Fig. 7.

Canonical WNT activation induces EMT programming.

a-c) WNT activation induced EMT at all time periods, witnessed by the increase in the transcription (a) and protein expression (b) of vimentin, and in the release of fibronectin (c), both being markers of EMT. WNT inhibition, conversely, slightly but significantly decreased them.

d-e) Representative blots for phospho (p)-SMAD2, vimentin, and housekeeping GAPDH proteins (d), and quantitative analysis for phospho (p)-SMAD2, upon control (CT), vehicle (DMSO), WNT activation (CHIR99021), and WNT inhibition (XAV939) conditions (e). In parallel with increased EMT markers, CHIR99021-induced WNT activation increased the phosphorylation of SMAD2, a pivotal component of the canonical TGF-β pathway. In contrast, XAV939 decreased its expression at T1 and T3.

f-g) Concordantly with increased pSMAD2 expression upon CHIR99021-induced WNT activation, TGF-β₁ release in basolateral supernatants was increased in WNT activation conditions (f), whilst no difference was seen upon WNT inhibition. No difference was observed at the transcriptional level (g).

*, ** indicate p-values of less than 0•05 and 0•01, respectively (analysed using the Mann-Whitney test). Columns in graphs represent medians. ALI, air/liquid interface; CHIR^act, CHIR99021-induced WNT activation condition; CT, control; HKG, housekeeping genes; XAV^inh, XAV939-induced inhibition condition.