FIGURE 5.

Application of electromagnetic force to α₆ β₁ integrin receptors activates TACE and releases HB-EGF and TGF-α. A, E17 type II cells were incubated with magnetic beads coated with integrin α6, β1, α2 antibodies or AcLDL (negative control) and then exposed to magnetic force for 15 min. Activation of TACE was assessed using an active fluorescence FRET substrate. Results are expressed as the percentage of change from unstrained samples. n = 4, *, p < 0.05 versus static. B–E, E17 type II cell monolayers from wild-type (B and C) or TACE knock-out mice (D and E) transfected with plasmids encoding alkaline phosphatase-tagged HB-EGF (B and D) or TGF-α (C and E) were incubated with magnetic beads coated with integrin α6, β1, α2 antibodies and then exposed to electromagnetic force for the indicated periods of time. AcLDL was used as a negative control. Supernatants were collected to measure AP-HB-EGF or TGF-α shedding. Samples were normalized to total AP protein content. Data are from four independent experiments. *, p < 0.05, **, p < 0.01 versus static.