Figure 4. Inhibition of ER stress by PBA ameliorated hypoxia-induced VEGF and TNF-α expression in HREC.

A). HREC were treated with hypoxia (2% O₂) for 16h and GPR78 expression was determined by immunostaining. A-a: control; A-b: hypoxia. B–E). HREC were pre-treated with PBA at the doses as indicated for 8h and then exposed to hypoxia (2% O₂) for 16h. B–C). Expression of phospho-IRE1α, phospho-eIF2α, and ATF4 was determined by Western blot analysis and quantified by densitometry (mean ± SD, n= 3) D–E). Expression of VEGF and TNF-α was measured by Western blot analysis and quantified by densitometry (mean ± SD, n = 3). The values statistically different from control were indicated as ** p<0.01; from hypoxia indicated as † p<0.05, ‡ p<0.01.