Figure 6. Inhibition of pERK or pAkt does not affect VEGF expression. Western blot analysis of ERK1/2 and Akt phosphorylation inhibition
on HIF-1α, HIF-2α, or downstream VEGF expression in hypoxia. HLE-B3 cells were incubated with 25 µM of LY294002 or 10 µM UO126
in 0.05% DMSO for 8 h under hypoxia. Control cells were incubated in serum-free media with 0.05% DMSO. Cell lysates were collected
for western blot analysis, and cell-free supernatants were collected for ELISA. LY294002 blocked Akt phosphorylation without
interrupting pERK, while UO126 prevented ERK phosphorylation without interfering with pAkt (A). Inhibition of Akt phosphorylation suppressed HIF-1α expression, but HIF-2α levels remained unchanged. Inhibition of ERK1/2
phosphorylation did not repress HIF-1α and HIF-2α expression (B). C and D represent the corresponding densitometry analysis. Neither phosphorylation inhibitor diminished VEGF synthesis relative to
control cells (E). One-way ANOVA analysis was performed to compare the VEGF levels between the control and the LY294002- or UO126-treated
samples, and the p value was >0.05.