Figure 6. Integrin subunits α3 and α6 regulate FGF10- or GDNF-induced cellular spreading and proliferation on LM-511 via PI3K-dependent Akt activation.
Itgα3f/fα6f/f CD cells were treated with DMSO or the PI3K inhibitor LY294002 (25 μM) for 1 h and plated on LM-511 for 1 h . Itgα3f/fα6f/f CD cells were also infected with ad-GFP or ad-Δp85 for 48 h prior to plating on LM-511. The cells were treated with FGF10 or GDNF (10 ng/ml each). Cell spreading (A-B) and proliferation (C) were evaluated at 1 and 24 h after addition of growth factors, respectively. (A) Representative confocal images of the cells stained with rhodamine-phalloidin are shown; bar: 10 μM. (B) The individual measurements of cell surface (in pixels) of 15-30 cells with the mean is shown; *p≤0.05 between Itgα3f/fα6f/f CD cells pretreated with DMSO and LY; or between infected with ad-GFP and ad-Δp85. ≤0.05 between Itgα3f/fα6f/f untreated or treated with FGF10 or GDNF. (C) Proliferation as measured by the OD of BrdU-positive cells ±SEM of 4-6 independent experiments is shown; *p≤0.05 between cells pretreated with DMSO and LY; or between infected with ad-GFP and ad-Δp85. ≤0.05 between Itgα3f/fα6f/f untreated or treated with FGF10 or GDNF. (D-E) Phosphorylation of Akt was evaluated at 5, 15 and 30 min after addition of FGF10 (D) or GDNF (E). β-actin was used as loading control.