Fig. 6. Controlled TCPTP activation inhibits VEGF-driven morphological changes, chemokinesis and chemotaxis. (A) HUVECs were cultured in fibrin gels and treated with or without VEGF and TAT peptides (200 nM). After 24 hours, the changes in endothelial morphology and alignment were semi-quantitatively scored. Representative images show HUVECs at the beginning of the assay and untreated (control, ctrl) HUVECs without and with VEGF stimulation after 24 hours of incubation taken at 20x magnification. The graph shows the effects of the indicated treatments on the morphology index. ^**P<0.01. (B) HUVECs were plated on gelatin in the presence of the peptides (200 nM) or left untreated for 1 hour. The cells were stimulated as indicated and the migration of individual cells was tracked using time-lapse microscopy. Cumulative migration distance was plotted for randomly picked individual cells (B, top) (mean ± s.e.m.; n=40 cells; ^***P<0.0005; B, bottom). (C) HUVECs were treated with the 200 nM peptides and the chemotaxis assay was performed as in Fig. 2B. ^*P<0.05. (D, top) HUVECs were transfected with no oligo, with siRNA against TCPTP or with a control siRNA (ScrsiRNA), and TCPTP silencing was analyzed by immunofluorescence. The same exposures of TCPTP (green) and DAPI (blue) stainings at 63x magnification are shown. Scale bars: 10 µm. (D, bottom) 48 hours post-transfection, cells were subjected to chemotaxis assay as in C.