Figure 6.

Runx2 was essential for HDM-induced goblet cell differentiation and AHR in mouse lungs. A) Knockdown of Runx2 blocked HDM-induced mucin 5AC expression in mouse lungs. Adenovirus expressing GFP (Ad-GFP) or Runx2 shRNA (Ad-shRunx2, 3 × 10¹⁰ PFU/ml, 50 µl) were intranasally administered to HDM-sensitized mice as described in Materials and Methods. Lung tissues were collected 3 d after last HDM challenge, and Western blot analysis was performed to examine protein expression as indicated. B) Quantification of protein expression shown in A by normalizing to GAPDH level. *P < 0.01 compared to Ad-GFP (GFP) group (n = 5). C) Knockdown of Runx2 blocked HDM-induced mucin production in pulmonary epithelium. Control (Ad-GFP)- or Runx2 shRNA (Ad-shRNA)-transduced lung sections were processed for PAS staining for mucin, IHC staining for Runx2, and GFP expression for adenovirus delivery as indicated. Scale bar, 100 µm. D) Mucin production and Runx2 and GFP expression were quantified by normalizing to staining intensity in control sections for each individual protein. Relative levels are shown. *P < 0.01 compared to Ad-GFP group for each corresponding protein (n = 5). E, F) Knockdown of Runx2 diminished HDM-induced asthmatic responses to methacholine. Mice were anesthetized, and methacholine (Meth) challenge test was performed by using FlexiVent to measure airway resistance (AR; E) and airway compliance (AC; F) as indicated. *P < 0.01 compared to corresponding Ad-GFP group (n = 5).