Adaptation to long chain fatty acid oxidation deficiency

适应长链脂肪酸氧化缺陷

• 批准号: 6710988
• 负责人: ARNOLD W STRAUSS
• 金额: $ 36.68万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2008-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6710988
• 关键词: acyl coA dehydrogenases; arrhythmia; bioenergetics; calcium metabolism; carcinogenesis; clinical research; electrophysiology; electrospray ionization mass spectrometry; enzyme deficiency; gene mutation; genetic polymorphism; genetically modified animals; genotype; heart disorder; heart function; human genetic material tag; human subject; immunocytochemistry; laboratory mouse; microarray technology; obesity; oxidative stress; phenotype; sudden cardiac death; telemetry; acyl coA dehydrogenases; arrhythmia; bioenergetics; calcium metabolism; carcinogenesis; clinical research; electrophysiology; electrospray ionization mass spectrometry; enzyme deficiency; gene mutation; genetic polymorphism; genetically modified animals; genotype; heart disorder; heart function; human genetic material tag; human subject; immunocytochemistry; laboratory mouse; microarray technology; obesity; oxidative stress; phenotype; sudden cardiac death; telemetry

DESCRIPTION (provided by applicant): Very-long-chain acyI-CoA dehydrogenase (VLCAD) catalyzes the first step of the mammalian mitochondrial fatty acid oxidation (FAO) spiral that generates energy in the heart and other highly oxidative tissues. Human recessive VLCAD deficiency produces phenotypes of early fatal cardiomyopathy and arrhythmias, infantile hypoketotic hypoglycemia and liver failure, sudden death in infancy (SIDS), and later episodic skeletal myopathy. Our first hypothesis is that VLCAD deficiency has a genotype-phenotype correlation that we will investigate (Aim 1) through molecular genetics, correlating with clinical phenotypes, and by studying the pathogenetics of some VLCAD mutations, particularly V243A that exists in patients discovered by newborn screening. Our second hypothesis is that VLCAD is essential for cardiac function both because of its enzymatic role, but also because VLCAD is required for transcriptional regulation of multiple genes. This will be investigated by characterizing the 20 bp long VLCAD enhancer we have isolated (Aim 2) and by characterizing VLCAD-deficient mice and their heterozygote littermates that exhibit the phenotypes of sudden death, late-onset obesity, development of tumors, and inducible arrhythmias and that die in response to fasting and exposure to cold. This characterization includes use of transgenic mice and cell transfections to examine VLCAD transcriptional regulation (Aim 2) and telemetry, invasive electrophysiology, microarray analysis, exercise testing, and dietary manipulation of VLCAD -/- and +/- animals (Aim 3). We will also create tissue-specific (heart, brown fat, liver, muscle) knockouts (Aim 4) to ascertain the relative contributions of these organs to phenotypes. We know that VLCAD -/- animals exhibit marked alterations in tissue gene expression by one day, a perinatal "adaptive response". We hypothesize that this live-saving adaptive response creates differences in gene expression that are the substrate for the later pathologies of sudden death, arrhythmias, obesity, and tumorigenesis. This is, thus, a model of how polymorphisms or mutations in one gene modify expression of other later in life, leading to pathology. One highly induced gene in this genetic response is a novel protein, designated heart endothelin-related substance (HERS) that, based upon homology and expression data, we postulate functions in cardiac development and calcium metabolism. We will investigate its role by generating a HERS knockout in the last specific aim.

描述（由申请人提供）：非常长的链Acyi-COA脱氢酶（VLCAD）催化哺乳动物线粒体脂肪酸氧化（FAO）螺旋的第一步，可在心脏和其他高度氧化组织中产生能量。人类隐性VLCAD缺乏会产生早期致命性心肌病和心律不齐，婴儿低血糖低血糖和肝衰竭，婴儿猝死（SIDS）以及后来的情节性骨骼肌病的表型。我们的第一个假设是，VLCAD缺乏症具有基因型 - 表型相关性，我们将通过分子遗传学研究（AIM 1），与临床表型相关，并通过研究某些VLCAD突变的病原体，尤其是通过新生儿筛查发现的患者中的V243a的病原体。我们的第二个假设是，VLCAD对于心脏功能至关重要，这既是其酶促作用，又是因为VLCAD对于多个基因的转录调节所必需。这将通过表征我们分离的20 bp长的VLCAD增强剂来进行调查（AIM 2），并表征VLCAD缺陷型小鼠及其杂合子的杂合子，这些小鼠表现出了猝死，晚期肥胖，肿瘤的发育，肿瘤的发展，以及对快速疾病的疾病响应，对快速疾病的疾病而变化。该特征包括使用转基因小鼠和细胞转染来检查VLCAD转录调控（AIM 2）和遥测，侵入性电生理学，微阵列分析，运动测试以及对VLCAD - / - / - 和+/ +/-动物的饮食操纵（AIM 3）。我们还将创建组织特异性（心脏，棕色脂肪，肝脏，肌肉）敲除（AIM 4），以确定这些器官对表型的相对贡献。我们知道，VLCAD - / - 动物在一天中表现出明显的组织基因表达改变，这是围产期“适应性反应”。我们假设这种挽救生命的自适应反应会在基因表达上产生差异，这是后来的猝死，心律不齐，肥胖和肿瘤发生的底物。因此，这是一个模型，一种模型是一种基因中多态性或突变如何修饰后来生命中另一个基因的表达，从而导致病理学。在这种遗传反应中，一种高度诱导的基因是一种新型蛋白质，指定为心脏内皮素相关物质（HERS），基于同源性和表达数据，我们假设心脏发育和钙代谢中的功能。我们将通过在最后一个特定目标中产生自己的淘汰赛来调查其角色。