Latrophilin-3 and ADHD: A new potential mechanism

Latrophilin-3 和 ADHD：一种新的潜在机制

• 批准号: 8690165
• 负责人: Charles V Vorhees
• 金额: $ 22.95万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8690165
• 关键词: Acoustics; Affect; Animals; Attention; Attention deficit hyperactivity disorder; Behavioral; Binding; Brain; Centers for Disease Control and Prevention (U.S.); Child; Cognitive; Data; Densitometry; Development; Disease; Dopamine; Dopamine-beta-monooxygenase; Effectiveness; Ensure; Etiology; Future; Genes; Glutamates; Hyperactive behavior; Immunohistochemistry; Impulsivity; Knock-out; Modeling; Motor Activity; Mutation; N-Methylaspartate; NR1 gene; Norepinephrine; Orphan; Pharmaceutical Preparations; Phenotype; Positioning Attribute; Prevalence; Process; Proteins; Rattus; Reaction Time; Research; Reverse Transcriptase Polymerase Chain Reaction; Risk; Role; Serotonin; Severities; Short-Term Memory; Signal Transduction; Staining method; Stains; Symptoms; System; Testing; Therapeutic Intervention; Tyrosine 3-Monooxygenase; Western Blotting; alpha-latrotoxin receptor; base; behavior test; boys; cost; drug development; flexibility; follow-up; gamma-Aminobutyric Acid; girls; high risk; improved; inattention; innovation; insight; interest; loss of function; monoamine; neurochemistry; novel; performance tests; prepulse inhibition; public health relevance; receptor; research study; response; reuptake

DESCRIPTION (provided by applicant): Attention Deficit Hyperactivity Disorder (ADHD) affects 5.4 million children at a cost >$72 billion/year, yet its etiology is poorly understood. A new gene for an orphan receptor has been identified that conveys high risk for ADHD: Latrophilin-3 (LPHN3). We have a new Lphn3 knock-out (KO) rat. This rat shows hyperactivity and hyper-reactivity. But ADHD also affects attention and impulse control. Objective-1 will test Lphn3 KO rats for attention and inhibitory control. ADHD is treated with stimulants, which increase attention and reduce distractibility and activity. Objective-2 is to test the effects of ADHD medications in Lphn3 KO rats. Effective ADHD medications increase dopamine and norepinephrine signaling (and some increase 5HT) by acting on monoamine reuptake and release processes or receptors. Objective-3 is to determine the effects of Lphn3 disruption on monoamines, transporters, and receptors. The overall purpose is to identify the contribution of Lphn3 to the behavioral and neurochemical phenotype of ADHD. The proposed experiments will generate essential data for how Lphn3 contributes to each of the symptoms and neurochemical changes associated with ADHD. Lphn3 could become a novel target for development of drugs that modulate Lphn3 function or its binding partner (Flrt3) to alleviate the underlying deficit in ADHD. As such this represents innovative research on a cause of ADHD. We are the only group with the Lphn3 KO rat and pilot phenotypic data. Therefore, we are uniquely position to pursue this model. Specific Aim-1 will determine the ADHD-like phenotype of Lphn3 KO rats. The role of Lphn3 loss of function in extended locomotor activity, sensorimotor gating, cognitive flexibility/attention (set shifting), attention/flexibility (continuous performance test), working memory, and response to ADHD medications will be assessed. The data will demonstrate the range and severity of ADHD phenotype. Specific Aim-2 will elucidate the neurochemical changes in Lphn3 KO rats. Exp-2a: KO and WT rats will be compared by immunohistochemistry for changes in monoamines implicated in ADHD (dopamine (by tyrosine hydroxylase), 5HT, and dopamine beta hydroxylase (for NE), and as controls GAD67 (for GABA) and NMDA-NR1 (for glutamate). Stains for each transporter will be performed. Because the dopamine D4 and 5HT2B receptors have been implicated in ADHD they will also be assessed. Exp-2b: Once histological regions of change are identified, other animals will have these regions analyzed by Western blot. Exp-2c: Once Westerns from Aim-2b identify significant changes, this will be used to guide which markers will be analyzed in Aim-2c in animals after behavioral testing; then correlations between neurochemical and behavioral data will be performed. In addition, RT-PCR for Flrt3 will be performed to determine it is altered by the Lphn3 mutation. These experiments will materially advance the field of ADHD research.

描述（由申请人提供）：注意力缺陷多动障碍 (ADHD) 影响着 540 万儿童，每年造成的损失超过 720 亿美元，但其病因却知之甚少。已鉴定出一种孤儿受体的新基因，它会带来 ADHD 的高风险：Latrophilin-3 (LPHN3)。我们有一只新的 Lphn3 敲除 (KO) 大鼠。这只老鼠表现出多动症和过度反应性。但多动症也会影响注意力和冲动控制。 Objective-1 将测试 Lphn3 KO 大鼠的注意力和抑制控制能力。注意力缺陷多动症可以通过兴奋剂来治疗，从而提高注意力并减少注意力分散和活动。 Objective-2 是测试 ADHD 药物对 Lphn3 KO 大鼠的作用。有效的 ADHD 药物通过作用于单胺再摄取和释放过程或受体来增加多巴胺和去甲肾上腺素信号传导（有些会增加 5HT）。 Objective-3 是确定 Lphn3 破坏对单胺、转运蛋白和受体的影响。总体目的是确定 Lphn3 对 ADHD 行为和神经化学表型的贡献。拟议的实验将生成有关 Lphn3 如何促成与 ADHD 相关的每种症状和神经化学变化的基本数据。 Lphn3 可能成为开发调节 Lphn3 功能或其结合伴侣 (Flrt3) 药物的新靶标，以缓解 ADHD 的潜在缺陷。因此，这代表了针对多动症病因的创新研究。我们是唯一拥有 Lphn3 KO 大鼠和试验表型数据的组。因此，我们具有独特的优势来追求这种模式。特定的 Aim-1 将确定 Lphn3 KO 大鼠的 ADHD 样表型。将评估 Lphn3 功能丧失在延长运动活动、感觉运动门控、认知灵活性/注意力（​​设定转换）、注意力/灵活性（持续表现测试）、工作记忆和对 ADHD 药物的反应中的作用。这些数据将证明 ADHD 表型的范围和严重程度。具体的 Aim-2 将阐明 Lphn3 KO 大鼠的神经化学变化。 Exp-2a：将通过免疫组织化学比较 KO 和 WT 大鼠与 ADHD 相关的单胺的变化（多巴胺（通过酪氨酸羟化酶）、5HT 和多巴胺 β 羟化酶（对于 NE），以及作为对照的 GAD67（对于 GABA）和 NMDA-NR1（对于谷氨酸）。将对每个转运蛋白进行染色。因为 多巴胺 D4 和 5HT2B 受体与 ADHD 有关，因此也将对其进行评估。 Exp-2b：一旦确定了组织学变化区域，其他动物将通过蛋白质印迹分析这些区域。 Exp-2c：一旦来自 Aim-2b 的西方人发现了显着变化，这将用于指导在行为测试后在动物 Aim-2c 中分析哪些标记；那么神经化学和行为数据之间的相关性将是 执行。此外，还将对 Flrt3 进行 RT-PCR 以确定其是否因 Lphn3 突变而改变。这些实验将极大地推进多动症研究领域。