Eosinophil Mechanisms of Sensory Neuroplasticity in a Murine Model of Asthma

描述（由申请人提供）：哮喘是一种慢性肺部炎症性疾病，是一种重要的健康负担。虽然适当使用哮喘药物可以成功地减少损害，但它们不能减缓病情进展，并可能增加病情恶化的风险。哮喘也是一种异质性疾病，具有多种病理特征和治疗耐药亚型。以下项目旨在深入了解感觉神经可塑性，或哮喘中感觉神经元的变化，这是一个既定的治疗靶点和表征哮喘亚型的有用工具。哮喘气道感觉神经元功能障碍，引起气道高反应性。由于表征气道神经支配的障碍，尚不清楚神经元结构的上游变化和感觉功能障碍背后的刺激因素。对于目前的项目，开发了一种新的方法，允许全气道神经支配的可视化和神经分支和神经密度的计算机量化。我们已经表明，气道中嗜酸性粒细胞的增加导致神经分支点和长度加倍。这项研究的长期目标是将这项技术与转基因、体外和分子方法结合使用，以表征和了解哮喘相关的感觉神经可塑性。在类似疾病的数据和初步数据的指导下，目前的项目将测试两种哮喘模型中感觉神经元分支和密度是否通过嗜酸性粒细胞增加，分支生长是否与感觉神经诱导的反射性支气管收缩增加相关。初步数据已经证明了其中的一些变化。该项目随后将研究嗜酸性粒细胞衍生的神经营养因子在哮喘相关感觉神经可塑性产生中的作用。目前的项目将使用几种哮喘小鼠模型，包括1.)和白蛋白致敏和激发模型，2.)缺乏嗜酸性粒细胞的转基因小鼠，以及3.)表现出过度嗜酸性粒细胞的转基因小鼠。第一个目的是，气道神经分支和长度将通过计算神经模型进行量化，并与反射性支气管收缩的功能读数进行比较。第二个目的是利用共培养系统研究嗜酸性神经营养因子（NGF， BDNF, NT-3, NT-4）释放对感觉神经可塑性的作用。嗜酸性粒细胞和感觉神经元共培养将与外源性神经营养因子和神经营养因子阻断抗体一起使用，随后定量神经元分支生长。

DESCRIPTION (provided by applicant): Asthma is a chronic inflammatory disease of the lung and a significant health burden. Although appropriate usage of asthma medications successfully reduces impairment they do not slow progression and potentially increase risk of exacerbation. Asthma is also a heterogenous disease with various pathologic features and treatment-resistant subtypes. The following project aims to offer insight into sensory neuroplasticity, or how sensory neurons change in asthma, which is an established therapeutic target and useful tool to characterize asthma subtypes. Airway sensory neurons in asthma malfunction and cause airway hyperreactivity. The upstream changes to neuron structure and inciting factor behind sensory dysfunction are unknown due to obstacles in characterizing airway innervation. For the current project a novel method was developed permitting the visualization of whole airway innervation and computerized quantification of nerve branching and nerve density. We have shown that increased eosinophils in the airway results in a doubling of nerve branchpoints and length. The long term goal of this research is to use this technique in tandem with transgenic, in vitro, and molecular approaches to characterize and understand asthma-related sensory neuroplasticity. Guided by data from similar diseases and preliminary data, the current project will test if sensory neuron branching and density increases via eosinophils in two asthma models and if branched outgrowth correlates with increased sensory nerve-induced reflex bronchoconstriction. Preliminary data has already demonstrated some of these changes. This project will subsequently investigate the role of eosinophil-derived neurotrophins in producing asthma-related sensory neuroplasticity. The current project will use several mouse models of asthma including 1.) an valbumin sensitization and challenge model, 2.) transgenic mice lacking eosinophils, and 3.) transgenic mice exhibiting overabundant lung eosinophils. For the first aim, airway nerve branching and length will be quantified with computational nerve modeling and compared to a functional readout, that of reflex bronchoconstriction. The second aim is to investigate the role of eosinophil neurotrophin (NGF, BDNF, NT-3, NT-4) release on sensory neuroplasticity using a co-culture system. Eosinophil and sensory neuron co-cultures will be used with exogenous administration of neurotrophins, and neurotrophin blocking antibodies followed by quantification of neuron branched outgrowth.