LIPID METABOLISM: DYNAMICS OF INTRACELLULAR TRANSFER

在细胞水平上，动脉粥样硬化的一种机制涉及失衡。 在胆固醇的生物合成、吸收和外流之间，作为一个重要的 在这一疾病过程中的因素。通过以下方式降低心血管风险 高密度脂蛋白水平升高归因于胆固醇流出增加 从高密度脂蛋白促进的外周组织中转运到肝脏。一个 另一种观点认为，高密度脂蛋白可能只是一个标记物 心血管风险。关于细胞内调节的最新观点 胆固醇合成的配方中几乎没有关于 速率限制过程、速率限制步骤的蜂窝位置和 胆固醇和脂肪酸竞争过程的相对比率 运输。由热力学确定的脂类分布有 没有区别于那些作为动力的结果而存在的 通过被动转移和细胞转移阻止脂质快速移动的屏障 传输机制。目标是定义动力学和 细胞摄取、细胞内转运和外排的机制 培养的小鼠3T3L1前脂肪细胞的胆固醇和脂肪酸 人类成纤维细胞。数字荧光成像和数字技术的结合 建议通过生物化学实验来回答以下问题。 1.脂肪酸结合蛋白的作用是细胞内的 是缓冲液还是膜之间的运输囊泡？ 2.哪些细胞内膜具有连续的类脂结构域，哪些 膜对脂类的被动转移造成了动能障碍？ 3.胆固醇在细胞间的重新分配 增加3-羟基-3-甲基戊二酰辅酶A还原酶的合成？ 4.是FABP和脂蛋白转录和翻译的调控 脂肪酶主要受脂肪酸流动还是激素作用的影响？

One mechanism of atherosclerosis, at a cellular level, involves imbalances between cholesterol biosynthesis, uptake and efflux, as one important factor in this disease process. Reduction in cardiovascular risk by elevated HDL levels has been attributed to increased cholesterol efflux from peripherial tissues promoted by HDL for transport to the liver. An alternate view is that HDL may be simply a marker in persons with reduced cardiovascular risk. Current ideas about intracellular regulation of cholesterol synthesis have been formulated with little information about rate limiting processes, the cellular location of rate limiting steps and the relative rates of competing processes of cholesterol and fatty acid transport. Lipid distributions that are determined by thermodynamics have not been distinguished from those that exist as the result of kinetic barriers that prevent rapid lipid movement by passive transfer and cellular transport mechanisms. The objective is to define the kinetics and mechanisms of cellular uptake, intracellular transfer, and efflux of cholesterol and fatty acids in cultured murine 3T3L1 preadipocytes and human fibroblasts. A combination of digital fluorescence imaging and biochemical experiments are proposed to answer the following questions. 1. Is the role of fatty acid binding protein that of an intracellular buffer or a transport vesicle between membranes? 2. Which intracellular membranes have continuous lipid domains and which membranes create kinetic barriers to passive transfer of lipids? 3. Does redistribution of cholesterol between cellular compartments increase synthesis of 3-hydroxy-3-methyglutaryl-CoA reductase? 4. Is the control of transcription and translation of FABP and lipoprotein lipase influenced primarily by fatty acid flux or by hormone action?