Aberrant expression and association of TJs and epithelial cell
markers in nasal biopsy specimens of CRSwNP patients.
First, we investigated the expression and localization of TJs proteins
(ZO-1, occludin and Cldn3) and epithelial cell marker MUC5AC (goblet
cell) and βIV-tubulin (ciliated cell) in control subjects and CRSwNP
patients. The epithelium in CRSwNP patients was damage as shown by loss
of cilia and abnormal epithelium remodeling (goblet cell hyperplasia) by
IF staining (figure 1A-F, G-L, P and Q ). In control
subjects, ZO-1 was consistently expressed and localized at superficial
side of the nasal epithelium (figure 1A and G ) and
occludin was localized at both superficially and suprabasally at the
cell boundaries but a higher intensity at the superficial layer
(figure 1C and I ). Cldn3 was found at the cell
boundaries and at the superficial layer of nasal epithelium
(figure 1E and K ). On the other hand, in CRSwNP
patients, protein expression of ZO-1, occludin and Cldn3 was reduced
(all P <.001; figure 1B, H, M; D, J, N andF, L, O ). Similarly, the mRNA expression levels of ZO-1 ,occludin and Cldn3 were reduced in CRSwNP patients as
compared to the control subject (figure 1R-T ).
Despite higher MUC5AC protein expression in CRSwNP, its mRNA expression
was lower in tissue of CRSwNP (P <.001; figure
1U ) while there was no significant change in mRNA expression ofFoxj1 (figure 1V ). Furthermore, we found that MUC5AC
expression was negatively correlated with occludin (r =-0.374,P =.003; figure 2B ) and Cldn3 (r =-0.386,P =.002; figure 2C ) but not with ZO-1 (r =-0.128,P =.328; figure 2A ) in
nasal biopsies. βIV-tubulin
expression was positively correlated with ZO-1 (r =.529, P<.001; figure 2D ), occludin (r =.566, P<.001; figure 2E ) and Cldn3 (r =.622, P<.001; figure 2F ). Then, we examined the expression
of TJs in ciliated and goblet cells by single cell staining of primary
nasal cells. We found that both ZO-1 (figure 2G and J )
and occludin (figure 2H and K ) were co-stained with
goblet and ciliated cell. Interestingly, Cldn3 staining was only
observed in ciliated cell (figure 2L ) but not goblet cell
(figure 2I ).