Figure 5.

EDA-FN activates FAK via α₄β₇ integrin receptor. Cell lysates obtained from fibroblasts exposed to EDA-FN, non EDA-containing pFN, EDA-containing peptides (EDA⁺) or EDA-lacking peptides (EDA⁻) were separated by SDS-PAGE and subjected to immunoblotting with anti-phospho-FAK and anti-FAK antibodies. Densitometric analysis calculated as ratio of phospho-FAK to total FAK was then assessed. A) Time course of FAK activation by EDA-FN showed a maximum effect after 3–6 h of incubation. B) Exposure to EDA-FN increased FAK activation in comparison with pFN. **P < 0.01 vs. pFN; ***P < 0.001 vs. untreated cells. C) Lysates from cells treated with EDA⁺ peptides showed greater FAK activation than lysates treated with EDA⁻ peptides. D) Blocking of α₄β₇ integrin reduced EDA-FN-induced FAK activation. **P < 0.01. Blots shown are representative of 2 or 3 independent experiments from different lysates.