(A, E) Airway smooth muscle cells were either left unstimulated (vehicle basal) or stimulated with TGF-β (2 ng/ml) in the presence or absence of LL-Z1640-2 (0.1 µM, 0.5 µM, 1.0 µM) for 24 hours. Expression of WNT-5A mRNA(A) and collagen IαI and fibronectin mRNA (E) was determined by qRT-PCR, corrected for 18S rRNA and expressed relative to vehicle basal. Data represent mean ± SEM of 4-5 independent experiments. **p<0.01, ***p<0.001 compared to vehicle basal, # p<0.05, ## p<0.01, ### p<0.001 compared to TGF-β-stimulated cells; 2-way ANOVA followed by Bonferroni multiple comparisons test. (B) Airway smooth muscle cells were stimulated with TGF-β (2 ng/ml) in the presence or absence of LL-Z1640-2 (0.5 µM) for 48 hours. Western analysis was performed on whole cells extracts for WNT-5A protein. Expression of GAPDH was analyzed as loading control. (C–D, F) Airway smooth muscle cells were transfected with TAK1-specific siRNA or a non-targeting siRNA as control. Subsequently, cells were stimulated with TGF-β (2 ng/ml) for 24 hours and analyzed for the expression of TAK1 mRNA (C), WNT-5A mRNA (D) and collagen IαI and fibronectin mRNA (F) by qRT-PCR and expressed relative to non-targeting siRNA-transfected, untreated control. Data represent mean ± SEM of 4 independent experiments. *p<0.05, **p<0.01, ***p<0.001 compared to non-targeting siRNA-transfected untreated control, #p<0.05, ## p<0.01 compared to non-targeting siRNA-transfected, TGF-β-stimulated cells; 1-way ANOVA followed by Newman-Keuls multiple comparisons test.