Expression of GABAergic system in pulmonary neuroendocrine cells and airway epithelial cells in GAD67-GFP knock-in mice
Expression of GABAergic system in pulmonary neuroendocrine cells and airway epithelial cells in GAD67-GFP knock-in mice
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DOI：
10.1007/s00795-007-0391-6
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发表时间：
2008-05
影响因子：
1.8
通讯作者：
Yasuaki Yabumoto;Masahito Watanabe;Y. Ito;K. Maemura;Y. Otsuki;Yumi Nakamura;Y. Yanagawa;K. Obata;Katsuya Watanabe
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文献类型：
--
作者：
Yasuaki Yabumoto;Masahito Watanabe;Y. Ito;K. Maemura;Y. Otsuki;Yumi Nakamura;Y. Yanagawa;K. Obata;Katsuya Watanabe
γ-氨基丁酸（GABA）是大脑中主要的抑制性神经递质，也位于许多外周非神经元组织中。谷氨酸脱羧酶67-绿色荧光蛋白（GAD 67-GFP）基因敲入小鼠是研究GABA能细胞在多种组织器官中分布的理想模型。这些小鼠的肺含有仅在气道上皮中具有强烈GFP信号的细胞。我们的目的是表征GFP阳性细胞，并阐明它们与GABA能系统的关系。我们通过免疫组织化学的蛋白基因产物9.5和降钙素基因相关肽和超微结构分析，确定GFP阳性细胞为肺神经内分泌细胞（PNECs）。GADs和GABA的免疫组化显示GAD 65/67和GABA在GFP阳性的PNEC中。逆转录-聚合酶链反应分析显示，在肺中，编码GABA受体亚单位的mRNA是功能性受体R1和R2组装所必需的。GABA受体亚单位R1和R2蛋白表达于许多气道上皮细胞，包括肺泡上皮细胞，而不是GFP阳性的PNEC。本研究结果表明，在气道上皮细胞的PNEC有一个GABA的生产系统，并表明GABA通过GABA受体在气道上皮细胞中发挥功能作用。
Gamma-aminobutyric acid (GABA), a major inhibitory neurotransmitter in the brain, is also located in many peripheral nonneuronal tissues. The glutamate decarboxylase 67-green fl uorescent protein (GAD67-GFP) knock-in mouse is a useful model for studying the distribution of GABAergic cells in many tissues and organs. The lungs of these mice contain cells with an intense GFP signal exclusively in the airway epithelium. We aimed to characterize the GFP-positive cells and to clarify their relationship with the GABAergic system. We identified the GFPpositive cells as pulmonary neuroendocrine cells (PNECs) by immunohistochemistry for the protein gene product 9.5 and calcitonin gene-related peptide and by ultrastructural analysis. Immunohistochemistry for GADs and GABA revealed GAD65/67 and GABA in GFP-positive PNECs. Reverse transcription-polymerase chain reaction analyses revealed mRNAs encoding the GABABreceptor subunits necessary for the assembly of functional receptors, R1 and R2, in the lung. GABABreceptor subunit R1 and R2 proteins were expressed in many airway epithelial cells including alveolar epithelial cells other than GFP-positive PNECs. The present findings demonstrated that PNECs in the airway epithelium have a GABA production system and indicated that GABA plays functional roles in airway epithelial cells through GABABreceptors.