In situ localization of mRNA for the fibrinolytic factors uPA, PAI-1 and uPAR in endometriotic and endometrial tissue

Endometriotic tissue grows invasively. The plasminogen-activating system is suggested to participate in degradation of extracellular matrix (ECM) and modulation of cell adhesion and migration. We have previously demonstrated elevated levels of the fibrinolytic factors urokinase plasminogen activator (uPA) and plasminogen activator inhibitor (PAI-1) in endometriotic tissue and endometrium from women with endometriosis. The aim of the present study was to localize the uPA, PAI-1 and urokinase plasminogen activator receptor (uPAR) mRNA in endometriotic tissue and in endometrium both from women with and without endometriosis. With in situ hybridization, we found that uPA mRNA seems to be up-regulated in endometriotic glands and endometrial stroma as well as PAI-1 mRNA in endometriotic and endometrial stroma from women with endometriosis. uPAR mRNA likewise appears to be up-regulated in both glands and stroma in endometriotic tissue and in endometrial glands from patients compared to endometrial glands and stroma from healthy women. These differences might be important for menstrual shedding and adherence of endometrial fragments to peritoneal lining in women developing endometriosis and for the invasive growth of endometriotic tissue.