Mifepristone increases AQP1 mRNA expression, angiogenesis, and cell permeability through the ERK MAPK pathway

The purpose of this study was to investigate the mechanism of mifepristone serves as an anti-implantation contraceptive drug on aquaporins 1 (AQP1) expression.

Human umbilical vein endothelial cells (HUVECs) were used to detect the effects of different concentrations of mifepristone (0, 0.065, 0.2, and 1 μmol/L) on the activity of angiogenesis and AQP1 expression. The expression of AQP1 was tested by the real-time PCR. The angiogenesis and penetration function of HUVECs was investigated by Matrigel lumen formation and trans-well assay, respectively.

The expression of AQP1, angiogenesis and cell permeability were significantly higher than control groups in HUVECs treatment with mifepristone at 1 μmol/L for 12 h. Estrogen and progesterone decreased the up-regulation of AQP1 and cell permeability, not angiogenesis, induced by mifepristone. Mifepristone increased protein levels of p-ERK, not p-p38 or p-JNK, and pre-treatment with ERK MAPK-specific inhibitor significantly inhibited the up-regulation of AQP1 mRNA expression, angiogenesis and cell permeability induced by mifepristone. si-AQP1 significantly reduced the up-regulation of angiogenesis, cell permeability and p-ERK/ERK ratio expression induced by mifepristone treatment. Overexpression of AQP1 enhanced the increase of expression ratio of p-ERK/ERK induced by mifepristone.

Low-dose mifepristone increased cell permeability, angiogenesis and AQP1 expression, which was involved in MAPK pathways. This provides new insights into the molecular mechanism of mifepristone serves as an anti-implantation contraceptive drug.