FIGURE 6.

MMP1 activates focal adhesion kinase (FAK) in LECs. LECs were grown to ∼70–80% confluence and then pre-treated with solvent (DMSO), or (A) 20 μM apigenin, or (B) 20 μM luteolin and then stimulated with 100 ng/mL activated recombinant MMP1 for 4 h. Cells were lysed, proteins were separated by SDS gel electrophoresis and analyzed by Western blotting using the indicated antibodies. Equal sample loading was controlled by Ponceau S staining and β-actin immunoblotting. The relative protein expression (Prot. expr.) was quantified by densitometry facilitating the comparison with β-actin control, which was set to a value of “1.” The calculated FAK protein expression levels are shown in the bar graphs next to the FAK Western blots. The relative phosphorylation of FAK (p-FAK; corresponding to FAK activity) was quantified by densitometry facilitating the comparison with FAK protein expression, which was set to a value of “1.” The calculated FAK protein activity levels (Prot. Act.) are shown in the bar graphs next to the p-FAK Western blots. The numbers below the bar graphs refer to the respective treatment conditions indicated in the blot lanes. Densitometries are means ± SEM from at least three experiments (asterisks indicate significances, p < 0.05; t-test) and the Western blot images are representatives for illustration. Hashes (#; rhomboids) indicate significance.