Prostaglandin E2 regulates the plasminogen activator pathway in human endometrial endothelial cells: a new in vitro model to investigate heavy menstrual bleeding.

OBJECTIVE

To study the role of PGE2 in regulating plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (tPA) in human primary endometrial endothelial cells (HEECs) from women with normal menstrual bleeding (NMB) and heavy menstrual bleeding (HMB).

DESIGN

In vitro study using endometrial endothelial cells.

SETTING

Research laboratory setting.

PATIENTS: Women with NMB and HMB provided endometrial biopsy samples.

INTERVENTIONS: Prostaglandin E2 and PGE2 receptor-selective agonists were administered to cultured HEECs.

MAIN OUTCOME MEASURES: Levels of PAI-1 and tPA in NMB-HEECs and HMB-HEECs after treatment with PGE2 and receptor-selective agonists.

RESULTS

Prostaglandin E2 increased total PAI-1 levels in NMB-HEECs, but not in HMB-HEECs, which had higher baseline PAI-1 levels. PGE2 receptors (PTGER)1 and PTGER2 agonists increased PAI-1 in NMB-HEECs, whereas PTGER3 and PTGER4 did not. Prostaglandin E2 had no effect on tPA levels in either NMB-HEECs or HMB-HEECs.

CONCLUSIONS

Prostaglandin E2, through PTGER1 and PTGER2, regulates the plasminogen activator system in NMB-HEECs, suggesting a role in reducing fibrinolytic activity during normal menstrual cycles. The lack of PGE2 effect and elevated baseline PAI-1 in HMB-HEECs support using this in vitro model to further understand prostaglandin pathways in NMB and HMB.