Fig. 9. PAI1 does not disrupt the association of 5β1 integrin with fibronectin matrix. Cells were incubated for 3 hours in DMEM in the presence or absence of PAI1, subsequently fixed, permeabilized and immunostained. (A) Fibronectin matrix and β5 integrin were visualized by indirect immunofluorescence in untreated cells (panels a and b) and PAI1 treated cells (panels c and d). Scale bar, 20 µm. (B) Fibronectin and activated β1 integrin (detected with 9EG7 antibody) were visualized by indirect immunofluorescence in untreated cells (panels a and b) and PAI1 treated cells (panels d and e). Panels c and f shows merged pictures. Yellow staining indicates areas of colocalization of β1 integrin with fibronectin matrix. Scale bar, 20 µm.