MicroRNA-16 inhibits hypoxia-induced vascular endothelial growth factor expression in ARPE-19 cells

To investigate the effect of microRNA-16 on hypoxia-induced VEGF expression of ARPE-19 cells.

ARPE-19 cells were cultivated under normoxia and hypoxia state. At 0 h, 12 h, 24 h, and 48 h after cultivation, the supernate of the culture medium was separated to test the VEGF secretion by ELISA, and the cells were purified to measure the expression of VEGF mRNA and microRNA-16 by qRT-PCR; microRNA-16 mimic was then transfected into ARPE-19 cells by the Hiperfect transfection reagent, a liposome transfection system. Scramble group and the non-transfected group were set as the controls. VEGF secretion and the level of VEGF mRNA were measured in these three groups.

The VEGF secretion of the hypoxia ARPE cells was significantly higher than the initial state (p < 0.01). Compared with the normoxia cells, the VEGF secretion of the hypoxia cell was significantly increased (p < 0.01), and the division of VEGF secretion between these two groups increased by time. VEGF mRNA of the hypoxia ARPE cell was significantly higher than the initial state (p < 0.01). Compared with the normoxia cells, VEGF mRNA of the hypoxia cells was significantly increased (p < 0.01), and the division of VEGF mRNA between these two groups increased by time. After cultivating under hypoxia, the expression of microRNA-16 in ARPE-19 cells decreased significantly compared with the normal group, and the division of these two groups augmented by time. MicroRNA-16 was successfully transfected into ARPE-19 cells by the Hiperfect transfection system. Twenty four hours and 48 h after the transfection, the VEGF secretion of the miR-16 transfected cell was decreased significantly (p < 0.01) compared with the scramble and the non-transfected group under hypoxia, while VEGF mRNA level had no significant difference among these three groups.

Hypoxia can increase the expression of VEGF mRNA and the secretion of VEGF protein of ARPE-19 cells. At the same time, microRNA-16 expression can be down-regulated by hypoxia. Transfection of microRNA-16 exogenously can down-regulate the VEGF protein secretion but cannot affect the expression of VEGF mRNA.