The Role of Genome-Coded ME2 in Epilepsy

基因组编码的 ME2 在癫痫中的作用

• 批准号: 7937921
• 负责人: DAVID A. GREENBERG
• 金额: $ 40.25万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7937921
• 关键词: Absence Epilepsy; Accounting; Adolescence; Adolescent; Affect; Applications Grants; Area; Biological; Biological Assay; Biological Process; Brain; Bromodomain; Candidate Disease Gene; Childhood; Chromosomes, Human, Pair 18; Citric Acid Cycle; Code; Cultured Cells; DNA Sequence Analysis; Data; Decarboxylation; Elements; Enzymes; Epilepsy; Etiology; Exons; Family; GABA Receptor; Gene Expression; Generalized Epilepsy; Genes; Genetic; Genetic Polymorphism; Genetic Predisposition to Disease; Genetic Transcription; Genetic Variation; Genome; Glutamates; Goals; Haplotypes; Introns; Juvenile Myoclonic Epilepsy; Lead; Link; Malates; Methods; Mitochondria; Molecular; Mutation; Neuraxis; Neuroglia; Neurons; Neurotransmitters; Outcome; Play; Predisposition; Process; Pyruvate; Pyruvates; RNA Splicing; Reporter; Reporter Genes; Research; Risk; Risk Factors; Role; Sampling; Sequence Analysis; Shunt Device; Site; Susceptibility Gene; Syndrome; System; Testing; Tissues; Tonic - clonic seizures; Variant; base; case control; drug mechanism; gamma-Aminobutyric Acid; gene interaction; genetic linkage analysis; malic enzyme; novel; promoter; protein expression; relating to nervous system; research study

DESCRIPTION (provided by applicant): Idiopathic Generalized Epilepsy (IGE) is one of the most common forms of epilepsy, representing about 30% of all epilepsies; and, its etiology is considered to be mostly genetic. Both linkage and association studies have identified several candidate genes for IGE, namely: malic enzyme 2 (ME2) and bromodomain containing 2 (BRD2). In addition, previous studies have also suggested that IGE susceptibility results from gene-gene interaction. We will focus on establishing a clear biological link between ME2 and IGE, and we will also test for an interaction between ME2 and BRD2. The strong linkage and association results on chromosome 18 suggest that ME2 is a general IGE susceptibility locus, and that it follows a recessive mode of inheritance. Sequence analysis in 20 IGE cases and 18 controls, revealed a region in intron 1 of ME2 where polymorphic sites in cases are mostly monomorphic in controls. Moreover, ME2 is an excellent biological candidate for susceptibility to IGE due to: 1) its abundance in brain neurons; 2) its localization to the mitochondria; and most compelling, 3) its catalytic function of malate decarboxylation, producing a critical supply of pyruvate for glutamate and GABA synthesis. GABA is the main inhibitory neurotransmitter in the central nervous system, and is involved in the modulation of epileptiform spike-wave activity. Anti-epilepsy drug mechanisms also modulate the GABA neurotransmitter system, and mutations in GABA receptors have been shown to play a role in susceptibility to some forms of epilepsy. In this grant application, we will determine the different haplotypes of ME2 intron 1 based on our selected sample of cases for whom sequence data is available. Then, we will use reporter constructs to examine the isolated effects of different intron 1 haplotypes on splicing and levels of transcription. Note that our reporter constructs will only contain proximal promoter elements and intron 1. Next, we will examine the effects of intron 1 variants in neuronal and/or glial cells; and unlike our reporter constructs, these experiments will involve the entire ME2 gene. Finally, using standard resampling methods and a novel statistical approach, we will test for an interaction between ME2 and BRD2 with respect to juvenile myclonic epilepsy-an IGE subtype. Overall, this propose research should help to elucidate the general role of ME2 as a susceptibility gene for IGE, as well as its particular role in a network of other contributing genetic factors. PUBLIC HEALTH RELEVANCE: Epilepsy affects 2.7 million people in the US alone. Idiopathic Generalized Epilepsy (IGE) accounts for 30% of all epilepsy, starts in childhood or adolescence, and, is thought to have a genetic etiology. Our studies have identified a gene (ME2) as both linked and strongly associated with several different, common IGE syndromes, including Juvenile Myoclonic Epilepsy (JME), Juvenile Absence Epilepsy (JAE), and Epilepsy with Generalized Tonic-Clonic Seizures (EGTCS). We propose to determine how polymorphisms found in the ME2 gene increase susceptibility to a broad class of related epilepsy syndromes.

描述（由申请人提供）：特发性一般性癫痫（IgE）是最常见的癫痫的形式之一，约占所有癫痫的30％；而且，其病因被认为主要是遗传。连锁和关联研究都确定了IgE的几个候选基因，即：苹果酶2（ME2）和含有2（BRD2）的溴化域。此外，先前的研究还表明，基因 - 基因相互作用产生IgE敏感性。我们将专注于建立ME2和IGE之间的明确生物学联系，我们还将测试ME2和BRD2之间的相互作用。第18号染色体的牢固联系和关联结果表明ME2是一个普通的IgE敏感性基因座，它遵循一种隐性的继承方式。在20例IgE病例和18个对照中的序列分析显示，ME2内含子1中的一个区域，其中多态性位点在对照中主要是单态的。此外，由于以下原因，ME2是对IgE敏感性敏感性的出色生物学候选者，其丰富性在脑神经元中； 2）将其定位到线粒体；最引人注目的是，3）其苹果酸脱羧的催化功能，为丙酮酸和GABA合成产生关键的丙酮酸供应。 GABA是中枢神经系统中的主要抑制性神经递质，参与了癫痫样峰波活性的调节。抗癫痫的药物机制还调节GABA神经递质系统，GABA受体中的突变已显示在对某些形式的癫痫病的敏感性中起作用。在本赠款应用程序中，我们将根据我们选择的序列数据的案例样本来确定ME2内含子1的不同单倍型。然后，我们将使用报告基因构建体来检查不同内含子1单倍型对剪接和转录水平的孤立作用。请注意，我们的记者构建体仅包含近端启动子元素和内含子1。接下来，我们将检查内含子1变体在神经元和/或神经胶质细胞中的影响；与我们的记者结构不同，这些实验将涉及整个ME2基因。最后，使用标准的重采样方法和一种新颖的统计方法，我们将测试ME2和BRD2之间相对于少年肌癫痫 - An IgE亚型的相互作用。总体而言，这项提出的研究应有助于阐明ME2作为IgE的易感基因的一般作用，及其在其他造成其他遗传因素网络中的特殊作用。公共卫生相关性：仅在美国，癫痫就影响了270万人。特发性全身性癫痫（IgE）占所有癫痫的30％，从童年或青春期开始，被认为具有遗传病因。我们的研究已经确定了一个基因（ME2）是与几种不同的常见IgE综合征相关的，包括少年肌阵挛性癫痫（JME），少年缺勤癫痫（JAE）和癫痫与广泛性强调癫痫发作（EGTCS）。我们建议确定ME2基因中发现的多态性如何增加对一系列相关癫痫综合征的敏感性。