Low-dose mifepristone increased angiogenesis in a manner involving AQP1.

PURPOSE: To investigate the molecular mechanisms governing aquaporin-1 (AQP1)-mediated, mifepristone-induced angiogenesis and improve the understanding of low-dose mifepristone serving as an anti-implantation contraceptive drug.

METHODS

Human umbilical vein endothelial cells (HUVECs) were used to explore the effects of different concentrations of mifepristone (0, 65, and 200 nmol/L) on the activity of angiogenesis. Forty-five pregnant mice during the "window of implantation" were treated with different concentrations of mifepristone. HUVECs' proliferation was examined using a methyl thiazolyl tetrazolium (MTT) assay. The microvessel density (MVD) and the expression of AQP1 in endometrium were determined with immunohistochemical methods.

RESULTS

The MVD and the expression of AQP1 were significantly higher than controls. Mifepristone at 200 nmol/L significantly affected HUVECs' proliferation during culture over 12 h, and pretreatment with AQP1-specific siRNA significantly inhibited the mifepristone-enhanced cell proliferation.

CONCLUSIONS

Low-dose mifepristone increased angiogenesis in a manner involving AQP1. This affords a new insight into the molecular mechanism underpinning the angiogenic effects of low-dose mifepristone.