A new function of aquaporin provide a insight into the molecular mechanism to inhibit inflammatory response

水通道蛋白5（AQP 5）表达于支气管浆液细胞和外分泌腺，对气道水平衡起重要作用。在本研究中，我们研究了AQP 5在炎症反应中的作用。AQP 5在各种细胞中的过表达增加了细胞因子的表达、磷酸化ERK的稳定水平和NF-κ B的活性。因此，我们假设ERK和NF-κ B对AQP 5的这种新功能很重要。此外，AQP 1和AQP 5 -1CT嵌合体（其将AQP 5的C-末端转化为AQP 1）均未能增加细胞因子表达，表明AQP 5的C-末端对于增加炎症反应是重要的。最后，我们发现肉桂提取物作为ERK磷酸化和AQP 5细胞因子表达的抑制剂。总之，我们提出了一个新的功能，AQP 5，作为一种细胞因子信号增强剂，肉桂可能是有用的，以控制AQP 5表达细胞的炎症反应。

Aquaporin-5 (AQP5) is expressed in bronchial serous cells and exocrine gland, plays an important role for water homeostasis in airway. In the present study, we have examined the role of AQP5 for inflammatory response. Overexpression of AQP5 to various cells increased cytokine expression, steady level of phosphorylated ERK, and activity of NF-kappaB. Therefore, we assume that ERK and NF-kappaB are important for this new function of AQP5. Further, both AQP1 and AQP5-1CT chimera, which is converted C-terminal of AQP5 to AQP1, failed to increase cytokine expression, suggesting C-terminal of AQP5 is important for increased inflammatory response. Finally, we found extract of cinnamon as an inhibitor of ERK phosphorylation and cytokine expression by AQP5. Take together, we propose a new function of AQP5, as a cytokine signal enhancer, and cinnamon may be useful to control inflammatory response in AQP5 expressing cells.