Translational investigation of abnormal fat metabolism in mitochondrial disease

线粒体疾病中脂肪代谢异常的转化研究

• 批准号: 9025785
• 负责人: SHANA ERIN MCCORMACK
• 金额: $ 17.29万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2018-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9025785
• 关键词: Acids; Adolescent; Adult; Antimycin A; Area; Award; Carbohydrates; Cell Line; Cell Respiration; Cell model; Cells; Cellular Metabolic Process; Child; Childhood; Citrates; Citric Acid Cycle; Clinical; Collaborations; Complement; Complex; Diabetes Mellitus; Diet; Disease; Dyslipidemias; Electron Transport Complex III; Endocrine; Endocrine System Diseases; Endocrinology; Energy-Generating Resources; Equilibrium; Etiology; Euglycemic Clamping; Faculty; Fatty Acids; Fatty acid glycerol esters; Functional disorder; Funding; Future; Genetic; Glucose; Glucose Clamp; Glutamine; Goals; Health; HepG2; High Density Lipoprotein Cholesterol; High Density Lipoproteins; Human; Human Cell Line; Hypertriglyceridemia; Imaging technology; Impairment; In Vitro; Incidence; Individual; Insulin; Insulin Resistance; Investigation; Journals; Knowledge; Lead; Learning; Lipids; Lipolysis; Liver; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Mass Spectrum Analysis; Medicine; Mentored Patient-Oriented Research Career Development Award; Mentors; Metabolic; Metabolic Diseases; Metabolic Pathway; Metabolism; Methodology; Mitochondria; Mitochondrial DNA; Mitochondrial Diseases; Modeling; Muscle; Mutation; NADH; Nicotinamide adenine dinucleotide; Non-Insulin-Dependent Diabetes Mellitus; Nuclear; Nutrient; Obesity; Oxidation-Reduction; Pathogenesis; Pathway interactions; Patients; Peer Review; Performance; Phenotype; Physicians; Physiological; Plasma; Population; Proteins; Public Health; Publishing; Reporting; Research; Research Infrastructure; Research Personnel; Resources; Respiratory Chain; Rhabdomyosarcoma; Risk; Role; Rotenone; Scientist; Secure; Skeletal Muscle; Solid; Source; Techniques; Testing; Therapeutic Intervention; Tissues; Tracer; Training; Training and Infrastructure; Triglycerides; Work; alpha ketoglutarate; base; career; career development; clinical care; cohort; design; diagnosis evaluation; energy balance; epigenomics; fatty acid oxidation; genetic disorder diagnosis; glucose production; glucose uptake; healthy volunteer; hepatoma cell; improved; in vivo; inhibitor/antagonist; insight; insulin sensitivity; lipid biosynthesis; lipid metabolism; meetings; member; metabolic phenotype; mitochondrial DNA mutation; mitochondrial dysfunction; non-diabetic; novel; nutrition; obesity in children; oxidation; patient oriented research; research study; response; skills; spectroscopic imaging; stable isotope; treatment strategy; tumor

 DESCRIPTION (provided by applicant): Pediatric obesity is an increasingly prevalent public health crisis that contributes to the rising global burden of type 2 diabetes. Obesity and diabetes, at the most fundamental level, represent disorders of energy balance. In obesity, energy storage exceeds utilization. In diabetes, available energy sources (glucose) are improperly used. Energy balance is sensed and controlled by the cell's mitochondria. Focused study of key mitochondrial pathways that are disrupted in disorders of energy balance will improve our understanding of endocrine complications of obesity, and may lead to new treatment approaches. A particularly relevant group to study to better understand the intersection of mitochondrial dysfunction and obesity-related endocrine disorders are patients with primary (genetic) mitochondrial diseases, who develop similar profiles of disordered fat metabolism even in the absence of overt diabetes or obesity, including hypertriglyceridemia and low high density lipoprotein (HDL) cholesterol. Through the proposed K23 Mentored Patient-Oriented Research Career Development Award, I will investigate the mechanistic basis and metabolic consequences of disrupted lipid metabolism in primary mitochondrial disease. The proposed studies will directly support my main career goals as I progress towards independence as a physician-scientist. These goals are to [1] advance our understanding of the role of mitochondria, energy balance, and metabolism in pediatric endocrine disease, and to [2] apply physiologic insights to develop rational, targeted, and effective therapeutic interventions to improve the health of patients with endocrine and metabolic diseases. These goals will be advanced during the K23 award period through the pursuit of 3 overarching training and career development objectives: First, I will acquire didactic and technical knowledge critical for the successful design and execution of patient-oriented research in this area. During the three years of the proposed award, I will learn to perform valuable in vitro and in vivo phenotyping techniques under the guidance of content-area expert advisors. Specifically, in vitro utilization of stable isotopes and manipulation of "cybrid" cell lnes, and in vivo performance of hyperinsulinemic-euglycemic clamp studies complemented by stable isotope studies will be invaluable skills. Second, I will accrue new expertise in the diagnosis, evaluation, and management of patients with primary mitochondrial disease. This population has a large, unmet clinical need for better-informed subspecialists in all areas, particularly including Pediatric Endocrinology. They further provide a focused opportunity to study the role of the mitochondrial dysfunction in common endocrine disorders. This goal will be met by providing clinical care for mitochondrial disease patients and performing both in vitro and in vivo research investigations to characterize the extent and basis of their dyslipidemia. Third, I will transition to independence as an investigator. I will continue to work and develop productive multi-disciplinary collaborations with the expert members of my mentoring committee. I will gain necessary expertise to transition to independence through completing of the proposed studies, presenting at national meetings, publishing in peer-reviewed journals, and securing subsequent R01 funding.. Performing this proposed project will help accomplish these goals. These experiments will test our central hypotheses that: [1] altered cellular NAD+/NADH redox balance in the setting of primary respiratory chain (RC) impairment leads to increased de novo lipid synthesis from alpha-ketoglutarate (αKG)- derived citrate and decreased fatty acid oxidation (FAO) capacity and [2] the resulting excess accumulation of lipids in skeletal muscle causes skeletal muscle insulin resistance. To test these hypotheses, we will employ both in vitro and in vivo approaches. We will use in vitro human cell line models to test whether RC inhibition quantifiably increases de novo lipogenesis via "reversed" citric acid cycle flow. A complementary in vivo approach will look for evidence of increased de novo lipogenesis, muscle lipid accumulation, and decreased insulin sensitivity in (i) adults with primary RC disease, with hypertriglyceridemia but without DM. We will compare this group to (ii) appropriately matched healthy individuals. To assess whether "reversed" citric acid cycle flux might also contribute to hypertriglyceridemia in "typical" non-diabetic obese individuals, we will also study (iii) appropriately matched obese individuals. In future, we can extend aspects of these studies to the pediatric population. This project leverages many unique resources at CHOP and Penn. First, my primary mentor, Dr. Marni J. Falk, has a large and well-phenotyped cohort of patients with clear genetic diagnoses of mitochondrial disease that provides a ready source of ideal subjects, and tissues, in which to perform the proposed studies. CHOP's Center for Mitochondrial and Epigenomic Medicine (CMEM) further offers world-class infrastructure in this field. Penn's Diabetes Research Center (DRC) has faculty and core expertise already in place to assure successful completion of detailed metabolic phenotyping studies, where key faculty are comentors. Our collaborators at Penn's Center for Advanced Magnetic Resonance Imaging and Spectroscopy (CAMRIS) have developed metabolic imaging technologies to estimate and localize mitochondrial function. This work will allow me to establish a solid background from which to pursue future, independently-funded studies on the role of mitochondria, energy balance, and metabolism in pediatric endocrine disease

 描述（由申请人提供）： 儿童肥胖是一种日益普遍的公共卫生危机，导致全球 2 型糖尿病负担不断增加。从根本上来说，肥胖和糖尿病代表着能量平衡紊乱。在糖尿病中，能量储存超过了利用。能量平衡是由细胞线粒体感知和控制的，对能量平衡紊乱中被破坏的关键线粒体途径的集中研究将提高我们对肥胖内分泌并发症的理解，并可能带来新的治疗方法。为了更好地了解线粒体功能障碍和肥胖相关内分泌疾病的交叉点，需要研究的一个特别相关的群体是患有原发性（遗传性）线粒体疾病的患者，即使没有明显的糖尿病或肥胖，他们也会出现类似的脂肪代谢紊乱特征，包括高甘油三酯血症和低高密度脂蛋白 (HDL) 胆固醇 通过拟议的 K23 指导的以患者为导向的研究职业发展奖，我将研究初级线粒体中脂质代谢紊乱的机制基础和代谢后果。随着我作为一名医师科学家的独立发展，拟议的研究将直接支持我的主要职业目标，这些目标是[1]增进我们对线粒体、能量平衡和代谢在儿科内分泌疾病中的作用的理解。 [2] 应用生理学见解来制定合理、有针对性和有效的治疗干预措施，以改善内分泌和代谢疾病患者的健康。这些目标将在 K23 奖励期间通过追求 3 个总体培训和职业发展目标来推进。 : 首先我要买说教式的 在该领域成功设计和执行以患者为导向的研究的关键知识和技术知识在拟议奖项的三年内，我将学习在内容领域专家顾问的指导下执行有价值的体外和体内表型分析技术。具体来说，稳定同位素的体外利用和“细胞杂种”细胞系的操作，以及由稳定同位素研究补充的高胰岛素正常血糖钳研究的体内表现将是非常宝贵的技能。在原发性线粒体疾病患者的诊断、评估和管理方面积累新的专业知识，该人群对所有领域（特别是儿科内分泌学）的更了解的亚专科医生都有大量未满足的临床需求。线粒体功能障碍在常见内分泌疾病中的作用将通过为线粒体疾病患者提供临床护理并在体外和体内进行来实现。 第三，我将过渡为独立的调查员，我将继续与我的指导委员会的专家成员开展富有成效的多学科合作，以获得必要的专业知识。通过完成拟议的研究、在全国会议上发表报告、在同行评审的期刊上发表文章以及获得后续的 R01 资金，过渡到独立。执行此拟议的项目将有助于实现这些目标，这些实验将检验我们的中心假设：[1]。 ] 蜂窝在初级呼吸链 (RC) 损伤的情况下，NAD+/NADH 氧化还原平衡会导致从 α-酮戊二酸 (αKG) 衍生的柠檬酸盐从头合成脂质增加，并降低脂肪酸氧化 (FAO) 能力，以及 [2] 由此产生的过量积累骨骼肌中脂质的增加会导致骨骼肌胰岛素抵抗。为了检验这些假设，我们将采用体外和体内方法来测试 RC 是否受到抑制。通过“逆转”柠檬酸循环流量可定量地增加从头脂肪生成 补充性减少体内方法将在（i）患有原发性 RC 疾病、患有高甘油三酯血症但患有原发性 RC 疾病的成人中寻找从头脂肪生成、肌肉脂质积累和胰岛素敏感性增加的证据。我们将将此组与 (ii) 适当匹配的健康个体进行比较，以评估“逆转的”柠檬酸循环通量是否也可能导致“典型”的高甘油三酯血症。非糖尿病肥胖个体，我们还将研究 (iii) 适当匹配的肥胖个体。将来，我们可以将这些研究的各个方面扩展到儿科人群。该项目利用了 CHOP 和我的主要导师 Penn First 的许多独特资源。 Marni J. Falk 博士拥有大量具有明确线粒体疾病遗传诊断的表型良好的患者群体，这为开展 CHOP 线粒体疾病中心的理想受试者和组织提供了现成的来源。表观基因组医学 (CMEM) 进一步提供了该领域的世界一流基础设施，宾夕法尼亚大学糖尿病研究中心 (DRC) 拥有充足的师资和核心专业知识，可确保成功完成详细的代谢表型研究，其中关键师资是我们在宾夕法尼亚大学的合作者。高级磁共振成像和波谱学中心 (CAMRIS) 开发了代谢成像技术来估计和定位线粒体功能，这项工作将使我能够为追求未来的独立资助奠定坚实的背景。线粒体、能量平衡和代谢在儿科内分泌疾病中的作用研究