Introduction of human apolipoprotein E4 "domain interaction" into mouse apolipoprotein E
Introduction of human apolipoprotein E4 "domain interaction" into mouse apolipoprotein E
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DOI：
10.1073/pnas.201279298
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发表时间：
2001-09-25
影响因子：
11.1
通讯作者：
Weisgraber, KH
中科院分区：
文献类型：
--
作者：
Raffaï, RL;Dong, LM;Weisgraber, KH
人载脂蛋白 E4 (apoE4) 优先与低密度脂蛋白（包括极低密度脂蛋白）结合，并与动脉粥样硬化和神经退行性疾病（包括阿尔茨海默病）风险增加相关。这种结合偏好是 Arg-112 存在的结果，它导致氨基末端结构域中的 Arg-61 与羧基末端结构域中的 Glu-255 相互作用。 ApoE2 和 apoE3 具有 Cys-112，优先与高密度脂蛋白 (HDL) 结合，并且不显示 apoE4 结构域相互作用。小鼠 apoE 与 apoE4 一样，含有 Arg-112 和 Glu-255 的等价物，但缺乏关键的 Arg-61 等价物（它含有 Thr-61）。因此，小鼠 apoE 不显示 apoE4 结构域相互作用，因此其行为类似于人类 apoE3，包括优先结合 HDL。为了评估 apoE4 结构域相互作用在动脉粥样硬化和神经变性中的潜在作用，我们试图将 apoE4 结构域相互作用引入小鼠 apoE。用精氨酸替换小鼠 apoE 中的 Thr-61，在体外将结合偏好从 HDL 转变为极低密度脂蛋白，这表明 apoE4 结构域相互作用可以在体内引入小鼠 apoE 中。利用胚胎干细胞中的基因靶向，我们创造了表达 Arg-61 apoE 的小鼠。杂合的 Arg-61/野生型 apoE 小鼠表现出人类 apoE4/E3 杂合子中发现的两种表型：优先与低密度脂蛋白结合，血浆中 Arg-61 apoE 的丰度降低，反映出其分解代谢更快。这些发现证明 apoE4 结构域相互作用已成功引入小鼠 apoE 体内。 Arg-61 apoE 小鼠模型将允许确定 apoE4 结构域相互作用对脂蛋白代谢、动脉粥样硬化和神经变性的影响。
Human apolipoprotein E4 (apoE4) binds preferentially to lower density lipoproteins, including very low density lipoproteins, and is associated with increased risk of atherosclerosis and neurodegenerative disorders, including Alzheimer's disease. This binding preference is the result of the presence of Arg-112, which causes Arg-61 in the amino-terminal domain to interact with Glu-255 in the carboxyl-terminal domain. ApoE2 and apoE3, which have Cys-112, bind preferentially to high density lipoproteins (HDL) and do not display apoE4 domain interaction. Mouse apoE, like apoE4, contains the equivalent of Arg-112 and Glu-255, but lacks the critical Arg-61 equivalent (it contains Thr-61). Thus, mouse apoE does not display apoE4 domain interaction and, as a result, behaves like human apoE3, including preferential binding to HDL. To assess the potential role of apoE4 domain interaction in atherosclerosis and neurodegeneration, we sought to introduce apoE4 domain interaction into mouse apoE. Replacing Thr-61 in mouse apoE with arginine converted the binding preference from HDL to very low density lipoproteins in vitro, suggesting that apoE4 domain interaction could be introduced into mouse apoE in vivo. Using gene targeting in embryonic stem cells, we created mice expressing Arg-61 apoE. Heterozygous Arg-61/wild-type apoE mice displayed two phenotypes found in human apoE4/E3 heterozygotes: preferential binding to lower density lipoproteins and reduced abundance of Arg-61 apoE in the plasma, reflecting its more rapid catabolism. These findings demonstrate the successful introduction of apoE4 domain interaction into mouse apoE in vivo. The Arg-61 apoE mouse model will allow the effects of apoE4 domain interaction in lipoprotein metabolism, atherosclerosis, and neurodegeneration to be determined.