Metabolic flux in a model of reduced oxidative capacity

氧化能力降低模型中的代谢通量

• 批准号: 8279343
• 负责人: CHARLES ROBERT EVANS
• 金额: $ 14万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8279343
• 关键词: Animals; Basic Science; Biogenesis; Biological; Biological Assay; Branched-Chain Amino Acids; Caloric Restriction; Carbohydrates; Carbon; Characteristics; Chemicals; Citric Acid Cycle; Clinical Research; Collaborations; Consumption; Critical Pathways; Data; Defect; Development; Diabetes Mellitus; Discipline; Doctor of Philosophy; Dyslipidemias; Environment; Environmental Risk Factor; Equilibrium; Exercise; Faculty; Foundations; Future; Genetic; Genetic Predisposition to Disease; Glucose; Grant; Health; Housing; Human; In Vitro; Incubated; Individual; Insulin Resistance; Internal Medicine; Kinesiology; Label; Lead; Lipids; Location; Mass Fragmentography; Measurement; Measures; Medical; Mentors; Metabolic; Metabolic Diseases; Metabolic syndrome; Metabolism; Methodology; Methods; Michigan; Mitochondria; Modeling; Muscle; Muscle Contraction; Nature; Non-Insulin-Dependent Diabetes Mellitus; Nutrient; Obesity; Oxygen; Phenotype; Plasma; Play; Population; Positioning Attribute; Postdoctoral Fellow; Proteomics; Protocols documentation; Rattus; Recovery; Relative (related person); Research; Research Methodology; Research Personnel; Research Training; Rest; Role; Running; Schools; Science; Site; Skeletal Muscle; Societies; Solid; Stable Isotope Labeling; System; Techniques; Testing; Tissues; Tracer; Training; Translational Research; United States National Institutes of Health; Universities; Work; analytical method; assay development; biological systems; career; design; experience; glucose transport; graduate student; high risk; improved; in vivo; instrumentation; interest; member; metabolomics; method development; muscle metabolism; novel; nutrition; oxidation; professor; programs; protein metabolite; stable isotope

DESCRIPTION (provided by applicant): Candidate. Dr. Charles Evans is a junior faculty member at the University of Michigan in the department of Internal Medicine. Dr. Evans is trained as an analytical chemist, and has over 7 years of experience working with LC-MS and GC-MS instrumentation for quantitative analysis of metabolites, proteins and other biological molecules. Over the course of his career, Dr. Evans has been extensively involved in instrumentation design and optimization, assay and method development, proteomic and metabolomic studies, and mass isotopomer analysis for metabolic flux analysis. Dr. Evans has maintained a career-long interest in the biological systems which he has frequently studied as an application for the analytical methodology he has developed. Through the research and training proposed in this application, Dr. Evans seeks to become established as an independent investigator in the field of metabolism; in this position he will develop and use novel analytical methods to tackle major issues in the field of metabolic disease. Environment. The University of Michigan is an excellent location to implement the training and research proposed in this application due to the great breadth of basic and clinical research it houses spanning a wide variety of biomedical disciplines. The candidate's mentor, Dr. Charles Burant, is Professor of Metabolism in the Department of Internal Medicine at Michigan. Dr. Burant has extensive experience in basic and translational research in nutrition and metabolic diseases with a career-long interest in the relationship between nutrients and the development of insulin resistance. Dr. Burant is PI on 3 NIH grants and has previously mentored numerous Ph.D. graduate students, postdoctoral fellows, and junior faculty. The co- mentor, Dr. Gregory Cartee, is Professor in the School of Kinesiology. His research is focused on skeletal muscle metabolism especially related to the modulation of glucose transport by exercise and calorie restriction. Dr. Cartee's lab uses in vitro muscle contraction in studies as a model for exercise, and will support Dr. Evans' training in these protocols. Research. In humans, oxidative capacity is a well-established measure of metabolic health. Low oxidative capacity is prevalent in people with the metabolic syndrome, obesity and type 2 diabetes. As the ultimate site of oxygen reduction, mitochondria are key to overall oxidative capacity. Diminished mitochondrial metabolism is seen in populations at high risk for type 2 diabetes and obesity, suggesting a genetic component to oxidative capacity. Reduced mitochondrial mass along with intrinsic changes in carbohydrate and lipid oxidation have been described in obesity and diabetes. However, other evidence suggests that acquired changes in mitochondrial metabolism could lead to many of the defects described in muscle metabolism. Moreover, alterations in mitochondria could be both genetically determined and amplified by environmental factors. What is still unclear is the specific nature of the alterations in metabolism that occur as a result of the genetic predisposition and environmental challenges. To help understand the causes of the metabolic syndrome, a line of low capacity runner (LCR) and high capacity runner (HCR) rats developed by a program of artificial selection for exercise endurance will be investigated. Many of the phenotypic characteristics of the LCR animals parallel those seen in humans with metabolic syndrome, including relative obesity, dyslipidemia as well as reduced oxidative capacity, mitochondrial biogenesis rates, and mitochondrial mass compared to the HCR line. In these studies, in vivo and in vitro metabolomics will be used to measure steady state levels and flux of central carbon metabolism to fully understand the mechanisms that underlie the enhanced oxidative capacity of the HCR compared to the LCR rats. We hypothesize that differences in the balance between anaplerotic and cataplerotic flux of TCA cycle intermediates are fundamental to the difference in oxidative capacity of the LCR and HCR animals and are central to the connection between low oxidative capacity and the metabolic syndrome. To test this hypothesis, quantitative targeted metabolomic assays will be performed in skeletal muscle and plasma of LCR and HCR running rats at rest and during exercise. Next, an in vitro contraction protocol will be established to probe the effects of selected metabolites on exercise endurance of skeletal muscle of LCR and HCR rats. Finally, metabolic flux will be quantified in skeletal muscle from LCR and HCR rats using stable isotope tracers. When complete, these studies will help illuminate the alterations in fuel utilization in a genetically defined model of obesity and the metabolic syndrome. The studies will also provide improved techniques for assessment of metabolic flux in mammalian tissue which will be of benefit to a wide range of future studies in both animals and humans.

描述（由申请人提供）：候选人。查尔斯·埃文斯博士是密歇根大学内科系的一名初级教员。Evans博士是一名分析化学家，拥有超过7年的LC-MS和GC-MS仪器定量分析代谢物、蛋白质和其他生物分子的经验。在他的职业生涯中，Evans博士广泛参与了仪器设计和优化、测定和方法开发、蛋白质组学和代谢组学研究以及代谢通量分析的质量同位素异构体分析。埃文斯博士在职业生涯中一直对生物系统保持着浓厚的兴趣，他经常将其作为他开发的分析方法的应用进行研究。通过本申请中提出的研究和培训，Evans博士寻求成为代谢领域的独立研究者;在这个职位上，他将开发和使用新的分析方法来解决代谢疾病领域的重大问题。环境密歇根大学是实施本申请中提出的培训和研究的绝佳地点，因为它拥有广泛的基础和临床研究，涵盖各种生物医学学科。候选人的导师查尔斯·伯兰特博士是密歇根州内科学系的代谢学教授。Burant博士在营养和代谢疾病的基础和转化研究方面拥有丰富的经验，对营养素与胰岛素抵抗发展之间的关系有着长期的兴趣。Burant博士是3个NIH赠款的PI，此前曾指导过许多博士。研究生、博士后和初级教员。共同导师格雷戈里·卡蒂博士是运动机能学院的教授。他的研究重点是骨骼肌代谢，特别是与运动和热量限制对葡萄糖转运的调节有关。Cartee博士的实验室在研究中使用体外肌肉收缩作为运动模型，并将支持Evans博士在这些方案中的培训。Research.在人类中，氧化能力是代谢健康的公认指标。低氧化能力在代谢综合征、肥胖和2型糖尿病患者中普遍存在。作为氧还原的最终位点，线粒体是整体氧化能力的关键。在2型糖尿病和肥胖症高危人群中观察到线粒体代谢减少，表明氧化能力的遗传成分。线粒体质量的减少沿着碳水化合物和脂质氧化的内在变化已经在肥胖和糖尿病中被描述。然而，其他证据表明，线粒体代谢的获得性变化可能导致肌肉代谢中描述的许多缺陷。此外，线粒体的改变既可以由遗传决定，也可以由环境因素放大。目前尚不清楚的是，由于遗传易感性和环境挑战而发生的代谢变化的具体性质。为了帮助理解代谢综合征的原因，将研究通过运动耐力人工选择程序开发的一系列低能力跑步者（LCR）和高能力跑步者（HCR）大鼠。LCR动物的许多表型特征与患有代谢综合征的人类中观察到的那些相似，包括相对肥胖、血脂异常以及与HCR系相比降低的氧化能力、线粒体生物合成速率和线粒体质量。在这些研究中，将使用体内和体外代谢组学来测量中心碳代谢的稳态水平和通量，以充分了解与LCR大鼠相比，HCR大鼠氧化能力增强的机制。我们假设，在TCA循环中间体的回补和cataplerotic流量之间的平衡的差异是根本的LCR和HCR动物的氧化能力的差异，是低氧化能力和代谢综合征之间的连接的核心。为了检验这一假设，将在休息和运动期间对LCR和HCR跑步大鼠的骨骼肌和血浆进行定量靶向代谢组学测定。接下来，将建立体外收缩方案以探索所选代谢物对LCR和HCR大鼠骨骼肌运动耐力的影响。最后，将使用稳定同位素示踪剂定量LCR和HCR大鼠骨骼肌中的代谢通量。完成后，这些研究将有助于阐明在遗传定义的肥胖和代谢综合征模型中燃料利用的变化。这些研究还将为评估哺乳动物组织中的代谢通量提供改进的技术，这将有利于未来在动物和人类中进行的广泛研究。