LXA4 stimulates ZO-1 expression and transepithelial electrical resistance in human airway epithelial (16HBE14o-) cells

Lipoxin A4 (LXA4) is a biologically active eicosanoid produced in human airways that displays anti-inflammatory properties. In cystic fibrosis and severe asthma, LXA4 production has been reported to be decreased, and, in such diseases, one of the consequences of airway inflammation is disruption of the tight junctions. In the present study, we investigated the possible role of LXA4 on tight junction formation, using transepithelial electrical resistance (TER) measurements, Western blotting, and immunofluorescence. We observed that exposure to LXA4 (100 nM) for 2 days significantly increased zonula occludens-1 (ZO-1), claudin-1, and occludin expression at the plasma membrane of confluent human bronchial epithelial 16HBE14o- cells. LXA4 (100 nM) stimulated the daily increase of the 16HBE14o- cell monolayer TER, and this effect was inhibited by boc-2 (LXA4 receptor antagonist). LXA4 also had a rapid effect on ZO-1 immunofluorescence at the plasma membrane and increased TER within 10 min. In conclusion, our experiments provide evidence that LXA4 plays certainly a new role for the regulation of tight junction formation and stimulation of the localization and expression of ZO-1 at the plasma membrane through a mechanism involving the LXA4 receptor.