Inborn Errors of Long Chain Fat Metabolism

长链脂肪代谢先天性错误

• 批准号: 8485595
• 负责人: GERARD VOCKLEY
• 金额: $ 31.37万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8485595
• 关键词: Acyl CoA Dehydrogenases; Affect; Biochemical; Biogenesis; Biological Assay; Carbon; Cells; Chemicals; Clinical; Collaborations; Complex; Cryoelectron Microscopy; Data; Disease; Electron Transport; Enzymes; Equilibrium; Exhibits; Fatty Acids; Frequencies; Funding; Generations; Genes; Genetic; Genotype; Goals; Grant; Hereditary Disease; Human; Inborn Genetic Diseases; Incidence; Knock-out; Knockout Mice; Lead; Learning; Left; Lipids; Liver Failure; Location; Long-Chain-Acyl-CoA Dehydrogenase; Lung diseases; Metabolic; Metabolism; Mitochondria; Mus; Mutation; Null Lymphocytes; Pathway interactions; Patients; Phenotype; Physiological; Play; Point Mutation; Process; Production; Proteins; Pulmonary Surfactants; Rattus; Recurrence; Reporting; Respiratory Chain; Role; Sampling; Side; Structure; Structure-Activity Relationship; Symptoms; Transfection; acyl-CoA dehydrogenase; clinical effect; crosslink; enzyme activity; enzyme deficiency; expression vector; fatty acid oxidation; fatty acid oxidation complex; genetic pedigree; lipid metabolism; long chain fatty acid; mouse model; mutant; novel; null mutation; oxidation; pneumocyte; protein complex; protein structure; protein structure function; reconstitution; repository; research study; surfactant; surfactant deficiency; tissue culture

DESCRIPTION (provided by applicant): Mitochondrial fatty acid ¿-oxidation is traditionally viewed as an energy-generating, catabolic pathway but intermediates of this pathway can serve as key substrates for synthesis of other complex lipids. The long range objective of this project is to define the role of fatty acid oxidaton proteins in intermediary metabolism and the clinical impact of their deficiency due to inborn errors. The goal of the first funding period was to characterize the functional roles of LCAD, VLCAD, and ACAD9 and to explore the ramifications of genetic deficiencies of these enzymes in humans and mouse models. Significant progress has been made on each of these aims. Our chief findings include the ground breaking identification and partial purification of a multifunctional fatty acid oxidation complex containing all of the activities of this pathway in association with the mitochondrial respiratory chain super complexes and identification of the first patient with LCAD deficiency, presenting as predicted with a surfactant deficiency. The goal of this renewal application is to examine the expanding role of long chain fatty acid oxidation in normal metabolism and disease. It has three specific aims. Specific Aim 1 is to characterize the structure of the multifunctional fatty acid oxidation complex and its interaction with the mitochondrial respiratory chain. I hypothesize that this contact is critical to the channeling of reducing equivalents from fatty acid oxidation to the respiratory chain and that disruption of this process reduces the efficiency of mitochondrial energy generation. Specific Aim 1a is to elucidate the mechanism of electron transfer by first deducing the structure of the multifunctional FAOD complex using cryoelectron microscopy. Specific Aim 1b is to examine the role of patient identified mutations on VLCAD function, including their effect on the integrity of the FAOD multifunctional complex. Specific Aim 1c is to characterize the integrity of the fatty acid oxidatin complex in VLCAD and LCAD deficient mouse models. Specific Aim 2 is to characterize the disparate effects of null and point mutations in the ACAD9 gene on protein structure and function. I hypothesize that ACAD9 serves a duel function in mitochondria as a metabolic enzyme and a respiratory chain assembly/stability factor. Specific Aim 2a is to examine the metabolic and moonlighting functions of ACAD9 in cells from deficient human patients. Specific Aim 2b is to characterize the range of biochemical and clinical effects in an ACAD9 knock out mouse model. Specific Aim 3 is to further characterize LCAD deficiency in patients and a knock out mouse model, and to elucidate its function in surfactant metabolism. Specific Aim 3a is to examine surfactant metabolism in wild type and LCAD deficient primary pneumocytes. Specific Aim 3b is to characterize the incidence and spectrum of clinical symptoms in LCAD deficiency.

描述(由申请人提供)： 线粒体脂肪酸氧化传统上被认为是一种产生能量的分解代谢途径，但这一途径的中间产物可以作为合成其他复杂脂质的关键底物。这个项目的长期目标是确定脂肪酸氧化蛋白在中间代谢中的作用，以及由于先天错误而导致的缺乏对临床的影响。第一个资助期的目标是确定LCAD、VLCAD和ACAD9的功能角色，并探索这些酶在人类和小鼠模型中遗传缺陷的后果。在这些目标中的每一个方面都取得了重大进展。我们的主要发现包括开创性地鉴定和部分纯化了一种多功能脂肪酸氧化复合体，该复合体包含了与线粒体呼吸链超级复合体相关的这一途径的所有活性，并鉴定了第一例LCAD缺乏症患者，正如预测的那样，出现了表面活性物质缺乏症。这一更新应用的目标是研究长链脂肪酸氧化在正常代谢和疾病中的扩展作用。它有三个具体目标。具体目标1是表征多功能脂肪酸氧化复合体的结构及其与线粒体呼吸链的相互作用。我推测，这种接触对于从脂肪酸氧化到呼吸链的还原当量的传导以及这种破坏是至关重要的。 这一过程降低了线粒体能量产生的效率。具体目标1a是通过首先推导出多功能的结构来阐明电子转移的机制 冷冻电子显微镜观察FOD复合体。具体目标1b是检查患者识别的突变对VLCAD功能的作用，包括它们对food多功能复合体完整性的影响。具体目的1c是在VLCAD和LCAD缺陷小鼠模型中表征脂肪酸氧化复合体的完整性。具体目标2是表征ACAD9基因零突变和点突变对蛋白质结构和功能的不同影响。我推测ACAD9在线粒体中作为代谢酶和呼吸链组装/稳定因子具有双重功能。具体目标2a是检测ACAD9在缺乏人类患者的细胞中的代谢和兼职功能。具体目标2b是在ACAD9基因敲除小鼠模型中表征生化和临床影响的范围。具体目的3是进一步确定LCAD缺陷患者和基因敲除小鼠模型的特征，并阐明其在表面活性物质代谢中的作用。目的：检测野生型和LCAD缺陷型原代肺泡细胞表面活性物质的代谢。具体目的3b是描述LCAD缺乏的临床症状的发生率和谱系。