The Role of ES-4 in the Hydrolysis of Cholesteryl Ester in Hepatic Cells

ES-4 在肝细胞胆固醇酯水解中的作用

• 批准号: 7404622
• 负责人: SAJESH PARATHATH
• 金额: $ 4.96万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-01 至 2010-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7404622
• 关键词: Agonist; Alzheimer' s Disease; Arteries; Atherosclerosis; Back; Basic Science; Bile Acids; Bile fluid; Binding Sites; Biological Assay; Cardiovascular Diseases; Cause of Death; Cell Line; Cell physiology; Cells; Cessation of life; Cholesterol; Cholesterol Esters; Cholesterol Homeostasis; Clinical; Coronary heart disease; Data; Disease; Environment; Equilibrium; Esterification; Functional disorder; Gene Expression; Genes; Goals; Hepatic; Hepatocyte; High Density Lipoproteins; Hormones; Hydrolase; Hydrolysis; Incidence; Lipids; Liver; Lysosomes; Measurement; Measures; Mediating; Membrane; Messenger RNA; Metabolism; Myocardial Infarction; Names; Nucleic Acid Regulatory Sequences; Pathway interactions; Play; Production; Protein Overexpression; Proteins; RXR; Radiolabeled; Rat Protein; Regulation; Reporter; Research; Role; Site; Small Interfering RNA; Standards of Weights and Measures; Steroids; Stroke; Technology; Testing; Transcript; Transcriptional Regulation; Transfection; United States; base; cholesterol control; esterase; lipid metabolism; mRNA Expression; prevent; promoter; protein expression; protein function; radiotracer; reconstitution; research study; response; reverse cholesterol transport; transcription factor; uptake

DESCRIPTION (provided by applicant): Cardiovascular disease in the United States is the leading cause of death (AHA). The long term objective of this research study is to understand basic cholesterol metabolism in order to prevent and combat diseases of cholesterol dysfunction such as atherosclerosis (heart attack, stroke), Newman Pick-C and Alzheimer's. The ability of cells to control cholesterol levels is a balance between the de novo synthesis and uptake of cholesterol versus secretion and efflux of cholesterol. Excess cholesterol in cells is toxic and is neutralized by esterification and stored as cholesteryl esters (CE). Hydrolysis of CE is necessary for the utilization of cholesterol for bile synthesis, hormone production, efflux of excess cholesterol and many other cellular functions. Our hypothesis is that, ES-4 is a hepatic neutral cholesteryl ester hydrolase (NCEH), and propose the following experiments. In our first aim we seek to define and understand the contribution of ES- 4 in CE hydrolysis. ES-4 protein will be suppressed or overexpressed using siRNA or transfection strategies. Using hepatic cells with various ES-4 levels, CE turnover, cholesterol mass, selective uptake and direct measurements of CE hydrolysis will be determined. The second aim of the study tests the hypothesis that the 5-kb region upstream of ES-4 transcriptional start site contains regulatory regions and these regions are necessary for the induction elicited by cholesterol and LXR agonist. This hypothesis will be tested using cholesterol loading/unloading, treatments with LXR agonist in conjunction with reporter constructs. Identifying the hepatic NCEH has significant basic science and clinical implications; it provides a new target for reducing VLDL/LDL CE production and would provide further understanding of the hepatic cholesterol cycle. Atherosclerosis (hardening of arteries due to excess cholesterol) mediated diseases (heart attack and strokes) are the leading cause of illness and death in the United States (NHLBI). This proposal examines ES-4, potentially a key player in modulating cholesterol levels/metabolism in the liver. Research in cholesterol metabolism is vital when considering that decreasing total cholesterol levels by 10% may result in an estimated 30 percent reduction in the incidence of coronary heart disease (CDC-2000).

描述（由申请人提供）：心血管疾病是美国的首要死因（AHA）。这项研究的长期目标是了解基本胆固醇代谢，以预防和对抗胆固醇功能障碍疾病，如动脉粥样硬化（心脏病、中风）、Newman Pick-C 和阿尔茨海默病。细胞控制胆固醇水平的能力是胆固醇的从头合成和摄取与胆固醇的分泌和流​​出之间的平衡。细胞中过量的胆固醇是有毒的，可以通过酯化作用中和并以胆固醇酯（CE）的形式储存。 CE 的水解对于利用胆固醇进行胆汁合成、激素生成、过量胆固醇流出和许多其他细胞功能是必需的。我们的假设是，ES-4是一种肝中性胆固醇酯水解酶(NCEH)，并提出以下实验。我们的首要目标是定义和理解 ES-4 在 CE 水解中的贡献。使用 siRNA 或转染策略将抑制或过度表达 ES-4 蛋白。使用具有不同 ES-4 水平的肝细胞，将确定 CE 周转、胆固醇质量、选择性摄取和 CE 水解的直接测量。该研究的第二个目的是测试以下假设：ES-4 转录起始位点上游的 5 kb 区域包含调节区域，并且这些区域对于胆固醇和 LXR 激动剂引发的诱导是必需的。该假设将通过胆固醇加载/卸载、LXR 激动剂与报告基因构建体的治疗进行测试。鉴定肝脏 NCEH 具有重要的基础科学和临床意义；它为减少 VLDL/LDL CE 的产生提供了一个新的目标，并将提供对肝脏胆固醇循环的进一步了解。动脉粥样硬化（胆固醇过多导致的动脉硬化）介导的疾病（心脏病和中风）是美国 (NHLBI) 疾病和死亡的主要原因。该提案研究了 ES-4，它可能是调节肝脏胆固醇水平/代谢的关键因素。考虑到总胆固醇水平降低 10% 可能导致冠心病发病率估计降低 30% (CDC-2000)，胆固醇代谢研究至关重要。