Fig. 4.

EDB-FN splice variant expression is mediated by cell contractility. (A) Western blot of total protein extract from cells plated on 10-kPa substrates and treated with or without the ROCK inhibitor Y27632 showing a decrease in EDB-FN compared with control. Corresponding densitometric quantification showing both EDB-FN normalized against GAPDH content and the ratio of EDB-FN to total FN. (B) Representative images of EDB-FN and total fibronectin of EC cells cultured overnight on 10-kPa substrates and treated with or without Y27632. (C) Western blot for ROCK, EDB-FN, and total FN expression after treatment with siRNA against ROCK compared with control. Corresponding densitometric quantification showing both EDB-FN normalized against GAPDH content and the ratio of EDB-FN to total FN. (D) Fluorescent staining for EDB-FN after treatment with siRNA against ROCK on stiff (E = 10 kPa) substrates. Images were acquired using the same exposure settings. Plots are mean ± SE, Student t test: *P < 0.05, **P < 0.01. Images were acquired using the same exposure settings. (Scale bars, 30 μm.)