Airway Epithelial Cell Release of GABA is Regulated by Protein Kinase A.
Airway Epithelial Cell Release of GABA is Regulated by Protein Kinase A.
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DOI：
10.1007/s00408-016-9867-2
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发表时间：
2016-06
期刊：
影响因子：
5
通讯作者：
Emala CW
中科院分区：
文献类型：
--
作者：
Danielsson J;Zaidi S;Kim B;Funayama H;Yim PD;Xu D;Worgall TS;Gallos G;Emala CW
γ-氨基丁酸（GABA）不仅是中枢神经系统（CNS）中主要的抑制性神经递质，而且在肺、介导气道平滑肌松弛和粘液生成等方面也起着重要作用。由于已知蛋白激酶A （PKA）等激酶通过GABA转运体调节GABA在中枢神经系统中的释放和再摄取，我们假设β-激动剂会通过激活PKA来影响气道上皮细胞中GABA的释放。C57/BL6小鼠接受β-激动剂或载体（PBS）预处理，然后给予甲胆碱或PBS。收集支气管肺泡灌洗液（BAL）， HPLC质谱法测定GABA的含量。在体外研究中，培养的BEAS-2B人气道上皮细胞负载3H-GABA。在PKA和酪氨酸激酶信号通路的激活和抑制过程中测量3H-GABA的释放。在甲胆碱攻击前，β-激动剂预处理可降低小鼠BAL体内GABA的释放和去极化BEAS-2B细胞中3H-GABA的释放。BEAS-2B细胞中GABA的释放也因cAMP的增加而减少，但Epac或酪氨酸激酶的激活并没有减少。β-激动剂通过激活cAMP和PKA减少气道上皮中GABA的释放。这具有重要的治疗意义，因为β-激动剂和GABA是粘液产生和气道平滑肌张力的重要介质。
γ-amino butyric acid (GABA) is not only the major inhibitory neurotransmitter in the central nervous system (CNS), but it also plays an important role in the lung, mediating airway smooth muscle relaxation and mucus production. As kinases such as protein kinase A (PKA) are known to regulate the release and reuptake of GABA in the CNS by GABA transporters, we hypothesized that β-agonists would affect GABA release from airway epithelial cells through activation of PKA. C57/BL6 mice received a pretreatment of a β-agonist or vehicle (PBS), followed by methacholine or PBS. Bronchoalveolar lavage (BAL) was collected and the amount of GABA was quantified using HPLC mass spectrometry. For in vitro studies, cultured BEAS-2B human airway epithelial cells were loaded with 3H-GABA. 3H-GABA released was measured during activation and inhibition of PKA and tyrosine kinase signaling pathways. β-agonist pretreatment prior to methacholine challenge attenuated in vivo GABA release in mouse BAL and 3H-GABA release from depolarized BEAS-2B cells. GABA release was also decreased in BEAS-2B cells by increases in cAMP but not by Epac or tyrosine kinase activation. β-agonists decrease GABA release from airway epithelium through the activation of cAMP and PKA. This has important therapeutic implications as β-agonists and GABA are important mediators of both mucus production and airway smooth muscle tone.