Role of cholesteryl ester transfer protein in cellular lipid homeostasis

胆固醇酯转移蛋白在细胞脂质稳态中的作用

• 批准号: 8386903
• 负责人: RICHARD E MORTON
• 金额: $ 37.37万
• 依托单位: CLEVELAND CLINIC LERNER COM-CWRU
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-25 至 2014-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8386903
• 关键词: Acute; Adipocytes; Adipose tissue; Affect; Alternative Splicing; Amino Acids; Applications Grants; Atherosclerosis; Biochemical; Biological Process; Cell Culture Techniques; Cell physiology; Cell secretion; Cells; Cholesterol; Cholesterol Ester Transfer Proteins; Cholesterol Esters; Cholesterol Homeostasis; Cytoplasm; Data; Deposition; Development; Disease; Endoplasmic Reticulum; Enterocytes; Exons; Extrahepatic; Failure; Fatty acid glycerol esters; Generations; Genetic; Hamsters; Heart Diseases; Hepatocyte; Homeostasis; Hormones; In Vitro; Inflammation; Inflammatory Response; Insulin Resistance; Intestines; Kinetics; Learning; Length; Link; Lipids; Lipoproteins; Liver; Measures; Mediating; Messenger RNA; Metabolic; Metabolism; Microscopy; Microsomes; Mining; Molecular; Movement; Organelles; Pathway interactions; Pharmaceutical Preparations; Plasma; Play; Process; Protein Biosynthesis; Protein Deficiency; Protein Inhibition; Protein Isoforms; Protein Overexpression; Proteins; Regulation; Role; Site; Structure; Techniques; Testing; Tissues; Triglycerides; Variant; absorption; adipokines; atherogenesis; cell type; density; glucose metabolism; in vivo; insight; lipid metabolism; lipid transport; novel; protein expression; protein metabolism; protein structure; protein transport; sugar

PROJECT SUMMARY/ABSTRACT Cholesteryl ester transfer protein (CETP) exchanges cholesteryl ester (CE) and triglyceride (TG) between lipoproteins and is well recognized as a regulator of plasma lipoprotein metabolism. CETP also resides inside cells where two isoforms exist: full-length (FL) and exon 9 (E9)-deleted CETP. The function of CETP inside cells is not understood, but it is clearly essential since inhibiting CETP biosynthesis in adipocytes impairs lipid storage. We postulate this occurs because intracellular CETP is required for CE and TG transport from their site of synthesis to their site of storage. To test this general hypothesis, we propose three specific aims. Aim 1 - Determine the CETP isoform(s) that promote cellular lipid storage, and define the structural features of CETP that are essential to its intracellular function. This aim tests the hypothesis that E9-deleted CETP facilitates intracellular lipid transport directly or by interacting with FL CETP, and also examines how this cellular activity depends on CETP structure. Aim 2 - Define the role of CETP in cellular lipid metabolism. To unravel the mechanisms by which CETP deficiency disrupts cellular lipid metabolism, this aim quantifies metabolic alterations and defines changes in lipid droplet formation that occur when CETP isoform expression is altered. Aim 3 - Define the role of CETP in the formation and utilization of lipid storage droplets in lipoprotein- synthesizing cells. Consistent with preliminary studies, we propose that in lipoprotein-synthesizing cells CETP assists in both lipid droplet formation and the reverse transport of stored lipids to microsomes for lipoprotein assembly. Genetic and adenoviral approaches will alter expression of FL and/or E9-deleted CETPs in SW872 adipocytes, Caco-2 intestinal enterocytes, and in hamster. The consequences of these molecular manipulations on lipid synthesis, interorganelle lipid transport, lipid droplet formation and lipoprotein assembly will be studied through biochemical and microscopy techniques. These studies will describe a novel function for CETP and advance our understanding of cellular lipid transport and storage mechanisms. Lipid storage in adipocytes is linked to their secretion of hormones that regulate glucose and lipid metabolism, which directly affect processes such as inflammation and atherogenesis.

项目摘要/摘要 胆固醇酯转移蛋白（CETP）交换胆固醇酯（CE）和甘油三酸酯（TG）（TG） 脂蛋白，被广泛认为是血浆脂蛋白代谢的调节剂。 CETP也位于内部 存在两个同工型的细胞：全长（FL）和外显子9（E9）删除CETP。内部CETP的功能 细胞尚不清楚，但显然是必不可少的，因为抑制脂肪细胞中的CETP生物合成会损害脂质 贮存。我们认为这是因为CE和TG从其运输中需要的细胞内CETP 合成的位置到其存储地点。为了检验这一普遍的假设，我们提出了三个具体目标。目标1 - 确定促进细胞脂质储存的CETP同工型，并定义CETP的结构特征 对于其细胞内功能至关重要。这个目的检验了E9删除的CETP促进的假设 细胞内脂质转运直接或与FL CETP相互作用，还研究了这种细胞活性 取决于CETP结构。 AIM 2-定义CETP在细胞脂质代谢中的作用。解开 CETP缺乏破坏细胞脂质代谢的机制，这一目标量化了代谢 改变并定义了CETP同工型表达改变时发生的脂质液滴形成的变化。 AIM 3-定义CETP在脂蛋白中脂质储存液滴形成和利用中的作用 合成细胞。与初步研究一致，我们建议在脂蛋白合成细胞中CETP 辅助脂质液滴形成和储存的脂质与微粒体的反向转运 集会。遗传和腺病毒方法将改变SW872中FL和/或E9删除CETP的表达 脂肪细胞，Caco-2肠肠上皮细胞和仓鼠。这些分子的后果 脂质合成，脂质脂质转运，脂质液滴形成和脂蛋白组装的操作 将通过生化和显微镜技术研究。这些研究将描述一个新的功能 CETP并提高我们对细胞脂质转运和存储机制的理解。脂质存储进 脂肪细胞与调节葡萄糖和脂质代谢的激素分泌有关 影响炎症和动脉粥样硬化等过程。