Asthmatic Airway Vagal Hypertonia Involves Chloride Dyshomeostasis of Preganglionic Neurons in Rats
Asthmatic Airway Vagal Hypertonia Involves Chloride Dyshomeostasis of Preganglionic Neurons in Rats
复制标题
哮喘气道迷走神经张力亢进涉及大鼠节前神经元的氯化物动态平衡失调
DOI：
10.3389/fnins.2020.00031
复制
发表时间：
2020-01-31
影响因子：
4.3
通讯作者：
Wang, Jijiang
中科院分区：
文献类型：
--
作者：
He, Ding;Chen, Hong;Wang, Jijiang
气道迷走神经张力增高与哮喘的严重程度密切相关，但其发生机制尚不清楚。本研究旨在证明哮喘气道迷走神经张力增高与神经元氯离子稳态失调有关。用卵白蛋白制备雄性成年SD大鼠实验性气道变态反应模型。体积描记法用于评价脑池内注射γ-氨基丁酸（GABA）对气道迷走神经的反应。采用免疫荧光染色和Western-blot法检测小胶质细胞特异性蛋白质Na+-K+-2 Cl（-）共转运蛋白1（NKCC 1）、K+-Cl-共转运蛋白2（KCC 2）和脑源性神经生长因子（BDNF）在气道迷走神经中枢的表达。肺组织切片HE染色及支气管肺泡灌洗液（BALF）卵清蛋白特异性IgE（IgE）ELISA检测。结果表明，实验性气道变态反应激活了小胶质细胞，上调了NKCC 1，下调了KCC 2，增加了气道迷走神经中枢BDNF的含量。在功能上，实验性气道过敏增强了对脑池内注射GABA的兴奋性气道迷走神经反应，脑池内预注射NKCC 1抑制剂布美他尼可减弱GABA的兴奋性气道迷走神经反应。慢性侧脑室或腹腔注射米诺环素（一种小胶质细胞活化抑制剂）可预防或减轻实验性气道过敏引起的所有变化。这些结果表明，实验性气道变态反应增强气道迷走神经中枢对GABA的兴奋性反应，这可能是小胶质细胞激活后神经元Cl-稳态失调、BDNF释放增加和Cl-转运体表达改变的结果。气道迷走神经中枢Cl-稳态失调可能参与哮喘气道迷走神经张力增高的发生.
Airway vagal hypertonia is closely related to the severity of asthma; however, the mechanisms of its genesis are unclear. This study aims to prove that asthmatic airway vagal hypertonia involves neuronal Cl- dyshomeostasis. The experimental airway allergy model was prepared with ovalbumin in male adult Sprague-Dawley rats. Plethysmography was used to evaluate airway vagal response to intracisternally injected gamma-aminobutyric acid (GABA). Immunofluorescent staining and Western-blot assay were used to examine the expression of microglia-specific proteins, Na+-K+-2Cl(-) co-transporter 1 (NKCC1), K+-Cl- co-transporter 2 (KCC2) and brain-derived nerve growth factor (BDNF) in airway vagal centers. Pulmonary inflammatory changes were examined with hematoxylin and eosin staining of lung sections and ELISA assay of ovalbumin-specific IgE in bronchoalveolar lavage fluid (BALF). The results showed that histochemically, experimental airway allergy activated microglia, upregulated NKCC1, downregulated KCC2, and increased the content of BDNF in airway vagal centers. Functionally, experimental airway allergy augmented the excitatory airway vagal response to intracisternally injected GABA, which was attenuated by intracisternally pre-injected NKCC1 inhibitor bumetanide. All of the changes induced by experimental airway allergy were prevented or mitigated by chronic intracerebroventricular or intraperitoneal injection of minocycline, an inhibitor of microglia activation. These results demonstrate that experimental airway allergy augments the excitatory response of airway vagal centers to GABA, which might be the result of neuronal Cl- dyshomeostasis subsequent to microglia activation, increased BDNF release and altered expression of Cl- transporters. Cl- dyshomeostasis in airway vagal centers might contribute to the genesis of airway vagal hypertonia in asthma.