Figure 6. αvβ6 integrin inhibition blocks adhesion of human cholangiocytes to fibronectin and reduces activation of endogenous TGFβ1.
(A) TFK-1 cholangiocarcinoma cells were allowed to adhere to fibronectin-coated wells for 30min in the presence or absence of EMD527040 and adherent cells were measured by calcein AM fluorescence at 520 nm. Supernatants were collected and endogenously activated TGFβ1 was measured by an ELISA for active human TGFβ1 (B), or total TGFβ1 was measured after chemical activation by 1 N HCl (C). The ratio of spontaneously active to total TGFβ1 reflects the percentage of endogenous TGFβ1 activation (n=6 per group, means±SD); *p<0.05 vs. untreated controls.