KLF4 transcriptionally activates VEGF expression.

<p><b>A.</b> Luciferase reporter assays were performed to assess KLF4 activation of the VEGF promoter. Luciferase activities in KLF4 expressing and control HRMECs were measured at 24h after transfection with 1.5kb and 0.2kbVEGF promoter luciferase constructs in serum-free conditions. Data were presented as the mean ± SE from three independent experiments. Significance of luciferase activity was found between KLF4 expressing and control cells when 1.5Kb VEGF promoter was transfected in both cells (**p<0.01). <b>B.</b> There are three predicted KLF4 binding sites (CACCC) at the VEGFA promoter. The specific binding sites of KLF4 at the VEGFA promoter was detected by ChIP assay and enrichment of KLF4 binding to sites a and b of VEGFA promoter was significant, not c in KLF4 expressing compared to control cells (*p<0.05,**p<0.01) C: VEGF expression in HRMECs was detected by Western Blot at different time points. Significance was compared to 0h from 3, 6 and 12h (*p<0.05, **p<0.01, ***p<0.001). D: VEGF and KLF4 expression was imaged following immunofluorescence staining at 24h following KLF4 induction. E. VEGF released in cell media was detected using VEGF ELISA assay and significance was observed in KLF4 expressing compared to controls at the indicated time points(*p<0.05). F. Cell migration in KLF4 expressing and control HRMECs following VEGF knockdown using VEGF siRNA was examined using transwell migration assay. (*p<0.05, **p<0.01).