Regulation of influenza virus replication by Wnt/β-catenin signaling
(A) A549 cells were co-transfected with a TOPflash reporter vector and a pRL-TK normalization vector. Twenty four h post transfection, the cells were treated with Wnt3a_CM or Con_CM in the presence or absence of iCRT14 (12.5 μM) for 24 h. TOPFlash firefly luciferase activity was normalized to pRL-TK Renilla luciferase activity. **p<0.01. n = 3 (one-way ANOVA, followed by Tukey's test). (B, C) A549 cells were treated with iCRT14 (12.5 μM) or vehicle control for 12 h and then infected with influenza virus A/PR/8/34 (B) or A/WSN/33 (C) at an MOI of 1. The cell culture medium was collected at various times post-infection, and viral titers were determined by TCID50 assay. (D) A549 cells were treated with iCRT14 (12.5 μM) or vehicle control for various times, and cell viability was measured using the CellTiter Glo kit (Promega). The results of 3 independent experiments are displayed as the mean ± SE. *p<0.05 vs. vehicle control, **p<0.01 vs. vehicle control at the corresponding time points (Two-way ANOVA, post hoc Tukey). (E) A549 cells were cotrasnfected with an influenza virus sensor reporter (NP-UTR-Luc) and pRL-TK vector. Twenty-four h post-transfection, the cells were infected with A/PR/8/34, pdm/Ok/09 and H3N2 A/Wisconsin/67/05 at an MOI of 0.1 for 48 h. Firefly luciferase activity was normalized to Renilla luciferase activity. *p<0.05 vs. vehicle control, **p<0.01 vs. vehicle control, ***p<0.001 vs. vehicle control (Student’s t-test).