Treatment of human endometrial stromal cells with chorionic gonadotropin promotes their morphological and functional differentiation into decidua

Comparative efficacy of intrauterine infusion treatments for recurrent implantation failure: a network meta-analysis of randomized controlled trials

OBJECTIVE

Recurrent implantation failure (RIF) is a significant challenge in assisted reproductive technology (ART), affecting many women undergoing in vitro fertilization (IVF). This study aims to compare the efficacy of various intrauterine infusion treatments, including granulocyte colony-stimulating factor (G-CSF), platelet-rich plasma (PRP), human chorionic gonadotropin (HCG), and peripheral blood mononuclear cells (PBMCs), in improving clinical pregnancy rate (CPR), live birth rate (LBR), and miscarriage rate (MR) in women with RIF.

METHODS

A comprehensive search was conducted in multiple databases, including Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Web of Science, and China National Knowledge Internet (CNKI), to identify randomized controlled trials (RCTs) evaluating the efficacy of intrauterine infusion treatments for RIF. Data extraction and quality assessment were performed independently by two reviewers. Network meta-analysis was conducted using a random-effects model to compare the outcomes of different treatments.

RESULTS

A total of 25 RCTs involving 3035 patients were included in the network meta-analysis. The treatments involved G-CSF, PRP, HCG, PBMCs, placebo, and blank control. The results of the network meta-analysis for CPR and LBR were statistically significant among treatments, but there was no statistical significance in MR. The surface under cumulative ranking curve (SUCRA) ranking of CPR and LBR showed that intrauterine infusion treatments of G-CSF, PRP, HCG, and PBMCs were much better than placebo and blank. The SUCRA values of CPR were ranked probabilistically from high to low as follows: PRP (84.5%) > PBMCs (76.5%) > G-CSF (65.7%) > HCG (52.5%) > placebo (20.8%) > blank (0.1%). The SUCRA values of LBR were ranked probabilistically from high to low as follows: PRP (81.4%) > PBMCs (64.6%) > G-CSF (58.0%) > HCG (48.7%) > placebo (42.4%) > blank (4.9%).

CONCLUSION

All these findings confirmed that intrauterine infusions of PRP and PBMCs significantly improve pregnancy outcomes in women with RIF. PRP emerged as the most effective treatment. However, to establish the most effective approach for managing patients with RIF, future research should prioritize direct and robust comparisons between PRP and other therapeutic strategies, ensuring a comprehensive evaluation of their relative efficacy.

Enhancing endometrial receptivity: the roles of human chorionic gonadotropin in autophagy and apoptosis regulation in endometrial stromal cells

Inadequate endometrial receptivity often results in embryo implantation failure and miscarriage. Human chorionic gonadotropin (hCG) is a key signaling molecule secreted during early embryonic development, which regulates embryonic maternal interface signaling and promotes embryo implantation. This study aimed to examine the impact of hCG on endometrial receptivity and its underlying mechanisms. An exploratory study was designed, and endometrial samples were obtained from women diagnosed with simple tubal infertility or male factor infertile (n = 12) and recurrent implantation failure (RIF, n = 10). Using reverse transcription-quantitative PCR and western blotting, luteinizing hormone (LH)/hCG receptor (LHCGR) levels and autophagy were detected in the endometrial tissues. Subsequently, primary endometrial stromal cells (ESCs) were isolated from these control groups and treated with hCG to examine the presence of LHCGR and markers of endometrial receptivity (HOXA10, ITGB3, FOXO1, LIF, and L-selectin ligand) and autophagy-related factors (Beclin1, LC3, and P62). The findings revealed that the expressions of receptivity factors, LHCGR, and LC3 were reduced in the endometrial tissues of women with RIF compared with the control group, whereas the expression of P62 was elevated. The administration of hCG to ESCs specifically activated LHCGR, stimulating an increase in the endometrial production of HOXA10, ITGB3, FOXO1, LIF and L-selectin ligands. Furthermore, when ESCs were exposed to 0.1 IU/mL hCG for 72 h, the autophagy factors Beclin1 and LC3 increased within the cells and P62 decreased. Moreover, the apoptotic factor Bax increased and Bcl-2 declined. However, when small interfering RNA was used to knock down LHCGR, hCG was less capable of controlling endometrial receptivity and autophagy molecules in ESCs. In addition, hCG stimulation enhanced the phosphorylation of ERK1/2 and mTOR proteins. These results suggest that women with RIF exhibit lower levels of LHCGR and compromised autophagy function in their endometrial tissues. Thus, hCG/LHCGR could potentially improve endometrial receptivity by modulating autophagy and apoptosis.

Serum LH level prior to progestin administration is significant on pregnancy and live birth in programmed frozen-thawed embryo transfer cycles

Purpose

To evaluate the impact of serum LH levels prior to progestin administration on the outcomes of programmed frozen-thawed embryo transfer (FET) cycles.

Methods

Retrospective cohort study was conducted to compare the treatment outcomes between four groups based on the 25 percentiles of serum LH levels before progestin administration in 596 cycles of 518 patients undergoing artificial endometrial preparation protocols for FET. Primary outcome measures were ongoing and live birth rates. Secondary outcome measures were the pregnancy rates, clinical pregnancy rates, and pregnancy loss rates.

Results

The trends in clinical pregnancy (CPR) and live birth rates (LBR) increased from the first to the fourth quartile (Q1 to Q4) of serum LH levels prior to progestin administration (37,0% to 48,3%, p = 0.042, and 22.6% to 39.5%, respectively, p = 0.003). Pregnancy loss rates (PLR) were higher in group Q1, although the difference was not statistically significant. Based on a multivariate logistic regression analysis, a low serum LH level before progestin initiation was found to be the most significant predictor associated with a negative effect on live birth (OR: 0,421, 95% CI 0,178 - 0,994, p=0,048). The day of estrogen initiation was significantly correlated with serum LH levels and quartiles of serum LH levels before progestin administration (r=0,200, p=0,015 and r=0,215, p=0,009, respectively).

Conclusion

The serum LH level prior to progestin administration significantly affects pregnancy and live birth rates in patients undergoing an artificial endometrial preparation protocol for FET. LH monitoring should be incorporated into the follow-up, in addition to assessing endometrial thickness and morphology in artificial FET cycles.

Local immune recognition of trophoblast in early human pregnancy: controversies and questions

The role of the maternal immune system in reproductive success in humans remains controversial. Here we focus on the events that occur in the maternal decidua during the first few weeks of human pregnancy, because this is the site at which maternal leukocytes initially interact with and can recognize fetal trophoblast cells, potentially involving allorecognition by both T cells and natural killer (NK) cells. NK cells are the dominant leukocyte population in first-trimester decidua, and genetic studies point to a role of allorecognition by uterine NK cells in establishing a boundary between the mother and the fetus. By contrast, definitive evidence that allorecognition by decidual T cells occurs during the first trimester is lacking. Thus, our view is that during the crucial period when the placenta is established, damaging T cell-mediated adaptive immune responses towards placental trophoblast are minimized, whereas NK cell allorecognition contributes to successful implantation and healthy pregnancy.

Does Intrauterine Injection of hCG Improve IVF Outcome? A Systematic Review and a Meta-Analysis

Various interventions have been proposed to improve embryo implantation in IVF. Among these, intrauterine injections of human chorionic gonadotropin seem to have promising results. Consequently, we conducted a review and meta-analysis to assess IVF outcomes by comparing couples who underwent intrauterine hCG injection transfer versus those who underwent embryo transfer with intrauterine injection of placebo, or without any additional intervention. The primary outcome was the clinical pregnancy rate. Secondary outcomes were the implantation rate, miscarriage rate, and live birth rate. A meta-analysis was conducted using the random effects model, while bias within studies was detected using the Cochrane risk of bias tool. Ectopic pregnancies and stillbirths were also assessed. The clinical pregnancy (RR 1.38, 95% CI 1.17−1.62, p < 0.0001) and implantation rate (RR 1.40, 95% CI 1.12−1.75, p = 0.003) were significantly higher in women who underwent hCG injection than in the control group. These significant effects persisted only in women who underwent cleavage-stage embryo transfer. No significant differences between groups were observed in the other secondary outcomes. In conclusion, our systematic review and meta-analysis demonstrate that intrauterine injection of hCG could be a valuable approach in women who undergo cleavage-stage embryo transfer. Given the lack of data about the live birth rate, caution should be exercised in interpreting these data.

Expression and function of the luteinizing hormone choriogonadotropin receptor in human endometrial stromal cells

The human luteinising hormone choriogonadotropin receptor (LHCGR) is a G-protein coupled receptor activated by both human chorionic gonadotropin (hCG) and luteinizing hormone (LH), two structurally related gonadotropins with essential roles in ovulation and maintenance of the corpus luteum. LHCGR expression predominates in ovarian tissues where it elicits functional responses through cyclic adenosine mononucleotide (cAMP), Ca²⁺ and extracellular signal-regulated kinase (ERK) signalling. LHCGR expression has also been localized to the human endometrium, with purported roles in decidualization and implantation. However, these observations are contentious. In this investigation, transcripts encoding LHCGR were undetectable in bulk RNA sequencing datasets from whole cycling endometrial tissue and cultured human endometrial stromal cells (EnSC). However, analysis of single-cell RNA sequencing data revealed cell-to-cell transcriptional heterogeneity, and we identified a small subpopulation of stromal cells with detectable LHCGR transcripts. In HEK-293 cells expressing recombinant LHCGR, both hCG and LH elicited robust cAMP, Ca²⁺ and ERK signals that were absent in wild-type HEK-293 cells. However, none of these responses were recapitulated in primary EnSC cultures. In addition, proliferation, viability and decidual transformation of EnSC were refractory to both hCG and LH, irrespective of treatment to induce differentiation. Although we challenge the assertion that LHCGR is expressed at a functionally active level in the human endometrium, the discovery of a discrete subpopulation of EnSC that express LHCGR transcripts may plausibly account for the conflicting evidence in the literature.

Effect of intrauterine perfusion of human chorionic gonadotropin before embryo transfer after two or more implantation failures: A systematic review and meta-analysis

OBJECTIVE

To investigate whether intrauterine perfusion of hCG before embryo transfer (ET) is effective in women experienced two or more implantation failures.

STUDY DESIGN

Systematic review and meta-analysis. In the current meta-analysis, Pubmed, EMBASE and The Cochrane Library were searched for trials which compared the efficacy of intrauterine perfusion of hCG with no perfusion of hCG in women undergoing in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), or frozen embryo transfer (FET) before ET. The primary outcomes are the clinical pregnancy rate (CPR) and live birth rate (LBR).

RESULTS

Six trials consisted of 1432 women were eligible for quantitative analysis. CPR (including 6 trials consisted of 1432 women) and LBR (including 3 trials consisted of 870 women) were significantly improved in the hCG group compared to the control group, with a CPR of 41.8 % vs. 31.2 % (RR 1.30, 95 % CI 1.14∼1.50, P < .001), an LBR of 27.8 % vs. 18.0 % (RR 1.52, 95 % CI 1.18∼1.96, P = .001).

CONCLUSION

Intrauterine perfusion of hCG is effective in improving clinical pregnancy rate and live birth rate in women who experienced two or more implantation failures, which might provide a potential therapeutical intervention for recurrent implantation failure (RIF). Although promising, further evidence from multicenter, randomized controlled trials are needed to confirm the conclusion from the current meta-analysis.

Regulation of Embryonic Signal on Talin1 in Mouse Endometrium

Embryonic signals can affect the spatiotemporal-specific expression of the uterus to establish a successful pregnancy. Our previous study has found that talin1 underwent dynamic changes in the mouse endometrium during peri-implantation period. However, whether talin1 is affected by the embryo signals is not clear. In order to investigate the effect of embryonic signals, especially human chorionic gonadotropin (HCG) on talin1, we have designed mouse models of pseudopregnancy, delayed implantation and activation, and HCG treatment. Using these models, the expression of talin1 in the mouse endometrium was determined by immunohistochemistry and Western blotting. In the pseudopregnancy model, an increased expression of talin1 was found from day 3 to day 5, whereas the talin1 protein was decreased on day 5 in the normal pregnant mice. In the delayed implantation model, a strong cytoplasmic staining of talin1 was found, especially in stromal cells. However, after activation of the implantation, the expression of talin1 decreased (P < .05). Furthermore, a significantly lower expression of talin1 was found at the implantation site when compared to the interimplantation sites (P < .05). In the HCG treatment model, an intrauterine perfusion of 10u HCG significantly reduced the expression of talin1 in both stromal and epithelial cells in pseudopregnant mice (P < .05), although further increase in the HCG concentration did not have additional effect on expression of talin1. Taken together, our data suggest that the presence of embryos can affect expression of talin1 in the mouse endometrium, and a certain concentration of HCG can regulate its expression.

Gonadotropins and their receptors: coevolution, genetic variants, receptor imaging, and functional antagonists

Gonadotropins belong to the family of dimeric glycoprotein hormones and regulate gonadal physiology mediated by G protein-coupled, seven-transmembrane receptors. These glycoprotein hormones are widely used in the clinic to promote ovarian follicle development and for treating some cases of male infertility. We traced the coevolution of dimeric gonadotropin hormones and their receptors, together with thyrotropin and its receptor. We updated recent findings on human genetic variants of these genes and their association with dizygotic twining, polycystic ovarian syndrome, primary ovarian insufficiency, male-limited precocious puberty, and infertility. In addition to the known physiological roles of gonadotropin-receptor signaling in gonadal tissues, we also discussed emerging understanding of extragonadal functions of gonadotropins in bones and adipose tissues, together with recent advances in in vivo imaging of gonadotropin receptors in live animals. Recent development of gonadotropin receptor agonists and antagonists were summarized with an emphasis on the development of functional antagonists for FSH receptors to alleviate osteoporosis and obesity associated with menopause.

Intrauterine infusion of human chorionic gonadotropin before embryo transfer in IVF/ET cycle: The critical review

Intrauterine infusion of human chorionic gonadotropin (IUI-hCG) has been proposed to improve the outcome of in vitro fertilization-embryo transfer (IVF-ET), since it plays a critical role in synchronizing endometrial and fetal development. As the early mediator from embryo, hCG promotes the decidualization, angiogenesis, maternal immune tolerance, and trophoblast invasion, favoring successful implantation of embryo. Although multiple clinical trials have been conducted to verify the efficacy of IUI-hCG on IVF-ET outcome in recent years, the findings remained controversial. The difference in study design and population might be the cause to the different consequences after administration of hCG. More importantly, the endometrial receptivity, which might affect the efficacy of IUI-hCG, has not been assessed in women receiving this intervention. Selecting the right population suitable for IUI-hCG based on known etiology would be crucial in enhancing its efficacy and minimize any possible complications. Investigation of optimal indications for IUI-hCG should be highlighted in the future.

Low LH Level on the Day of GnRH Agonist Trigger Is Associated With Reduced Ongoing Pregnancy and Live Birth Rates and Increased Early Miscarriage Rates Following IVF/ICSI Treatment and Fresh Embryo Transfer

Objective: To examine the correlation between serum luteinizing hormone (LH) levels on the day of GnRH agonist (GnRH-a) trigger and reproductive outcomes following in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment and fresh embryo transfer, and to identify a pre-trigger serum LH threshold which would be compatible with the most optimal cycle outcome. Design: This study is based on data from a previously published randomized controlled trial conducted from 2014 to 2016. Patients: A total of 322 participants were enrolled. Setting: Private IVF center. Intervention(s): GnRH-antagonist-based IVF cycles triggered with GnRH-a. For the purpose of the study, patients were stratified according to preovulatory LH quartiles (Q1-Q4). Main Outcome Measure(s): Ongoing pregnancy rates (OP), live birth rates (LB) and early pregnancy loss (EPL) rates. Results: The results of the present study showed increasing OP as well as LB rates and decreasing EPL rates with increasing pre-trigger serum LH levels (P for trend < 0.06, 0.07, and 0.02), respectively. The absolute difference between the highest LH(Q4) and the lowest LH (Q1) group was 13.4%, 12.1%, and 12% in OP, LB, and EPL rates, respectively. In multivariate regression analysis, a pre-trigger serum LH level of 1.60 mIU/ml was identified as a threshold below which reproductive outcomes decreased. The ROC curve values were statistically significant for OP, LB, and EPL; the AUC (95% CI) = [0.57 (0.50-0.63) P < 0.04; 0.57 (0.50-0.63) P < 0.05, and 0.60 (0.51-0.70) P < 0.04], respectively. A significant positive correlation was found on the day of GnRH-a trigger between serum LH, the number of follicles, serum P4, and serum E2, p < 0.03; P < 0.03; and P < 0.001, respectively. Conclusion: Low serum LH levels on the day of GnRH-a trigger is associated with reduced ongoing pregnancy and live birth rates and increased early miscarriage rates. Our findings suggest a lower threshold of serum LH values on the day of GnRH-a trigger necessary to optimize reproductive outcomes in fresh embryo transfer cycles. Clinical Trial Registration: www.ClinicalTrials.gov, Number: 02053779.

Recombinant luteinizing hormone supplementation in assisted reproductive technology: a systematic review

OBJECTIVE

To assess the role of recombinant human LH (r-hLH) supplementation in ovarian stimulation for ART in specific subgroups of patients.

DESIGN

Systematic review.

SETTING

Centers for reproductive care.

PATIENT(S)

Six populations were investigated: 1) women with a hyporesponse to recombinant human FSH (r-hFSH) monotherapy; 2) women at an advanced reproductive age; 3) women cotreated with the use of a GnRH antagonist; 4) women with profoundly suppressed LH levels after the administration of GnRH agonists; 5) normoresponder women to prevent ovarian hyperstimulation syndrome; and 6) women with a "poor response" to ovarian stimulation, including those who met the European Society for Human Reproduction and Embryology Bologna criteria.

INTERVENTION(S)

Systematic review.

MAIN OUTCOME MEASURE(S)

Implantation rate, number of oocytes retrieved, live birth rate, ongoing pregnancy rate, fertilization rate, and number of metaphase II oocytes.

RESULT(S)

Recombinant hLH supplementation appears to be beneficial in two subgroups of patients: 1) women with adequate prestimulation ovarian reserve parameters and an unexpected hyporesponse to r-hFSH monotherapy; and 2) women 36-39 years of age. Indeed, there is no evidence that r-hLH is beneficial in young (<35 y) normoresponders cotreated with the use of a GnRH antagonist. The use of r-hLH supplementation in women with suppressed endogenous LH levels caused by GnRH analogues and in poor responders remains controversial, whereas the use of r-hLH supplementation to prevent the development of ovarian hyperstimulation syndrome warrants further investigation.

CONCLUSION(S)

Recombinant hLH can be proposed for hyporesponders and women 36-39 years of age.

Human chorionic gonadotropin induces decidualization of ectopic human endometrium more effectively than forskolin in an in-vivo endometriosis model

Endometriosis, characterized by the presence of endometrial tissue at ectopic sites, is a leading cause of pelvic pain and subfertility in women. The stromal compartment of the endometrium is considered to play a pivotal role in the establishment and persistence of endometriotic lesions, thus impaired decidualization of these cells may result in enhanced invasion capacity at ectopic sites. Consequently, stimulation of decidualization may alleviate this disease. To analyze the effect of systemically applied compounds on decidualization of ectopic endometrial tissue, endometriosis was induced by suturing human eutopic endometrium to the peritoneum of 22 NOD/SCID mice. Each mouse received four tissue fragments from the same patient. Mice were randomly allocated either to one control and three experimental groups ( n = 4/group) which were treated with progesterone alone or in combination with forskolin or human chorionic gonadotropin for seven days or to one control and one experimental group ( n = 3/group) which was treated with progesterone and human chorionic gonadotropin for 10 days followed by 7 days without treatment. At the end of the experiments, lesions were measured and analyzed for markers of decidualization (FOXO-1, prolactin) and proliferation (Ki-67). Decidualization was induced in the ectopic lesions by systemic treatment in vivo. This induction was significantly stronger after treatment with progesterone in combination with human chorionic gonadotropin than with forskolin or with progesterone alone. Only the combination with human chorionic gonadotropin led to induction of FOXO1 protein expression and a significant physiologic transformation of the ectopic endometrial stromal cells after seven days of treatment. After termination of human chorionic gonadotropin treatment, the decidualization process continued, leading to a significant inhibition of proliferation. Thus, decidualization of human ectopic endometrial tissue can be induced in a humanized endometriosis mouse model in vivo. This model may help to decipher the signal pathways involved in this decidualization process and to develop novel therapeutical approaches to alleviate this painful disease. Impact statement Impaired decidualization of endometrial stromal cells may contribute to the development of endometriosis, and an increased decidualization reaction may prevent or alleviate this prevalent gynecological disease. Human chorionic gonadotropin (hCG) has been shown to promote decidualization in eutopic endometrium. Up to now in vitro studies mainly used cAMP for successful induction of decidualization of isolated endometrial stromal cells. Here, for the first time, decidualization of ectopic endometrial lesions is induced in an experimental endometriosis mouse model, comparing the effectiveness of hCG with that of the direct adenylyl cyclase activator Forskolin. In this 3D-organ structure in vivo, hCG proved to be more effective in the induction of decidualization than forskolin. Particularly in case of progesterone resistance, alternative pathways inducing decidualization could alleviate endometriosis, and the sophisticated hCG action could constitute a therapeutical tool to induce terminal differentiation in ectopic endometrial lesions.

The Role of HCG in Implantation: A Mini-Review of Molecular and Clinical Evidence

Embryo implantation is a complex process involving continuous molecular cross-talk between the embryo and the decidua. One of the key molecules during this process is human chorionic gonadotropin (HCG). HCG effectively modulates several metabolic pathways within the decidua contributing to endometrial receptivity. Herein, a brief overview of the molecular mechanisms regulated by HCG is presented. Furthermore, we summarize the existing evidence regarding the clinical impact on reproductive outcomes after endometrial priming with HCG prior to embryo transfer. Although promising, further evidence is needed to clarify the protocol that would lead to beneficial outcomes.

Non-invasive prediction of implantation window in controlled hyperstimulation cycles: Can the time from the menstrual day at embryo transfer to expected menstrual cycle give a clue?

Objective:

The aim of this study was to assess whether the time from the menstrual day at embryo transfer to expected menstrual cycle (TETEMC) is associated with the implantation in women with regular cycles or not.

Materials and Methods:

Forty women with successful implantation and forty women without implantation with regular cycles were randomly selected from prospectively collected database of assisted reproductive technology clinic of Zeynep Kamil Women And Children’s Health Training and Research Hospital. TETEMC was calculated for each case to assess relationship with the successful implantation.

Results:

Comparison of groups revealed significant differences with regard to TETEMC and the menstrual period (p<0.05).

In ROC analyses both the TETEMC (AUC=0.824, p<0.001) and the menstrual period (AUC=0.797, p<0.001) were significant predictors for clinical pregnancy. Cut off value for the menstrual period was found to be 27.5 days with 82.6% sensitivity and 65% specificity. Cut off value for TETEMC was 11.5 days with 75% sensitivity and 63.2% specificity.

Conclusion:

Longer menstrual cycle and the TETEMC seem to be associated with the implantation failure.

Therapeutic Potential of Human Chorionic Gonadotropin Against Painful Bladder Syndrome/Interstitial Cystitis

Painful bladder syndrome/interstitial cystitis is a debilitating chronic bladder disease that primarily affects women. The disease is due to a damage of urothelial cell lining. As a result, potassium particles and other toxic substances in urine can leak into bladder mucosa, causing the symptoms of lower abdominal/pelvic discomfort, pain, increased urination frequency, urgency, nocturia, and so on, all of which can substantially reduce the quality of daily life. There are multiple symptom reliving therapies. Among them, only pentosan polysulfate sodium, sold under the brand name of Elmiron, has been approved for oral use by US Food and Drug Administration. It provides the relief after several months of use. Based on the scientific leads presented in this article, we propose that human chorionic gonadotropin has a therapeutic potential that is worth investigating for the treatment of this disease.

Reproducibility and clinical significance of pre-ovulatory serum progesterone level and progesterone/estradiol ratio on the day of human chorionic gonadotropin administration in infertile women undergoing repeated in vitro fertilization cycles

BACKGROUND

The objective of this study was to explore the cycle-to-cycle reproducibility of serum progesterone level and progesterone/estradiol (P/E2) ratio in the final step of triggering oocyte maturation in patients undergoing repeated consecutive controlled ovarian hyperstimulation for in vitro fertilization (COH-IVF) treatment and to investigate the clinical parameters associated with serum progesterone concentration and P/E2 ratio.

METHODS

We retrospectively studied 524 cycles in 203 infertile women who underwent two or more fresh COH-IVF cycles from July 1998 to May 2012 in a university hospital IVF unit. The patients were divided into groups according to the number (2, 3 or >=4) of total successive IVF cycles with successful oocyte retrieval. The within-subject reproducibility of serum P and P/E2 was tested by calculating intra-class correlation coefficients (ICCs). Multiple linear regression analysis was used to assess the association between patient variables and pre-ovulatory serum P level and P/E2 ratio.

RESULTS

The ICCs in women who underwent 2, 3 and >=4 IVF cycles were -0.052, 0.163 and 0.212, respectively, for serum P concentration and 0.180, 0.168 and 0.148, respectively, for P/E2 ratio. All ICCs for both serum P and P/E2 ratio were indicative of poor reproducibility. The number of oocytes was significantly positively related to P concentration, and endometrial thickness was significantly negatively related to P concentration and P/E2 ratio.

CONCLUSION

The cycle-to-cycle reproducibility of pre-ovulatory serum P concentration and P/E2 ratio was poor in individual patients, and these fluctuations were more cycle- than patient-dependent. The number of oocytes was the most significant factor relating to P concentration. By using milder stimulation approach to produce fewer oocytes in the next cycle is a strategy to overcome the high serum P concentration, while clinicians should consider each patient's general condition including the age, ovarian reserve, embryo grading and the capacity of frozen-thawed embryo transfer.

HLA-G Orchestrates the Early Interaction of Human Trophoblasts with the Maternal Niche

Extravillous trophoblasts (EVTs) play a central role in educating maternal leukocytes, endometrial stromal and endothelial cells to generate a receptive decidual microenvironment tailored to accept the semi-allogeneic fetus. HLA-G, a non-classical HLA class I molecule endowed with immune-regulatory functions, is primarily expressed on EVTs lining the placenta and on the naturally occurring tolerogenic dendritic cells, named DC-10, which are enriched in the human first trimester decidua. Decidual DC-10 are involved in HLA-G-mediated tolerance at the maternal–fetal interface. EVTs not only establish a tolerogenic microenvironment through the interaction with maternal innate and adaptive cells but also orchestrate placenta vascular and tissue remodeling, leading to a successful pregnancy. Here, we discuss the potential implications of the HLA-G-mediated cross-talk among the cells present at the maternal–fetal interface, and its role in maintaining a positive relationship between the mother and the fetus.

Effects of vitamin C, vitamin E, and molecular hydrogen on the placental function in trophoblast cells

AIM

This study aimed to investigate the effects of three different antioxidants, namely vitamin C, vitamin E, and molecular hydrogen, on cytotrophoblasts in vitro.

METHODS

Two trophoblast cell lines, JAR and JEG-3, were exposed to different concentrations of vitamin C (0, 25, 50, 100, 500, 1,000, 5,000 μmol/L), vitamin E (0, 25, 50, 100, 500, 1,000, 5,000 μmol/L), and molecular hydrogen (0, 25, 50, 100, 500 μmol/L) for 48 h. The cell viability was detected using the MTS assay. The secretion of human chorionic gonadotropin (hCG) and the tumor necrosis factor-α (TNF-α) were assessed and the expression of TNF-α mRNA was observed by real-time RT-PCR.

RESULTS

Cell viability was significantly suppressed by 500 μmol/L vitamins C and E (P < 0.05), but not by 500 μmol/L molecular hydrogen (P > 0.05). The expression of TNF-α was increased by 100 μmol/L vitamin C and 50 μmol/L vitamins E, separately or combined (P < 0.05), but not by molecular hydrogen (0-500 μmol/L), as validated by real-time RT-PCR. But the secretion of hCG was both inhibited by 50-500 μmol/L molecular hydrogen and high levels of vitamin C and E, separately or combined.

CONCLUSION

High levels of antioxidant vitamins C and E may have significant detrimental effects on placental function, as reflected by decreased cell viability and secretion of hCG; and placental immunity, as reflected by increased production of TNF-a. Meanwhile hydrogen showed no such effects on cell proliferation and TNF-α expression, but it could affect the level of hCG, indicating hydrogen as a potential candidate of antioxidant in the management of preeclampsia (PE) should be further studied.

Cyclic decidualization of the human endometrium in reproductive health and failure

Decidualization denotes the transformation of endometrial stromal fibroblasts into specialized secretory decidual cells that provide a nutritive and immunoprivileged matrix essential for embryo implantation and placental development. In contrast to most mammals, decidualization of the human endometrium does not require embryo implantation. Instead, this process is driven by the postovulatory rise in progesterone levels and increasing local cAMP production. In response to falling progesterone levels, spontaneous decidualization causes menstrual shedding and cyclic regeneration of the endometrium. A growing body of evidence indicates that the shift from embryonic to maternal control of the decidual process represents a pivotal evolutionary adaptation to the challenge posed by invasive and chromosomally diverse human embryos. This concept is predicated on the ability of decidualizing stromal cells to respond to individual embryos in a manner that either promotes implantation and further development or facilitates early rejection. Furthermore, menstruation and cyclic regeneration involves stem cell recruitment and renders the endometrium intrinsically capable of adapting its decidual response to maximize reproductive success. Here we review the endocrine, paracrine, and autocrine cues that tightly govern this differentiation process. In response to activation of various signaling pathways and genome-wide chromatin remodeling, evolutionarily conserved transcriptional factors gain access to the decidua-specific regulatory circuitry. Once initiated, the decidual process is poised to transit through distinct phenotypic phases that underpin endometrial receptivity, embryo selection, and, ultimately, resolution of pregnancy. We discuss how disorders that subvert the programming, initiation, or progression of decidualization compromise reproductive health and predispose for pregnancy failure.

Expression of sex hormone receptors in juvenile angiofibromas and antiproliferative effects of receptor modulators

BACKGROUND

Predilection of juvenile angiofibromas in adolescent boys has prompted the hypothesis of hormone-dependent tumor growth. However, knowledge on expression and function of sex hormone receptors in juvenile angiofibromas is still sparse and inconsistent.

METHODS

Transcript and protein expression of sex hormone receptors in juvenile angiofibromas was studied by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and immunohistology/fluorescence. A bromodeoxyuridine assay was used to assess the antiproliferative effects of flutamide (androgen receptor antagonist) and tamoxifen (estrogen receptor modulator).

RESULTS

Significantly increased transcript levels were observed for androgen receptor, estrogen receptor α, follicle-stimulating hormone receptor, and luteinizing hormone receptor in juvenile angiofibromas versus the stroma of nasal mucosa. Estrogen receptor β and progesterone receptor mRNA levels were low and similar for both tissues. Estrogen receptor α protein was detected in juvenile angiofibroma tumors and mesenchymal cell lines. Flutamide and tamoxifen inhibited proliferation of cultured juvenile angiofibroma mesenchymal cells.

CONCLUSION

These findings contribute to the understanding of juvenile angiofibroma pathophysiology and offer novel therapeutic options.

The Endocrine Milieu and CD4 T-Lymphocyte Polarization during Pregnancy

Acceptance of the fetal semi-allograft by the mother's immune system has become the focus of intensive research. CD4+ T cells are important actors in the establishment of pregnancy. Th1/Th2 paradigm has been expanded to include CD4+ regulatory T (Treg) and T helper 17 (Th17) cells. Pregnancy hormones exert very significant modulatory properties on the maternal immune system. In this review, we describe mechanisms by which the endocrine milieu modulates CD4 T cell polarization during pregnancy. We first focused on Treg and Th17 cells and on their importance for pregnancy. Secondly, we review the effects of pregnancy hormones [progesterone (P4) and estradiol (E2)] on immune cells previously described, with a particular attention to human chorionic gonadotropin (hCG). The importance of Treg cells for pregnancy is evidenced. They are recruited before implantation and are essential for pregnancy maintenance. Decreased number or less efficient Treg cells are implicated in fertility disorders. As for Th17 cells, the few available studies suggest that they have a negative impact on fertility. Th17 frequency is increased in infertile patients. With the combination of its pro-effects on Th2 and Treg cells and anti-effects on Th1 and Th17 cells, P4 contributes to establishment of a favorable environment for pregnancy. E2 effects are more dependent on the context but it seems that E2 promotes Treg and Th2 cells while it inhibits Th1 cells. hCG positively influences activities of Treg and uterine natural killer cells. This embryo signal is an essential actor for the success of pregnancy, both as the endocrine factor regulating P4 secretion by the ovarian corpus luteum, but also as a paracrine agent during implantation as well as an angiogenic and immunologic mediator during the course of gestation. Luteinizing hormone (LH) immune properties begin to be studied but its positive impact on Treg cells suggests that LH could be a considerable immunomodulator in the mouse.

Transcriptome analysis reveals new insights into the modulation of endometrial stromal cell receptive phenotype by embryo-derived signals interleukin-1 and human chorionic gonadotropin: possible involvement in early embryo implantation

The presence of the conceptus in uterine cavity necessitates an elaborate network of interactions between the implanting embryo and a receptive endometrial tissue. We believe that embryo-derived signals play an important role in the remodeling and the extension of endometrial receptivity period. Our previous studies provided original evidence that human Chorionic Gonadotropin (hCG) modulates and potentiates endometrial epithelial as well as stromal cell responsiveness to interleukin 1 (IL1), one of the earliest embryonic signals, which may represent a novel pathway by which the embryo favors its own implantation and growth within the maternal endometrial host. The present study was designed to gain a broader understanding of hCG impact on the modulation of endometrial cell receptivity, and in particular, cell responsiveness to IL1 and the acquisition of growth-promoting phenotype capable of receiving, sustaining, and promoting early and crucial steps of embryonic development. Our results showed significant changes in the expression of genes involved in cell proliferation, immune modulation, tissue remodeling, apoptotic and angiogenic processes. This points to a relevant impact of these embryonic signals on the receptivity of the maternal endometrium, its adaptation to the implanting embryo and the creation of an environment that is favorable for the implantation and the growth of this latter within a new and likely hostile host tissue. Interestingly our data further identified a complex interaction between IL1 and hCG, which, despite a synergistic action on several significant endometrial target genes, may encompass a tight control of endogenous IL1 and extends to other IL1 family members.

Human chorionic gonadotropin (hCG) modulation of TIMP1 secretion by human endometrial stromal cells facilitates extravillous trophoblast invasion in vitro

STUDY QUESTION

Are secreted extracellular matrix (ECM) remodelling elements, relevant to embryo implantation and placentation, modified by hCG in endometrial stromal cells (ESCs)?

SUMMARY ANSWER

hCG decreases tissue inhibitor of metalloproteinase 1 (TIMP-1) secretion in ESCs, thereby facilitating extravillous trophoblast invasion in vitro.

WHAT IS KNOWN ALREADY

Successful embryo implantation and placentation depend on the appropriate invasion of the trophoblast into the maternal endometrial stroma. hCG is one of the earliest embryo-derived secreted signals in the endometrium which abundantly expresses hCG receptors. However, there is little data concerning the effects of hCG on endometrial ECM remodelling with respect to embryo implantation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

This study was conducted in an academic research laboratory within a tertiary-care hospital. Samples were collected from 36 women undergoing benign gynaecological surgery during the mid-secretory phase. ESCs were isolated and stimulated with hCG (10 UI/ml) or vehicle. Conditioned media (CM) were analysed to determine changes in the secreted profile of nine matrix metalloproteinases (MMPs) and three tissue-specific inhibitors of MMPs (TIMPs) using an ELISA array. Data were confirmed by gelatine zymography, western blot and ELISA. The HTR8/SVneo cell line served as a model for trophoblast cells. The invasive potential of trophoblast cells was assessed using Transwell invasion assays under CM or co-culture conditions with ECS and the role of regulated molecules was examined by using immunoprecipitation in CM prior to the assessment of invasive potential.

MAIN RESULTS AND THE ROLE OF CHANCE

MMP-2 levels increased 30%, whereas TIMP-1 levels decreased 20% in CM from ESCs stimulated with hCG (P < 0.05). Gelatine zymography confirmed an increase in MMP-2 activity (P < 0.05). ELISA and western blotting also confirmed the reduction in TIMP-1 upon hCG treatment (P < 0.05). Invasion assays revealed a ∼50% increase in invading HTR8/SVneo cells in chambers with hCG-stimulated ESCs compared with the control (P < 0.05). Immunodepletion of TIMP-1 from control ESC-CM partially resembled the effect of CM from hCG-stimulated ESCs in the trophoblast invasion assays.

LIMITATIONS, REASONS FOR CAUTION

The assays were performed in vitro and ESCs were not decidualized, therefore they reflected the very early stages of embryo implantation or the advanced stages when decidualization fails.

WIDER IMPLICATIONS OF THE FINDINGS

Our data suggest that hCG induces endometrial stromal extracellular remodelling by modulating secreted MMP-2 and TIMP-1. This regulation may be physiologically relevant because it increases the invasive potential of trophoblast-derived cells. At present, few data exist concerning the implications of hCG and endometrial ECM remodelling in embryo implantation. Hence, our results should be confirmed by further in vivo studies.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by FONDECYT 11100443, PBCT-PSD51 (IDIMI) and FONDAP 15010006. None of the authors have any conflicts of interest to declare.

Human chorionic gonadotropin (hCG) regulation of galectin-3 expression in endometrial epithelial cells and endometrial stromal cells

Previous investigations on galectin-3 (gal-3) have focused mainly on its role in some malignant tumors. It was believed that gal-3 plays important roles in cell proliferation, apoptosis and adhesion in many cell types. Recently, gal-3 has been recognized as a factor related to endometrial receptivity in the human endometrium and trophoblast during embryo implantation. Human chorionic gonadotropin (hCG) is a specific embryonic hormone providing a signal from the embryo involved in preparing the receptive endometrium for embryo implantation. The current study aimed to determine whether hCG regulates gal-3 expression in endometrial cells. Our results showed that expression of gal-3 in both endometrial epithelial cells (EECs) and endometrial stromal cells (ESCs) could be regulated by hCG in an intricate manner. These results indicate that gal-3 might be regulated by hCG in preparing the endometrium for embryonic implantation.

Low-dose human chorionic gonadotropin may improve in vitro fertilization cycle outcomes in patients with low luteinizing hormone levels after gonadotropin-releasing hormone antagonist administration

OBJECTIVE

To evaluate the effect of low levels of endogenous luteinizing hormone (LH) and low-dose human chorionic gonadotropin (hCG) supplementation on in vitro fertilization (IVF) cycle outcomes in a gonadotropin-releasing hormone (GnRH) antagonist protocol.

DESIGN

Retrospective study.

SETTING

Military medical center.

PATIENT(S)

General in vitro fertilization/embryo transfer (IVF-ET) population.

INTERVENTION(S)

Addition of low-dose urinary hCG to IVF stimulations using a recombinant follicle-stimulating hormone (FSH) and GnRH antagonist protocol.

MAIN OUTCOME MEASURE(S)

Implantation and live-birth rates.

RESULT(S)

As part of a larger cohort of 239 patients, 42 patients with LH levels ≤ 0.5 mIU/mL were evaluated. In the larger cohort, there were no differences in implantation and pregnancy rates between the recombinant FSH only (n = 113) and the recombinant FSH with low-dose hCG supplementation (n = 126) groups. In the FSH-only group, patients with LH levels ≤ 0.5 mIU/mL had decreased implantation rates (19% vs. 42%) and live-birth rates (25% vs. 54%) as compared with patients with LH levels >0.5 mIU/mL. Low LH patients in the recombinant FSH with low-dose urinary hCG group had statistically significantly higher implantation rates (54% vs. 19%) and live-birth rates (64% vs. 25%) as compared with patients with similar low LH levels in the recombinant FSH-only group.

CONCLUSION(S)

Endogenous LH levels ≤ 0.5 mIU/mL after GnRH antagonist treatment are associated with statistically significantly lower implantation and pregnancy rates in recombinant FSH-only cycles. The addition of low-dose urinary hCG results in improved implantation and live-birth rates in patients with low LH levels.

Differential effects of urinary and recombinant chorionic gonadotropin on oxidative stress responses in decidualizing human endometrial stromal cells

Human chorionic gonadotropin (hCG) is one of the earliest signals secreted by the implanting embryo. In addition to its well-known luteotropic function in early pregnancy, hCG also acts directly on decidualizing endometrium. Recently, we demonstrated that recombinant hCG (rhCG) prevented apoptosis in decidualizing human endometrial stromal cells (HESCs) exposed to oxidative stress. Two hCG preparations are widely used clinically: rhCG, produced by recombinant DNA technology, and urinay hCG (uhCG), extracted from urine of post-menopausal women. However, an analysis of the direct effects of rhCG and uhCG on the decidual phenotype of HESCs has not yet been done. In this study, we investigated the effects of uhCG and rhCG on the morphological and functional profiles of decidualizing HESCs. We demonstrate that neither rhCG nor uhCG alter the morphological appearance of the decidual HESC cultures, although rhCG but not uhCG attenuated prolactin expression, a major decidual marker protein. Moreover, rhCG, but not uhCG, protected decidualizing HESCs from oxidative cell death, mediated at least in part by two major mechanisms. First, rhCG, but not uhCG, enhances the expression of manganese superoxide dismutase, a cardinal enzyme in the cellular defense against oxidative damage. Second, rhCG signaling selectively limits activation of the apoptotic machinery in decidualizing HESCs by enhancing Bcl-2 expression whereas uhCG induces the expression of Fas ligand. Our results suggest that rhCG might be a preferable agent to protect the maternal decidua against oxidative damage in pregnancy, especially at the time of implantation and beyond.

Low-dose HCG may improve pregnancy rates and lower OHSS in antagonist cycles: a meta-analysis

Human chorionic gonadotrophin (HCG) may substitute FSH to complete follicular growth in IVF cycles. This may be useful in the prevention of ovarian hyperstimulation syndrome. Relevant studies were identified on Medline. To evaluate outcomes, a meta-analysis of low-dose HCG-supplemented IVF cycles versus non-supplemented ones was performed with data from 435 patients undergoing IVF who were administered low-dose HCG in various agonist and antagonist protocols and from 597 conservatively treated patients who served, as control subjects. Using these published data, a decision analysis evaluated four different management strategies. Effectiveness and economic outcomes were assessed by FSH consumption, clinical pregnancy and incremental cost-effectiveness ratios. Clinical pregnancy and ovarian hyperstimulation were the main outcome measures. Nine trials published in 2002-2007 were included. From the prospective studies, in the gonadotrophin-releasing hormone antagonist group, a trend for significance in clinical pregnancy rate was evident (odds ratio [OR], 1.54; 95% confidence interval [CI], 0.98-2.42). Ovarian hyperstimulation was less significant in the antagonist low-dose HCG protocol compared with the non-supplemented agonist protocol (OR 0.30; 95% CI 0.09-0.96). Less FSH was consumed in the low-dose HCG group but this difference was not statistically significant. Low-dose HCG supplementation may improve pregnancy rates in antagonist protocols. Overall, low-dose HCG-supplemented protocols are a cost-effective strategy.

Prokineticin 1, homeobox A10, and progesterone receptor messenger ribonucleic acid expression in primary cultures of endometrial stromal cells isolated from endometrium of healthy women and from eutopic endometrium of women with endometriosis

OBJECTIVE

To examine prokineticin 1 (PROK1), homeobox (HOX) A10, and P receptor (PR) messenger ribonucleic acid (mRNA) expression in primary cultures of endometrial stromal cells (ESC) obtained from eutopic endometrial samples of patients with endometriosis and to clarify whether in vitro steroid hormone dependence of PROK1 gene expression is altered in endometriosis.

DESIGN

Prospective laboratory study.

SETTING

Tertiary university hospital.

PATIENT(S)

Twelve normal women (controls) and 12 patients affected by moderate to severe endometriosis in the midsecretory phase of the menstrual cycle.

INTERVENTION(S)

Endometrial specimens were obtained from control women and from women affected by endometriosis; ESC were isolated from endometrial biopsies, and primary cultures were established.

MAIN OUTCOME MEASURE(S)

Real-time polymerase chain reaction analysis of PROK1, HOXA10, and PR mRNA expression in ESC after 1-4 days of steroid hormone treatment and after decidual differentiation.

RESULT(S)

Contrary to ESC from control women, in ESC obtained from women affected by endometriosis PROK1 and PR mRNA expression was not induced by 1-4 days of treatment with steroid hormones. Nevertheless, when ESC from both groups of women were differentiated to decidual phenotype, PROK1 mRNA was up-regulated and PR and HOXA10 mRNA were down-regulated to the same extent.

CONCLUSION(S)

Our results provide additional evidence for P resistance in endometriosis.

Expression of endometrial protein kinase a during early pregnancy in bonnet monkeys (Macaca radiata)

Embryo-induced signaling pathways are considered to be important for initiation and sustenance of pregnancy. However many of these pathways remain to be deciphered in primates. In the present study, differential display RT-PCR was used to identify genes or gene fragments that are differentially expressed in endometrium of bonnet monkeys (Macaca radiata) on Day 6 of pregnancy. Of several fragments found to be differentially expressed, a fragment of 567 base pair (named GG1) was characterized in detail. GG1 was highly represented in endometrium of pregnant animals compared with that of nonpregnant animals. Sequencing analysis revealed homology of this fragment to exons 7, 8, 9, and 10 and surprisingly to intron 6 of cAMP-dependent protein kinase A (PKA) regulatory type I alpha (tissue-specific extinguisher 1) (PRKAR1A). The increased expression of this fragment in gestational endometrium was confirmed by quantitative PCR studies. Two transcripts of 3.0 kilobase (kb) and 1.5 kb were detected in Northern blot probed with labeled GG1. Protein expressions of alpha regulatory (PRKAR1A) and alpha catalytic (PRKCA) subunits of PKA were also higher in gestational endometrium compared with that in nongestational endometrium. Further in vitro studies using human endometrial explants demonstrated regulation of PRKAR1A (or GG1) and prostaglandin-endoperoxide synthase 2 or cyclooxygenase 2 (PTGS2) by estradiol. This is the first study to date on the differential expression of PKA in primate endometrium during early pregnancy and its in vitro regulation by estradiol.

Epithelial human chorionic gonadotropin is expressed and produced in human secretory endometrium during the normal menstrual cycle

The objective of this study was to determine whether beta human chorionic gonadotropin (hCG) (CGB) subunits and alpha hCG (CGA) subunits are expressed and the hCG dimer is produced in normal human cyclic endometrium. Endometrial specimens were collected for histological dating from women undergoing treatment in our division of human reproduction. RNA from normal secretory endometrium was extracted, and CGB and CGA gene expression was assessed by semiquantitative PCR. Adequate secretory endometrial specimens were homogenized using protease inhibitors. Proteins present in the supernatant were separated electrophoretically, and molecular hCG isoforms were detected by Western blot. The supernatant hCG concentrations were measured by ELISA. We characterized hCG and leukocytes in endometrial specimens by immunohistochemistry. Uterine flushing was performed to confirm endometrial hCG secretion into the uterine fluid. A full-length CGB mRNA encompassing the exon 1 promoter region and the structure exons 2 and 3 (including the C-terminal peptide) was expressed in normal secretory endometrial specimens (similar to CGA) during the early secretory phase of the menstrual cycle, up to an optimum at the midsecretory to late secretory phases. In homogenate supernatants obtained from normal secretory endometrium, hormone concentrations of dimeric hCG were approximately 5 mU per 10 mg of tissue, compared with considerably smaller concentrations of corresponding single free CGB subunit. Single chains of CGB, CGA, and dimeric molecular hCG isoforms were found in endometrial specimens by Western blot. Glandular endometrial hCG production is demonstrated immunohistochemically, with an increase toward the late secretory phase vs. the early secretory phase of the normal secretory menstrual cycle. However, glandular hCG release is diminished or absent in the dyssynchronous or missing endometrial secretory transformation. Endogenous endometrial hCG may be important for implantation and maintenance of pregnancy.

Modulation of HOXA10 and other markers of endometrial receptivity by age and human chorionic gonadotropin in an endometrial explant model

OBJECTIVE

To characterize the endometrial response to human chorionic gonadotropin (hCG), as influenced by uterine age, using endometrial receptivity markers including HOXA10, vascular endothelial growth factor (VEGF), and glycodelin in an endometrial explant culture system.

DESIGN

In vitro molecular biology research.

SETTING

Academic infertility clinic and molecular biology laboratory.

PATIENT(S)

Fourteen prospective recipients of egg donation (mean age, 44 +/- 8 years).

INTERVENTION(S)

Subjects received cyclical estrogen (E(2)) and progesterone (P(4)) and underwent an endometrial biopsy on day 7 of P(4). Endometrial biopsy samples were cut into 1-mm(3) pieces and cultured in Dulbecco's modified Eagle's medium/Ham's F-12 with E(2) and P(4), without (control) or with hCG (400, 4000, and 40,000 mIU/mL) on Millicell-CM inserts for 24 hours.

MAIN OUTCOME MEASURE(S)

Explant viability was assessed using immunohistochemistry (IHC). Semiquantitative polymerase chain reaction was performed to evaluate relative gene expression via mRNA levels of HOXA10, VEGF, and glycodelin.

RESULT(S)

Explant viability was confirmed on IHC by histology and Ki-67 staining, a marker of proliferation. HOXA10, VEGF, and glycodelin gene expression increased at all concentrations of hCG over those of controls. HOXA10 gene expression was inversely correlated with age (-0.08- +/- 0.03-fold decrease in gene expression/year of age).

CONCLUSION(S)

The endometrial explant culture system is a promising model for the study of endometrial response as it maintains interactions among the stroma, glands, and epithelium. HOXA10, VEGF, and glycodelin all demonstrated increased gene expression in response to increasing hCG concentrations, supporting the role of hCG as a candidate protein for blastocyst-endometrial communication. Statistically significant associations between age and expression of HOXA10 provide novel evidence that uterine age may play a role in endometrial response on a molecular level.

Low-dose human chorionic gonadotropin during the proliferative phase may adversely affect endometrial receptivity in oocyte recipients

The effect of low-dose human chorionic gonadotropin (hCG) administration in the proliferative phase of oocyte recipients was investigated in a prospective randomized trial. Sibling oocytes from the same donor were shared at random among two different recipients. In group I oocyte recipients received 750 IU of hCG every three days concomitant to endometrial preparation with estradiol until hCG injection to the donor, whereas in group II recipients received no hCG during endometrial priming with estradiol. Endometrial thickness was significantly lower in group I compared with group II, although similar endometrial thickness was detected during the mock cycle. Pregnancy rates were significantly lower in group I than in group II (13.6% vs. 45.4%, p<0.05). Implantation rates were also significantly lower in group I (1.7% vs. 22.4%, p<0.01). The study was discontinued prematurely for ethical reasons when 22 cycles were completed, as pregnancy rates were very low in group I. In conclusion, hCG administration in the proliferative phase might directly affect endometrial proliferation and receptivity.

Human chorionic gonadotropin stimulates trophoblast invasion through extracellularly regulated kinase and AKT signaling

Chorionic gonadotropin (CG) is indispensable for human pregnancy because it controls implantation, decidualization, and placental development. However, its particular role in the differentiation process of invasive trophoblasts has not been fully unraveled. Here we demonstrate that the hormone promotes trophoblast invasion and migration in different trophoblast model systems. RT-PCR and Western blot analyses revealed expression of the LH/CG receptor in trophoblast cell lines and different trophoblast primary cultures. In vitro, CG increased migration and invasion of trophoblastic SGHPL-5 cells through uncoated and Matrigel-coated transwells, respectively. The hormone also increased migration of first-trimester villous explant cultures on collagen I. Proliferation of the trophoblast cell line and villous explant cultures measured by cumulative cell numbers and in situ 5-bromo-2'-deoxyuridine labeling, respectively, was unaffected by CG. Addition of the hormone activated ERK-1/2 and AKT in SGHPL-5 cells and pure, extravillous trophoblasts. Inhibition of MAPK kinase/ERK and phosphatidylinositide 3-kinase/AKT blocked phosphorylation of the kinases and attenuated CG-dependent invasion of SGHPL-5 cells. Similarly, the inhibitors decreased hormone-stimulated migration in villous explant cultures. Western blot analyses and gelatin zymography suggested that CG increased matrix metalloproteinase (MMP)-2 protein levels and activity in both culture systems. Inhibition of ERK or AKT diminished CG-induced MMP-2 expression. In summary, the data demonstrate that CG promotes trophoblast invasion and migration through activation of ERK and AKT signaling involving their downstream effector MMP-2. Because the increase of CG during the first trimester of pregnancy correlates with rising trophoblast motility, the hormone could be a critical regulator of the early invasion process.

Morphometric study of GnRH analog/HMG/HCG effects on ultrastructure of human endometrial epithelium in early and mid-luteal phase

AIM

The aim of the present study was to investigate the effects of long protocol ovulation induction on the ultrastructure of the human endometrial epithelium on days luteinizing hormone (LH) + 4 and LH+ 6 of the menstrual cycle.

METHODS

Endometrial biopsies were obtained on days LH+ 4 (n = 9) and LH+ 6 (n = 10) from infertile women who were under standard long protocol with luteal phase supplementation with IM (intramuscular) progesterone, but where the embryo had not been formed or transferred, due to the male factor problem. Biopsies were also taken on days LH+ 4 (n = 5) and LH+ 6 (n = 5) from fertile women who had not received ovulation induction drugs as control groups. After preparation and taking light and electron micrographs from samples, qualitative and quantative evaluations (morphological and morphometric) were accomplished and the data was compared using the unpaired student t-test.

RESULTS

Qualitative results showed the presence of the nuclear channel system, vacuoles of glycogen and giant mitochondria in all of the samples. Qualitative analysis showed that the volume fraction (Vv) of the euchromatin to the nucleus, the rough endoplasmic reticulum and the mitochondria to the cell, were not statistically different (P > 0.05) in samples taken on LH+ 4 in both control and test groups. The Vv of these features, however, to the cell in the test group was significantly (P < 0.05) higher than those in the control taken on LH+ 6.

CONCLUSIONS

These results suggest that long protocol ovulation induction with luteal phase support with progesterone alter the normal development of the human endometrium in the mid luteal phase and could decrease the implantation success rate.

Human chorionic gonadotrophin attenuates NF-kappaB activation and cytokine expression of endometriotic stromal cells

Recently, a clinical study provided evidence that treatment of endometriotic women with human chorionic gonadotrophin (hCG) alleviates disease-related pain and sleeplessness suggesting therapeutic effects of the hormone. Since endometriosis is associated with aberrant concentrations of inflammatory mediators in the peritoneal fluid, we investigated whether hCG may affect cytokine-dependent activation of the key-regulatory transcription factor NF-kappaB and expression of two nuclear factor kappa B (NF-kappaB)-inducible genes, tumour necrosing factor (TNF-alpha) and interleukin (IL)-1beta, in stromal cells isolated from ectopic endometriotic tissues. Electrophoretic mobility shift assay revealed that treatment of these cultures with the urinary preparation hCG-A suppressed TNF-alpha- or IL-1beta-induced NF-kappaB DNA-binding activity, whereas another urinary hCG preparation (hCG-B) was less effective. Recombinant alphahCG or epidermal growth factor (EGF), a contaminant of some urinary hCG preparations, did not alter cytokine-dependent NF-kappaB activation. Immunofluorescene of its p65 subunit revealed that pre-incubation with hCG-A strongly decreased TNF-alpha-dependent nuclear expression of NF-kappaB. Accordingly, hCG-A diminished IL-1beta-induced TNF-alpha transcript levels and protein release measured by quantitative real-time PCR and enzyme-linked immunosorbent assay. The hormone also attenuated TNF-alpha-dependent mRNA expression of IL-1beta. Western blot analyses revealed that hCG-A impaired TNF-alpha-mediated phosphorylation and degradation of the inhibitor IkappaBalpha suggesting that the hormone may reduce nuclear import of NF-kappaB by stabilizing its inhibitor. The data suggest that hCG attenuates inflammation-dependent NF-kappaB activation and cytokine expression that could provide one explanation for the beneficial role of the hormone in endometriotic patients.

Extragonadal LH/hCG action--not yet time to rewrite textbooks

Gonadotropins are indispensable in both sexes in the regulation of gonadal sex steroid production and gametogenesis. In addition to their well-established classical actions, numerous recent publications have indicated the presence and function of luteinizing hormone/chorionic gonadotropin receptors (LH/hCG-R) in a variety of extragonadal tissues. However, the physiological significance of such effects has remained unclear. We have generated two genetically modified mouse models, one with excessive production of hCG and the other with targeted disruption of LH/hCG-R gene, and used them to address the functions of LH and hCG. Numerous gonadal and extragonadal phenotypes were found in the models with the two extremes of LH/hCG action. However, when the extragonadal effects were scrutinized in greater detail, they all appeared to arise through modification of gonadal function, either through enhanced or inhibited response to LH/hCG stimulation. Hence, further evidence is needed before the extragonadal LH/hCG-R expression can be considered functionally significant.

Decidualization Regulates the Expression of the Endometrial Chorionic Gonadotropin Receptor in the Primate1

Chorionic gonadotropin (CG) plays an important role in establishing a receptive endometrium by directly modulating the function of both endometrial stromal and epithelial cells in the baboon. The focus of this study was to characterize changes in CG receptor (LHCGR, also known as CG-R) expression during the menstrual cycle and early pregnancy, particularly during decidualization. LHCGR was localized by using a peptide-specific antibody generated against the extracellular domain. Immunostaining was absent in any of the cell types during the proliferative phase of the cycle. In contrast, during the secretory phase, both luminal and glandular epithelial cells stained positively. Stromal staining was confined to the cells around spiral arteries (SAs) and in the basalis layer. This stromal staining pattern persisted at the implantation site between Days 18 and 25 of pregnancy and after CG infusion. However, as pregnancy progressed (Days 40 to 60), staining for LHCGR was dramatically decreased in the stromal cells. These data were confirmed by nonisotopic in situ hybridization. To confirm whether the loss of LHCGR was associated with a decidual response, stromal fibroblasts were decidualized in vitro, and cell lysates obtained after 3, 6, and 12 days of culture were analyzed by Western blotting. LHCGR protein decreased with the onset of decidualization in vitro, confirming the in vivo results. Addition of CG to decidualized cells resulted in the reinduction of LHCGR in the absence of dbcAMP. We propose that CG acting via its R on stromal cells modulates SA in preparation for pregnancy and trophoblast invasion. As pregnancy progresses, further modification of SA by migrating endovascular trophoblasts and subsequent decidualization results in the downregulation of LHCGR. This inhibition of LHCGR expression also coincides with the decrease of measurable CG in peripheral circulation.

The only effects of recombinant follicle-stimulating hormone for ovulation induction in the pre-implantation period of rats

OBJECTIVE

The aim of this study was to evaluate the changes in follicular development, serum hormonal levels, and endometrium in the pre-implantation period of rats by using recombinant FSH (rFSH) without human chorionic gonadotropin (hCG).

METHODS

Thirty female rats were studied in six groups of five specimens. Two groups determined as controls (groups 1 and 2). Two groups received constant doses of rFSH (groups 3 and 4) and other two decreasing doses (groups 5 and 6). One of the paired groups was mated. Uterus, ovaries, and blood samples were taken from non-mated groups (groups 1, 3, and 5) at the proestrus period and from mated groups (groups 2, 4, and 6) in the pre-implantation period.

RESULTS

In non-mated groups antral follicles and corpus luteum periodicum and in mated groups antral follicles, corpus luteum periodicum, and corpus luteum graviditatis were increased in rFSH groups, especially in decreasing dose groups. Estradiol (E2) levels were increased and progesterone (P)/E2 ratio was significantly decreased in decreasing dose groups. Endometrium surface epithelium was columnar, irregular, and folded in rFSH groups. Endometrium glandular epithelium was cuboidal in all groups. In decreasing dose groups endometrial stroma was smooth and fibroblastic. Mitotic indices of endometrium surface, glandular epithelium, and stroma were significantly decreased in rFSH groups. Primary follicles and P levels showed no change.

CONCLUSION

It seems likely that decreasing doses of rFSH might be used in order to improve follicular development, although it has negative effects with E2 on endometrium in the pre-implantation period of rats.

Tumour necrosis factor-alpha impairs chorionic gonadotrophin beta-subunit expression and cell fusion of human villous cytotrophoblast

Growth factors expressed at the fetal-maternal interface modulate hormone expression of placental trophoblasts. The aim of this study was to investigate the effects of different cytokines on hCG subunit mRNA expression in differentiating villous cytotrophoblasts. Quantitative real-time PCR revealed a 1.8- and 6.9-fold increase of hCG-alpha and hCG-beta mRNA levels, respectively, between 36 and 60 h of term trophoblast syncytialization. Compared with controls, neither interleukin (IL)-1beta, IL-2, IL-4, IL-6, IL-10, IL-13 and IL-15 nor tumour necrosis factor (TNF)-alpha significantly altered hCG-alpha mRNA expression. Similarly, the ILs did not affect hCG-beta transcript levels. In contrast, TNF-alpha suppressed hCG-beta mRNA 3.8- and 1.8-fold at 36 and 60 h of term trophoblast differentiation. Accordingly, hCG secretion was impaired by TNF-alpha but not by the different ILs. Moreover, TNF-alpha reduced luciferase expression of reporter plasmids harbouring the proximal hCG-beta5 promoter to 35 and 77%, respectively, in primary term trophoblasts and trophoblastic SHGPL-5 cells. In addition, counting of nuclei in syncytialized, desmoplakin-negative areas revealed a 1.9-fold reduction of term trophoblast fusion in the presence of TNF-alpha. Similarly, floating explant cultures prepared from first trimester-denuded villi recovered the syncytium 2.8-fold less efficiently during 72 h of cytokine treatment. Concomitantly, TNF-alpha impaired induction of endogenous and secreted hCG-beta protein levels in these cultures. The data suggest that TNF-alpha decreases hCG-beta mRNA and protein expression by reducing gene transcription and trophoblast cell fusion. Suppression of these processes by TNF-alpha could partly explain the adverse effects of the cytokine on placental function and pregnancy outcome.

Hormonal and cytokine regulation of early implantation

Implantation of the blastocyst into the endometrium is a delicately controlled process and a prerequisite for the furtherance of the mammalian species. A complex network of molecules is involved in preparing both the endometrium and blastocyst for a successful interaction. However, the exact molecular steps are poorly understood. Studies so far have shown that disruption of certain pathways results in fertility defects. Impaired implantation is currently considered to be the most important limiting factor for the establishment of viable pregnancies in assisted reproduction. It is expected that elucidating the molecular background of the process will enable accurate diagnosis and effective treatment of infertility.

Human chorionic gonadotropin expression in human trophoblasts from early placenta: comparative study between villous and extravillous trophoblastic cells

Human trophoblast differentiates into two pathways: extravillous cytotrophoblasts (EVCT) that invade the uterus wall and villous cytotrophoblasts (VCT) that fuse to form the syncytiotrophoblast (ST) involved in placental exchanges and endocrine function. It is established that hCG is produced and secreted by the ST into the maternal compartment where it plays a key endocrine role and stimulates ST formation in an autocrine manner. Herein, we investigated hCG expression in early placentas by immunohistochemistry using different antibodies. We then compared hCG secretion by primary cultures of VCT and EVCT isolated from the same first trimester human chorionic villi. In situ hCG was immunodetected in EVCT all along their invasive differentiating pathway except in cells near the stromal core of the proximal column. hCG expression was confirmed in vitro by immunocytochemistry and hCG secretion quantified in cell supernatants. Interestingly, whereas hCG secretion increased during VCT differentiation into ST (from 60 to 350UI/L/microg DNA), EVCT secretion remained constant and at a high level during the same culture period (160UI/L/microg DNA). Our data demonstrated that in addition to the ST, invasive EVCT also expressed and secreted high levels of hCG, suggesting a specific paracrine and/or autocrine role for hCG from EVCT origin.