Lowering Caveolin-1 Expression in Human Vascular Endothelial Cells Inhibits Signal Transduction in Response to Shear Stress
Figure 4
Activation of Akt and
ERK1/2 in response to external stimuli. HUVECs were transfected with either
caveolin-1 siRNA, negative control siRNA, or left untreated. 48 hours after
transfection, cells were subjected to the following stimuli. (a), (b) Cells
were kept in suspension for 30 minutes and then plated on fibronectin-coated
culture plates to activate integrin-mediated signaling. Phosphorylation of both
(a) Akt and (b) ERK1/2 increased significantly when compared to cells in
suspension. No significant differences in activation levels were detected
between HUVECs with high or low caveolin-1 levels. (c), (d) Cells were starved
in basal medium and then treated with 200 ng/mL VEGF for 10 minutes. Phosphorylation
of both (c) Akt and (d) ERK1/2 in response to this stimulus was significantly
lower in cells with low levels of caveolin-1 than in cells that were treated
with negative control siRNA (). All bars are averages of
three separate experiments.
