MITOCHONDRIAL SHORT CHAIN 3-OH-ACYL-COA DEHYDROGENASES

线粒体短链 3-OH-酰基-COA 脱氢酶

• 批准号: 6517631
• 负责人: ARNOLD W STRAUSS
• 金额: $ 24.08万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-20 至 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6517631
• 关键词: Reye's syndrome; acyl coA dehydrogenases; clinical research; developmental genetics; environmental stressor; enzyme deficiency; enzyme mechanism; enzyme structure; fatty acid metabolism; gene expression; gene mutation; genetic regulatory element; genetically modified animals; human genetic material tag; human subject; human tissue; isozymes; laboratory mouse; liver failure; mitochondria; oxidation; physiologic stressor; point mutation; short chain fatty acid; transcription factor

Mitochondrial fatty acid beta-oxidation is the major source of energy in highly oxidative mammalian tissues and is essential for intermediary metabolism and production of ketone bodies in liver. Human genetic defects in fatty acid oxidation genes cause acute liver failure, a Reye's syndrome-like phenotype of hypoketotic, hypoglycemia; cardiomyopathy; skeletal myopathy; or sudden, unexpected childhood death. This pathway consists of four enzymatic steps catalyzed by 12 different nuclearly-encoded enzymes that are developmentally-regulated and tissue- specifically expressed. This proposal focuses on two enzymes catalyzing the third step, the short chain 3-hydroxy-acyl-CoA dehydrogenases (SCHAD). Aims 1 and 2 will examine the hypothesis that tissue-specific and developmental expression of the SCHAD-1 and -2 genes is coordinated with other fatty acid oxidation enzyme genes and involves nuclear hormone receptor transcription factors responsive to energy requirements and nutritional cues. Aim 2 will use the human SCHAD-1 gene and in vitro transfection and transgenic mice to locate critical regulatory sequences. Based upon the SCHAD-1 crystal structure and protein homologies, Aim 3 will determine structure-function relationships of SCHAD-1 of normal and mutant SCHADs after expression in bacteria to explore the hypothesis that SCHAD-1 and long chain 3-hydroxy- acyl-CoA dehydrogenase share common structural domains. Using the human gene sequences we have determined, Aim 4 will delineate SCHAD-1 or -2 mutations in children to examine the proposal that SCHAD deficiency and environmental stresses cause a Reye's syndrome-like phenotype of acute hepatic failure. Aim 5 will examine the effects of the three human SCHAD-1 mutations we have discovered on structure and function, the pathogenetics of SCHAD deficiency, to explore the hypothesis that SCHAD missense mutations result in rapid intramitochondrial degradation secondary to misfolding. Aim 6 is to define the phenotype of SCHAD-1 gene ablation we created in mice as a model of human disease, to examine the effects of environmental and drug (aspirin and acetaminophen) stressors on outcome and to similarly study an SCHAD-2 knockout. These studies will augment understanding of the pathogenesis of fatty acid oxidation disorders causing acute liver failure, cardiomyopathy, and sudden death in children.

线粒体脂肪酸β-氧化是高度氧化的哺乳动物组织中的主要能量来源，并且对于肝脏中酮体的中间代谢和产生至关重要。人类脂肪酸氧化基因的遗传缺陷导致急性肝衰竭，一种低酮性、低血糖的雷氏综合征样表型;心肌病;骨骼肌病;或儿童期突然意外死亡。 该途径由12种不同的核编码酶催化的四个酶促步骤组成，这些酶受发育调节和组织特异性表达。 该提议集中于催化第三步的两种酶，短链3-羟基酰基-CoA脱氢酶（SCHAD）。 目的1和2将检查的假设，组织特异性和发育的SCHAD-1和-2基因的表达是协调与其他脂肪酸氧化酶基因，并涉及核激素受体转录因子对能量的需求和营养线索。目的二是利用人SCHAD-1基因，通过体外转染和转基因小鼠，定位其关键调控序列。基于SCHAD-1晶体结构和蛋白质同源性，目的3将确定在细菌中表达后的正常和突变SCHAD的SCHAD-1的结构-功能关系，以探索SCHAD-1和长链3-羟基-酰基-CoA脱氢酶共享共同结构域的假设。 使用我们已经确定的人类基因序列，目的4将描述SCHAD-1或-2突变在儿童中检查的建议，SCHAD缺乏症和环境压力导致急性肝功能衰竭的雷氏综合征样表型。 目的5将研究我们发现的三种人类SCHAD-1突变对结构和功能的影响，SCHAD缺陷的发病机制，探索SCHAD错义突变导致线粒体内快速降解继发于错误折叠的假设。 目的6是确定我们在小鼠中创建的SCHAD-1基因消融的表型作为人类疾病的模型，以检查环境和药物（阿司匹林和对乙酰氨基酚）应激源对结果的影响，并类似地研究SCHAD-2敲除。 这些研究将增加对脂肪酸氧化紊乱导致儿童急性肝衰竭、心肌病和猝死的发病机制的理解。