気道上皮細胞のaquaporin-5はin vivo 実験系でLPSによって誘発される炎症性サイトカイン発現を亢進する．

抄録

Aquaporins (AQPs) are the water channel that facilitate water transport through plasma membrane. Among 13 AQP isoforms, AQP5 is selectively expressed in apical membrane of exocrine glands, airway and alveolar epithelial cells, and plays important role to maintain water secretion and clearance in airway tracts. Recently, it is revealed that AQPs have new functions, as well as water transport. In our previous study, AQP5 enhances TNF-α-induced chemokine expression in vitro experiments. It has also known that the expression of AQP5 is markedly reduced in airway inflammation mouse model. Therefore, changes in AQP5 expression may be contribute to the pathogenesis of inflammatory respiratory diseases. In this study, we have established a transgenic (Tg) mouse in which AQP5 is highly expressed specifically in the airway epithelial cells, to confirm the significance of the AQP5-madiated regulation in cytokine expression. Intratracheal treatment of LPS increased the expression of inflammatory cytokines, such as KC, TNF-α and IL-6 in WT mice. In AQP5-Tg mice, the increase in the expression of these cytokines by LPS was considerably less than that in WT. These results indicated that AQP5 can enhance airway inflammation not only in vitro, but also in vivo conditions.