Regulation of ciliary beat frequency by the nitric oxide signaling pathway in mouse nasal and tracheal epithelial cells

ObjectivesOur purpose was to investigate the role of the nitric oxide (NO) signaling pathway in the regulation of ciliary beat frequency (CBF) in mouse nasal and tracheal epithelial cells.MethodsWe studied the effects of the NO donor l-arginine (L-Arg) and specific inhibitors of the NO signaling pathway on CBF of both nasal and tracheal epithelial cells by using high-speed digital microscopy. We also examined eNOS, sGC β, PKG I and acetylated α tubulin expression in native mouse nasal and tracheal epithelium using immunohistochemical methods.ResultsL-Arg significantly increased CBF of cultured nasal and tracheal epithelial cells, and the effects were blocked by pretreatment with NG-nitro-l-arginine methyl ester (L-NAME), a NOS inhibitor, with LY-83583, a sGC inhibitor, or with KT-5823, a PKG inhibitor. Positive immunostaining for NO signaling molecules including eNOS, sGC β and PKG I was observed in either nasal or tracheal ciliated epithelium.ConclusionNO plays a role in regulating CBF of mouse respiratory epithelial cells via a eNOS–NO–sGC β–cGMP–PKG I pathway.