Is neonatal uterine bleeding responsible for early-onset endometriosis?

BACKGROUND: It has been hypothesized that the origin of early-onset endometriosis could be from endometrial mesenchymal stem cells (eMSCs) in neonatal uterine blood (NUB). There is no information on the possible mechanistic basis linking an association between NUB/neonatal endometrium and development of early-onset endometriosis. In this study we performed a series of experiments to clarify the mechanistic link between NUB and/or neonatal endometrium and development of early-onset endometriosis. METHODS: We retrospectively collected postmortem neonatal endometria (n = 15) and prospectively collected NUB (n = 18) of female babies for the analysis of different biological markers including eMSCs. Immunohistochemical analysis of neonatal endometria was performed to examine the expression patterns of ovarian steroid receptors (ER/PGR), decidualization (prolactin, IGFBP1), pre-decidualization (Glycodelin A, α-SMA), proliferation (Ki-67 index), vascularity (CD31 + cells), immunocompetent CD68+, CD45+, CD56 + cells and some putative markers of eMSCs. Cell transfer method and immunocytochemistry were used to investigate the eMSCs and/or endometrial cells in NUB. RESULTS: Immunohistochemical analysis of postmortem neonatal endometria revealed variable staining response to ER/PGR, decidual markers, and substantial proliferative and angiogenic activity. A moderate to strong immunoexpression of Glycodelin-A was found in both neonatal and adult endometria. The tissue infiltration of CD56+, CD45 + and CD68 + immunocompetent cells was significantly low in neonatal endometria than that in adult endometria (p = 0.0003, p < 0.0001, p = 0.034, respectively). No eMSCs or even endometrial cells were detected in NUB. However, a variable expression of some phenotypes of eMSCs (CD90/CD105) was found in neonatal endometria. CONCLUSIONS: Based on our serial experiments we did not find any supporting evidence for the role of NUB in early-onset endometriosis. Neonatal endometria showed variable expression of ovarian steroid receptors, decidualization, and a substantial amount of proliferative and angiogenic activity. As an alternative mechanism, a significantly less tissue accumulation of immunocompetent cells in neonatal endometria may explain the survival of ER + and PGR + cells should they make entry into the pelvis and consequent development of early endometriosis with the onset of ovarian function. Future study with large sample size and application of modified technological tools is warranted to test the NUB hypothesis and to clarify their biological or clinical significance. TRIAL REGISTRATION: not applicable.

The uterine natural killer cell, cytotoxic T lymphocyte, and granulysin levels are elevated in the endometrium of women with nonstructural abnormal uterine bleeding.

OBJECTIVE: To examine the expression of uterine natural killer (uNK) cells and cytotoxic T lymphocytes (CTLs) in endometrial biopsies from reproductive-age women with and without nonstructural abnormal uterine bleeding (AUB) and evaluate the expression of granulysin within these cell populations and potential modulation of matrix metalloproteinase (MMP) expression. DESIGN: Experimental study, retrospective design. SETTING: Academic research laboratory. PATIENT(S): Patients with nonstructural AUB with no other gynecological pathologies and control patients without AUB. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Immunohistochemical analysis of granulysin, CD56 (uNK cell marker), and CD8 (CTL marker) expression as well as granulysin messenger ribonucleic acid (mRNA) expression levels in endometrial biopsy samples. Assessment of granulysin regulation of human endometrial stromal cell MMP-1 and MMP-3 mRNA expression. RESULT(S): The numbers of uNK cells and CTLs were significantly greater in endometrial biopsy tissue from women with AUB than those from controls. In accord with the increased expression of uNK cells and CTLs, granulysin expression was significantly greater in endometrial biopsies from patients with AUB than in from controls and colocalized to both cell types but not endometrial stromal or epithelial cells. The increased granulysin protein expression was associated with the increased granulysin mRNA expression in adjacent serial sections from these same samples. The treatment of the human endometrial stromal cell line t-HESC with granulysin resulted in a significant increase in MMP-1 and MMP-3 mRNA expression. CONCLUSION(S): In the current study, immunohistochemistry showed an increased expression of uNK cells, CTLs, and granulysin among subjects with AUB compared with that of subjects without AUB, leading to conclusions that disturbances in the balance of immune cells and an increase in granulysin expression may have implications in the pathophysiology of AUB and include enhanced MMP-1 and MMP-3 expression.

Which Factors Contribute to False-Positive, False-Negative, and Invalid Results in Fetal Fibronectin Testing in Women with Symptoms of Preterm Labor?

Objective We assessed the influence of external factors on false-positive, false-negative, and invalid fibronectin results in the prediction of spontaneous delivery within 7 days. Methods We studied symptomatic women between 24 and 34 weeks' gestational age. We performed uni- and multivariable logistic regression to estimate the effect of external factors (vaginal soap, digital examination, transvaginal sonography, sexual intercourse, vaginal bleeding) on the risk of false-positive, false-negative, and invalid results, using spontaneous delivery within 7 days as the outcome. Results Out of 708 women, 237 (33%) had a false-positive result; none of the factors showed a significant association. Vaginal bleeding increased the proportion of positive fetal fibronectin (fFN) results, but was significantly associated with a lower risk of false-positive test results (odds ratio [OR], 0.22; 95% confidence intervals [CI], 0.12-0.39). Ten women (1%) had a false-negative result. None of the investigated factors was significantly associated with a significantly higher risk of false-negative results. Twenty-one tests (3%) were invalid; only vaginal bleeding showed a significant association (OR, 4.5; 95% CI, 1.7-12). Conclusion The effect of external factors on the performance of qualitative fFN testing is limited, with vaginal bleeding as the only factor that reduces its validity.

Endometrial breakdown with sustained progesterone release involves NF-κB-mediated functional progesterone withdrawal in a mouse implant model.

Irregular uterine bleeding is a major side effect of long-acting progestogen-only contraceptives in women, and is the primary reason women discontinue their use. In this study, a mouse model of endometrial breakdown was established using a subcutaneous progesterone implant to understand how irregular bleeding begins. Although progestogens sustained decidualization, endometrial breakdown was still observed in this model. We, therefore, hypothesized that endometrial breakdown might involve functional progesterone withdrawal. Using co-immunoprecipitation assays, we observed the constitutive activation of nuclear factor kappa-b (NF-κB) p65 and its interaction with the progesterone receptor (PGR); moreover, transcriptional activity of the PGR was also repressed by NF-κB activity in primary mouse and human decidual stromal cells that mimic progesterone maintenance. Yet the ratio of PGR-B to PGR-A was not increased in the mouse model. In vivo comparison of endometrial breakdown induced by progesterone withdrawal to that seen during sustained progesterone exposure, in the presence of NF-κB inhibitors, revealed that NF-κB-mediated functional progesterone withdrawal is involved in endometrial breakdown in this implant model. These data prompt further studies to determine the homology of this functional progesterone withdrawal mechanism in human endometrium. Mol. Reprod. Dev. 83: 780-791, 2016 © 2016 Wiley Periodicals, Inc.

Maternal Early Pregnancy Serum Metabolomics Profile and Abnormal Vaginal Bleeding as Predictors of Placental Abruption: A Prospective Study.

BACKGROUND & OBJECTIVE: Placental abruption, an ischemic placental disorder, complicates about 1 in 100 pregnancies, and is an important cause of maternal and perinatal morbidity and mortality worldwide. Metabolomics holds promise for improving the phenotyping, prediction and understanding of pathophysiologic mechanisms of complex clinical disorders including abruption. We sought to evaluate maternal early pregnancy pre-diagnostic serum metabolic profiles and abnormal vaginal bleeding as predictors of abruption later in pregnancy. METHODS: Maternal serum was collected in early pregnancy (mean 16 weeks, range 15 to 22 weeks) from 51 abruption cases and 51 controls. Quantitative targeted metabolic profiles of serum were acquired using electrospray ionization liquid chromatography-mass spectrometry (ESI-LC-MS/MS) and the Absolute IDQ® p180 kit. Maternal sociodemographic characteristics and reproductive history were abstracted from medical records. Stepwise logistic regression models were developed to evaluate the extent to which metabolites aid in the prediction of abruption. We evaluated the predictive performance of the set of selected metabolites using a receiver operating characteristics (ROC) curve analysis and area under the curve (AUC). RESULTS: Early pregnancy vaginal bleeding, dodecanoylcarnitine/dodecenoylcarnitine (C12 / C12:1), and phosphatidylcholine acyl-alkyl C 38:1 (PC ae C38:1) strongly predict abruption risk. The AUC for these metabolites alone was 0.68, for early pregnancy vaginal bleeding alone was 0.65, and combined the AUC improved to 0.75 with the addition of quantitative metabolite data (P = 0.003). CONCLUSION: Metabolomic profiles of early pregnancy maternal serum samples in addition to the clinical symptom, vaginal bleeding, may serve as important markers for the prediction of abruption. Larger studies are necessary to corroborate and validate these findings in other cohorts.

E-Cadherin, CD44v6, and Insulin-Like Growth Factor-II mRNA-Binding Protein 3 Expressions in Different Stages of Hydatidiform Moles.

E-cadherin, CD44v6, and IMP3 expression in partial, complete, and invasive hydatidiform moles (HMs) was evaluated. High E-cadherin expression with low CD44v6 expression was observed in partial, complete, and invasive HMs, as well as in normal placental tissues; and there was no significant difference in E-cadherin and CD44v6 expression among the four groups. However, IMP3 expression was gradually decreased in the order of normal placental tissues, partial HMs, complete HMs, and invasive HMs; wherein, invasive HMs had the lowest level. Low IMP3 expression may serve as a prognostic biomarker for HMs, and IMP3 may play a certain role in HMs progression.

Analysis of the reason of abnormal uterine bleeding induced by copper corrosion of IUD Cu.

OBJECTIVES: This study aimed to analyze relationship of the copper corrosion of copper intrauterine device (TCu220 IUD) and abnormal uterine bleeding. MATERIALS AND METHODS: Sixty-four patients of abnormal uterine bleeding (too much blood volume, shorten cycle, lengthen period or irregular vaginal bleeding) and 72 cases of normal menstrual cycle and quantity in the present hospital, which were removed of IUD due to non-medical reasons, were enrolled, and 36 regular menstruation cases without placing IUD were selected as control group, in which had assessed in vitro copper ion release of TCu220 IUD and content of copper ions and VEGF in endometrial tissue of each group of women. RESULTS: Daily Cu I UD copper dissolution quantities of abnormal uterine bleeding women was significantly higher than that of regular menstruation women (p < 0.05). Copper ion content and the expression of VEGF in endometrial tissue of abnormal uterine bleeding women was significantly higher than that of regular menstruation women endometrial tissue (p < 0.05), and the endometrial VEGF expression had a positive correlation with copper ion concentration in endometrial tissue. CONCLUSION: High dissolution quantity of Cu IUD may lead to increase of copper ion content in endometrial tissue and may cause VEGF secretion in the endometrium, and then the occurrence of abnormal uterine bleeding.

Progestins Upregulate FKBP51 Expression in Human Endometrial Stromal Cells to Induce Functional Progesterone and Glucocorticoid Withdrawal: Implications for Contraceptive- Associated Abnormal Uterine Bleeding.

Use of long-acting progestin only contraceptives (LAPCs) offers a discrete and highly effective family planning method. Abnormal uterine bleeding (AUB) is the major side effect of, and cause for, discontinuation of LAPCs. The endometria of LAPC-treated women display abnormally enlarged, fragile blood vessels, decreased endometrial blood flow and oxidative stress. To understanding to mechanisms underlying AUB, we propose to identify LAPC-modulated unique gene cluster(s) in human endometrial stromal cells (HESCs). Protein and RNA isolated from cultured HESCs treated 7 days with estradiol (E2) or E2+ medroxyprogesterone acetate (MPA) or E2+ etonogestrel (ETO) or E2+ progesterone (P4) were analyzed by quantitative Real-time (q)-PCR and immunoblotting. HSCORES were determined for immunostained-paired endometria of pre-and 3 months post-Depot MPA (DMPA) treated women and ovariectomized guinea pigs (GPs) treated with placebo or E2 or MPA or E2+MPA for 21 days. In HESCs, whole genome analysis identified a 67 gene group regulated by all three progestins, whereas a 235 gene group was regulated by E2+ETO and E2+MPA, but not E2+P4. Ingenuity pathway analysis identified glucocorticoid receptor (GR) activation as one of upstream regulators of the 235 MPA and ETO-specific genes. Among these, microarray results demonstrated significant enhancement of FKBP51, a repressor of PR/GR transcriptional activity, by both MPA and ETO. q-PCR and immunoblot analysis confirmed the microarray results. In endometria of post-DMPA versus pre-DMPA administered women, FKBP51 expression was significantly increased in endometrial stromal and glandular cells. In GPs, E2+MPA or MPA significantly increased FKBP51 immunoreactivity in endometrial stromal and glandular cells versus placebo- and E2-administered groups. MPA or ETO administration activates GR signaling and increases endometrial FKBP51 expression, which could be one of the mechanisms causing AUB by inhibiting PR and GR-mediated transcription. The resultant PR and/or GR-mediated functional withdrawal may contribute to associated endometrial inflammation, aberrant angiogenesis, and bleeding.

[Characteristics of gonadotropic function in patients with pubertal uterine bleeding in the modern society].

The character of gonadotropin changes, which have been studied in patients with pubertal uterine bleeding, enable the authors to establish that its nature depends on the body weight value against the background of uterine bleeding. The study provides evidence that only half of all patients with bleeding has normal hormone levels. Disorders in gonadotropin levels have been registered in one third of our patients. The authors have also revealed that bleeding in patients with body weight excess significantly more often is accompanied by the increased LH and PRL morning levels and LH/FSH ratio, which occurs against the background of hypothalamic-pituitary function activation. Positive effect of insulin level on the LH production has been found in patients of the above group.

Shenghua Decoction reduces uterine bleeding and regulates T-cell paradigm in human deciduas of RU486 medical abortion.

ETHNOPHARMACOLOGICAL RELEVANCE: Excessive uterine bleeding is the most common and problematic side effect of RU486 medical abortion. Shenghua Decoction (SHD) is a well-known traditional Chinese herbal prescription for reducing uterine bleeding induced by RU486 medical abortion. However, its therapeutic mechanism still remains unclear. The Th1/Th2/Th17/Treg paradigm plays an important role in achieving maternal-fetal immunotolerance and its bias participates in RU486-induced abortion. Our previous research on mice demonstrated that the uterine bleeding volume is negatively related to the proportions of Th1 and Th17 cells whereas positively related to the proportions of Th2 and Treg cells. Additionally, Th1-type cytokine inducing effect was identified in our previous study. Therefore, it was hypothesized that SHD reduced the uterine bleeding in RU486 medical abortion by inducing Th1/Th2/Th17/Treg paradigm bias. The purpose of this study was to determine the regulatory effect and the mechanism of SHD on human decidual Th1/Th2/Th17/Treg paradigm for alleviating uterine bleeding in RU486 medical abortion. MATERIALS AND METHODS: 90 women within seven weeks of a normal intrauterine pregnancy, who elected for termination of pregnancy, were divided into three groups; vacuum aspiration group, RU486 group, and SHD-RU486 group. Duration of uterine bleeding was recorded and volume of uterine bleeding was measured by the method of alkaline hematin photometric. To determine the regulatory effect of SHD on Th1/Th2/Th17/Treg paradigm, the proportions of Th1/Th2/Th17/Treg cells in the decidua of different groups were analyzed using a FACS calibur. Correlation was analyzed in order to demonstrate the relationship between the Th1/Th2/Th17/Treg paradigm and the uterine bleeding in RU486 medical abortion. Moreover, to elucidate the mechanism underlying the T-cell paradigm regulating of SHD, the mRNA and protein expressions of subset-specific transcription factors (T-bet, GATA-3, RORγt, and Foxp3) for the differentiation of Th1/Th2/Th17/Treg paradigm in human decidual CD4(+) T cells were detected by reverse transcription-polymerase chain reaction (RT-PCR) assay and western blot analysis respectively. Moreover, the mRNA expression of the characteristic cytokines of Th1/Th2/Th17/Treg paradigm (IFNγ, IL-4, IL-17A, TGF-ß) were analyzed by RT-PCR assay. RESULT: Compared with RU486 group, both the uterine bleeding volume and duration reduced significantly in SHD-RU486 group. Both the duration and the volume of the uterine bleeding demonstrated negative correlation with the proportions of Th1 and Th17 cells, whereas showed positive correlation with Th2 and Treg cells. SHD increased the proportions of Th1 and Th17 cells whereas decreased those of Th2 and Treg cells. Thus, the ratios of Th1/Th2 and Th17/Treg cells elevated markedly after SHD treatment. SHD promoted the mRNA as well as the protein expressions of subset-specific transcription factors for the differentiation of Th1 and Th17 subsets (T-bet and RORγt) while inhibited those of Th2 and Treg cells (GATA-3 and Foxp3). Moreover, the mRNA expression of Th1- and Th17- type cytokines (IFNγ and IL-17A) was up-regulated while that of Th2-type and Treg-produced cytokines (IL-4 and TGF-ß) was down-regulated significantly after SHD administration. CONCLUSION: Th1/Th2/Th17/Treg paradigm bias was involved in RU486 medical abortion. SHD reduced the uterine bleeding efficiently by inducing Th1 and Th17 skews in the maternal-fetal of RU486 medical abortion patients. The regulatory effect of SHD on Th1/Th2/Th17/Treg paradigm in RU486 medical abortion is attributed to the modulation of transcription and protein expression of subset-specific transcription factors for T-cell subsets differentiation and their characteristic cytokines.

Markers of insulin resistance in perimenopausal women with endometrial pathology.

OBJECTIVES: To determine and compare the prevalence of insulin resistance and carbohydrate metabolism parameters in women with endometrial pathology MATERIAL AND METHODS: 100 perimenopausal women with abnormal uterine bleeding and/or abnormal endometrium were included into the study. Hysteroscopy with biopsy was performed. The study population was divided into four groups according to histopathological results of the endometrium: non-atypical endometrial hyperplasia, endometrial polyp, endometrial cancer and controls. Fasting glucose and insulin levels and OGTT, IR indexes, occurrence of diabetes, pre-diabetic state, overweight, obesity and hypertension were assessed. RESULTS: Insulin resistance was diagnosed in 41.0% of the patients. The prevalence of markers of insulin resistance increased to 57.1% in cases with confirmed endometrial pathology compared to 31.8% in histologically normal endometrium (p<0.01). The frequency of insulin resistance was 52.6% (p=0.059) and 55.5% (p=0.04), respectively in women with non-atypical hyperplasia and patients with endometrial polyps when compared to the control group. Abnormal parameters of carbohydrate metabolism indicate little sensitivity and specificity in predicting endometrial hyperplastic lesions. The insulin levels at 120 minutes of OGTT correlate best with such changes (concentration >57 microU/ml in case of hyperplasia and >61 microU/ml in endometrial polyps). CONCLUSION: Insulin resistance and carbohydrate metabolism disturbances are common in women with endometrial pathologies. In these patients there is clinical basis for recommending lifestyle modification (change of diet, more physical activity), or for introduction of pharmaceutical insulin-sensitizing agents.

Endometrial haemostasis and menstruation.

Under normal physiological circumstances menstruation is a highly regulated, complex process that is under strict hormonal control. During normal menstruation, progesterone withdrawal initiates menstruation. The cessation of menstrual bleeding is achieved by endometrial haemostasis via platelet aggregation, fibrin deposition and thrombus formation. Local endocrine, immunological and haemostatic factors interact at a molecular level to control endometrial haemostasis. Tissue factor and thrombin play a key role locally in the cessation of menstrual bleeding through instigation of the coagulation factors. On the other hand, fibrinolysis prevents clot organisation within the uterine cavity while plasminogen activator inhibitors (PAI) and thrombin-activatable fibrinolysis inhibitors control plasminogen activators and plasmin activity. Abnormalities of uterine bleeding can result from imbalance of the haemostatic factors. The most common abnormality of uterine bleeding is heavy menstrual bleeding (HMB). Modern research has shown that an undiagnosed bleeding disorder, in particular von Willebrand disease (VWD) and platelet function disorders, can be an underlying cause of HMB. This has led to a change in the approach to the management of HMB. While full haemostatic assessment is not required for all women presenting with HMB, menstrual score and bleeding score can help to discriminate women who are more likely to have a bleeding disorder and benefit from laboratory haemostatic evaluation. Haemostatic agents (tranexamic acid and DDAVP) enhance systemic and endometrial haemostasis and are effective in reducing menstrual blood loss in women with or without bleeding disorders. Further research is required to enhance our understanding of the complex interactions of haemostatic factors in general, and specifically within the endometrium. This will lead to the development of more targeted interventions for the management of abnormal uterine bleeding in the future.

Vaginal bleeding in early pregnancy and circulating markers of thrombin generation.

OBJECTIVE: To determine if subjects experiencing acute vaginal bleeding in early pregnancy have increased plasma markers of thrombin generation compared to nonbleeding controls. METHODS: Subjects with clinically apparent acute (within 24 h of sample collection) vaginal bleeding between 6 and 20 weeks estimated gestational age and without known thrombophilias were enrolled, along with nonbleeding controls, and underwent collection of maternal plasma. Concentrations of thrombin-antithrombin (TAT) and fragment 1 + 2 (F1 + 2) were determined by enzyme-linked immunosorbent assay. Differences between bleeding and nonbleeding subjects were assessed through linear regression with adjustment for gestational age. RESULTS: Twenty subjects with vaginal bleeding and 20 controls were included. Bleeding was significantly associated with increased concentrations of TAT (p = 0.007) and F1 + 2 (p = 0.044) when corrected for gestational age. Among bleeding subjects, there was no association between markers of thrombin generation and the subject's description of bleeding quantity, though higher concentrations were associated with a longer self-reported duration of bleeding. CONCLUSIONS: Clinically apparent vaginal bleeding in early pregnancy is associated with increased circulating maternal markers of thrombin generation. Thus, these maternal markers may have a future role in risk stratification.

Up-regulation of Fas/FasL activation contribute to the apoptosis enhancement of RU486 by Gong-Qing Decoction, a traditional Chinese prescription.

AIM OF THE STUDY: To elucidate the mechanisms of Gong Qing Decoction(GQD) on human trephocytes and decidual cells in vivo based upon the effective practice of alleviating uterine bleeding in RU486 medical abortion. MATERIALS AND METHODS: 90 intrauterine pregnancy women within 7 weeks, presenting for elective termination of pregnancy, were divided into the GQD-RU486 group, the RU486 group and the vacuum aspiration group. Duration of uterine bleeding was recorded and volume of uterine bleeding was measured by the method of alkaline hematin photometric. Ultramicrostructure of trephocytes and decidual cells were observed with transmission electron microscope (TEM), and apoptosis rate (AR) was assessed by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay. At the same time, immunohistochemical staining was performed and integral optical density was analyzed to evaluate the protein expression of Fas, FasL, Caspase-8 and Caspase-3 in both trephocytes and decidual cells preliminarily. RESULTS: In comparison with the RU486 group and the vacuum aspiration group, both the duration and volume of uterine bleeding decreased significantly in the GQD-RU486 group. At the same time, both trephocytes and decidual cells in the GQD-RU486 group showed typical character of apoptotic ultramicrostructure and displayed up-regulated apoptosis rate. Synchronously, the integral optical density showed increased protein expression of Fas, FasL, Caspase-8 and Caspase-3 in both trephocytes and decidual cells in the GQD-RU486 group compared with other groups. CONCLUSION: These data suggest that GQD can alleviate uterine bleeding effectively in RU486 medical abortion by way of apoptosis induction. The apoptosis enhancement of RU486 by GQD may be attributable to the activation of Fas and FasL.

[Non-medicamental correction of the hormonal and psycho-autonomic status in women with pathology of the reproductive system treated at health resort of the Krasnodar Krai (region)].

The authors report the results of the study on the hormonal and psychovegetative status, functional activity of the vegetative nervous system, the level of activity of the protective and adaptive hemostatic mechanisms, and the clinical features of concomitant extragenital pathology in 90 adolescent girls suffering uterine bleeding. All the patients had gone through in-patient and out-patient phases of therapy, sixty of them were selected for the spa and resort rehabilitative treatment. The use of rehabilitative technologies on an individual basis at a spa and resort facility made it possible to ensure rather high efficacy of the combined therapeutic and preventive treatment of reproductive system pathology and concomitant psycho-vegetative disorders. It helped to decrease the frequency of relapses of uterine bleeding and exacerbation of the accompanying extragenital diseases.

The expression of angiopoietin-1 and -2 in the endometrium of women with abnormal bleeding induced by an intra-uterine device.

This study identified differences in expression of angiopoietin-1 (Ang-1) and angiopoietin-2 (Ang-2) in the endometrium of 33 women with abnormal bleeding induced by an intra-uterine device (IUD; 23 proliferative phase, 10 secretory phase) compared with 28 control samples from normal endometria in women without an IUD fitted (12 proliferative phase, 16 secretory phase). Expression of Ang-1, Ang-2 and endothelial cell-specific tyrosine kinase receptor-2 (Tie-2) mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR), and Ang-1 and Ang-2 protein levels were detected by immunohistochemistry. The RT-PCR results showed significantly decreased Ang-1 expression in the endometrium from IUD patients during both phases compared with the control women. Expression of Tie-2 mRNA and the Ang-1:Ang-2 mRNA ratio were also significantly decreased in endometria from IUD patients in the secretory phase compared with the control women. Immunohistochemical analysis showed elevated Ang-2 protein levels in secretory phase endometrium from IUD patients compared with the control women. These results suggest that the angiopoietin/Tie-2 system promotes vascular remodelling in the endometrium and that changes in the expression of Ang-1, Ang-2 and Tie-2 may contribute to abnormal uterine bleeding in some IUD users.

Involvement of human decidual cell-expressed tissue factor in uterine hemostasis and abruption.

Vascular injury increases access and binding of plasma-derived factor VII to perivascular cell membrane-bound tissue factor (TF). The resulting TF/VIIa complex promotes hemostasis by cleaving pro-thrombin to thrombin leading to the fibrin clot. In human pregnancy, decidual cell-expressed TF prevents decidual hemorrhage (abruption). During placentation, trophoblasts remodel decidual spiral arteries into high conductance vessels. Shallow trophoblast invasion impedes decidual vascular conversion, producing an inadequate uteroplacental blood flow that elicits abruption-related placental ischemia. Thrombin induces several biological effects via cell surface protease activated receptors. In first trimester human DCs thrombin increases synthesis of sFlt-1, which elicits placental ischemia by impeding angiogenesis-related decidual vascular remodeling. During pregnacy, the fibrillar collagen-rich amnion and choriodecidua extracellular matrix (ECM) provides greater than additive tensile strength and structural integrity. Thrombin acts as an autocrine/paracrine mediator that degrades these ECMs by augmenting decidual cell expression of: 1) matrix metalloproteinases and 2) interleukin-8, a key mediator of abruption-associated decidual infiltration of neutrophils, which express several ECM degrading proteases. Among the cell types at the maternal fetal interface at term, TF expression is highest in decidual cells indicating that this TF meets the hemostatic demands of labor and delivery. TF expression in cultured term decidual cells is enhanced by progestin and thrombin suggesting that the maintenance of elevated circulating progesterone provides hemostatic protection and that abruption-generated thrombin acts in an autocrine/paracrine fashion on decidual cells to promote hemostasis via enhanced TF expression.

Abnormal expression of MMP-9 and imbalance of MMP-9/TIMP-1 is associated with prolonged uterine bleeding after a medical abortion with mifepristone and misoprostol.

OBJECTIVE: To investigate the expression of matrix metalloproteinase-9 (MMP-9) and tissue inhibitory of metalloproteinase-1 (TIMP-1) in women who had undergone a medical abortion and explore their possible role in the mechanism of prolonged uterine bleeding after a mifepristone-misoprostol abortion. DESIGN: Cross-sectional study. SETTING: Tertiary referral university hospital. SAMPLE: Forty women were recruited following a medical abortion with mifepristone and misoprostol, 20 with duration of bleeding >14 days and 20 with duration of bleeding 14 days after a medical abortion (bleeding group), whereas each sample of women with duration of bleeding

Decreased expression of endometrial vessel AQP1 and endometrial epithelium AQP2 related to anovulatory uterine bleeding in premenopausal women.

OBJECTIVE: Aquaporins (AQPs) may be involved in the occurrence of abnormal uterine bleeding as the mediators between ovarian steroids and cyclic endometrial changes. The aim of the present study was to investigate the characteristics of endometrial AQPs in women with anovulatory uterine bleeding and explore the relationship between endometrial AQPs and ovarian steroids. DESIGN: Sixty-one women with premenopausal anovulatory uterine bleeding and 108 women with normal cycles were involved in this study. Endometrial biopsies were obtained from the women with anovulatory uterine bleeding and normal control women. Serum estradiol and progesterone concentrations were measured with enzyme-linked immunosorbent assay on the same day as an endometrial biopsy was performed. AQP1 and AQP2 mRNA expression was evaluated using reverse-transcriptase polymerase chain reaction. Immunohistochemistry was used to localize AQP1 and AQP2 in the endometrium, and their expression was quantified by an image analysis/measuring system. RESULTS: AQP1 was located in the endothelium of small vessels, whereas AQP2 was mainly found in luminal and glandular epithelium. The expression levels of AQP1 and AQP2 mRNA and protein were higher in the secretory phase than those in the proliferative phase (P < 0.01) in normal endometrium, and their expression was related to serum steroid hormones (P < 0.01). However, the expression of AQP1 and AQP2 decreased in the endometrium in anovulatory uterine bleeding comparing with normal endometrium (P < 0.01). The correlation between AQP expression and ovarian steroids vanished (P > 0.05) in anovulatory uterine bleeding. CONCLUSIONS: Our findings indicate that cyclic expression of endometrial AQP1/AQP2 correlated with steroid hormone levels may be essential to normal endometrial function and decreased AQP1/AQP2 expression in endometrial vessels or epithelium may be involved in the occurrence of anovulatory uterine bleeding.

Endometrial expression of steroid receptors in postmenopausal hormone replacement therapy users: relationship to bleeding patterns.

BACKGROUND: Mechanisms of menopausal hormone replacement therapy (HRT)-related bleeding, undoubtedly mediated through endometrial steroid receptors, are poorly understood. We aimed to determine the steroid receptor expression in HRT-exposed endometrium in relation to disturbances of bleeding patterns. METHODS: Prospective observational study in a tertiary referral menopause clinic in Western Australia. Thirty-eight outpatient endometrial biopsies (seven from women not on HRT, 31 from HRT users) were collected from 21 postmenopausal women during and outside bleeding episodes. Eleven women provided multiple biopsies. We performed an immunohistochemical analysis of endometrial glandular, stromal, epithelial, perivascular and endothelial expression of progesterone receptor (PR), glucocorticoid receptor (GR), androgen receptor (AR), estrogen receptors alpha and beta (ERalpha and ERbeta) and studied their relationship to bleeding patterns. RESULTS: In HRT users, during a bleeding episode, there was a trend (non-significant) towards a decrease in PR and an increase in GR in endometrial glandular cells. No differences were observed in AR and ER expression. CONCLUSIONS: We have been unable to demonstrate significant differences in steroid receptor expression in endometrium of women using HRT who report unscheduled bleeding episodes. These observations differ from the endometrial steroid receptor expression observed with normal menstruation and long-term progestogen-only administration, suggesting that different local mechanisms are involved in HRT-related unscheduled bleeding.