Endometrial epithelial-mesenchymal transition (EMT) by menstruation-related inflammatory factors during hypoxia

Endometriosis is characterised by inflammation and fibrotic changes. Our previous study using a mouse model showed that proinflammatory factors present in peritoneal haemorrhage exacerbated inflammation in endometriosis-like grafts, at least in part through the activation of prostaglandin (PG) E2 receptor and protease-activated receptor (PAR). In addition, hypoxia is a well-known inducer of fibrosis that may be associated with epithelial-mesenchymal transition (EMT). However, the complex molecular interactions between hypoxia and proinflammatory menstruation-related factors, PGE2 and thrombin, a PAR1 agonist, on EMT in endometriosis have not been fully characterised. To explore the effects of hypoxia and proinflammatory factors on EMT-like changes in endometrial cells, we determined the effects of PGE2 and thrombin (P/T) on EMT marker expression and cell migration in three dimensional cultured human endometrial epithelial cells (EECs) and endometrial stromal cells (ESCs). Treatment of EECs with P/T under hypoxia stimulated cell migration, increased the expression of mesenchymal N-cadherin, vimentin and C-X-C chemokine receptor type 4 (CXCR4), and reduced the expression of epithelial E-cadherin. Furthermore, treatment with C-X-C motif chemokine ligand 12 (CXCL12), a ligand for CXCR4, increased EMT marker expression and cell migration. In ESCs, P/T or oestrogen treatment under hypoxic conditions increased the expression and secretion of CXCL12. Taken together, our data show that hypoxic and proinflammatory stimuli induce EMT, cell migration and inflammation in EECs, which was increased by CXCL12 derived from ESCs. These data imply that inflammatory mediators in retrograde menstrual fluid contribute to ectopic endometrial EMT and migration in the presence of peritoneal hypoxia.

Regulation of decidualization in human endometrial stromal cells through exchange protein directly activated by cyclic AMP (Epac)

INTRODUCTION

Human endometrial stromal cells (ESCs) undergo differentiation during the decidualization process. Decidualization is characterized by their enhanced production of IGF binding protein-1 (IGFBP-1), prolactin (PRL), and the forkhead transcriptional factor FOXO1, and transformation into more rounded cells, during the secretory phase of the menstrual cycle and subsequent pregnancy. Protein kinase A (PKA)-mediated cAMP signaling is crucial for this process. The present study was undertaken to examine the involvement of a mediator of cAMP signaling, exchange protein directly activated by cAMP (Epac), in decidualization of cultured ESCs.

RESULTS

Treatment of ESCs with the Epac-selective cAMP analog 8-CPT-2-OMe-cAMP (CPT) had no effect on IGFBP-1, PRL, and FOXO1 mRNA expression. However, CPT potentiated IGFBP-1 and PRL expression stimulated by the PKA-selective cAMP analog N(6)-Phe-cAMP (Phe) and activated Rap1, a downstream regulator of Epac signaling. Knock-down of Epac1, Epac2, or Rap1 significantly inhibited the Phe- or Phe/CPT-induced increase in IGFBP-1 and PRL expression, as well as Rap1 activation. Furthermore, CPT enhanced IGFBP-1 and PRL expression and the morphological differentiation induced by ovarian steroids, whereas Epac1, Epac2, or Rap1 knock-down suppressed these events.

CONCLUSION

These data provide evidence for the involvement of the Epac/Rap1 signaling pathway in cAMP-mediated decidualization of human ESCs.

IFPA Meeting 2012 Workshop Report II: epigenetics and imprinting in the placenta, growth factors and villous trophoblast differentiation, role of the placenta in regulating fetal exposure to xenobiotics during pregnancy, infection and the placenta

Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2012 there were twelve themed workshops, four of which are summarized in this report. These workshops related to various aspects of placental biology: 1) epigenetics and imprinting in the placenta; 2) growth factors and villous trophoblast differentiation; 3) role of the placenta in regulating fetal exposure to xenobiotics during pregnancy; 4) infection and the placenta.

Differential Localization of Decidual Stathmin During Pregnancy in Rats

The present study was undertaken to determine the precise localization of stathmin, a protein associated with microtubule dynamics, during decidualization in rat uterus and to compare it with that of cyclin D3. Immunohistochemical analysis revealed that stathmin is exclusively localized in decidual cells, especially in the primary decidual zone surrounding the embryo, on days 7 and 9 of pregnancy. The intensity of staining was much higher on day 9 than day 7. On day 14, when the endometrial stromal cells had completely differentiated into decidual cells, the staining of decidual cells was faint. Cyclin D3 was expressed in decidual cells of the secondary but not the primary decidual zone on days 7 and 9. On day 14, cyclin D3 levels were low in decidua. Proliferating cell nuclear antigen (PCNA) was broadly detected in the uterus on days 7 and 9, and in the placenta and fetus on day 14. In an artificial decidualization model, cyclin D3 expression was stimulated as deciduoma was formed after an artificial stimulus. Stathmin mRNA levels also increased within 24 h and peaked at 48 h. The specific spatio-temporal uterine expression of stathmin and cyclin D3 suggest that they have a specific role in decidualization in rats.

[Heparin concentration and hemostatic alterations with low systemic heparinization during CPB using heparin-coated circuits]

Extracorporeal circulation with heparin coated circuits allows reduction of systemic heparin. The authors investigated the effects of this method on the hemostatic and fibrinolytic systems and heparin concentration simultaneously. Ten patients undergoing coronary artery bypass surgery were studied. The dose of heparin was 100 IU.kg-1, and the target activated clotting time (ACT) was more than 300 seconds. Blood samples were obtained at the following times; before and after giving heparin, 10 and 40 minutes after the start of extracorporeal circulation, after cross-clamp release, and after giving protamine, and heparin concentration, ACT, thrombin-antithrombin complex (TAT), plasmin alpha 2 plasmin inhibition complex (PIC), and D-dimer were measured. ACT was kept over 300 seconds without additional heparin administration. Heparin concentration was maintained at 1.0 IU.ml-1. However, after release of the aortic cross-clamp, TAT, PIC, D-dimer increased significantly. Despite reduced systemic heparinization, heparin concentration was maintained adequately. Thrombin generation and fibrinolytic activity showed no significant increase until the release of the aortic cross-clamp.

High colony forming capacity of primary cultured hepatocytes as a dominant trait in hepatocarcinogenesis-susceptible and resistant mouse strains

When hepatocytes isolated from mouse liver are cultivated in vitro, a small fraction of cells can survive, forming colonies, while most cells die within a few weeks. We compared the colony forming capacity of hepatocytes in three mouse strains; two strains susceptible for hepatocarcinogenesis, C3H/HeJ (C3) and DBA/2J mice (D2), and one resistant strain, C57BL/6J mice (B6). The colony forming capacity was about 3:2:1 for D2, C3 and B6 at the 4th week after start of culture, indicating that this capacity correlated with the susceptibility to tumor induction. When the colony forming capacity was compared in F1 hybrids between the three strains, the high colony forming capacity was dominant, again resembling the trait for hepatocarcinogenesis. In F1 hybrids between the two susceptible strains, the colony numbers were more than those of the parental strains, indicating the high colony forming capacity of the two susceptible strains to be additive. During 4 weeks of culture period, the cells continuously proliferated, but fairly large numbers of cells died, some showing characteristics of apoptosis and others of lysis. Although the proliferation rate was not different among the three strains until the 2 week time point, it was significantly lower in B6 than in C3 or D2 strains by the 4th week. On the other hand, the cell death rate was lower in D2 cells than in B6 or C3 cells after 2 weeks. These results indicate that the genetic background affects proliferation and death rates of cultured hepatocytes, which may be related to the different colony forming capacity of these three strains.

Malignant amelanotic melanoma of the esophagus

The clinical, histological, and electron microscopic features of a case of malignant amelanotic melanoma of the esophagus are described. Amelanotic melanoma is difficult to distinguish from other malignant lesions, but in our case electron microscopy was helpful in the diagnosis.