Nuclear factor kappa B pathway down-regulates aquaporin 5 in the nasal mucosa of rats with allergic rhinitis.

Nuclear factor kappa B (NF-κB) induces gene transcription by binding CREB-binding protein (CBP). The aim of the study was to detect the mechanisms by which NF-κB pathway regulated aquaporin 5 (AQP5) in the nasal mucosa of rats with allergic rhinitis (AR). Rats were divided into control (group C), model (group M), low-dose proline dithiocarbamate (PDTC) (group L) and high-dose PDTC (group H) groups. AR model was established by the sensitization with ovalbumin, then groups L and H were treated with PDTC (50 or 100 mg/kg/day) for 5 days. AQP5, interleukin-1β, NF-κBp65 and phosphorylated cAMP-response element binding protein (p-CREB) were detected by immunohistochemistry, Western blotting or real-time PCR. AQP5 expression in group M was lower than in group C, but in groups L and H it increased. NF-κBp65 expression in group M was higher than group C, but in groups L and H it reduced. p-CREB expression in group M was lower than group C, but in groups L and H it increased. Interleukin-1β gene level in group M was higher than group C, but in groups L and H it was lower. These data show that the NF-κB pathway could down-regulate AQP5 by interleukin-1β which inhibited CREB phosphorylation or by NF-κBp65 which competitively bound CBP.