Figure 4: MT1-MMP is a negative regulator for LYVE-1-mediated signalling.

(a) Serum-starved WT and Mmp14^−/− LECs were stimulated with various growth factors at (10 ng ml⁻¹) and HA (3 μg ml⁻¹), and subjected to MTT assays. Control cells were incubated with culture medium alone (*P<0.05, n=3, two-tailed t-test). (b) The cell migration of serum-starved WT and Mmp14^−/− LECs towards HA and FGF2. Control cells cultured with medium alone served as a control (*P<0.05; **P<0.01, n=3, two-tailed t-test). (c) Serum-starved WT and Mmp14^−/− LECs were treated with HA for indicated times. Phosphorylation of Akt was detected by western blotting (left panel). Total Akt served as a loading control. Quantification of Akt phosphorylation in relative to total Akt was shown in the right panel (*P<0.05; ***P<0.001, n=3, two-tailed t-test). (d) MT1-MMP sheds LYVE-1 to inhibit LYVE-1-mediated signalling. HEK293T cells stably expressing LYVE-1 were transfected with either empty vector, or WT MT1-MMP, or catalytic-dead mutant MT1-MMP (MT1 EA). The conditioned media and total cell lysates were analysed by western blotting using indicated antibodies (left panel). Phosphorylation of Akt was examined for the response of cells to HA stimulation. Quantification of Akt phosphorylation in relative to total Akt was shown in the right panel (*P<0.05, n=3, two-tailed t-test). Data represent the mean±s.e.m. The experiments were repeated at least three times.