Phospholipid-Mediated Metabolic Control in the Pathogenesis of NAFLD

NAFLD 发病机制中磷脂介导的代谢控制

基本信息

批准号：
10589147
负责人：
DAVID E. COHEN
金额：
$ 49.51万
依托单位：
BRIGHAM AND WOMEN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-12-23 至 2025-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10589147
关键词：
Acyl Coenzyme A Address Binding Binding Proteins Biological Models Carbon Cells Characteristics CoASH Data Disease Elements Enzymes Esterification Esters Event Fasting Fatty Acids Fatty Liver Fatty acid glycerol esters Glean Glucose Glycerol Goals Grant Head Health Hepatic Hepatocyte High Fat Diet Homeostasis In Vitro Inflammation Insulin Resistance Intake Intervention Intracellular Membranes Lecithin Length Light Link Lipids Liver Mediating Medication Management Membrane Membrane Fluidity Metabolic Metabolic Control Metabolic Pathway Metabolism Mission Mitochondria Molecular Molecular Conformation Mus Muscle Fibers Mutation Analysis National Institute of Diabetes and Digestive and Kidney Diseases Nonesterified Fatty Acids Nutrient Nutritional Obesity Outcome Study Overnutrition Pathogenesis Pathogenicity Pathway interactions Phospholipids Phosphorylcholine Physiological Proteins Public Health Regulation Research Research Proposals Resistance Saturated Fatty Acids Skeletal Muscle Specificity Stress Testing Therapeutic Tissues Translating Variant biophysical techniques blood glucose regulation design endoplasmic reticulum stress experimental study extracellular vesicles fatty acid metabolism fatty acid oxidation feeding glucose metabolism insight insulin sensitivity insulin signaling lipid metabolism member mouse model muscle metabolism new therapeutic target non-alcoholic fatty liver disease novel nutrient metabolism pharmacologic phosphatidylcholine transfer protein protein function response sensor skeletal muscle metabolism small molecule small molecule inhibitor vesicular release

项目摘要

PROJECT SUMMARY/ABSTRACT Altered regulation of lipid and glucose homeostasis, most often in the setting of insulin resistance and obesity, is central to the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Because current management options remain limited, the discovery of new metabolic pathways will serve to identify novel opportunities for pharmacologic intervention. This research proposal addresses the unanswered question of whether membrane phospholipids regulate nutrient homeostasis. Our long-term goal is to understand how phospholipid-mediated metabolic control can be leveraged for therapeutic purposes. The objective of this research is to determine the molecular mechanisms whereby sensing of membrane phosphatidylcholines by phosphatidylcholine transfer protein (PC-TP) is translated into metabolic control by thioesterase superfamily member 2 (Them2), a mitochondria-associated long chain acyl-CoA thioesterase. The central hypothesis is that key regulatory events occur in the skeletal muscle when PC-TP binds specific membrane phosphatidylcholine molecular species and then activates Them2. The rationale is that regulation of skeletal muscle metabolism by Them2 should yield new insights into hepatic insulin resistance and steatosis. Guided by extensive preliminary data, the central hypothesis will be tested in three specific aims: 1) To demonstrate that Them2 controls lipid and glucose metabolism in skeletal muscle; 2) To define mechanisms whereby Them2 in skeletal muscle promotes hepatic steatosis; and 3) To elucidate the molecular determinants of Them2 activity and regulation by PC-TP. In Aim 1, mouse models will be used to determine mechanisms whereby Them2 regulates fatty acid and glucose metabolism in skeletal muscle and promotes insulin resistance in response to overnutrition. Cell autonomous functions of Them2 will be gleaned from systematic studies in cultured myotubes. Aim 2 will establish the mechanisms in high fat fed mice whereby Them2 in skeletal muscle promotes hepatic insulin resistance and steatosis. Cultured hepatocytes will be used to determine whether Them2-dependent myokines or extracellular vesicles released from myotubes control hepatic lipid and glucose metabolism. Aim 3 will determine structural characteristics that enable Them2 to respond to changes in membrane phosphatidylcholine composition. Small molecules designed to bind and inhibit Them2 will be used as probes to characterize Them2 function and interactions with PC-TP using an array of biophysical techniques. Phosphatidylcholine-dependent conformational changes in PC-TP will be leveraged to identify specific motifs that are critical for Them2 activity and stability. The interacting domains of Them2 and PC-TP will be identified and confirmed by mutational analyses. Overall, this proposal will elucidate new mechanisms of phospholipid-mediated metabolic regulation that control hepatic nutrient metabolism, which is significant because the fatty acyl composition of membrane phosphatidylcholines varies in health and disease. These studies are expected to establish Them2 as a tractable target for the management of NAFLD.

项目概要/摘要改变脂质和葡萄糖稳态的调节，最常见的是在胰岛素抵抗和肥胖的情况下，是非酒精性脂肪性肝病 (NAFLD) 发病机制的核心。因为现在的管理层选择仍然有限，新代谢途径的发现将有助于确定新的机会药物干预。这项研究提案解决了膜是否磷脂调节营养稳态。我们的长期目标是了解磷脂如何介导代谢控制可用于治疗目的。这项研究的目的是确定通过磷脂酰胆碱转移传感膜磷脂酰胆碱的分子机制蛋白 (PC-TP) 被硫酯酶超家族成员 2 (Them2) 翻译成代谢控制，硫酯酶超家族成员 2 线粒体相关的长链酰基辅酶A硫酯酶。中心假设是关键监管事件当 PC-TP 结合特定的膜磷脂酰胆碱分子种类时，会在骨骼肌中发生然后激活Them2。基本原理是 Them2 对骨骼肌代谢的调节应该产生对肝脏胰岛素抵抗和脂肪变性的新见解。在大量初步数据的指导下，中央假设将在三个具体目标上进行检验：1）证明 Them2 控制脂质和葡萄糖骨骼肌的新陈代谢； 2) 明确骨骼肌中 Them2 促进肝功能的机制脂肪变性； 3) 阐明 Them2 活性的分子决定因素以及 PC-TP 的调节。在目标 1 中，小鼠模型将用于确定 Them2 调节脂肪酸和葡萄糖的机制骨骼肌的新陈代谢，并促进胰岛素抵抗以应对营养过剩。细胞自治 Them2 的功能将从培养肌管的系统研究中收集。目标 2 将建立高脂肪喂养小鼠的机制，骨骼肌中的 Them2 促进肝脏胰岛素抵抗脂肪变性。培养的肝细胞将用于确定 Them2 依赖性肌因子还是细胞外肌因子从肌管释放的囊泡控制肝脏脂质和葡萄糖代谢。目标 3 将确定结构这些特性使 Them2 能够对膜磷脂酰胆碱成分的变化做出反应。小的设计用于结合和抑制 Them2 的分子将用作探针来表征 Them2 功能和使用一系列生物物理技术与 PC-TP 相互作用。磷脂酰胆碱依赖性 PC-TP 的构象变化将用于识别对 Them2 活性至关重要的特定基序和稳定性。 Them2 和 PC-TP 的相互作用域将通过突变来鉴定和确认分析。总体而言，该提案将阐明磷脂介导的代谢调节的新机制控制肝脏营养代谢，这很重要，因为膜的脂肪酰基成分磷脂酰胆碱因健康和疾病而异。这些研究预计将 Them2 确立为 NAFLD 管理的易处理目标。