Elucidating Molecular Mechanisms Linking Fructose to Cholesterol Metabolism

阐明果糖与胆固醇代谢之间的分子机制

基本信息

批准号：
10542839
负责人：
Robert Nathaniel Helsley
金额：
$ 10.05万
依托单位：
UNIVERSITY OF KENTUCKY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-01-01 至 2026-12-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10542839
关键词：
Acetyl Coenzyme A Acetylation Advisory Committees Affect Aging Animals Atherosclerosis Biological Assay Biopsy Carbon Cardiometabolic Disease Cardiovascular Diseases Carnitine Palmitoyltransferase I Catabolism Cells Cholesterol Cholesterol Homeostasis Citrates Clustered Regularly Interspaced Short Palindromic Repeats Collaborations Committee Members Communication Consumption Coupled Data Development Development Plans Dietary Sugars Dyslipidemias Educational workshop Ensure Enzymes Epigenetic Process Exhibits Fat-Restricted Diet Female Food Fructose Funding Genes Genetic Transcription Goals Hepatic Hepatocyte Human Image Impairment In Vitro Isotope Labeling Kentucky Ketohexokinase Knock-out Knockout Mice Laboratory Study Learning Link Lipids Liver LoxP-flanked allele Lysine Mass Spectrum Analysis Measures Mediating Mentored Research Scientist Development Award Mentors Messenger RNA Metabolic Metabolic Diseases Metabolism Methodology Mitochondria Modification Molecular Monosaccharides Mus Mutagenesis Non-Insulin-Dependent Diabetes Mellitus Nuclear Obesity Obesity associated liver disease Observational Study PPAR alpha Pathway interactions Patients Persons Phenotype Phosphorylation Prevalence Process Production Proteins Proteomics Radiolabeled Reducing diet Regulation Reporter Research Research Institute Research Personnel Risk Factors Rodent Role SRE-2 binding protein Serum Signal Pathway Signal Transduction Small Interfering RNA Stable Isotope Labeling Sterols Techniques Testing Tracer Training Transcriptional Regulation Triglycerides Universities Water Woman acylcarnitine cardiometabolic risk cardiovascular disorder risk career development cholesterol biosynthesis cohort dietary fast protein liquid chromatography fatty acid oxidation fatty acid-transport protein feeding genetic variant hypercholesterolemia in vivo innovation insight knock-down lipid biosynthesis liquid chromatography mass spectrometry male men metabolomics mortality mouse model non-alcoholic fatty liver disease novel therapeutics nutrient metabolism overexpression protein expression response skills stable isotope sugar sweetened beverage symposium

项目摘要

PROJECT SUMMARY Fructose consumption is not only a major risk factor for development of non-alcoholic fatty liver disease (NAFLD), but also promotes hypercholesterolemia and atherosclerosis in humans and rodents. Identification of the mechanisms linking NAFLD to cardiovascular disease (CVD) remains poorly understand. This proposal focuses on identifying the influence dietary fructose has on synthesis and metabolism of cholesterol. Using a mouse model of sugar-sweetened beverage consumption, the candidate shows that fructose metabolism increases citrate, acetyl-CoA, and hepatic cholesterol levels. In addition, the candidate demonstrates fructose decreases the protein expression of carnitine palmitoyltransferase 1a (Cpt1a), a mitochondrial fatty acid transport protein. Moreover, conditional CPT1a knockout mice exhibit similar lipid perturbations as mice fed fructose. Therefore, aim 1 utilizes dual stable isotope techniques coupled with NMR and mass spectrometry to quantify cholesterol synthesis and fructose-derived carbon enrichment into the cholesterol biosynthetic pathway in male and female mice. Livers from the mice will be used for acetyl-proteomics to delineate potential mechanisms linking fructose to cholesterol biosynthesis. Aim 2 determines how transcriptional regulation of Cpt1a alters fructose-induced suppression of fatty acid oxidation and enhanced cholesterol synthesis using both in-vitro and in-vivo approaches. The purpose of this aim is to uncover a previous unrecognized role of Cpt1a in coordinating the regulation of both lipid-signaling pathways (fatty acid oxidation and cholesterol synthesis) in response to fructose. Completion of these aims will yield mechanistic insight linking dietary sugar metabolism to hypercholesterolemia. The novelty of the proposed research is the comprehensive dual-stable isotope approach in conjunction with analytical techniques to measure cholesterol synthesis and fructose-derived carbon enrichment into the sterol synthesis pathway in the same cohort of animals. In addition, the proposed research reveals several innovative mechanisms that have yet to be explored, including acetylation of cholesterol synthesis enzymes and regulation of Cpt1a through transcriptional mechanisms. Strong collaborations among the Metabolomics Core at the University of Kentucky, Mass Spectrometry Core at the Buck Institute for Research on Aging, and scientific advisory committee members ensure successful completion of the proposed research by the candidate. This research is complimented by a career development plan in which the candidate will learn new experimental methodology in stable isotope metabolomics, broaden his scientific network through attending workshops and conferences, and develop his communication skills so that he is poised to become an independent investigator. This K01 award will allow him to reach his long-term goals of establishing a well-funded laboratory studying dietary mechanisms in cardiometabolic disease.

项目概要果糖摄入不仅是发生非酒精性脂肪肝（NAFLD）的主要危险因素，但也会促进人类和啮齿动物的高胆固醇血症和动脉粥样硬化。鉴定 NAFLD 与心血管疾病 (CVD) 之间的联系机制仍知之甚少。该提案重点确定膳食果糖对胆固醇合成和代谢的影响。使用鼠标含糖饮料消费模型中，候选者表明果糖代谢增加柠檬酸盐、乙酰辅酶A和肝胆固醇水平。此外，候选人表现出果糖减少肉毒碱棕榈酰转移酶 1a (Cpt1a)（一种线粒体脂肪酸转运蛋白）的蛋白表达。此外，条件性 CPT1a 敲除小鼠表现出与喂食果糖的小鼠相似的脂质扰动。所以，目标 1 利用双稳定同位素技术结合核磁共振和质谱来量化胆固醇男性和女性胆固醇生物合成途径的合成和果糖衍生碳富集老鼠。小鼠肝脏将用于乙酰蛋白质组学，以描绘连接果糖的潜在机制胆固醇生物合成。目标 2 确定 Cpt1a 的转录调控如何改变果糖诱导的利用体外和体内抑制脂肪酸氧化并增强胆固醇合成接近。这一目标的目的是揭示 Cpt1a 在协调响应果糖调节脂质信号通路（脂肪酸氧化和胆固醇合成）。完成这些目标将产生将膳食糖代谢与高胆固醇血症联系起来的机制见解。该研究的新颖之处在于综合双稳定同位素方法测量胆固醇合成和果糖衍生的碳富集到甾醇的分析技术同一组动物中的合成途径。此外，拟议的研究揭示了一些创新尚未探索的机制，包括胆固醇合成酶的乙酰化和调节 Cpt1a 通过转录机制。代谢组学核心之间的密切合作肯塔基大学巴克衰老研究所的质谱核心和科学咨询委员会成员确保候选人成功完成拟议的研究。这研究得到职业发展计划的补充，候选人将在其中学习新的实验稳定同位素代谢组学方法论，通过参加研讨会和扩大他的科学网络会议，并培养他的沟通技巧，使他做好成为一名独立调查员的准备。这个 K01 奖项将使他能够实现建立资金充足的实验室研究的长期目标心脏代谢疾病的饮食机制。