Decreased connexin 43 expression correlated with eosinophil infiltration in nasal polyps

A nasal polyp usually is characterized by eosinophil infiltration. Eosinophil-fibroblast interaction is an important event of persistent inflammation in airways. We have found abundant connexin 43 (Cx43) expression in subepithelial fibroblasts of nasal mucosa. Thus, we aim to analyze the relationship of Cx43 expression and eosinophil in nasal polyps.

In 25 nasal polyps and 19 inferior turbinates, indirect immunofluorescent and hematoxylin and eosin staining were performed in adjacent sections. We calculated the density of Cx43 staining and eosinophil individually by fluorescent and light microscope.

Positive Cx43 staining under confocal microscope was shown as punctated spots on cell margin. The density of Cx43 and eosinophil staining was significantly different between groups of inferior turbinate and nasal polyp (p = 0.01 and 0.03, respectively). Decreased Cx43 expression in the subepithelial fibroblast was correlated with eosinophil infiltration in nasal polyps. Spearman rank order coefficient was equal to -0.43 (p < 0.05).

This is the first demonstration of decreased Cx43 expression related to eosinophil infiltration. To the best of our knowledge, interleukin-8 may be a link between Cx43 and eosinophil and orchestrating both in developing nasal polyps.