FIGURE 3.
Ultrasound does not elicit its effect through integrin activation. A, flow cytometry of K562 cells following ultrasound stimulation using monoclonal antibody 12G10, which recognizes an activation epitope of human β1 integrin. 1 mm manganese was used as a positive control to drive integrin activation. Green, IgG control; black, 12G10 with calcium/magnesium; blue, 12G10 with calcium/magnesium plus ultrasound; red, 12G10 with manganese. B, binding of biotinylated 50K to isolated, purified α5β1 integrin in a solid phase assay either with (closed bars) or without (open bars) a 20-min ultrasound stimulation or the addition of the activating antibody 12G10. C, rate of integrin-mediated spreading of control (open circles) or ultrasound-stimulated (closed circles) MEFs. The area of 150 cells was measured using Image J software. Error bars, S.E. D and E, the areas of MEFs plated onto poly-l-lysine, H/0 or 50K for 120 min were unaffected by stimulation with ultrasound. Bar, 50 μm. F, fibroblasts spread on 50K or the inhibitory β1 monoclonal antibody, mab13, and stimulated with ultrasound were stained for vinculin (green) and actin (red). Bar, 5 μm. Error bars, S.E. Each result is representative of three independent experiments.