Central Nervous System Plasticity in Airway Disease

项目摘要 急性发作（哮喘发作）占所有哮喘死亡的近三分之一。尽管精神疾病作为 哮喘死亡的危险因素，以及哮喘恶化和焦虑之间的许多联系， 引发焦虑的杏仁核区域作为哮喘恶化的驱动因素受到的关注有限。 这是这一领域的一个相当大的差距，如果得到解决，可能会导致新的基于机制的 治疗哮喘恶化和减少患者死亡的方法。对照组小鼠的初步数据令人兴奋 这表明基底外侧杏仁核急性光遗传学激活是焦虑的关键输入中心， 降低气道阻力。在表现出焦虑的哮喘小鼠中，基底外侧的光遗传学激活 杏仁核不能降低气道阻力，提示杏仁核功能障碍。杏仁核功能障碍是 与焦虑有机械联系并以增强的活动和棘突发生为特征（例如，发展 新的树枝状棘）。哮喘小鼠表现出棘状突起形成，活动增强， 对基底外侧杏仁核的功能和结构重塑很重要的基因。调查是否 这些变化在机械上与气道阻力调节受损有关，我们阻断NMDA 谷氨酸受体与MK-801，一种抗焦虑药物，防止焦虑相关的基底外侧杏仁核 脊髓生成和一类降低哮喘气道阻力的药物。我们发现MK-801减轻了 支气管收缩和减少哮喘小鼠的基因表达升高。广泛干扰cAMP- 反应元件结合蛋白（CREB），一种NMDA受体信号传导下游的转录因子 这是维持杏仁核神经可塑性所必需的，也减弱了哮喘小鼠的支气管收缩。 这些数据指导了我们的中心假设，即基底外侧杏仁核经历NMDA-CREB依赖性 可塑性，破坏气道调节和促进病理性支气管收缩。为了验证这个假设， 我们提出三个具体目标。在目标1中，我们将使用光遗传学方法来激活或抑制兴奋性神经元 的小鼠基底外侧杏仁核，以检验基底外侧杏仁核调节气道的假设 阻力在目标2中，我们使用药理学方法，磁共振成像，RNA显微镜和高尔基体， 染色以检验实验性哮喘在结构和功能上重塑基底外侧 杏仁核通过NMDA受体信号传导。最后，在目的3中，我们使用CRE-lox技术和转基因小鼠， 为了检验基底外侧杏仁核中CREB的消融或过表达使杏仁核中CREB的表达增加或减少的假设， 分别促进支气管收缩。该提案的完成将建立NMDA-CREB信令， 基底外侧杏仁核是哮喘恶化的关键驱动因素，并强调NMDA受体拮抗剂 哮喘的独立或辅助缓解药物。

PROJECT SUMMARY Exacerbations (asthma attacks) account for nearly one-third of all asthma deaths. Despite psychiatric illness as a risk factor for death from asthma, and many connections between asthma exacerbations and anxiety, the brain region that initiates anxiety, the amygdala, has received limited attention as a driver of asthma exacerbations. This represents a considerable gap in the field, which, if addressed, may lead to new mechanism-based approaches to treat asthma exacerbations and reduce patient deaths. Exciting preliminary data from control mice suggest that acute optogenetic activation of the basolateral amygdala, a key input center essential for anxiety, reduces airway resistance. In asthmatic mice, which show anxiety, optogenetic activation of the basolateral amygdala fails to reduce airway resistance, suggesting amygdala dysfunction. Amygdala dysfunction is mechanistically linked to anxiety and characterized by heightened activity and spinogenesis (e.g., development of new dendritic spines). Asthmatic mice showed spinogenesis, heightened activity, and elevated expression of genes important for functional and structural remodeling in the basolateral amygdala. To investigate whether these changes were mechanistically linked to impaired regulation of airway resistance, we blocked NMDA glutamate receptors with MK-801, an anxiolytic drug that prevents anxiety-associated basolateral amygdala spinogenesis and in a class of drugs that reduce airway resistance in asthma. We found that MK-801 mitigated bronchoconstriction and diminished elevated gene expression in asthmatic mice. Broadly disrupting the cAMP- responsive element-binding protein (CREB), a transcription factor downstream of NMDA receptor signaling necessary for maintenance of amygdala neuroplasticity, also attenuated bronchoconstriction in asthmatic mice. These data guide our central hypothesis that the basolateral amygdala undergoes NMDA-CREB-dependent plasticity that disrupts airway regulation and promotes pathologic bronchoconstriction. To test this hypothesis, we propose 3 Specific Aims. In Aim 1, we will use optogenetic approaches to activate or inhibit excitatory neurons of the murine basolateral amygdala to test the hypothesis that the basolateral amygdala regulates airway resistance. In Aim 2, we use pharmacologic approaches, magnetic resonance imaging, RNAscope, and Golgi staining to test the hypothesis that experimental asthma structurally and functionally remodels the basolateral amygdala through NMDA receptor signaling. Finally, in Aim 3, we use CRE-lox technology and transgenic mice to test the hypothesis that ablation or overexpression of CREB in the basolateral amygdala alleviates or promotes, respectively, bronchoconstriction. Completion of this proposal will establish NMDA-CREB signaling in the basolateral amygdala as a key driver of asthma exacerbations and highlight NMDA receptor antagonists as a stand-alone or adjunct relief medications for asthma.