Figure 1. Lovastatin treatment inhibits VEGFR-2 internalization.

A, VEGFR-2 internalization in HUVEC was evaluated by immunofluorescence. HUVEC were treated with solvent control or 2 µM lovastatin for 24 hrs in serum-free media followed by 30 min of stimulation with VEGF₁₆₅. Immunofluorescence staining of HUVEC revealed a punctate intracellular staining pattern upon VEGF₁₆₅ ligand binding in the control but not in cells treated with 2 µM lovastatin. The data is typical of 3 independent experiments. B, Cell Surface Pinpoint Protein Isolation revealed a decrease in VEGFR-2 on the surface of control HUVEC upon VEGF stimulation but not with 2 µM lovastatin treatment. Actin was readily pulled down in control cells but not in lovastatin treated HUVEC indicating a lack of association of surface proteins with actin in lovastatin treated cells. C and D, Western blot analysis reveals that VEGFR-2 receptor levels decrease with 30 min of stimulation with VEGF₁₆₅ stimulation in control HUVEC and H28 cells respectively. Lovastatin treatments of 0.5, 1 and 5 µM inhibited VEGFR degradation in a dose dependant manner. The data is typical of at least 3 independent experiments and the membranes were stained with Ponceau Red to visualize total protein loading.