Characterization of Lphn3 function using a mutant murine model

使用突变小鼠模型表征 Lphn3 功能

• 批准号: 8283758
• 负责人: Deeann Wallis-Schultz
• 金额: $ 22.21万
• 依托单位: TEXAS A&M UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-20 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8283758
• 关键词: Adult; Affect; Anxiety; Attention; Attention deficit hyperactivity disorder; Behavior; Behavior assessment; Behavioral; Behavioral Assay; Biological Assay; Brain; Brain region; Candidate Disease Gene; Cell Differentiation process; Clinical; Consumption; Data; Development; Diagnosis; Disease; Dopamine Receptor; Etiology; G Protein-Coupled Receptor Genes; Gene Expression; Genes; Genetic Polymorphism; Genotype; Glutamates; Growth; Image; Impulsivity; In Vitro; Knockout Mice; Learning; Measures; Memory; Mental Depression; Modeling; Molecular Analysis; Motivation; Motor; Motor Activity; Mus; Mutant Strains Mice; Neurites; Neuronal Differentiation; Neurons; Orphan; Pathway interactions; Pattern; Pharmaceutical Preparations; Pharmacogenetics; Phenotype; Play; Reaction Time; Research; Reverse Transcriptase Polymerase Chain Reaction; Role; Seminal; Series; Serotonin; Serotonin Receptor 5-HT2A; Signal Transduction; Sucrose; Swimming; System; Testing; Time; Tissue-Specific Gene Expression; addiction; base; design; dopaminergic neuron; gene function; genome-wide linkage; grasp; human GPRC5C protein; inattention; male; monoamine; mutant; neuron development; neurotransmitter release; novel; receptor; response; serotonin receptor; serotonin transporter

DESCRIPTION (provided by applicant): Though relatively unknown and uncharacterized, the orphan GPCR LPHN3 has already been correlated in genome-wide linkage and association studies to both addictive phenotypes and Attention Deficit Hyperactivity Disorder (ADHD) independently. Vulnerability to addiction and ADHD are frequently comorbid, suggesting a common etiology. Further, initial data indicate that LPHN3 genotype may be a pharmacogenetic marker predicting response to stimulant medication. Unfortunately, as no disease-associated functional polymorphisms have been identified in LPHN3, its mechanism of action is completely unknown, and further characterization of its function is essential as there are far reaching implications for such an important gene. The central hypothesis to be tested in this proposal is that Lphn3 signalling affects neurotransmitter release and concentrations of monoamines in the brain that may affect neural cell differentiation, development, and function. These alterations ultimately play out in an effect on basic behavior that may influence phenotypes such as ADHD and vulnerability to addiction. We propose to utilize the novel Lphn3 null mutant mouse to investigate gene function. Preliminary data indicate that the Lphn3 null mouse is hyperactive, has altered DA and 5-HT levels in the brain, and demonstrates altered expression levels of genes involved in neuronal differentiation and development as well as other ADHD candidate genes involving the dopaminergic and serotonergic pathways including dopamine and serotonin receptors. These scant clues have been used by us to construct our research plan. We will begin with defining the Lphn3 developmental expression pattern in the brain and look at co-expression with other well-characterized neuronal markers. We will also utilize TaqMan Gene Expression Assays to look for changes in expression of genes known to play a role in neuronal differentiation, development, survival, and function as a function of Lphn3 genotype. Assays will be preformed across developmental time points and in specific brain regions. Next we will isolate primary neurons from WT and mutant mice and evaluate their viability, growth and function based on Lphn3 genotype. Finally, we have designed a battery of behavioral assays to begin to evaluate the basic behavioral deficits in the Lphn3 mice. This battery includes preliminary assessment of: activity, motor function, anxiety, depression, motivation, attention, impulsivity, learning and memory. Data derived from this project will be a first step toward characterizing the basic functions of Lphn3, which could enable better understanding, diagnosis, and treatment of ADHD and addiction. PUBLIC HEALTH RELEVANCE: LPHN3 is a GPCR that has been associated with ADHD and addiction whose function is relatively uncharacterized despite significant clinical and pharmacological relevance. The central hypothesis to be tested in this proposal is that Lphn3 signalling affects neurotransmitter release and concentrations of monoamines in the brain that may affect neural cell differentiation, development, and function such that ultimately behavior is also affected. We propose to utilize the novel Lphn3 null mutant mouse to investigate gene function.

描述（由申请人提供）：虽然相对未知且未表征，但孤儿 GPCR LPHN3 已在全基因组连锁和关联研究中与成瘾表型和注意力缺陷多动障碍 (ADHD) 独立相关。成瘾易感性和多动症经常并存，这表明有共同的病因。此外，初始数据表明 LPHN3 基因型可能是预测对刺激性药物的反应的药物遗传学标记。不幸的是，由于 LPHN3 中尚未发现与疾病相关的功能多态性，因此其作用机制完全未知，并且对其功能的进一步表征至关重要，因为对于如此重要​​的基因具有深远的影响。该提案要测试的中心假设是 Lphn3 信号传导会影响神经递质的释放和大脑中单胺的浓度，从而可能影响神经细胞的分化、发育和功能。这些改变最终会对基本行为产生影响，从而可能影响多动症和成瘾脆弱性等表型。我们建议利用新型 Lphn3 缺失突变小鼠来研究基因功能。初步数据表明，Lphn3 缺失小鼠过度活跃，大脑中 DA 和 5-HT 水平发生改变，并且涉及神经元分化和发育的基因以及涉及多巴胺能和血清素通路（包括多巴胺和血清素受体）的其他 ADHD 候选基因的表达水平发生改变。我们利用这些很少的线索来制定我们的研究计划。我们将首先定义大脑中 Lphn3 的发育表达模式，并研究与其他明确表征的神经元标记物的共表达。我们还将利用 TaqMan 基因表达测定来寻找已知在神经元分化、发育、存活和功能中发挥作用的基因的表达变化，作为 Lphn3 基因型的函数。检测将在整个发育时间点和特定的大脑区域进行。接下来，我们将从 WT 和突变小鼠中分离原代神经元，并根据 Lphn3 基因型评估其活力、生长和功能。最后，我们设计了一系列行为测定来开始评估 Lphn3 小鼠的基本行为缺陷。该电池包括以下方面的初步评估：活动、运动功能、焦虑、抑郁、动机、注意力、冲动、学习和记忆。从该项目获得的数据将是表征 Lphn3 基本功能的第一步，这可以使人们更好地理解、诊断和治疗 ADHD 和成瘾。 公共健康相关性：LPHN3 是一种与 ADHD 和成瘾相关的 GPCR，尽管具有显着的临床和药理学相关性，但其功能相对未表征。该提案要测试的中心假设是，Lphn3 信号传导会影响神经递质的释放和大脑中单胺的浓度，这可能会影响神经细胞的分化、发育和功能，从而最终影响行为。我们建议利用新型 Lphn3 缺失突变小鼠来研究基因功能。