BONE MARROW TRANSPLANTION AND ATHEROSCLEROSIS

骨髓移植和动脉粥样硬化

• 批准号: 2415649
• 负责人: MACRAE F LINTON
• 金额: $ 24.03万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-05-01 至 2000-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2415649
• 关键词: apolipoprotein E; atherosclerosis; blood lipoprotein metabolism; bone marrow transplantation; cholesterol; flow cytometry; genetic markers; genetic strain; immunofluorescence technique; laboratory mouse; low density lipoprotein; macrophage; remission /regression

Atherosclerosis is the major cause of morbidity and mortality in the Western World. The first recognizable lesion of atherosclerosis, the fatty streak, consists primarily of cholesteryl ester laden macrophages (foam cells) in the arterial intima. The goal of this project is to use murine bone marrow transplantation as a method to investigate the role of the macrophage in atherosclerosis and lipoprotein metabolism. The first specific aim is designed to test the hypothesis that the transfer of bone marrow cells bearing a specific genetic marker into a lethally irradiated host will result, under the appropriate atherogenic conditions, in the delivery of donor monocytes to the arterial intima and in the development of macrophage-derived foam cells of donor origin. The ROSA beta-geo 26 strain of mice which have ubiquitous expression of beta-galactosidase from the Lac Z gene will be used as bone marrow donors in these experiments, providing an easily detectable genetic marker to track the fate of donor macrophages. Once the conditions for repopulation of the host with macrophages of donor origin have been established, we will use this system to investigate the role of apolipoprotein (apo) E secretion by the macrophage in lipoprotein metabolism nd atherosclerosis. The majority of apoE in the plasma lipoproteins is of hepatic origin, and the relative contribution of extrahepatic apoE to the metabolism of the plasma lipoproteins is uncertain. ApoE is a ligand for the LDL receptor and promotes the clearance of several classes of lipoproteins from the plasma. Mice homozygous for the targeted disruption of the apoE gene develop severe hyperlipidemia and spontaneous aortic and coronary atherosclerosis. in the second specific aim, transplantation of bone marrow from mice with the normal apoE gene into apoE deficient mice will be performed to investigate the ability of extrahepatic apoE to contribute to plasma apoE levels and the clearance of plasma lipoproteins. The macrophage is known to secrete large amounts of apolipoprotein E and free cholesterol when exposed to acetylated-LDL in vitro. Foam cell formation can be viewed as an imbalance between cholesterol influx and efflux. ApoE secretion by the macrophage may facilitate cholesterol efflux from the macrophage, thus serving a protective role by preventing foam cell formation. Observations that apoE deficient mice develop spontaneous atherosclerosis, whereas transgenic mice expressing a defective apoE from the liver do not, suggest that macrophage apoE secretion may indeed play a protective role in regard to atherosclerosis susceptibility. In the third specific aim, the role of apo E secretion by the macrophage in promoting cholesterol efflux will be tested in vitro, and bone marrow transplantation experiments will test the hypothesis that apo E secretion by the macrophage influences susceptibility to atherosclerosis in vivo. To test the hypothesis that the inability of the macrophage to secrete apoE results in an increase in the susceptibility to atherosclerosis, bone marrow from apoE deficient mice will be transplanted into C57BL/6 mice. In addition, the transplantation of bone marrow from mice with the normal apoE gene into apo E deficient mice will be tested as a means of promoting regression of atherosclerosis in apoE deficient mice.

动脉粥样硬化是老年人发病和死亡的主要原因。 西方世界。动脉粥样硬化的第一个可识别的病变是脂肪 条纹，主要由含有胆固醇酯的巨噬细胞(泡沫)组成 细胞)在动脉内膜中。这个项目的目标是用小鼠 骨髓移植作为一种研究骨髓移植的方法 巨噬细胞与动脉粥样硬化和脂蛋白代谢第一 专门设计的目的是检验这样一种假设，即骨转移 携带特定遗传标记的骨髓细胞进入致死照射的 在适当的致动脉粥样硬化条件下，宿主将导致 供体单核细胞向动脉内膜和发育过程中的传递 供体来源的巨噬细胞来源的泡沫细胞。罗莎·贝塔-Geo 26 广泛表达β-半乳糖苷酶的小鼠品系 Lac Z基因将在这些实验中用作骨髓捐赠者， 提供了一种易于检测的遗传标记来追踪捐赠者的命运 巨噬细胞。一旦寄主具有再种群的条件 供体来源的巨噬细胞已经建立，我们将使用这个系统 探讨载脂蛋白E(apo-E)分泌在细胞周期调控中的作用 巨噬细胞在脂蛋白代谢和动脉粥样硬化中的作用 血浆脂蛋白中的载脂蛋白E大部分来自肝脏， 肝外载脂蛋白E对机体代谢的相对贡献 血浆脂蛋白是不确定的。载脂蛋白E是低密度脂蛋白受体的配体 并促进几类脂蛋白从 血浆。靶向破坏apoE基因的纯合子小鼠 出现严重的高脂血症和自发性主动脉和冠状动脉 动脉硬化。第二个具体目标是骨移植 将载脂蛋白E基因正常的小鼠骨髓移植到载脂蛋白E缺陷小鼠体内 以研究肝外载脂蛋白E对 血浆载脂蛋白E水平和血浆脂蛋白清除量。 已知巨噬细胞分泌大量载脂蛋白E和 在体外暴露于乙酰化低密度脂蛋白时的游离胆固醇。泡沫电池 形成可以看作是胆固醇流入和 外流。巨噬细胞分泌载脂蛋白可能促进胆固醇外流 巨噬细胞，从而起到保护作用，防止泡沫细胞 队形。载脂蛋白E缺陷小鼠自发发育的观察 动脉粥样硬化，而表达缺陷载脂蛋白E的转基因小鼠 肝脏没有，提示巨噬细胞载脂蛋白E的分泌可能确实起到了 在动脉粥样硬化易感性方面的保护作用。在第三节 特定目的：巨噬细胞分泌载脂蛋白E在促进 将在体外测试胆固醇外流，并进行骨髓移植 实验将检验巨噬细胞分泌载脂蛋白E的假设 在体内影响动脉粥样硬化的易感性。要测试 假设巨噬细胞不能分泌载脂蛋白E导致 载脂蛋白E的骨髓对动脉粥样硬化的易感性增加 将缺陷小鼠移植到C57BL/6小鼠体内。此外， 载脂蛋白E基因正常小鼠骨髓移植入载脂蛋白 E基因缺陷的小鼠将作为一种促进退化的手段进行测试 载脂蛋白E缺陷小鼠的动脉粥样硬化。