Kainate Receptors as a Target for the Anticonvulsant Perampanel

红藻氨酸受体作为抗惊厥药吡仑帕奈的靶点

基本信息

批准号：
10452382
负责人：
GEOFFREY T SWANSON
金额：
$ 23.07万
依托单位：
NORTHWESTERN UNIVERSITY AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-04-01 至 2024-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10452382
关键词：
AMPA Receptors Adverse effects Amino Acids Analgesics Animal Model Animals Anticonvulsants Anxiety Behavioral Assay Binding Binding Sites Brain Brain region Chronic Clinical Complex Data Dose Elements Epilepsy Equilibrium Exploratory/Developmental Grant Family Functional disorder Generations Glutamate Receptor Hippocampal Mossy Fibers Hippocampus (Brain)Kainic Acid Receptors Knockout Mice Lead Mediator of activation protein Modeling Molecular Mus Neurons Outcome Pharmaceutical Preparations Pharmacology Play Population Proteins Receptor Activation Receptor Inhibition Receptor Signaling Recombinants Recurrence Refractory Resolution Role Seizures Spinal Ganglia Synapses Testing Therapeutic Therapeutic Effect Therapeutic Index Treatment Efficacy antagonist cell type experimental study high risk hippocampal pyramidal neuron inhibitor innovation mossy fiber neurotransmission pain behavior pain model patch clamp postsynaptic pre-clinical receptor receptor sensitivity side effect

项目摘要

SUMMARY Perampanel (PMP) is a third-generation anticonvulsant that acts as a noncompetitive allosteric modulator (NAM) of AMPA receptors, the ionotropic glutamate receptors (iGluRs) that serve as principle mediators of excitatory neurotransmission in the CNS. Its anticonvulsant activity is thought to result from dampening hyperexcitability in an epileptic brain through AMPA receptor inhibition. The recent structural resolution of the binding site for PMP on the GluA2 AMPA receptor subunit revealed fine details into determinants of its NAM activity but also underscored the conservation of critical binding residues in AMPA and kainate receptor (KAR) subunits, a distinct but related family of iGluRs. KARs serve a variety of functions in the CNS that are generally characterized as modulating a balance between excitation and inhibition tone. We hypothesize that PMP acts as a NAM on KARs and that this activity in part contributes to its therapeutic efficacy. Our preliminary results provide initial tentative support for this hypothesis and additionally reveal that PMP inhibition depends on the incorporation of a specific KAR subunit, GluK5, into the receptor complex. In this project, we propose to explore this observation further in three related aims. In Specific Aim 1, we will test the hypothesis that PMP is a subunit-selective noncompetitive antagonist of KARs and explore the importance of key amino acid residues in the PMP binding domains that control sensitivity of KARs to the modulator. In Specific Aim 2, we will test if PMP inhibits neuronal KARs at hippocampal mossy fiber synapses on CA3 pyramidal neurons and in dorsal root ganglion neurons. Both of these types of neuronal receptors are known to contain the GluK5 subunit. We will compare relative inhibition of receptors in wildtype and GluK5-/- mice to test the hypothesis that GluK5 forms a key substrate for PMP inhibition in the CNS. In Specific Aim 3, we will discriminate between modulatory activity on AMPA vs. kainate receptors by comparing potency of PMP in wildtype and GluK5-/- knockout mice in animal seizure, anxiety, and pain models, indications in which PMP shows efficacy. These objectives are significant because they could change our understanding of the mechanism of action of the third-generation anticonvulsant perampanel. Optimization of inhibitors that effectively discriminate between AMPA and kainate receptors could lead to a new generation of drugs with larger therapeutic indices.

概括吡仑帕奈 (PMP) 是第三代抗惊厥药，充当非竞争性变构调节剂 AMPA 受体（NAM），离子型谷氨酸受体（iGluR），作为主要介质中枢神经系统的兴奋性神经传递。它的抗惊厥活性被认为是由于抑制通过抑制 AMPA 受体使癫痫大脑过度兴奋。最近的结构决议 GluA2 AMPA 受体亚基上 PMP 的结合位点揭示了其 NAM 决定因素的详细信息活性，但也强调了 AMPA 和红藻氨酸受体 (KAR) 中关键结合残基的保守性亚基，一个独特但相关的 iGluR 家族。 KAR 在 CNS 中具有多种功能，通常是其特征是调节兴奋和抑制音之间的平衡。我们假设 PMP 作为 KAR 上的 NAM，并且这种活性部分有助于其治疗功效。我们的初步结果为这一假设提供了初步的初步支持，并进一步表明 PMP 抑制取决于特定 KAR 亚基 GluK5 并入受体复合物。在在这个项目中，我们建议在三个相关目标中进一步探索这一观察结果。在具体目标 1 中，我们将测试假设 PMP 是 KAR 的亚基选择性非竞争性拮抗剂，并探讨其重要性 PMP 结合域中控制 KAR 对调节剂敏感性的关键氨基酸残基的数量。在具体目标 2，我们将测试 PMP 是否抑制 CA3 上海马苔藓纤维突触的神经元 KAR 锥体神经元和背根神经节神经元。已知这两种类型的神经元受体含有 GluK5 亚基。我们将比较野生型和 GluK5-/- 小鼠受体的相对抑制来进行测试假设 GluK5 是中枢神经系统中 PMP 抑制的关键底物。在具体目标 3 中，我们将通过比较 PMP 的效力来区分 AMPA 与红藻氨酸受体的调节活性动物癫痫、焦虑和疼痛模型中的野生型和 GluK5-/- 敲除小鼠，其中 PMP 的适应症显示功效。这些目标很重要，因为它们可以改变我们对作用机制的理解。第三代抗惊厥药吡仑帕奈。有效区分抑制剂的优化 AMPA 和红藻氨酸受体可能会产生具有更大治疗指数的新一代药物。