibits atherosclerosis. One mechanism is believed to be promotion of reverse cholesterol transport, but no direct proof of this concept exists. We developed a novel approach to trace reverse transport of labeled cholesterol specifically from macrophages to the liver and feces in vivo and have applied this approach to investigate the ability of apoA-I overexpression to promote macrophage-specific reverse cholesterol transport.Method and Results-J774 macrophages were loaded with cholesterol by incubation with acetylated LDL, labeled with H-3-cholesterol, and then injected intraperitoneally into mice. Plasma and feces were collected at 24 hours and 48 hours, when mice were exsanguinated, tissues were harvested, and all were analyzed for tracer counts. H-3-cholesterol was found in the plasma, liver, and feces. For apoA-I overexpression, mice were injected intravenously with apoA-I adenovirus (10(11) particles per animal) 3 days before labeled macrophages were injected. ApoA-I overexpression led to significantly higher H-3-cholesterol in plasma, liver, and feces. The amount of H-3-tracer in the liver was 35% higher (P < 0.05) and the H-3-tracer excreted into feces over 48 hours was 63% higher (P < 0.05) in apoA-I-expressing mice than in control mice.Conclusion-Injection of H-3-cholesterol-labeled macrophage foam cells is a method of measuring reverse cholesterol transport specifically from macrophages to feces in vivo, and apoA-I overexpression promotes macrophage-specific reverse cholesterol transport.