Genetic Models of Serotonin Transporter Regulation Linked to Mental Disorders

与精神疾病相关的血清素转运蛋白调节的遗传模型

• 批准号: 8585969
• 负责人: SAMMANDA RAMAMOORTHY
• 金额: $ 7.25万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8585969
• 关键词: Genetic; Models; Serotonin; Transporter; Regulation

DESCRIPTION (provided by applicant): Altered serotonergic transmission and presynaptic serotonin (5-hydroxytryptamine, 5-HT) transporter (SERT) expression have long been associated with psychiatric disorders including depression, suicide, autism, OCD, impulsive violence. Indeed, the drugs that block SERT such as tricyclic antidepressants and SSRIs are successfully used for the treatment of mental disorders. Studies from PI's group, collaborators and colleagues have identified signaling mechanisms of SERT regulation by kinases/phosphatases. Remarkably, the association of human SERT coding variants Gly56Ala, Ile425Val mutation with OCD, autism and other psychiatric disorders, and the discovery that these mutations alter PKG/p38 MAPK regulation of SERT activity suggest that this form of regulation is important in the normal physiology of SERT and dysregulation of SERT may influence risk for disorders attributed to compromised 5-HT signaling. Currently no transgenic animal models are available to test whether altered SERT phosphorylation is causative for altered behavior found in autism, OCD and other psychiatric disorders. In this R21 proposal, recognizing the risk versus reward mission, we propose to test the hypothesis that transgenic mouse models mimicking constitutive SERT PKG-phosphorylation show gain of 5-HT transport phenotype with loss of PKG-mediated upregulation and phosphorylation rescuing behavioral phenotypes that parallel Ile425Val mutant identified in OCD and Asperger syndrome. In Specific Aim 1, we propose to construct targeting vectors carrying Thr276Asp mutation that mimic PKG-phosphorylation and Ile425Val mutation associated with OCD and Asperger syndrome by inserting the mutations into mouse SERT genomic sequences to generate SERT transgenic SERT mice. Specific Aim 2 will validate SERT regulation and phosphorylation in Thr276Asp and Ile425Val SERT mice, and elucidate important 5-HT related behavioral phenotypes rescued in the knock-in mice. However, future studies that are beyond the scope of this proposal, will utilize Thr276Asp and/or Ile425Val knock-in SERT mice to analyze neurochemical, behavioral and gene expression profiles, and to measure responses to acute and chronic in vivo SSRI administrations and other therapeutic agents. Thus, generation of these unique mouse models provide innovative tools for exploring the kinase mediated SERT regulatory pathways that are set points in disrupting normal SERT function found in disease-linked human SERT variants. In addition, these SERT transgenic mice will aid future studies exploring serotonin-related gene regulatory network that may be linked to mental disorders and in the development of effective pharmacological agents for the treatment of mental disorders. PUBLIC HEALTH RELEVANCE: The association of human SERT coding variants Gly56Ala, Ile425Val mutation with OCD, autism and other psychiatric disorders, and the discovery that these mutants alter PKG/p38 MAPK regulation of SERT activity suggest that this form of regulation is important in the normal physiology of SERT. The proposed research to generate a knock-in mouse model will enable to identify the neuronal network linked to mental disorders and aid in the development of effective pharmacological agents for the treatment of mental disorders and other disease states resulting from aberrant monoamine transmission.

描述（由申请人提供）：血清素能传递和突触前血清素（5-羟色胺，5-HT）转运蛋白（SERT）表达的改变长期以来一直与精神疾病相关，包括抑郁症、自杀、自闭症、强迫症、冲动暴力。事实上，三环类抗抑郁药和 SSRI 等阻断 SERT 的药物已成功用于治疗精神障碍。 PI 团队、合作者和同事的研究已经确定了激酶/磷酸酶调节 SERT 的信号传导机制。值得注意的是，人类 SERT 编码变体 Gly56Ala、Ile425Val 突变与强迫症、自闭症和其他精神疾病的关联，以及这些突变改变 PKG/p38 MAPK 对 SERT 活性的调节的发现表明，这种形式的调节对于正常生理学非常重要。 SERT 和 SERT 失调可能会影响 5-HT 信号传导受损导致的疾病风险。目前还没有转基因动物模型可以测试 SERT 磷酸化的改变是否会导致自闭症、强迫症和其他精神疾病的行为改变。在这个 R21 提案中，认识到风险与回报任务，我们建议测试以下假设：模仿本构 SERT PKG 磷酸化的转基因小鼠模型显示出 5-HT 转运表型的增加，同时 PKG 介导的上调和磷酸化拯救行为表型的丧失，这与平行在强迫症和阿斯伯格综合症中发现了 Ile425Val 突变体。在具体目标 1 中，我们建议构建携带 Thr276Asp 突变的靶向载体，通过将突变插入小鼠 SERT 基因组序列来模拟与 OCD 和阿斯伯格综合征相关的 PKG 磷酸化和 Ile425Val 突变，以生成 SERT 转基因 SERT 小鼠。具体目标 2 将验证 Thr276Asp 和 Ile425Val SERT 小鼠中的 SERT 调节和磷酸化，并阐明在敲入小鼠中挽救的重要 5-HT 相关行为表型。然而，超出本提案范围的未来研究将利用 Thr276Asp 和/或 Ile425Val 敲入 SERT 小鼠来分析神经化学、行为和基因表达谱，并测量对急性和慢性体内 SSRI 给药和其他治疗的反应代理。因此，这些独特小鼠模型的产生为探索激酶介导的 SERT 调节途径提供了创新工具，这些途径是破坏与疾病相关的人类 SERT 变体中发现的正常 SERT 功能的设定点。此外，这些SERT转基因小鼠将有助于未来的研究，探索可能与精神障碍相关的血清素相关基因调控网络，并有助于开发治疗精神障碍的有效药物。 公共健康相关性：人类 SERT 编码变体 Gly56Ala、Ile425Val 突变与强迫症、自闭症和其他精神疾病的关联，以及这些突变体改变 PKG/p38 MAPK 对 SERT 活性的调节的发现表明，这种形式的调节在正常情况下很重要。 SERT 的生理学。拟议的生成敲入小鼠模型的研究将能够识别与精神障碍相关的神经元网络，并有助于开发有效的药物制剂来治疗精神障碍和由异常单胺传递引起的其他疾病状态。