Effects of hypoxia inducible factors-1α on autophagy and invasion of trophoblasts

OBJECTIVE This study was undertaken to determine the effect of hypoxia inducible factor (HIF)-1α on the cell death, autophagy, and invasion of trophoblasts. METHODS To understand the effect of HIF-1α, we inhibited HIF-1α using siRNA under normoxia and hypoxia conditions. Invasion assay and zymography were performed to determine changes in the invasion ability of HIF-1α. Western blotting and immunofluorescence were performed to determine some of the signal events involved in apoptosis and autophagy. RESULTS There was no difference in cell death through the inhibition of HIF-1α expression by siRNA; however, the expression of LC3 and autophagosome formation increased. On the other hand, autophagy was increased, and the invasive ability of trophoblast cells decreased according to the inhibition of HIF-1α expression by siRNA. These experimental results mean that HIF-1α genes regulate the invasive ability of trophoblasts by increasing autophagy. CONCLUSION This study contributes important data for understanding the mechanism of early pregnancy implantation and the invasive ability of trophoblasts by defining the relationship between the roles of HIF-1α and autophagy.