Department of Anatomy, Fujian Medical University, Fuzhou City, Fujian, China.
Rhinology. 2011 Oct;49(4):464-9. doi: 10.4193/Rhino10.107.
Aquaporin 5 (AQP5) is a water-specific channel protein. In this study, we investigated the possible role of the cyclic adenosine monophosphate-protein kinase A/cyclic adenosine monophosphate response element binding protein (cAMP-PKA/CREB) pathway in the regulation of AQP5 in nasal epithelial cells.
Rat nasal epithelial cells were cultured and treated with the PKA inhibitor H89 or cAMP inducing medicine forskolin for 12 or 24 hours in vitro. AQP5 and phosphorylated CREB (p-CREB) at serine133 (Ser133) were detected by immunocytochemistry, Western blotting or real-time PCR. Experiments were repeated 10 times.
After treatment with H89 for 12 or 24 hours, the number of cells positive for AQP5 and p-CREB (Ser133) were decreased, p-CREB (Ser133) and AQP5 protein decreased, and AQP5 mRNA decreased. After treatment with forskolin for 12 or 24 hours, the number of p-CREB (Ser133) and AQP5 positive cells increased, p-CREB (Ser133) and AQP5 protein increased, and AQP5 mRNA was increased.
Both H89 (PKA inhibitor) and forskolin (cAMP inducing medicine) regulate AQP5 production through the cAMP-PKA/CREB pathway, which could influence the secretory function of the submucosal glands in nasal epithelium.
水通道蛋白 5（AQP5）是一种水特异性通道蛋白。本研究旨在探讨环磷酸腺苷蛋白激酶 A/环磷酸腺苷反应元件结合蛋白（cAMP-PKA/CREB）通路在调节鼻黏膜上皮细胞 AQP5 中的可能作用。
体外培养大鼠鼻黏膜上皮细胞，用 PKA 抑制剂 H89 或 cAMP 诱导剂 forskolin 分别处理 12 或 24 小时。免疫细胞化学、Western blot 或实时 PCR 检测 AQP5 和磷酸化 CREB（Ser133）。实验重复 10 次。
H89 处理 12 或 24 小时后，AQP5 和磷酸化 CREB（Ser133）阳性细胞数减少，p-CREB（Ser133）和 AQP5 蛋白减少，AQP5mRNA 减少。用 forskolin 处理 12 或 24 小时后，p-CREB（Ser133）和 AQP5 阳性细胞数增加，p-CREB（Ser133）和 AQP5 蛋白增加，AQP5mRNA 增加。
H89（PKA 抑制剂）和 forskolin（cAMP 诱导剂）均通过 cAMP-PKA/CREB 通路调节 AQP5 的产生，从而影响鼻黏膜下腺的分泌功能。
