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

• 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
• 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

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.

项目摘要 果糖消耗不仅是发展非酒精性脂肪肝病（NAFLD）的主要危险因素， 但还促进了人和啮齿动物的高胆固醇血症和动脉粥样硬化。识别 将NAFLD与心血管疾病（CVD）联系起来的机制仍然很差。该提案重点是 在确定饮食果糖对胆固醇合成和代谢的影响时。使用鼠标 糖粉消耗的模型，候选人表明果糖代谢增加 柠檬酸盐，乙酰辅酶A和肝胆固醇水平。此外，候选人证明果糖降低 线粒体脂肪酸转运蛋白的肉碱棕榈转移酶1A（CPT1A）的蛋白质表达。 此外，有条件的CPT1A基因敲除小鼠表现出与喂养果糖相似的脂质扰动。所以， AIM 1利用双重稳定的同位素技术与NMR和质谱法相结合来量化胆固醇 合成和果糖衍生的碳富集到男性和女性的胆固醇生物合成途径中 老鼠。小鼠的肝脏将用于乙酰 - 蛋白质组学来描述与果糖联系的潜在机制 胆固醇生物合成。 AIM 2确定CPT1A的转录调节如何改变果糖诱导的 抑制脂肪酸氧化并使用体外和体内的胆固醇合成增强 方法。此目的的目的是揭示CPT1A以前未认识到的作用 响应于果糖的脂质信号途径（脂肪酸氧化和胆固醇合成）的调节。 这些目标的完成将产生机械洞察力，将饮食糖代谢与高胆固醇血症联系起来。 拟议的研究的新颖性是综合的双重同位素方法与 测量胆固醇合成和果糖衍生的碳富集到固醇的分析技术 同一动物队列中的合成途径。此外，拟议的研究揭示了一些创新的 尚未探索的机制，包括胆固醇合成酶的乙酰化和调节 通过转录机制的CPT1A。代谢组学核心之间的强有力合作 肯塔基大学，巴克衰老研究所的质谱核心和科学研究所 咨询委员会成员确保候选人成功完成拟议的研究。这 一项职业发展计划对研究表示赞赏，候选人将学习新的实验性 稳定同位素代谢组学中的方法论，通过参加研讨会和 会议，并发展他的沟通技巧，以便他准备成为一名独立的调查员。 这项K01奖将使他能够实现建立资金充足的实验室学习的长期目标 心脏代谢疾病的饮食机制。