APOE AND ATHEROGENESIS

描述（改编自研究者摘要）：本提案源于 根据首席研究员的观察，巨噬细胞- 人载脂蛋白E在apoE-/-细胞中特异性表达 小鼠减少动脉粥样硬化的发展。但目前还不清楚 如果ApoE +/+小鼠中巨噬细胞正常产生的apoE水平 给予最大的保护。因此，研究人员设计了 他们的实验回答了四个关键问题：a）将增加水平 野生型小鼠中巨噬细胞apoE表达的降低， 动脉粥样硬化病变的形成？B）将apoE在 在动脉粥样硬化病变的发展后， 使病变消退或停止恶化c）apoE的表达是否 增强胆固醇流出（1）有apoE 异构体特异性差异对动脉粥样硬化病变形成和 回归？因此，拟议的具体目标如下：这里 它们将产生具有巨噬细胞的C57 BL/6小鼠-1）为了确定 巨噬细胞特异性过表达apoE 3对成纤维细胞增殖的影响 动脉粥样硬化病变的apoE 3表达，然后他们将 检测这种表达对饮食诱导的动脉粥样硬化的影响。（二） 为了确定巨噬细胞特异性表达人apoE 3的作用， 对野生型和ApoE-/-小鼠中现有动脉粥样硬化病变的影响。 在这里，他们将用四环素产生野生型和ApoE-/-小鼠， apoE的受调节的巨噬细胞特异性表达。然后他们将 确定ApoE 3表达对动脉粥样硬化病变的影响 在这些小鼠中的进展或消退。最后，他们将决定 巨噬细胞特异性表达ApoE 3对巨噬细胞释放的影响 动脉粥样硬化病变的胆固醇。3)为了确定ApoE 2， ApoE 3和ApoE 4促进胆固醇的能力不同 如果ApoE 3和ApoE 4对细胞外排的影响不同， 动脉粥样硬化病变的形成和消退。在这里，他们将检查 ApoE-/-小鼠血浆巨噬细胞特异性 表达ApoE 2、ApoE 3或ApoE 4以诱导胆固醇流出， 胆固醇负载细胞。他们将比较腹膜的能力， 巨噬细胞和稳定转染的表达ApoE 2、ApoE 3或 ApoE 4释放胆固醇他们将确定的机制， ApoE 3和ApoE 4促进胆固醇流出的不同能力 并形成γ-LPE（一种具有γ- 含有apoE作为其唯一载脂蛋白的电泳运动性 成分）。最后，他们将检查巨噬细胞的作用- 载脂蛋白E4在动脉粥样硬化发生发展中特异性表达 回归分析

DESCRIPTION (Adapted from Investigator's Abstract): This proposal stems from the observation made by the principal investigator that macrophage- specific expression of human apolipoprotein E in apoE-null (Apoe-/-) mice reduces the development of atherosclerosis. However it is not known if the level of apoE normally produced by macrophages in ApoE +/+ mice gives maximal protection. Therefore the investigators have designed their experiments to answer four key questions: a) Will increased levels of expression of apoE by macrophages in wild-type mice decrease the formation of atherosclerotic lesions? b) Will expression of apoE in macrophages after the development of atheroslerotic lesions cause lesions to regress or halt their progression? c) Does expression of apoE in atherosclerotic lesions enhance cholesterol efflux? d) Are there apoE isoform-specific differences on atherosclerotic lesion formation and regression? The proposed specific aims are therefore as follows:. Here they will generate C57BL/6 mice with macrophage-1) To determine the effect of macrophage-specific over-expression of apoE3 on the formation of atherosclerotic lesions expression of apoE3, and then they will examine the effect this expression on diet-induced atherosclerosis. 2) To determine the effect of macrophage-specific expression of human apoE3 on existing atherosclerotic lesions in wild-type and in ApoE-/- mice. Here they will produce wild-type and ApoE-/- mice with tetracycline- regulated, macrophage-specific expression of apoE. They will then determine the effect of ApoE3 expression on atherosclerotic lesion progression or regression in these mice. Finally they will determine the effect of macrophage-specific expression of ApoE3 on the release of cholesterol from atherosclerotic lesions. 3) To determine if ApoE2, ApoE3, and ApoE4 differ in their abilities to facilitate cholesterol efflux from cells and if ApoE3 and ApoE4 differ in their effects on atherosclerotic lesion formation and regression. Here they will examine the ability of plasma from ApoE-/- mice with macrophage-specific expression of ApoE2, ApoE3, or ApoE4 to induce cholesterol efflux from cholesterol-loaded cells. They will compare the ability of peritoneal macrophages and of stably transfected cells expressing ApoE2, ApoE3, or ApoE4 to release cholesterol. They will determine the mechanism of the differential abilities of ApoE3 and ApoE4 to promote cholesterol efflux and to form gammaLPE (a lipid-poor lipoprotein particle with gamma- electrophoretic motility that contains apoE as its only apolipoprotein constituent). Finally they will examine the effect of macrophage- specific expression of ApoE4 on atherosclerosis development and regression.