Yasemin Seval

The Distribution of Angiopoietin-1, Angiopoietin-2 and Their Receptors Tie-1 and Tie-2 in the Very Early Human Placenta

Angiopoietins are integral to vasculogenesis and angiogenesis, which play crucial roles in the growth and development of the placenta. The current study assessed expression of angiopoietins (Ang-1 and Ang-2) and their receptors (Tie-1 and Tie-2) during development of the early human placenta. First-trimester placental tissues were obtained from women undergoing curettage during normal pregnancies. The use of immunohistochemistry (IHC) showed that Ang-1 was primarily localized to syncytiotrophoblasts where it displayed moderate immunoreactivity, whereas weak immunoreactivity for Ang-1 was observed in endothelial cells and angiogenic cell cords (ACC). Strong immunoreactivity for Ang-2 was also found predominantly in syncytiotrophoblasts with lower immunostaining levels evident in cytotrophoblasts. Moderate immunoreactivity for Ang-2 was observed in endothelial cells, ACC and Hofbauer cells. By contrast, the trophoblastic shell, as well as endothelial cells and ACC exhibited strong staining intensity for Tie-1 with the strongest immunoreactivity for Tie-2 observed in cytotrophoblasts, ACC and endothelial cells. Western blotting of tissue extracts confirmed the IHC results. Previous studies focused on VEGF and its receptors in controlling vasculogenesis and angiogenesis in human placenta. However, the specific localization patterns of angiopoietins and their receptors revealed by the current study emphasize the importance of these molecules in placental vascular development. Functional studies aimed at identifying the molecular mechanisms of actions of these factors and receptors may prove essential in elucidating the pathophysiology of placental disorders such as intrauterine growth restriction and pre-eclampsia.

Statins Inhibit Growth of Human Endometrial Stromal Cells Independently of Cholesterol Availability

Abstract Endometriosis is characterized by ectopic growth of endometrial tissues. Statins, inhibitors of 3-hydroxy-3methylglutaryl-coenzyme A reductase (HMGCR), have been shown to decrease proliferation of several mesenchymal tissues. Actions of statins may be related to decreased availability of cholesterol as well as intermediate metabolites of the mevalonate pathway downstream of HMGCR. This study was designed to evaluate effects of statins on growth of endometrial stromal cells and to investigate mechanisms of these effects. Human endometrial stromal cells were cultured in the absence and in the presence of serum and with or without mevastatin and simvastatin. DNA synthesis and viable cell numbers were determined. Effects of statins were also evaluated in the presence of mevalonate and squalene. Furthermore, effects on phosphorylation of mitogen-activated protein kinase 3/1 (MAPK3/1) (also known as extracellular signal-regulated kinase [ERK1/2]) were determined. Mevastatin and simvastatin induced a concentration-dependent inhibition of DNA synthesis and viable cell count in chemically defined media and in the presence of serum. Mevalonate, but not squalene, abrogated inhibitory effects of statins on cell proliferation. Statins inhibited MAPK3/1 phosphorylation. This is the first study demonstrating that statins inhibit growth of endometrial stromal cells. This effect is also demonstrable in the presence of a supply of cholesterol and may be related to decreased activation of MAPK3/1. The present observations may be relevant to potential therapeutic use of statins in conditions such as endometriosis.

Do glucose transporters have other roles in addition to placental glucose transport during early pregnancy

Human placenta regulates the transport of maternal molecules to the fetus. It is known that glucose transport occurs via glucose transporters (GLUTs) in the feto–placental unit. Data on the expression of GLUTs during implantation are very scarce. Moreover, the question of how the decidual leukocytes obtain the energy for their activation during implantation mechanism is still under investigation. We studied the distributions of GLUT1, GLUT3, and GLUT4 in tissue sections of first trimester pregnancies the human maternal–fetal interface. GLUT1 was present in apical microvilli of the syncytiotrophoblast, in cytotrophoblast, and in vascular patterns of the villous core, whereas GLUT3 was localized in cytotrophoblasts of placental villi and in some fetal endothelial cells. Moreover, the proliferating cells of the proximal cell columns were also immunopositive for GLUT1 and GLUT3. We did not observe any positive immunoreactivity for GLUT4 in placental and decidual tissues. Essentially, GLUT3 and also to some extent GLUT1 was present in maternal leukocytes and platelets. In conclusion, our results suggest that the glucose taken up via GLUT1 and GLUT3 from the maternal circulation might not only be needed for placental functions but also for successful implantation by trophoblast invasion, proliferation and also by having a role to support energy for maternal leukocytes.

Regulation of Monocyte Chemotactic Protein-1 Expression in Human Endometrial Endothelial Cells by Sex Steroids: A Potential Mechanism for Leukocyte Recruitment in Endometriosis

The main aim of this study is to describe the in vivo temporal and spatial expression of monocyte chemotactic protein 1 (MCP-1) in human endometrial endothelial cells (HEECs) and to compare the in vitro regulation of MCP-1 expression by sex steroids in HEECs from women with or without endometriosis. Eutopic endometrial tissues and endometriosis implants were grouped according to the menstrual cycle phase and were examined by immunohistochemistry for MCP-1 expression. No significant difference was observed for MCP-1 immunoreactivity in the endothelial cells of eutopic endometrium of women with endometriosis when compared to endometrium of women without endometriosis and to endometriosis implants. For in vitro studies, the purity of cultured HEECs (90%-95%) was confirmed by immunocytochemistry using endothelium-specific markers CD31 and CD146. The effects of estradiol (5 × 10— 8 mol/L), progesterone (10—7 mol/L), or both on MCP-1 messenger RNA (mRNA) and protein levels were analyzed by reverse transcriptase—polymerase chain reaction (RT-PCR) analysis and enzyme-linked immunosorbent serologic assay (ELISA), respectively. Sex steroids did not have significant effect on MCP-1 mRNA and protein expression in HEECs from women without endometriosis. However, we observed that the sex steroid treatment stimulated MCP-1 mRNA and protein expression in HEECs from women with endometriosis (P < .05). We postulate that the stimulation of chemokine expression by sex steroids in the endometrial endothelial cells in women with endometriosis may play a central role in recruiting mononuclear cells, therefore contributing to the inflammatory aspect of endometriosis.

Distribution patterns of leucocyte subpopulations expressing different cell markers in the cumulus–oocyte complexes of pregnant and pseudopregnant mice

The nature of leucocyte subpopulations expressing different cell markers around the cumulus-oocyte complex (COC) of pregnant and pseudopregnant mice was investigated in the present study. Immunolabelling for CD4, CD8, CD14, CD45 and CD163 and transmission electron microscopy were used to determine whether leucocytes differ between pregnant and pseudopregnant mice. Sexually mature female BALB/c mice (n = 36; 18 pregnant, 18 pseudopregnant) were stimulated to superovulate with pregnant mares serum gonadotropin and human chorionic gonadotrophin, then mated with either fertile or vasectomised males. Postovulatory oocytes were collected after mating. The cumulus cell masses of the pregnant group contained spermatozoa between cells and were more variable than COCs of the pseudopregnant group. Streptavidin-biotin-peroxidase immunohistochemical labelling of the cell markers CD4, CD8, CD14, CD45 and CD163 showed that there were fewer leucocytes in the COCs of the pseudopregnant group compared with the pregnant group. Transmission electron microscopy revealed that often there were macrophage-like cells containing spermiophagic bodies between the cumulus cells. These observations suggest that, together with other cumulus cells and oviducal cells, these macrophage-like cells may be involved in removing unsuitable or excess spermatozoa and, therefore, in maintaining a suitable microenvironment for normal fertilisation.

The restorative effect of a selective cyclooxygenase-2 inhibitor on urothelial cell–cell interactions after partial bladder outlet obstruction in rats

To determine the changes in cyclooxygenase‐2 (COX‐2), E‐cadherin and α‐catenin expression after partial bladder outlet obstruction (PBOO), and whether a selective COX‐2 inhibitor (celecoxib) might inhibit COX‐2 expression and have beneficial effects on urothelial cell‐to–cell interactions in rats subjected to PBOO.

Expression of interleukin-8 receptors in endometriosis

BACKGROUND Although the etiology of endometriosis is not well understood, chemokines and their receptors are believed to play a role in its pathogenesis. Therefore, we aimed to investigate the expression and localization of interleukin-8 (IL-8) receptors CXCR1 and CXCR2 in eutopic and ectopic endometrial tissues of women with endometriosis, and in endometrium of women without endometriosis. METHODS Ectopic (n = 27) and homologous eutopic endometrium (n = 25) from women with endometriosis and endometrium from women without endometriosis (n = 27) were used for immunohistochemical analysis of CXCR1 and CXCR2. RESULTS In normal endometrium, epithelial CXCR1 and CXCR2 immunostaining intensities were similar in the proliferative and secretory phase. Stromal CXCR1 expression was less then epithelial expression and did not show cyclical difference. No stromal CXCR2 expression was observed. In eutopic endometrium of women with endometriosis compared to endometrium of women without endometriosis, there was a significant increase in both proliferative and secretory phases for epithelial CXCR2 expression, and in proliferative phase for CXCR1 expression (P < 0.05). Both receptor immunoreactivities were significantly increased in the epithelial cells of ectopic endometrial tissues compared to that of normal endometrium (P < 0.05). CONCLUSIONS These findings suggest that IL-8 and its receptors may be involved in the pathogenesis of endometriosis.