REGULATION OF CHOLESTEROL TRAFFICKING IN ARTERIAL WALL CELLS

动脉壁细胞中胆固醇运输的调节

• 批准号: 6109454
• 负责人: EDWIN L BIERMAN
• 金额: $ 25.32万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-30 至 1999-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6109454
• 关键词: G protein; Primates; atherosclerosis; biological signal transduction; blood lipoprotein transport; cellular pathology; cholesterol; cytokine; fluorescence microscopy; growth factor receptors; high density lipoproteins; laboratory mouse; laboratory rabbit; oxidized lipid; phospholipase D; platelet derived growth factor; protein transport; protein tyrosine kinase; receptor binding; sterols; tissue /cell culture; transport inhibitor; transport proteins; vascular smooth muscle

An early feature of the developing atherosclerotic lesion is accumulation of cholesterol in artery wall cells. This accumulation may be modulated by cellular pathways that transport cholesterol from intracellular storage compartments to the cell surface for excretion. The overall objective of this project is to characterize the structural and regulatory properties of cellular cholesterol trafficking pathways and to evaluate the role of these pathways in atherogenesis. We have shown that cholesterol trafficking pathways in cultured cells are regulated in response to changes in the growth state and cholesterol status of cells and by the interaction of high.density lipoprotein (HDL) and platelet-derived growth factor (PDGF) with cell-surface binding sites or receptors. HDL cellular interactions function to stimulate translocation to the cell surface and excretion of intracellular stores of excess cholesterol, whereas PDGF receptor binding appears to stimulate cholesterol translocation to the plasma membrane for use as a structural component of newly-synthesized membranes. We propose to use these different regulated conditions to characterize the properties of cellular trafficking pathways and to test the hypothesis that the functionally-diverse stimuli, HDL and PDGF, may modulate these pathways by common mechanisms. We will examine the intracellular compartments and structures involved in HDL- and PDGF- regulated cholesterol transport using cell fractionation techniques, fluorescent microscopy, and intracellular transport inhibitors. We also propose to characterize intracellular signals that modulate HDL-mediated cholesterol trafficking by assaying cells for activation of different phospholipases, protein kinases, and other signals associated with stimulation of cholesterol transport and excretion. Additional studies will identify' signalling pathways involved in PDGF-mediated cholesterol trafficking using signalling enzyme inhibitors, different isoforms of PDGF, and cell lines expressing different wild-type and mutant forms of PDGF receptors. Lastly, we will evaluate whether proteins involved in sterol trafficking are expressed in lesion and non-lesion areas of the artery wall. These studies will generate important information about the mechanisms of cholesterol trafficking in cells and provide insight into how the lipoprotein and cytokine environment of the artery wall may influence cellular cholesterol homeostasis and contribute to atherogenesis.

发展中的动脉粥样硬化病变的早期特征是积聚。 动脉壁细胞中胆固醇的含量。这种积累可以通过以下方式进行调制 从细胞内储存运输胆固醇的细胞途径 细胞表面的隔间以供排泄。总的目标是 这一项目是为了表征结构和监管属性 对细胞胆固醇转运途径的研究，并评估其作用 动脉粥样硬化形成过程中的这些途径。我们已经证明，胆固醇 培养细胞中的运输途径受到调节，以响应 细胞生长状态和胆固醇状态的变化以及 高密度脂蛋白与血小板衍化生长的相互作用 具有细胞表面结合位点或受体的因子(PDGF)。高密度脂蛋白细胞 相互作用能刺激移位到细胞表面，并 排出细胞内储存的过量胆固醇，而PDGF 受体结合似乎刺激胆固醇转位到 用作新合成的一种结构元件的质膜 膜。我们建议利用这些不同的监管条件来 描述细胞传输路径的特性并进行测试 假设功能不同的刺激，高密度脂蛋白和血小板衍生生长因子，可能 通过共同的机制来调节这些通路。我们将研究 参与高密度脂蛋白和血小板衍生生长因子的细胞内间隔和结构- 使用细胞分级技术调节胆固醇的运输， 荧光显微镜和细胞内转运抑制剂。我们也 建议对调节高密度脂蛋白介导的细胞内信号进行表征 通过检测细胞激活不同的胆固醇来进行胆固醇转运 磷脂酶、蛋白激酶和其他与之相关的信号 刺激胆固醇的运输和排泄。其他研究 将确定参与PDGF介导的胆固醇的信号通路 使用信号酶抑制剂、不同亚型的 以及表达不同野生型和突变型PDGF的细胞系 PDGF受体。最后，我们将评估蛋白质是否参与了 固醇转运在大脑皮质的病变和非病变区域均有表达。 动脉壁。这些研究将产生关于 胆固醇在细胞内的转运机制，并提供了对 动脉壁的脂蛋白和细胞因子环境如何 影响细胞胆固醇动态平衡并有助于 动脉粥样硬化的形成。