Zeaxanthin Inhibits Hypoxia-Induced VEGF Secretion by RPE Cells through Decreased Protein Levels of Hypoxia-Inducible Factors-1α

Figure 2

Effects of hypoxia on secretion of VEGF by RPE cells. RPE cells were seeded into 24-well plates at a density of cells per well. After 24 h, cells were incubated in a sealed chamber in a controlled environment of 1% O₂ (a) or cultured with CoCl₂ at 50, 100, 150, and 200μM concentrations (b). Cells cultured under normal oxygen pressure (21% O₂, 5% CO₂, and 74% N₂) were served as the control. Conditioned medium was collected 24 h later; VEGF levels were measured by VEGF ELISA kits and expressed as percentages of the control (, ). Hypoxia significantly increased VEGF secretion by RPE cells. , compared with the controls.

(a)

(b)