Quantitative evaluation of the influence of ovarian steroids on plasminogen activators and inhibitors in human endometrial cells and trophoblasts

Impact of progestogens on hemostasis

Combined hormonal contraception containing estrogen and progestogen and postmenopausal hormone therapy with estrogen ± progestogen are reported risk factors for venous thrombosis. The thrombotic risk varies by estrogen dose and type of progestogen. Estrogen combined with "newer generation" progestogens in combined oral contraceptives may have higher thrombotic risk than estrogen combined with older generation progestogens. Among postmenopausal women thrombotic risk also varies by type of hormone and mode of delivery. Although the risk of thrombosis with the different hormonal compounds is uncertain, it has definitely been attributed to the pharmacological effect of the hormones on hemostasis. Animal and cell culture studies have demonstrated the pharmacodynamics of progestogens with respect to hemostasis. Extrapolation from these studies to clinical conditions and further to clinical end points such as cardiovascular disease is, however, controversial. Few clinical studies have focused on the effect of progestogen only therapy on the hemostatic system in vivo. Most of the current knowledge regarding the in vivo effect of progestogens on hemostasis is obtained from studies with combined contraceptives. These results obviously reflect the combined influence of both estrogen and progestogen on hemostasis, and extrapolation to progestogen-only conditions is challenging. This paper discusses the pharmacodynamics of progestogens in relation to the hemostatic system, addressing results obtained in animal and cell culture studies and in clinical studies employing progestogen-only and combined oral contraceptives. The compiled results suggest that the major effect of progestogens on hemostasis is related to alterations in platelet function and the tissue factor pathway of coagulation. More studies focusing on these topics are warranted.

Activation and expression of urokinase-type plasminogen activator are modulated by freezing/thawing process through activation of redox signal pathway in primary porcine endometrial cells

Plasminogen activators (PAs) play a pivotal role in a variety of uterine physiologies, such as endometrial function, trophoblast invasion, and implantation process, but its alteration in expression or activity during cryopreservation of primary uterine cells has received little attention. In this study, we investigated whether PA expression and activity were modulated in first passage primary porcine uterus endometrial epithelium cells (PUEECs) treated with or without a freezing-thawing procedure. Western blotting and zymographic analysis showed that uPA expression and activity increased significantly in frozen-thawed PUEECs in a passage-dependent manner as compared to freshly prepared control cells. Moreover, intracellular reactive oxygen species (ROS) were increased by freezing-thawing and longer culturing, and were more prominent in frozen-thawed PUEECs than in control cells. However, the increase in both uPA expression and activity was greatly reduced or alleviated by treatment with either ROS scavenger N-acetylcysteine or extracellular signal-regulated kinase (ERK) inhibitor PD98059. These results suggest that ROS/ERK-mediated uPA activation may be an important factor in cryo-damage of primary uterine cells.

Coagulation and fibrinolysis related cytokine imbalance in preeclampsia: the role of placental trophoblasts

OBJECTIVE

Cytokine imbalance might have a pivotal role in hypercoagulability seen in preeclampsia. Our objective was to determine the relationship of blood coagulation related factors in placental tissue and peripheral blood in preeclamptic and normal pregnancies.

METHODS

We compared mRNA and protein levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), and tissue factor (TF) in the placenta of normal and preeclamptic pregnancies. Placental and peripheral blood t-PA and PAI-1 levels were examined. Trophoblasts were used to study the effects of hypoxia, hypoxia-reperfusion, and inflammatory cytokines on t-PA, PAI-1, tissue factor pathway inhibitor (TFPI), and TF.

RESULTS

PAI-1 and TF mRNA and protein levels were higher in placental tissue of preeclamptic pregnancies and in the peripheral blood of patients with preeclampsia. mRNA and protein secretion of TF, TFPI, PAI-1, but not t-PA, was increased in trophoblast cell culture under hypoxia and hypoxia-reoxygenation. Cell cultures with high levels of tumor necrosis factor-alpha (TNF-alpha) exhibited increased expression and secretion of TF and PAI-1, decreased TFPI, and no significant change of t-PA.

CONCLUSIONS

Imbalanced synthesis of t-PA, PAI-1, TFPI, and TF in trophoblasts may contribute to hypercoagulability in patients with preeclampsia.

A polymorphism of the plasminogen activator inhibitor-1 gene promoter and the polycystic ovary syndrome

OBJECTIVE

To investigate the association of a common 5G/4G polymorphism of the plasminogen activator inhibitor-1 gene (PAI1) with occurrence and clinical characteristics of the polycystic ovary syndrome (PCOS).

STUDY DESIGN

In a case-control study, we evaluated a series of 106 Caucasian women with PCOS and 102 healthy controls. Women completed a detailed questionnaire and underwent a peripheral venous puncture, ultrasonography, and a standardized oral glucose tolerance test (OGTT). The PAI1 gene promoter polymorphism was evaluated using PCR.

RESULTS

Allele and genotype frequencies were not significantly different among women with PCOS and controls (P=0.3 and 0.6, respectively). In women with PCOS, presence of the 5G/4G polymorphism of PAI1 was not associated with changes in serum hormone levels or with clinical characteristics.

CONCLUSIONS

The 5G/4G polymorphism of the PAI1 promoter is not associated with occurrence and phenotype of the PCOS.