Validation of FGF14 as a New Molecular Target of GSK3

验证 FGF14 作为 GSK3 的新分子靶点

• 批准号: 8838257
• 负责人: Fernanda Laezza
• 金额: $ 38.25万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8838257
• 关键词: Action Potentials; Addictive Behavior; Binding; Biochemical; Biochemistry; Biological Assay; Biology; Bioluminescence; Brain; Cell Culture System; Cells; Chronic; Co-Immunoprecipitations; Complex; Confocal Microscopy; Data; Development; Disease; Drug Targeting; Electrophysiology (science); Enzymes; Functional disorder; Glycogen Synthase Kinase 3; Hippocampus (Brain); Image; Intervention; Life; Link; Maintenance; Mass Spectrum Analysis; Mental Depression; Mental disorders; Modeling; Molecular; Molecular Biology; Molecular Target; Mood Disorders; Neuronal Dysfunction; Neuronal Plasticity; Neurons; Outcome Study; Pathway interactions; Peptides; Pharmaceutical Preparations; Pharmacotherapy; Phenotype; Phosphorylation; Proto-Oncogene Proteins c-akt; Repressor Proteins; Rodent Model; Role; Schizophrenia; Site; Site-Directed Mutagenesis; Slice; Symptoms; Synapses; Synaptic Transmission; Technology; Testing; Therapeutic Intervention; Time; Validation; base; cellular imaging; cortico-limbic circuits; fibroblast growth factor-14; genetic approach; in vivo; innovation; insight; multidisciplinary; mutant; neuroadaptation; neuronal circuitry; neuronal excitability; novel; patch clamp; prevent; screening; success; tool

DESCRIPTION (provided by applicant): Psychiatric diseases are chronic, devastating disorders thought to arise from maladaptive brain plasticity, and potent and safe pharmacotherapies are in great need. Identifying the mechanistic links that might sustain these aberrant neuroadaptations will advance our understanding of the biology of mental disorders, potentially providing new platforms for medication development. Using an innovative bioluminescence-based molecular screening approach combined with biochemical, electrophysiological, and imaging assays, we provide breakthrough results showing a link between glycogen synthase kinase 3 (GSK3), a critical enzyme found dysfunctional in mood disorders, depression and schizophrenia, and neuronal excitability, which we propose as a potential mechanism underlying dysfunction of neuronal circuitries associated with psychiatric disorders and certain addictive behaviors. Building on previous discoveries demonstrating that fibroblast growth factor 14 (FGF14) is a functionally relevant component of the Nav channelosome that controls neuronal excitability, we present exciting new data showing that the FGF14:Nav channel complex formation is bi-directionally controlled by GSK3 and by the GSK3 constitutive repressor, protein kinase B (Akt), and that GSK3 directly phosphorylates FGF14. Pharmacological inhibition of Akt and GSK increases and prevents, respectively, the FGF14:Nav channel complex formation, whereas inhibition of GSK3 occludes the effect of Akt inhibition. In hippocampal neurons, GSK3 inhibition disperses the FGF14:Nav channel complex from the axonal initial segment (AIS), the site of action potential initiation, impairs intrinsic fring and reduces excitatory synaptic transmission, whereas inhibition of Akt leads to opposite phenotypes. Furthermore, we show that Fpep1, a small interfering peptide modeled upon the FGF14:Nav channel interface, prevents the FGF14:Nav channel complex assembly, providing a tool for minimizing the effect of GSK3 on neuronal excitability in vivo. In this proposal we will employ a combination of bioluminescence-based technology, mass spectrometry, phosphorylation assays, confocal imaging and electrophysiology to determine the molecular mechanism by which GSK3 controls the FGF14:Nav channel complex formation (Aim 1) and promotes targeting of the FGF14:Nav channel complex in neurons (Aim 2) and to evaluate whether GSK3 exerts an effect on excitability and neuroplasticity in cortico-limbic circuits through the FGF14:Nav channel complex that could be reversed by pharmacological or genetic approaches targeting FGF14 (Aim 3). Positive outcomes of this study will provide new insights into the molecular mechanisms of GSK3 in the brain and offer an unprecedented opportunity for new medication development against GSK3-linked psychiatric disorders.

描述（由申请人提供）：精神病是慢性，毁灭性疾病，认为是由适应不良的大脑可塑性引起的，并且非常需要强大而安全的药物治疗。确定可能维持这些异常神经适应的机械联系将提高我们对精神障碍生物学的理解，从而为药物开发提供新的平台。使用创新的生物发光的分子筛选方法结合生物化学，电生理和成像测定法，我们提供了突破性的结果，显示了糖原合酶激酶3（GSK3）之间的联系，这是一种关键的酶（一种关键的酶，发现情绪障碍，抑郁症和抑郁症，抑郁症，抑郁症和精神分裂元素功能障碍，兴奋性，我们建议是与精神疾病和某些成瘾行为相关的神经元电路功能障碍的潜在机制。基于先前的发现，表明成纤维细胞生长因子14（FGF14）是控制神经元兴奋性的NAV Channelosoms的功能相关组成部分，我们提供了令人兴奋的新数据，表明FGF14：NAV Channel Complect构造由GSK3和GSK3进行了双向控制。 GSK3组成型抑制剂，蛋白激酶B（AKT），GSK3直接磷酸化FGF14。 AKT和GSK的药理抑制作用分别增加和预防FGF14：NAV通道复合物的形成，而GSK3的抑制作用闭塞了Akt抑制的作用。在海马神经元中，GSK3抑制作用分散了FGF14：NAV通道复合物，从轴突初始段（AIS）（AIS）（动作电势启动部位）损害固有的边缘并减少兴奋性突触传播，而AKT的抑制会导致相反的现象。此外，我们表明FPEP1是一种模拟FGF14：NAV通道界面的小型干扰肽，可防止FGF14：NAV通道复合物组件，提供了一种工具，可将GSK3对VIVO神经元兴奋性的影响最小化。在此提案中，我们将采用基于生物发光的技术，质谱，磷酸化测定，共聚焦成像和电生理学的结合来确定GSK3控制FGF14：NAV通道复合物形成（AIM 1）并促进FGF14的靶向FGF14的分子机制：神经元中的NAV通道复合物（AIM 2）并评估GSK3是否对通过FGF14：NAV通道复合物在Cortico-limbic电路中对兴奋性和神经可塑性产生影响，而NAV通道复合物可以通过靶向FGF14的药理或遗传方法反转（AIM 3）。这项研究的积极结果将为大脑中GSK3的分子机制提供新的见解，并为针对GSK3连接的精神疾病提供新的药物开发提供了前所未有的机会。