Department of Biochemistry, National Defense Medical Center.
Department of Radiation Oncology, Tri-Service General Hospital, National Defense Medical Center.
Int J Med Sci. 2017 Sep 30;14(12):1268-1275. doi: 10.7150/ijms.21573. eCollection 2017.
Aquaporin 5 (AQP5) is most likely the primary water channel in the human nasal mucosa and acts as a key tight junction protein. The signaling cascades responsible for AQP5 regulation are still works in progress. This study sought to determine the effects of histamine and chlorpheniramine on AQP5 expression in human nasal epithelial cells (HNEpC) and to detect the signaling cascades responsible for these effects. HNEpC were cultured with four concentrations of histamine or chlorpheniramine in vitro. The sub-cellular distribution of AQP5 was explored using immunocytochemistry. The pharmacologic effects of histamine and chlorpheniramine on the expression of the phosphorylation of cyclic adenosine monophosphate-responsive element binding protein (p-CREB), the AQP5 and the NF-κB protein were examined using Western blotting. AQP5 was found to be located in cell membrane and cytoplasm and present in every group without significant difference. Histamine inhibits the expression of AQP5 and p-CREB in HNEpC, while chlorpheniramine dose-dependently increases these protein levels with statistical significance. HNEpC treated with histamine and chlorpheniramine in turn showed the same trends as those intervened separately with these two drugs. Moreover, chlorpheniramine had the ability to reverse the inhibitory effect of histamine. Western blotting analysis revealed that after incubation with 10 M histamine, NF-κB protein was significantly heightened by 165% compared with the untreated control group. Again, such increase can be significantly reversed after chlorpheniramine treatment. The current study demonstrated that histamine inhibits CREB phosphorylation in HNEpC, which results in decreased AQP5 expression via activation of NF-κB pathway. Chlorpheniramine attenuates the inhibitory effect of histamine in p-CREB/AQP5 expression via suppression of NF-κB signal cascades. This observation could provide additional insight into the anti-inflammatory effects of H1-antihistamines that contribute to maintain airway surface liquid and mucosal defense.
水通道蛋白 5（AQP5）很可能是人类鼻黏膜的主要水通道，并且作为关键的紧密连接蛋白发挥作用。负责 AQP5 调节的信号级联仍在进行中。本研究旨在确定组胺和氯苯那敏对人鼻上皮细胞（HNEpC）中 AQP5 表达的影响，并检测负责这些影响的信号级联。将 HNEpC 在体外与四种浓度的组胺或氯苯那敏一起培养。使用免疫细胞化学法探索 AQP5 的亚细胞分布。使用 Western blot 法检查组胺和氯苯那敏对环磷酸腺苷反应元件结合蛋白（p-CREB）、AQP5 和 NF-κB 蛋白磷酸化表达的药理作用。AQP5 位于细胞膜和细胞质中，在每组中均存在且无显着差异。组胺抑制 HNEpC 中 AQP5 和 p-CREB 的表达，而氯苯那敏则以剂量依赖性方式增加这些蛋白水平，具有统计学意义。用组胺和氯苯那敏处理的 HNEpC 表现出与单独用这两种药物干预相同的趋势。此外，氯苯那敏具有逆转组胺抑制作用的能力。Western blot 分析显示，在用 10 μM 组胺孵育后，NF-κB 蛋白与未处理的对照组相比显着增加了 165％。再次，在用氯苯那敏处理后，这种增加可以显着逆转。本研究表明，组胺抑制 HNEpC 中的 CREB 磷酸化，从而通过激活 NF-κB 途径导致 AQP5 表达减少。氯苯那敏通过抑制 NF-κB 信号级联来减弱组胺对 p-CREB/AQP5 表达的抑制作用。这种观察结果可以为 H1-抗组胺药的抗炎作用提供更多的见解，这些作用有助于维持气道表面液体和黏膜防御。
