Probing brain circuit and behavior with protein:protein interaction modulators

摘要 精神疾病是与脑回路的适应不良可塑性相关的复杂脑障碍， 我们缺乏临床疗效的预测性临床前测量。为了填补这一空白，我们需要使用分子 为开发新型探针提供信息的知识，以询问电路基础的机制 这些疾病的缺陷，并推动先进的治疗设计。离子内蛋白质-蛋白质相互作用（PPI） 通道复合物微调神经元的兴奋性，并正在成为精神疾病的生物学联系。 紊乱它们的高度特异性和灵活的界面使蛋白质-通道相互作用成为探针的理想靶点 发展这样的分子探针将为神经药理学界提供最佳的研究 分析大脑疾病的复杂性并实现更有效的药物设计的工具。 我们已经确定了电压门控Na+（Nav）Nav1.6通道及其辅助调节器之间的PPI 蛋白质，成纤维细胞生长因子14（FGF 14）作为功能相关的调节介质棘的兴奋性 神经元（MSN）在脑桥核（NAc）;中皮质边缘回路的中央组成部分， 功能障碍与广泛的神经精神障碍有关。通过 基于生物发光的高通量筛选（HTS）和一轮化学优化，我们已经确定 新的脑可渗透探针1028，其调节FGF 14：Nav1.6通道复合物的形成并增加 Nav1.6频道可用性和MSN射击。当全身给药时，1028增加了 在缺乏动机的情况下，神经元放电并促进享乐状态，这表明该化合物可以 调节中皮层边缘回路中与奖赏相关的行为。在此，我们建议进一步 通过提高其效力和代谢稳定性优化1028用于体内使用，并确定其 在分子（目标1）、细胞（目标2）、电路和行为水平（目标3）发挥作用。这件事的结果 拟议中的研究将产生一流的大脑渗透化学探针，以询问奖励 电路，为治疗前开发一类新的基于PPI的电极导线提供基础，用于广泛的 一系列精神疾病

ABSTRACT Psychiatric diseases are complex brain disorders associated with maladaptive plasticity of the brain circuit for which we lack predictive preclinical measures of clinical efficacy. To fill this gap, we need to use molecular knowledge to inform development of novel probes in order to interrogate the mechanisms that underlie circuit deficits in these disorders and drive advanced therapeutic design. Protein-protein interactions (PPI) within ion channel complexes fine-tune neuronal excitability and are emerging as links to the biology of psychiatric disorders. Their highly specific and flexible interfaces make protein-channel interactions ideal targets for probe development. Such molecular probes would provide the neuropharmacology community with optimal research tools to parse out brain disease complexities and enable more effective drug design. We have identified the PPI between the voltage-gated Na+ (Nav) Nav1.6 channel and its accessory regulator protein, fibroblast growth factor 14 (FGF14) as a functionally relevant regulator of excitability of medium spiny neurons (MSN) in the nucleus accumbens (NAc); a central component of the mesocorticolimbic circuit whose dysfunction has been associated with a wide spectrum of neuropsychiatric disorders. Through a bioluminescence-based high-throughput screen (HTS) and a round of chemical optimization we have identified the new brain permeable probe 1028 that modulates FGF14:Nav1.6 channel complex formation and increases Nav1.6 channel availability and MSN firing. When systemically administrated, 1028 increases accumbal neuron firing and promotes hedonic states in situations lacking motivation, suggesting the compound can modulate reward-related behaviors within the mesocorticolimbic circuit. Here, we are proposing to further optimize 1028 for in vivo use by improving its potency and metabolic stability and determine its mechanism of action at the molecular (Aim 1), cellular (Aim 2), circuital, and behavioral levels (Aim 3). Outcomes of this proposed research will generate the first-in-class brain-permeant chemical probes to interrogate the reward circuit, providing the foundation for pre-therapeutic development of a new class of PPI-based leads for a broad spectrum of psychiatric disorders.