Fig. 4.

EGFR tyrosine kinase inhibitor attenuates goblet cell metaplasia in HDM-induced lung disease. A: goblet cells were detected in lung sections from mice treated with HDM or saline for 6 wk. Top: immunohistochemical staining for CLCA3 in goblet cells (see high-power inset, brown arrows). Middle: Alcian blue histochemical staining that detects mucopolysaccharides in goblet cells (blue arrows). Increases in goblet cell markers CLCA3 and Alcian blue staining with chronic HDM treatment were reduced by treatment with the EGFR inhibitor erlotinib. Bottom: periodic acid-Schiff histochemical staining (red arrows). Bar = 100 μm. B: goblet cells identified by CLCA3 immunostaining were counted in 100- to 600-μm airways and normalized to the length of the basement membrane (mm). Data are from 5–7 animals per group. *P < 0.05 vs. WT saline control group; #P < 0.05 vs. WT HDM.