Localization of E-cadherin in villous, extravillous and vascular trophoblasts during intrauterine, ectopic and molar pregnancy

Previous reports have described down-regulation of E-cadherin in trophoblasts differentiating to an invasive phenotype. This study shows the localization of E-cadherin in a prospective design with stereological sampling of fetal and maternal first, second and third trimester tissue. E-cadherin was observed in villous cytotrophoblasts, and in non-proliferating, intermediate trophoblasts (IT) within cell columns and islands in intrauterine, ectopic and partial molar placentas. Highly proliferating IT with cytological atypia in complete molar placentas were also E-cadherin-positive. E-cadherin was present in trophoblasts throughout the anchoring cell columns. Trophoblasts undergoing epithelial mesenchymal transformation (EMT) detaching from the distal cell columns and deeper located single extravillous interstitial trophoblasts (EVT) showed E-cadherin-negative breaches in the cell membrane. Prior to the late second trimester, the relative number of E-cadherin-positive single EMT and EVT differed from the total number of cytokeratin-positive trophoblasts. Intraluminal, endovascular and perivascular trophoblasts adjacent to the maternal vessels were also E-cadherin-positive, but a highly varying pattern was observed at different ages of gestation. Our results indicate a temporary shift in E-cadherin expression in extravillous trophoblasts possessing a migrating and invasive potential. Functional E-cadherin may be restored as trophoblasts aggregate in the decidua and the vessel wall after completion of migration.

Immunohistochemical localization of interferons in human placental tissues in normal, ectopic, and molar pregnancy

Interferon (IFN)alpha, beta, and gamma have been localized in normal and pathological human pregnancy using both polyclonal and monoclonal antibodies in immunohistochemical techniques. IFN alpha was localized to fetal chorionic villous syncytiotrophoblast throughout normal pregnancy, as well as to extravillous trophoblast in the placental bed and chorion lave. Maternal decidual leukocytes, as well as fetal Hofbauer cells in the villous mesenchyme, also contained IFN alpha, IFN gamma was detected in villous syncytiotrophoblast, while anti-IFN beta showed only patchy weak reactivity with syncytiotrophoblast. Reaction patterns on ectopic pregnancy tissues were similar to those in early intrauterine pregnancy. In molar pregnancy, reactivity for IFN alpha, beta, and gamma was observed in syncytiotrophoblast. Along with their potential anti-viral effects, placental interferons could play a role in local immunomodulation or in regulation of embryonic cell proliferation and differentiation.

Localization of the cellular expression of inhibin in trophoblastic tissue

AIMS

Inhibin is a peptide hormone which is normally produced by ovarian granulosa cells and which inhibits the release of follicle stimulating hormone from the pituitary gland, thus acting as a modulator of folliculogenesis. Serum inhibin levels are higher during pregnancy than during the normal menstrual cycle and the placenta is thought to be a source of circulating inhibin. Previous studies have yielded conflicting results as to the cellular localization of inhibin in the placenta and the aim of the present study was to investigate the immunohistochemical localization of the hormone in placental tissue. We also wished to investigate whether inhibin could be demonstrated in choriocarcinoma and in non-gestational trophoblastic tissue.

MATERIALS AND RESULTS

Immunohistochemical staining was performed using a monoclonal antibody against the alpha subunit of human inhibin. Specimens included in the study were intrauterine products of conception (n = 36), extrauterine products of conception (n = 4), decidualized endometrium (n = 15), extrauterine decidualized tissue (n = 3), hydatidiform mole (n = 5), uterine choriocarinoma (n = 2) and testicular embryonal carcinoma with syncytiotrophoblast giant cells (n = 6). In cases of products of conception, including hydatidiform mole, there was consistent strong positive staining of syncytiotrophoblast but no staining of cytotrophoblast with anti-inhibin. Staining with anti-inhibin highlighted trophoblastic cells within the placental bed. In a small number of cases there was focal weak positive staining of decidua. There was positive staining of the two cases of uterine choriocarcinoma and of syncytiotrophoblast giant cells in the six cases of testicular embryonal carcinoma.

CONCLUSIONS

The study shows that immunohistochemically detectable inhibin alpha subunit in placental tissue is mainly localized within syncytiotrophoblast although in some cases there is also positive staining of decidua. Production of inhibin by these cells may account for raised serum levels during pregnancy. Inhibin can also be demonstrated in choriocarcinoma and in nongestational trophoblastic tissue. Inhibin is a sensitive marker of syncytiotrophoblast and staining with this antibody may prove useful in the diagnosis of choriocarcinoma and in the demonstration of trophoblastic cells in germ cell tumours.

Metalloproteinases, vascular endothelial growth factor, and angiopoietin 1 and 2 in eutopic and ectopic endometrium

OBJECTIVE

To evaluate the expression of vascular endothelial growth factor (VEGF), angiopoietin 1 and 2 (ANGPT1/ANGPT2), and matrix metalloproteinases 1, 2, and 9 (MMP-1, MMP-2, MMP-9) in eutopic and ectopic endometrium.

DESIGN

Experimental retrospective study.

SETTING

University hospital.

PATIENT(S)

Eutopic and ectopic endometrium samples from 30 women with endometriosis and endometrium biopsy samples from 30 healthy women.

INTERVENTION(S)

Biopsies of ovarian endometriomas and eutopic endometrium.

MAIN OUTCOME MEASURE(S)

Immunohistochemical staining to evaluate the expression of VEGF, ANGPT1, ANGPT2, MMP-1, MMP-2, and MMP-9, and real-time polymerase chain reaction analysis to quantify mRNA expression.

RESULT(S)

Patients with endometriosis had higher levels of angiogenic factors and metalloproteinases in endometriotic cysts than in eutopic endometrium. These substances were also overexpressed in eutopic endometrium of patients with endometriosis when compared with normal controls.

CONCLUSION(S)

Overexpression of angiogenic factors and metalloproteinases may be the characteristic feature of endometrium with greater potential to transform into endometriotic lesions in the peritoneal cavity. Structural and/or functional differences of eutopic endometrium could have a role in the pathogenesis of endometriosis secondary to the backward passage of endometrial cells into the peritoneal cavity. Whether these local factors may induce, promote, and/or regulate this transformation remains to be determined.

CB1 expression is attenuated in Fallopian tube and decidua of women with ectopic pregnancy

Background

Embryo retention in the Fallopian tube (FT) is thought to lead to ectopic pregnancy (EP), a considerable cause of morbidity. In mice, genetic/pharmacological silencing of cannabinoid receptor Cnr1, encoding CB1, causes retention of embryos in the oviduct. The role of the endocannabinoids in tubal implantation in humans is not known.

Methods and Findings

Timed FT biopsies (n = 18) were collected from women undergoing gynecological procedures for benign conditions. Endometrial biopsies and whole blood were collected from women undergoing surgery for EP (n = 11); management of miscarriage (n = 6), and termination of pregnancy (n = 8). Using RT-PCR and immunohistochemistry, CB1 mRNA and protein expression levels/patterns were examined in FT and endometrial biopsies. The distribution of two polymorphisms of CNR1 was examined by TaqMan analysis of genomic DNA from the whole blood samples. In normal FT, CB1 mRNA was higher in luteal compared to follicular-phase (p<0.05). CB1 protein was located in smooth muscle of the wall and of endothelial vessels, and luminal epithelium of FT. In FT from women with EP, CB1 mRNA expression was low. CB1 mRNA expression was also significantly lower (p<0.05) in endometrium of women with EP compared to intrauterine pregnancies (IUP). Although of 1359G/A (rs1049353) polymorphisms of CNR1 gene suggests differential distribution of genotypes between the small, available cohorts of women with EP and those with IUP, results were not statistically significant.

Conclusions

CB1 mRNA shows temporal variation in expression in human FT, likely regulated by progesterone. CB1 mRNA is expressed in low levels in both the FT and endometrium of women with EP. We propose that aberrant endocannabinoid-signaling in human FT leads to EP. Furthermore, our finding of reduced mRNA expression along with a possible association between polymorphism genotypes of the CNR1 gene and EP, suggests a possible genetic predisposition to EP that warrants replication in a larger sample pool.

Attenuated sex steroid receptor expression in fallopian tube of women with ectopic pregnancy

CONTEXT

Sex steroid hormone receptor (SHR) dynamics are well-documented in human endometrium but have not been comprehensively studied in Fallopian tube (FT).

OBJECTIVE

The aim of the study was to compare expression patterns and hormonal regulation of SHR in FT with that described in endometrium and to determine whether SHR expression is altered in FT of women with ectopic pregnancy (EP).

DESIGN

Tissue was analyzed and cultured.

PATIENTS OR OTHER PARTICIPANTS

Women undergoing surgery for benign gynecological conditions (n = 14) and EP (n = 6) participated in the study.

INTERVENTIONS

Quantitative RT-PCR and immunohistochemistry were used to determine SHR mRNA expression and protein localization, respectively. SHR levels were measured in tubal explant cultures stimulated with estrogen and progestogen.

RESULTS

ERalpha and ERbeta mRNAs were constitutively expressed in FT during the menstrual cycle. PR-AB and PR-B mRNAs were decreased in midluteal phase compared to follicular phase. ERalpha, PR-AB, and PR-B mRNAs were down-regulated in human FT in vitro by treatment with progestogen. ERalpha, ERbeta1, ERbeta2, PR, and AR proteins localized to cell nuclei of epithelium, stroma, and smooth muscle of nonpregnant FT. In FT from women with EP, PR-B mRNA was decreased when compared to midluteal FT, and ERalpha protein was not detected.

CONCLUSIONS

SHR expression in FT is different from that observed in endometrium recovered at similar stages of the menstrual cycle, and expression in FT from women with EP is also altered compared with normal FT. These data are an important benchmark for furthering the understanding of normal human FT physiology, changes in expression of SHR in FT in response to progesterone, and disorders of FT function, such as EP.

The frequency of CD25+CD4+ and FOXP3+ regulatory T cells in ectopic endometrium and ectopic decidua

BACKGROUND

The presence of regulatory T (Treg) cells in human endometrium is crucial for maintaining immunological homeostasis within the uterus. For this study we decided to evaluate the subpopulations of Treg cells in conditions where a disturbance in the immunological equilibrium in ectopic endometrium and decidua has been observed, such as in cases of ovarian endometriosis (involving local immune cell suppression) and ectopic pregnancy (involving an increase in local immune system activity). We then compared these findings to what we observed in the normal eutopic endometrium of women during the secretory phase of the menstrual cycle (with immune cells under individual control).

METHODS

The endometrium tissue samples evaluated in our study were obtained from 47 women during one of two kinds of laparoscopic procedures. 16 of the women underwent laparoscopies due to Fallopian tube pregnancies (EP), and 16 due to ovarian endometrioma, while 15 women made up a control group. The presence of regulatory T cells in these tissue samples was evaluated by FACS.

RESULTS

In our study, the percentages of FOXP3+ cells within the subpopulation of CD4+ T lymphocytes found in the decidua of the patients treated for Fallopian tube pregnancies were statistically significantly lower than both those observed in the ovarian endometriosis tissue samples and those found in the secretory eutopic endometrium samples of the control group.

CONCLUSION

The disturbance in the immunological equilibrium observed in ectopic endometrium and decidua would seem to be related to the alteration in the Treg cell population that occurs in these ectopic tissues.

HLA-G expression in extravillous trophoblasts is an intrinsic property of cell differentiation: a lesson learned from ectopic pregnancies

Human leukocyte antigen (HLA)-G is a major histocompatibility gene expressed almost exclusively in extravillous trophoblasts at the fetal-maternal interface. HLA-G may play a role in protecting the fetus from attack by the maternal natural killer cells. The extravillous trophoblasts invade the decidua and maternal spiral arteries. The factors which regulate the cell-specific expression of HLA-G are unknown. In this study we asked if HLA-G is expressed in extravillous trophoblasts that develop outside of their normal cellular environment, as in the case of ectopic pregnancies. Since all ectopic pregnancies implant in the absence of underlying decidua we also used a placenta accreta as an experimental control. We found that HLA-G mRNA and protein were expressed in the extravillous trophoblasts in the 13 ectopic specimens studied. In a case of placenta accreta (which develops without decidua basalis and is therefore adherent to the underlying myometrium), HLA-G mRNA and protein were also expressed. These results suggest that HLA-G expression is induced in a cell autonomous manner rather than determined by appropriate environmental cues.

Chlamydia trachomatis infection increases fallopian tube PROKR2 via TLR2 and NFκB activation resulting in a microenvironment predisposed to ectopic pregnancy

Chlamydia trachomatis and smoking are major risk factors for tubal ectopic pregnancy (EP), but the underlying mechanisms of these associations are not completely understood. Fallopian tube (FT) from women with EP exhibit altered expression of prokineticin receptors 1 and 2 (PROKR1 and PROKR2); smoking increases FT PROKR1, resulting in a microenvironment predisposed to EP. We hypothesize that C. trachomatis also predisposes to EP by altering FT PROKR expression and have investigated this by examining NFκB activation via ligation of the Toll-like receptor (TLR) family of cell-surface pattern recognition receptors. PROKR2 mRNA was higher in FT from women with evidence of past C. trachomatis infection than in those without (P < 0.05), and was also increased in FT explants and in oviductal epithelial cell line OE-E6/E7 infected with C. trachomatis (P < 0.01) or exposed to UV-killed organisms (P < 0.05). The ability of both live and dead organisms to induce this effect suggests ligation of a cell-surface-expressed receptor. FT epithelium and OE-E6/E7 were both found to express TLR2 and TLR4 by immunohistochemistry. Transfection of OE-E6/E7 cells with dominant-negative TLR2 or IκBα abrogated the C. trachomatis-induced PROKR2 expression. We propose that ligation of tubal TLR2 and activation of NFκB by C. trachomatis leads to increased tubal PROKR2, thereby predisposing the tubal microenvironment to ectopic implantation.

Effects of trophoblast invasion on the distribution of leukocytes in uterine and tubal implantation sites

OBJECTIVE

To distinguish endocrine and paracrine influences on leukocyte subpopulations at uterine and tubal implantation sites.

DESIGN

Retrospective immunohistochemical study.

SETTING

Departments of Anatomy, and Obstetrics and Gynecology, School of Medicine, RWTH University of Aachen, Aachen, Germany.

PATIENT(S)

Ten women with a viable ectopic pregnancy (EP), 25 women who had undergone elective first-trimester termination of pregnancy, and 4 women who had undergone hysterectomy with adnexectomy.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Quantitative analysis of leukocyte subpopulations at the implantation sites and their corresponding noninvaded tissues, decidual tissue from patients with EP, and tubal mucosa from normal menstrual cycle.

RESULT(S)

Similar numbers and characteristic distribution patterns of macrophages, T cells, and B cells were found at both normal intrauterine and tubal implantation sites. Natural killer (NK) cells were always absent from tubal mucosa. The number and distribution of leukocytes within decidual tissue from women with EP corresponded to those in the noninvaded decidual compartment in intrauterine pregnancy (IUP).

CONCLUSION(S)

Leukocyte populations present in the tubal and uterine mucosa are an intrinsic characteristic of these tissues. The distinct leukocyte distribution pattern at the implantation sites suggests that the invading trophoblast exerts a paracrine influence on endometrial and endosalpingeal leukocytes. The absence of natural killer cells from the tubal wall may be one reason for the higher degree of invasiveness of the trophoblast at the tubal implantation site.

Suppression of concentration of endometrial prostaglandin in early intra-uterine and ectopic pregnancy in women

Concentrations of prostaglandin F2 alpha (PGF2 alpha) and prostaglandin E (PGE) were measured in endometrium from 18 women with ectopic pregnancies. In the nine pregnancies not associated with vaginal bleeding or an intra-uterine contraceptive device (IUCD; intact ectopics), concentrations of PGF2 alpha (12.8 +/- 7.4 (S.E.M.) ng/g) and PGE (4.7 +/- 3.0 ng/g) were similar to those in decidua from nine intra-uterine pregnancies of comparable gestational age (14.4 +/- 4.4 and 8.2 +/- 2.2 ng/g respectively). In both ectopic and intra-uterine pregnancies concentrations of prostaglandins were significantly lower than those found in endometrium throughout the normal menstrual cycle (P < 0.01). In nine ectopic pregnancies with associated vaginal bleeding and/or an IUCD, concentrations of PGF2 alpha and PGE were significantly higher than in the intact group (P < 0.05), although the concentration of PGF2 alpha remained significantly lower than levels in normal secretory endometrium (P < 0.05). These results suggested that suppression of endometrial synsthesis of prostaglandin during early pregnancy may be mediated systemically rather than through a local action of the conceptus.

Brain-derived neurotrophic factor/tyrosine kinase B signaling regulates human trophoblast growth in an in vivo animal model of ectopic pregnancy

Although medical treatment of unruptured ectopic pregnancy using methotrexate has been established, development of more potent and safer medical treatment is needed due to limited indications and side effects of methotrexate. Brain-derived neurotrophic factor (BDNF) signals through its receptor tyrosine kinase B (TrkB) to regulate the growth of malignant trophoblastic, choriocarcinoma cell. We investigated possible involvement of this signaling system in nonmalignant human trophoblast growth in both ectopic and intrauterine pregnancy. Here, we demonstrated the expression of BDNF in syncytiotrophoblasts and extravillous trophoblasts (EVTs) together with TrkB in cytotrophoblasts and EVTs in human placental villi during both normal and ectopic pregnancies. Treatment of cultured villous explants with soluble TrkB ectodomain or a Trk receptor inhibitor K252a suppressed cytotrophoblast differentiation by inhibiting EVT outgrowth reflected by decreased levels of an EVT marker, human leukocyte antigen-G. These inhibitors also decreased cytotrophoblast proliferation and cellular viability based on histopathological analyses and monitoring glucose metabolism, together with increased apoptosis in cytotrophoblasts based on in situ terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end-labeling and caspase-3/7 assays. After xenotransplantation of human placental villi into SCID mice as an in vivo model of ectopic pregnancy, treatment with K252a suppressed transplanted villi growth as reflected by decreased cytotrophoblast differentiation and proliferation, reduced tissue levels of chorionic gonadotropin-β, and increased apoptosis and caspase-3/7 activities. Thus, paracrine signaling by the BDNF/TrkB system is important for human cytotrophoblast differentiation, proliferation, and survival, and inhibition of BDNF/TrkB signaling in cytotrophoblasts could provide a novel medical treatment for ectopic pregnancy.

Human ovaries contain immunoreactive oxytocin

Ovarian tissues (n = 26) obtained at surgery were assayed for oxytocin (OT) concentrations in different parts of the ovary by a specific and sensitive RIA after homogenization and extraction with 0.4 M acetic acid. Chromatography of the extract on a Sephadex G-25 column revealed a single peak identical to synthetic OT, as measured by RIA. Corpora lutea of the menstrual cycle had 10.8-53.0 ng immunoreactive OT/g tissue (n = 7), while those of early pregnancy had a concentration of 106.0 ng/g (n = 1). Ovarian stromal tissue had either undetectable or lower concentrations of OT (0-21.0 ng/g; n = 5) than the corpus luteum from the same ovary. While a luteoma of term pregnancy (n = 1), a benign cystadenoma (n = 2), and an endometriotic cyst (n = 1) had no detectable immunoreactive OT, the concentrations of immunoreactive OT were 20.0 ng/g in a thecoma, 1.4, 20.0, and 60.0 ng/g in preovulatory follicles (n = 3), and 41.0 and 37.0 ng/g in polycystic ovaries (n = 2). In one patient with premature ovarian failure, the ovaries had 9.0 ng/g and undetectable immunoreactive OT. These findings indicate the presence of immunoreactive OT in human ovaries, with significant concentrations in the corpus luteum and preovulatory follicles. It is probable that these tissues produce OTs or an OT-like material which may function as an ovarian luteolytic agent.

Ectopic pregnancy is associated with high anandamide levels and aberrant expression of FAAH and CB1 in fallopian tubes

CONTEXT

Ectopic pregnancy is associated with significant morbidity and mortality, but the molecular mechanisms underlying this condition remain unclear. Although the endocannabinoids, N-arachidonoylethanolamine (anandamide), N-oleoylethanolamine, and N-palmitoylethanolamine, are thought to play a negative role in ectopic pregnancy, their precise role(s) within the fallopian tube remains unclear. Anandamide activates cannabinoid receptors (CB1 and CB2) and, together with its degrading [e.g. fatty acid amide hydrolase (FAAH)] and synthesizing enzymes (e.g. N-acyl-phosphatidylethanolamine-specific phospholipase D), forms the endocannabinoid system. High anandamide levels are associated with tubal arrest of embryos in mice and may have a similar role in women.

OBJECTIVE

The aims were to quantify the levels of the endocannabinoids and evaluate the expression of the modulating enzymes and the cannabinoid receptors in fallopian tubes of women with ectopic pregnancy compared to those of nonpregnant women.

DESIGN AND SETTING

We conducted a prospective study at the University Hospitals of the Leicester National Health Service Trust.

PARTICIPANTS AND METHODS

Fallopian tubes collected from women with ectopic pregnancy and nonpregnant women with regular menstrual cycles were used for quantification of endocannabinoids by ultra-HPLC tandem mass spectrometry, were fixed in formalin for immunohistochemistry, and had RNA extracted for RT-quantitative PCR or protein extracted for immunoblotting.

RESULTS

Anandamide, but not N-oleoylethanolamine and N-palmitoylethanolamine, levels were significantly higher in ectopic fallopian tubes. Endocannabinoid levels from isthmus to ampulla were not significantly different. Cannabinoid receptors and endocannabinoid modulating enzymes were localized in fallopian tube epithelium by immunohistochemistry and showed reduced CB1 and FAAH expression in ectopic pregnancy.

CONCLUSION

High anandamide levels and reduced expression of CB1 and FAAH may play a role in ectopic implantation.

Gonadotropin receptors in human corpora lutea of the menstrual cycle and pregnancy

Binding of 125I-human choriogonadotropin (hCG) to homogenates of corpora lutea of the menstrual cycle and pregnancy was examined. While corpora lutea of the menstrual cycle bound 125I-hCG, most of the corpora lutea of pregnancy from six to 34 weeks' gestation bound little or none of the added 125 I-hCG. Further exploration into various possibilities for the above findings led to the conclusion that these corpora lutea either contain very few gonadotropin receptors or lack them altogether. The selected properties of gonadotropin receptors in corpora lutea of the cycle were studied. The apparent dissociation constant for binding was about the same (2.6 to 3.8 x 10-10M) in all but one corpus luteum. In this one sample the constant was three- to five-fold higher (1.3 x 10-9M). The binding was quite rapid and reversible, and it exhibited dependence on the amount of 125I-hCG, homogenate protein, pH of the incubation media, and duration of incubation. hCG and human lutropin (hLH') competed for 125I-hCG binding, but hCG subunits (alpha and beta), human follitropin, and ovine prolactin did not. Although hCG and hLH were parallel in inhibiting 125I-hCG binding, hLH was found to be relatively less effective. The studies with various enzymes revealed that gonadotropin receptors are protein in nature.

Decidual Interleukin-22-Producing CD4+ T Cells (Th17/Th0/IL-22+ and Th17/Th2/IL-22+, Th2/IL-22+, Th0/IL-22+), Which Also Produce IL-4, Are Involved in the Success of Pregnancy

Trophoblast expressing paternal HLA-C resembles a semiallograft, and could be rejected by maternal T cells. IL-22 seems to be involved in allograft rejection and thus could be responsible for miscarriages. We examined the role of decidual IL-22-producing CD4+ T on human pregnancy. In those experiencing successful pregnancy and those experiencing unexplained recurrent abortion (URA), the levels of IL-22 produced by decidual CD4+ T cells are higher than those of peripheral blood T cells. We found a correlation of IL-22 and IL-4 produced by decidual CD4+ T cells in those experiencing successful pregnancy, not in those experiencing URA. The correlation of IL-22 and IL-4 was also found in the serum of successful pregnancy. A prevalence of CD4+ T cells producing IL-22 and IL-4 (Th17/Th2/IL-22+, Th17/Th0/IL-22+, Th17/Th2/IL-22+, and Th0/IL-22+ cells) was observed in decidua of those experiencing successful pregnancy, whereas Th17/Th1/IL-22+ cells, which do not produce IL-4, are prevalent in those experiencing URA. Th17/Th2/IL-22+ and Th17/Th0/IL-22+ cells are exclusively present at the embryo implantation site where IL-4, GATA-3, IL-17A, ROR-C, IL-22, and AHR mRNA are expressed. T-bet and IFN-γ mRNA are found away from the implantation site. There is no pathogenic role of IL-22 when IL-4 is also produced by decidual CD4+ cells. Th17/Th2/IL-22+ and Th17/Th0/IL-22+ cells seem to be crucial for embryo implantation.

Modulation of leukemia inhibitory factor gene expression and protein biosynthesis in the human fallopian tube

OBJECTIVE

The fallopian tube is the site of fertilization and early embryonic growth and a common site of ectopic implantation. Although the factors responsible for early embryogenesis and implantation are incompletely understood, leukemia inhibitory factor may have an important role in early embryonic development and implantation. We set out to evaluate the production and modulation of leukemia inhibitory factor in the fallopian tube.

STUDY DESIGN

We first investigated leukemia inhibitory factor messenger ribonucleic acid levels in fallopian tubes. We then investigated leukemia inhibitory factor messenger ribonucleic acid and protein production in tubal epithelial and stromal cell cultures.

RESULTS

Leukemia inhibitory factor messenger ribonucleic acid is expressed in the fallopian tube with only slight variation during the menstrual cycle; however, it is markedly elevated in association with ectopic pregnancy. The level is higher in the tubal mucosa than in the remaining layers and is higher in the more distal segments of the fallopian tube. Estradiol and progesterone did not modulate leukemia inhibitory factor expression in epithelial or stromal cell cultures. Interleukin-1 alpha, tumor necrosis factor-alpha, and transforming growth factor-beta enhanced leukemia inhibitory factor expression in epithelial and stromal cells, with transforming growth factor-beta 1 enhancing expression by fourfold in stromal cells. Epithelial cells secreted high levels of leukemia inhibitory factor compared with stromal cells (332 +/- 89 vs 25 +/- 42 pg/mg total protein). Yet stromal cells treated with transforming growth factor-beta alone or in combination with epidermal growth factor and platelet-derived growth factor, as well as TNF-alpha alone or in combination with interleukin-1 alpha enhanced secretion of leukemia inhibitory factor at or above the levels found with epithelial cells.

CONCLUSIONS

We speculate that the high constitutive levels of leukemia inhibitory factor expressed in the ampullary portion of the fallopian tube may play a role in early embryonic development. Additionally, elevated expression with ectopic implantation and the marked induction of secretion in the tubal stroma by growth factors and cytokines suggest a link between inflammation, leukemia inhibitory factor, and tubal ectopic pregnancies.

Medical management should be routinely used as primary therapy for ectopic pregnancy

It does not appear that methotrexate can or should be used to totally replace laparoscopic salpingostomy. However, given its success rate in selected patients, its cost-effectiveness, and its low incidence of side effects, methotrexate therapy certainly can be used as an alternative therapy. The next step in developing this treatment option will be to conduct a randomized clinical trial comparing laparoscopic salpingostomy with intramuscular methotrexate. This type of study will answer questions regarding the patient's health related quality of life and economic impact of the two treatment modalities. For now, it seems prudent to offer methotrexate to those patients with an unruptured ectopic gestational mass 3.5 cm or less in greatest dimension.

Embryonic miRNA profiles of normal and ectopic pregnancies

Our objective was to investigate the miRNA profile of embryonic tissues in ectopic pregnancies (EPs) and controlled abortions (voluntary termination of pregnancy; VTOP). Twenty-three patients suffering from tubal EP and twenty-nine patients with a normal ongoing pregnancy scheduled for a VTOP were recruited. Embryonic tissue samples were analyzed by miRNA microarray and further validated by real time PCR. Microarray studies showed that four miRNAs were differentially downregulated (hsa-mir-196b, hsa-mir-30a, hsa-mir-873, and hsa-mir-337-3p) and three upregulated (hsa-mir-1288, hsa-mir-451, and hsa-mir-223) in EP compared to control tissue samples. Hsa-miR-196, hsa-miR-223, and hsa-miR-451 were further validated by real time PCR in a wider population of EP and control samples. We also performed a computational analysis to identify the gene targets and pathways which might be modulated by these three differentially expressed miRNAs. The most significant pathways found were the mucin type O-glycan biosynthesis and the ECM-receptor-interaction pathways. We also checked that the dysregulation of these three miRNAs was able to alter the expression of the gene targets in the embryonic tissues included in these pathways such as GALNT13 and ITGA2 genes. In conclusion, analysis of miRNAs in ectopic and eutopic embryonic tissues shows different expression patterns that could modify pathways which are critical for correct implantation, providing new insights into the understanding of ectopic implantation in humans.

Expression of epidermal growth factor receptor and transferrin receptor by human trophoblast populations

Epidermal growth factor (EGF) has several roles, including stimulation of cell division and differentiation. EGF receptor (EGFR) has been localized to villous syncytiotrophoblast, but expression by other human trophoblast populations has not been reported. EGFR expression was examined in normal and pathological placental tissues using a streptavidin-biotin-peroxidase technique; results were compared with expression of transferrin receptor (Tf-R) in similar tissues. EGFR was detected on villous syncytiotrophoblast in early and term pregnancy with labelling of the apical membrane, focal cytoplasmic reactivity, and patchy labelling of the trophoblast basement membrane. In contrast with other reports, EGFR was also consistently localized to villous cytotrophoblast, chorion laeve, and extravillous trophoblast populations in maternal uterine tissues. Maternal decidua showed diffuse labelling of stromal cells, particularly in the superficial zones. The reaction pattern in ectopic tubal pregnancy was similar to that in early intrauterine pregnancy. In molar pregnancy, EGFR was detected on villous syncytiotrophoblast and cytotrophoblast. In contrast, in normal, ectopic, and molar pregnancies labelling for Tf-R was confined to syncytiotrophoblast and to the proximal portions of the cytotrophoblast columns. Expression of EGFR by all trophoblast cells may represent a mechanism of placental growth and proliferation control. EGFR may also be involved with establishment of differentiated trophoblast functions including hormone secretion.

Localization of angiotensin II, the AT1 receptor, angiotensin-converting enzyme, aminopeptidase A, adipocyte-derived leucine aminopeptidase, and vascular endothelial growth factor in the human ovary throughout the menstrual cycle

OBJECTIVE

To assess the expression and cellular distribution of angiotensin II (Ang II), angiotensin type 1 receptor (AT1R), angiotensin-converting enzyme (ACE), aminopeptidase A (APA), adipocyte-derived leucine aminopeptidase (A-LAP), and vascular endothelial growth factor (VEGF) in human ovarian tissue during the menstrual cycle.

DESIGN

Ovarian tissues (n = 52) and corpora lutea (n = 34) were obtained from patients undergoing hysterectomy/oophorectomy, and tissue sections were immunostained for each antigen.

SETTING

University hospital.

PATIENT(S)

Patients undergoing hysterectomy or oophorectomy for benign conditions.

INTERVENTION(S)

Immunostaining of tissue sections using antibodies to each antigen.

MAIN OUTCOME MEASURE(S)

Microscopic evaluation to assess the presence, distribution, and cellular localization.

RESULT(S)

The luteal tissue is the major site of Ang II, ACE, AT1R, and VEGF, with highest staining intensity found during the midluteal phase and at pregnancy. The AT1R was found in theca cells. The APA was strongly immunolocalized in pericytes. Immunolocalization of AT1R was almost similar to that of VEGF including oocytes in the primordial and intermediate follicles.

CONCLUSION(S)

The expression and distinct pattern of the cellular localization of Ang II and its related proteins in human ovarian tissue during folliculogenesis and in the luteal tissue suggest their roles in the growth and differentiation of theca, granulose, and luteal cells.

Endometrial gene expression in early pregnancy: lessons from human ectopic pregnancy

Human endometrium undergoes modifications in preparation for embryonic implantation. This study investigated in vivo the endocrine effects of pregnancy on the endometrium, using the model of ectopic pregnancy. Endometrial biopsies from 9 subjects with ectopic pregnancy (Preg) were compared with 8 and 6 samples of mid and late secretory endometrium, respectively. After hybridizing with Affymetrix HGU133 Plus 2 chips, data were analyzed using GeneSpring GX and Ingenuity Pathways Analysis. From 54,675 genes, 3021 genes were significantly differentiated when mid-secretory endometrium was compared with the Preg (Volcano plot; P < .05, >or=2-fold change).The complement and coagulation cascade, phospholid degradation, glycosphingolipid biosynthesis (globoseries), retinol metabolism, antigen presentation pathway, glycosphingolipid biosynthesis, and O-glycan biosynthesis were main significant canonical pathways found in Preg samples. Validation was done with reverse transcriptase polymerase chain reaction. In conclusion, the ectopic embryo has a significant impact, by an endocrine mechanism, on endometrium, when compared with the window of implantation.

Tissue kallikrein and bradykinin B2 receptor in human uterus in luteal phase and in early and late gestation

This study was addressed to evaluate the temporospatial pattern of key components of the kallikreinkinin system in human uterus in luteal phase (n = 7), early pregnancy (isolated spontaneous abortions, n = 11; ectopic pregnancies, n = 9), idiopathic preterm deliveries (n = 5), and term gestations (n = 12). Tissue kallikrein mRNA and protein and the type 2 bradykinin receptor (B2R) protein were expressed in luminal and glandular epithelium and in endothelial cells of stromal and myometrial blood vessels, while tissue kallikrein mRNA and B2R, but not tissue kallikrein protein, were observed in decidual cells and in arteriolar and myometrial muscle. A greater signal intensity for tissue kallikrein mRNA and protein and of B2R protein was observed in the early pregnancy samples. The sites and variations of the tissue kallikrein mRNA and protein and of the B2R protein in the human uterus and in fallopian tubes during the luteal phase and in pregnancy coincide with those described for other vasoactive effectors such as nitric oxide, prostacyclins, growth factors, and renin. The uterine localization of the main enzyme and receptor of the tissue kallikrein-kinin system in key sites for embryo attachment, implantation, placentation, maintenance of placental blood flow, and parturition supports the notion that the kallikreinkinin system participates in these processes, probably through vasodilation, increased vasopermeability, enhanced matrix degradation, stimulation of cell proliferation, and myometrial contractility.