Functional analysis of variant BDNF (Val66Met)

BDNF 变体 (Val66Met) 的功能分析

• 批准号: 7071230
• 负责人: Francis Sang Yong Lee
• 金额: $ 26.56万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7071230
• 关键词: biochemistry; brain derived neurotrophic factor; cell migration; confocal scanning microscopy; developmental neurobiology; enzyme linked immunosorbent assay; genetically modified animals; hippocampus; laboratory mouse; methionine; neurotrophic factors; polymerase chain reaction; single nucleotide polymorphism; valine; western blottings

DESCRIPTION (provided by applicant): Brain derived neurotrophic factor (BDNF) plays critical roles in vertebrate nervous system development and function. Recently, a single nucleotide polymorphism (Val66Met) in the BDNF gene leading to a prodomain substitution at position 66 from a valine (Val) to methionme (Met) has been shown to lead in humans to hippocampal dependent memory impairments and susceptibility to neuropsychiatric disorders. This BDNF polymorphism represents the first alteration in a neurotrophin that has been linked to clinical pathology. Less is known about the molecular mechanisms underlying altered variant BDNF (BDNFMet) functioning. When overexpressed in hippocampal neurons, BDNFMet has reduced activity dependent secretion, suggesting the presence of a specific signal in the BDNF prodomain that is required for efficient BDNF trafficking to the regulated secretory pathway. Preliminary studies suggest the hypothesis that BDNFMet aberrantly engages the highly specialized biochemical mechanisms that regulate BDNF trafficking to secretory pathways, which are critical determinants of BDNF's biological responses. The proposed studies are designed to identify specific proteins that regulate aberrant BDNFMet trafficking, and to examine the in vivo consequences on hippocampal structure and function. Experiments in this proposal will primarily utilize a novel transgenic knock-in mouse expressing an epitope tagged version of variant BDNF (BDNF 9 e) to enable assessment of BDNFMet trafficking events under endogenously expressed conditions and analysis of in vivo consequences on hippocampal structure and function. The Specific Aims of the proposed studies are to 1) define the trafficking defect and functional consequences in neurons endogenously expressing BDNFMet, 2) identify proteins that are involved in aberrant BDNFMet trafficking, and 3) determine the in vivo consequences of BDNFMet on hippocampal function. These studies will contribute to a fundamental molecular understanding of the mechanisms that underlie aberrant BDNFMet trafficking in neurons, and directly address the physiological relevance of this variant BDNF on hippocampal function.

描述（由申请人提供）：脑源性神经营养因子（BDNF）在脊椎动物神经系统发育和功能中起关键作用。最近，BDNF基因中的单核苷酸多态性（Val66Met）导致缬氨酸（Val）在第66位的原结构域被蛋氨酸（Met）取代，这已被证明会导致人类海马依赖性记忆障碍和对神经精神疾病的易感性。这种BDNF多态性代表了与临床病理相关的神经营养因子的第一个改变。目前对BDNF （BDNFMet）功能变异的分子机制知之甚少。当BDNFMet在海马神经元中过度表达时，BDNFMet减少了活性依赖性分泌，这表明BDNF前域中存在一种特定的信号，该信号是BDNF有效运输到受调节的分泌途径所必需的。初步研究表明，BDNFMet异常参与高度专业化的生化机制，调节BDNF运输到分泌途径，这是BDNF生物反应的关键决定因素。拟议的研究旨在确定调节异常BDNFMet运输的特定蛋白质，并检查体内对海马结构和功能的影响。本实验将主要利用一种新型转基因敲入小鼠，表达一种表位标记的BDNF变异版本（BDNF 9e），以评估内源性表达条件下的BDNFMet转运事件，并分析体内对海马结构和功能的影响。拟进行的研究的具体目的是：1)确定内源性表达BDNFMet的神经元的转运缺陷和功能后果；2)鉴定参与异常BDNFMet转运的蛋白质；3)确定BDNFMet对海马功能的体内影响。这些研究将有助于对神经元中异常BDNFMet运输的基本分子机制的理解，并直接解决这种变体BDNF对海马功能的生理相关性。