Wnt/β-catenin signaling is inhibited during acute pulmonary inflammation. (A-B) Two-hit LPS and MV model: Mice were treated with LPS and MV (LM) or nonventilated (Control). The mRNA levels (A) of Wnt signaling components in the whole-lung tissues and freshly isolated AECs of LM-treated animals were analyzed by real-time PCR and plotted as a ratio against the control animals, with 18S rRNA as a reference gene. The protein levels (B) of ABC and total β-catenin in the whole-lung tissues of the control and LM-treated animals were determined by western blotting, with β-actin as an internal control. The density of the bands was quantified by ImageJ and normalized to β-actin. The results were expressed as a ratio of the control mice. Data are expressed as the mean ± SEM (n = 5 animals) and statistical significance was determined by Student t test. *P < .05 vs control. (C-D) Influenza viral pneumonia model: Mice were intranasally inoculated with H1N1 influenza A/PR/8/34 virus (250 pfu) and housed for 1 to 7 days (n = 3 per group). The mRNA levels (C) of Wnt signaling components in the whole-lung tissues were measured by real-time PCR and normalized to control animals (without infection) using 18S rRNA as a reference gene. The protein levels (D) of ABC, total β-catenin, and Dkk1 in whole-lung tissue of infected animals were determined by western blotting using β-actin as an internal control. The density of the ABC bands was quantified by ImageJ, normalized to control mice, and labeled on the top. PCR, polymerase chain reaction; rRNA, ribosomal RNA.