Figure 3.

EDA-FN induces myofibroblast differentiation via α₄β₇ integrin. Fibroblasts were exposed to 10 μg/ml EDA-FN in the presence of blocking antibodies for α₄β₇, α₅β₁, β₇, or β₁ integrins and expression of α-SMA was assessed by immunofluorescence, quantified and expressed as integrated optical density (IOD). Experiments were performed 4 times; representative images are shown. A) Preincubation with anti-α₄β₇ or anti-β₇ blocking antibodies (45 min, 37°C) inhibited EDA-FN-induced α-SMA expression in fibroblasts. Scale bar = 20 μm. B, C) EDA-FN-induced collagen deposition, assessed by the Sircol assay (B) and EDA-FN-induced TGF-β1 release, determined by ELISA (C), were abrogated in fibroblasts preincubated with anti-α₄β₇ blocking antibodies. ***P < 0.001.