SR-BI AND MACROPHAGE CHOLESTEROL METABOLISM

描述(改编自《调查者摘要》)：中心假设 在本提案中要考虑的是，SR-B1必须与小凹病毒相关联 促进选择性胆固醇酯摄取和游离胆固醇流出 巨噬细胞。目标1：确定SR-131需要小窝的程度 促进巨噬细胞胆固醇酯摄取和胆固醇外流。 我们已经建立了只表达SR-131或SR-BI和小窝蛋白的细胞系。 因此，我们可以研究SR-131介导的摄取和外排能力。 存在或不存在小凹时的脂质。我们将在以下时间确认我们的发现 人原代单核细胞来源的巨噬细胞。目标2：确定 哪些氧化的脂蛋白改变小窝结构并抑制SR BI依赖 巨噬细胞中的胆固醇流量。这将通过评估i) 氧化型脂蛋白对小窝脂肪组成的影响 氧化型脂蛋白对小窝结构的影响，III) 小窝修饰对SR-131亚细胞定位的影响， 4)氧化型脂蛋白对SR-131活性的影响。目标3：实现 确定巨噬细胞特异性过表达SR-B1和 小窝蛋白在转基因小鼠动脉粥样硬化病变发展中的作用。这 将通过使用过量表达SR-131、小窝蛋白、 或通过大唾液酸启动子在巨噬细胞中两者兼而有之。老鼠们将会是 与动脉粥样硬化易感载脂蛋白E-/-品系的杂交及其程度 动脉粥样硬化通过病变的大小和 病变的胆固醇/胆固醇酯含量。

DESCRIPTION (Adapted from Investigator's Abstract): The central hypothesis to be examined in this proposal is that SR-B1 must be associated with caveolae to promote selective cholesterol ester uptake and free cholesterol efflux from macrophages. Aim 1: To determine the extent to which SR-131 requires caveolae to facilitate cholesterol ester uptake and cholesterol efflux in macrophages. We have established cell lines that express only SR-131 or SR-BI and caveolin. Therefore, we can study the ability of SR-131 to mediated uptake and efflux of lipid in the presence or absence of caveolae. We will confirm our findings in human primary monocyte-derived macrophages. Aim 2: To determine the extent to which oxidized lipoproteins alter caveola structure and inhibit SR BI-dependent cholesterol flux in macrophages. This will be accomplished by assessing i) the effects of oxidized lipoproteins on the lipid composition of caveolae, ii) the effects of oxidized lipoproteins on the structure of caveolae, iii) the influence of caveolae modifications on the subcellular localization of SR-131, and iv) the effects of oxidized lipoproteins on SR-131 activity. Aim 3: To determine the effect of macrophage-specific over-expression of SR-B1 and caveolin on the development of atherosclerotic lesions in transgenic mice. This will be investigated by using transgenic mice over-expressing SR-131, caveolin, or both in macrophages by means of the macrosialin promoter. The mice will be crossbred to the atherosclerosis susceptible apoE -/- strain and the extent of atherosclerosis quantified by the size of the lesion and by the cholesterol/cholesterol ester content of the lesions.