Local and systemic factors and implantation: what is the evidence?

The transcription factor HAND2 up-regulates transcription of the IL15 gene in human endometrial stromal cells

Cyclic changes of the human endometrium, such as proliferation, secretion, and decidualization, occur during regular menstrual cycles. Heart- and neural crest derivatives-expressed transcript 2 (HAND2) is a key transcription factor in progestin-induced decidualization of human endometrial stromal cells (ESCs). It has been suggested that HAND2 regulates interleukin 15 (IL15), a key immune factor required for the activation and survival of uterine natural killer (uNK) cells. Activated uNK cells can promote spiral artery remodeling and secrete cytokines to induce immunotolerance. To date, no studies have evaluated the transcription factors that regulate IL15 expression in human ESCs. In the present study, we examined whether HAND2 controls IL15 transcriptional regulation in human ESCs. Quantitative RT-PCR and histological analyses revealed that HAND2 and IL15 levels increase considerably in the secretory phase of human endometrium tissues. Results from ChIP-quantitative PCR suggested that HAND2 binds to a putative HAND2 motif, which we identified in the upstream region of the human IL15 gene through in silico analysis. Using a luciferase reporter assay, we found that the upstream region of the human IL15 gene up-regulates reporter gene activities in response to estradiol and a progestin representative (medroxyprogesterone) in ESCs. The upstream region of the human IL15 gene also exhibited increasing responsiveness to transfection with a HAND2 expression vector. Of note, deletion and substitution variants of the putative HAND2 motif in the upstream region of IL15 did not respond to HAND2 transfection. These findings confirm that HAND2 directly up-regulates human IL15 transcription in ESCs.

The Impact of Endometriosis on the Quality of Life and the Incidence of Depression-A Cohort Study

The objective was to evaluate the quality of life and the incidence of depression among women suffering from endometriosis. Afterwards, the dependency between pelvic pain, its severity and stages of endometriosis were analyzed. The study protocol included women of reproductive ages with confirmed endometriosis. The stage of disease was conferred according to the ASRM (American Society of Reproductive Medicine) classification. Women fulfilled two questionnaires: “WERF EPHect Clinical Questionnaire” and self-prepared survey about fertility disorders. The study group comprised of 246 respondents. A total of 77.2% of women were symptomatic. The most common complaints were chronic pelvic pain (CPP, 71.1%), dysmenorrhea (69.0%) and dyspareunia (45.2%). Intensity of pain was independent from the stage of endometriosis. The incidence of infertility and the time to conceive increased with the stage of disease (stage 1—52.8%, 3.4 years; stage 2—66.7%, 4.1 years; stage 3—61.3%, 3.7 years; stage 4—96%, 6.1years; p = 0.02 and 0.03, respectively). The prevalence of depression was positively correlated with the beginning of dyspareunia (14.5 vs. 19.6 years old., p = 0.002). CPP (OR(odds ratio) = 3.8, 95% CI 1.2–12.8, p = 0.04) and painful defecation (OR = 7.7, 95% CI 1.4–42.3, p = 0.01) increased the risk of depression. Symptoms related to endometriosis and severity of pain correlate with the prevalence of depression. Stage of endometriosis is significantly related to the prevalence of infertility.

Corticosteroids Prior to Embryo Transfer in Assisted Reproduction in Women with Crohn's Disease and Ulcerative Colitis - A Nationwide Cohort Study

Purpose

Former studies have suggested that women with Crohn’s disease (CD) and ulcerative colitis (UC) have a decreased chance of a live born child after assisted reproductive technology (ART) treatment. It is debated whether corticosteroids before ART may improve outcomes, either by decreasing inflammatory bowel disease-related inflammation or increasing endometrial receptivity. We examined the efficacy of corticosteroids before embryo transfer in women with CD and UC.

Patients and Methods

Our cohort study is based on nationwide Danish health registries, comprising women with CD and UC receiving an embryo transfer (1 January 2006 through 2017). Exposed cohorts constituted women with CD and UC who had received corticosteroids within three months before embryo transfer, and the unexposed cohorts women with CD and UC who did not receive corticosteroids. Our primary outcome was live birth. We controlled for multiple covariates in the analyses.

Results

We examined 2408 embryo transfers. In patients with CD, 114 embryo transfers were preceded by a corticosteroid prescription, and 964 were not. The corresponding numbers in UC were 122 and 1208, respectively. The adjusted odds ratio (aOR) for live birth in women with CD receiving corticosteroids before embryo transfer, relative to women with CD not receiving corticosteroids, was 0.89 (95% CI 0.49–1.63). The corresponding aOR in UC was 0.98 (95% CI 0.55–1.74).

Conclusion

Corticosteroids prior to ART in women with CD and UC did not increase the chance of a live born child. The exact impact of corticosteroids prior to embryo transfer in patients with CD and UC still remains to be determined.

Does bacterial colonization during embryo transfer have an impact on pregnancy rate in ICSI? : Tunisian preliminary results

INTRODUCTION

Embryos' transfer into the uterine cavity remains a limiting factor in the success of intracytoplasmic sperm injection (ICSI). This study aimed to evaluate the impact of cervico-vaginal colonization on ICSI outcomes.

MATERIEL AND METHODS

Longitudinal, prospective and analytical study, conducted from February 1 st to October 31 st, 2017. On the day of embryos' transfer, patients with the following criteria were included: Age ≤ 40, normal uterine ultrasound and hysteroscopy, first or second attempt of ICSI, use of fresh semen and transfer of at least one good quality embryo. Three samples were done for microbiological analysis: vaginal secretions, cervical mucus and the tip of the transfer catheter.

RESULTS

The study included 40 patients. Pregnancy rate was 52.5 %. Catheter contamination occurred in nine cases (22.5 %). The most frequently isolated bacteria were Streptococcus anginosus (37 % of cases), Gardnerella vaginalis (27 % of cases) and Streptococcus agalactiae (18 % of cases). In all cases of contamination, the same bacteria were found also in the vagina and cervical mucus. In cases of contamination with Gardnerella vaginalis, the study of vaginal flora showed bacterial vaginosis. No pregnancy was obtained when contamination of the transfer catheter occurred. In the absence of contamination, pregnancy rate was 61.2 % (ρ = 0.003). Both populations (patients with catheter contamination and patients without catheter contamination) were comparable regarding epidemiological characteristics and ICSI attempt data.

CONCLUSION

Contamination of the transfer catheter by cervical-vaginal bacteria appears to affect IVF results. Systematic antibiotic prophylaxis could be proposed to reduce this negative impact.

Loss of HDAC3 results in nonreceptive endometrium and female infertility

Endometriosis is a disease in which tissue that normally grows inside the uterus grows outside the uterus and causes chronic pelvic pain and infertility. However, the exact mechanisms of the pathogenesis of endometriosis-associated infertility are unknown. Epigenetic dysregulation has recently been implicated in infertility. Here, we report a reduction of histone deacetylase 3 (HDAC3) protein amounts in eutopic endometrium of infertile women with endometriosis compared to a control group. To investigate the effect of HDAC3 loss in the uterus, we generated mice with conditional ablation of Hdac3 in progesterone receptor (PGR)-positive cells (Pgr^cre/+Hdac3^f/f ; Hdac3^d/d ). Loss of Hdac3 in the uterus of mice results in infertility due to implantation failure and decidualization defect. Expression microarray and ChIP-seq analyses identified COL1A1 and COL1A2 as direct targets of HDAC3 in both mice and humans. Reduction of HDAC3 abrogated decidualization in a primary culture of human endometrial stromal cells (hESCs) similar to that observed in infertile patients with endometriosis. Whereas attenuation of HDAC3 resulted in p300 recruitment to Col1a1 and Col1a2 genes in the uterus of mice as well as hESCs, inhibition of p300 permitted hESCs to undergo decidualization. Collectively, we found attenuation of HDAC3 and overexpression of collagen type I in the eutopic endometrium of infertile patients with endometriosis. HDAC3 loss caused a defect of decidualization through the aberrant transcriptional activation of Col1a1 and Col1a2 genes in mice and COL1A1 and COL1A2 genes in humans. Our results suggest that HDAC3 is critical for endometrial receptivity and decidualization.

Uterine Fluid Proteins for Minimally Invasive Assessment of Endometrial Receptivity

CONTEXT

Clinically used endometrial (EM) receptivity assays are based on transcriptomic patterning of biopsies at midsecretory endometrium (MSE) to identify the possible displacement or disruption of window of implantation (WOI) in patients with recurrent implantation failure (RIF). However, biopsies are invasive and cannot be performed in the same cycle with in vitro fertilization embryo transfer, while uterine fluid (UF) analysis is considered minimally invasive and can immediately precede embryo transfer.

OBJECTIVE

To determine whether UF proteome can be used for WOI monitoring and whether it would highlight the etiology of RIF.

PATIENTS

Paired early secretory endometrial (ESE) and MSE UF samples from six fertile control women for discovery, and an additional 11 paired ESE/MSE samples from controls and 29 MSE samples from RIF patients for validation.

RESULTS

Using discovery mass spectrometry (MS) proteomics we detected 3158 proteins from secretory phase UF of which 367 undergo significant (q < 0.05) proteomic changes while transitioning from ESE to MSE. Forty-five proteins were further validated with targeted MS, and 21 were found to display similar levels between control ESE and RIF MSE, indicating displacement of the WOI. A panel of PGR, NNMT, SLC26A2 and LCN2 demonstrated specificity and sensitivity of 91.7% for distinguishing MSE from ESE samples. The same panel distinguished control MSE samples from RIF MSE with a 91.7% specificity and 96.6% sensitivity.

CONCLUSION

UF proteins can be used for estimating uterine receptivity with minimal invasiveness. Women with RIF appear to have altered MSE UF profiles that may contribute to their low IVF success rate.

Proline-Rich Acidic Protein 1 (PRAP1) is a Target of ARID1A and PGR in the Murine Uterus

ARID1A and PGR plays an important role in embryo implantation and decidualization during early pregnancy. Uterine specific Arid1a knockout (Pgr^cre/+Arid1a^f/f) mice exhibit in non-receptive endometrium at day 3.5 of gestation (GD 3.5). In previous studies, using transcriptomic analysis in the uterus of Pgr^cre/+Arid1a^f/f mice, we identified proline-rich acidic protein 1 (PRAP1) as one of the down-regulated genes by ARID1A in the uterus. In the present study, we performed RT-qPCR and immunohistochemistry analysis to investigate the regulation of PRAP1 by ARID1A and determine expression patterns of PRAP1 in the uterus during early pregnancy. During early pregnancy, PRAP1 expression was strong at day 0.5 of gestation (GD 0.5) and then decreased at GD 3.5 in the epithelium and stroma. After implantation, PRAP1 expression was remarkably reduced in the uterus. However, the expression of PRAP1 at GD 3.5 was remarkably increased in the Pgr^cre/+Arid1a ^f/f mice. To determine the ovarian steroid hormone regulation of PRAP1, we examined the expression of PRAP1 in ovariectomized control, Pgr^cre/+Arid1a^f/f, and progesterone receptor knock-out (PRKO) mice treated with progesterone. While PRAP1 proteins were strongly expressed in the luminal and glandular epithelium of control mice treated with vehicle, progesterone treatment suppressed the expression of PRAP1. However, PRAP1 was not suppressed in both the Pgr^cre/+Arid1a^f/f and PRKO mice compared to controls. Our results identified PRAP1 as a novel target of ARID1A and PGR in the murine uterus.

Oestrogen-induced expression of decay accelerating factor is spatiotemporally antagonised by progesterone-progesterone receptor signalling in mouse uterus

Decay accelerating factor (DAF) is upregulated in the fetoplacental trophoblast, which protects the fetus from maternal complement injury. DAF was found to be downregulated in the endometrium of patients with repeated implantation failure. Thus, we examined the molecular mechanisms of DAF expression regulation by ovarian steroid hormones in the mouse uterus. Immunofluorescence staining demonstrated its exclusive localisation in the apical region of the epithelium in the uterus. Oestrogen (E2) significantly induced Daf mRNA in a time-dependent manner. Progesterone (P4) did not have any significant effect on Daf expression; however, it negatively modulated E2-induced DAF expression and RU486 effectively interfered with the inhibitory action of P4 in the uterus. During early pregnancy DAF was higher on Day 1 of pregnancy, but significantly decreased from Day 3, which is consistent with its E2-dependent regulation. Interestingly, DAF expression seemed to be influenced by the implanting blastocyst on Day 5 and it was gradually increased during preimplantation embryo development with peak levels at blastocyst stages. We demonstrated that E2-dependent DAF expression is antagonised by P4-progesterone receptor signalling in the uterine epithelium. Spatiotemporal regulation of DAF in the uterus and preimplantation embryos suggest that DAF functions as an immune modulator for embryo implantation and early pregnancy in mice.

Genome-wide analysis of long noncoding RNAs, microRNAs, and mRNAs forming a competing endogenous RNA network in repeated implantation failure

Repeated implantation failure (RIF) was mainly due to poor endometrium receptivity. Long noncoding RNAs (lncRNAs) could regulate endometrium receptivity and act in competing endogenous RNA (ceRNA) theory. However, the regulatory mechanism of the lncRNA-miRNA-mRNA network in repeated implantation failure (RIF) is unclear. We obtained RIF-related expression profiles of lncRNAs, mRNAs, and miRNAs using mid-secretory endometrial tissue samples from 5 women with RIF and 5 controls by RNA-sequencing. Co-expression analysis revealed that three functional modules were enriched in immune response/inflammation process; two functional modules were enriched in metabolic/ biosynthetic process, and one functional module were enriched in cell cycle pathway. By adding the miRNA data, ceRNA regulatory relationship of each module was reconstructed. The ceRNA network of the whole differentially expressed RNAs revealed 10 hub lncRNAs. Among them, TRG-AS1, SIMM25, and NEAT1 were involved in the module1, module2, and module3, respectively; LNC00511 and SLC26A4-AS1 in the module4; H19 in the module5. The real-time polymerase chain reaction (RT-PCR) results of 15 randomly selected RNAs were consistent with our sequencing data. These can be used as novel potential biomarkers for RIF. Furthermore, they might be involved in endometrium receptivity by acting as ceRNA.

Effects of hormone replacement therapy on endometrial hormone concentrations and progesterone receptor expression in recurrent pregnancy loss: a self-controlled study

AIM

To investigate the differential effects of endometrial preparation approaches, natural cycle (NC) and hormone replacement therapy (HRT), on the endometrial hormone conditions in patients with recurrent pregnancy loss (RPL).

METHODS

42 RPL patients were recruited, and a self-controlled trial was conducted to compare the effectiveness of NC to HRT on the same patient. The estradiol (E2) and progesterone (P) levels in both serum and endometrial tissue were measured in NC and HRT, respectively. Meanwhile, the expression levels of endometrial progesterone receptor A (PRA) and progesterone receptor B (PRB) were also compared between NC and HRT cycles during the window of receptivity. All statistical analyses were performed using GraphPad Prism 5, and data were averaged across subjects and tested for significance by pair-samples t-test.

RESULTS

Hormone replacement slightly decreased serum E2 and P levels (0.9- and 0.8-fold in average, respectively), significantly elevated endometrial E2 and P (2.1- and 14.5-fold in average, respectively), and reduced endometrial E2/P ratio (0.34-fold in average) compared to the NC condition. However, no correlation was found between serum and endometrial hormone concentrations. Further, the PRA/PRB ratios of both stromal and glandular cells were comparable between HRT and NC conditions, even though stromal PRA expression was slightly elevated by HRT compared to NC (1.63±0.96 vs 1.18±0.99, p =.0173).

CONCLUSION

The effects of HRT for endometrial preparation are similar or slightly superior to NC in RPL patients.

What is the clinical impact of the endometrial receptivity array in PGT-A and oocyte donation cycles?

PURPOSE

To evaluate the influence of the endometrial receptivity array (ERA) test on the implantation rate (IR) and pregnancy rate (PR) in patients with previous failed euploid embryo transfers (Euploid-ET) or oocyte donation embryo transfers (Donor-ET).

METHODS

Single-center retrospective study of patients with ≥ 1 previous failed Euploi-ET (n = 24) or ≥ 2 failed Donor-ET (n = 32) who underwent an ERA test and a post-ERA Euploid-ET/Donor-ET between 2012 and 2018. Controls were patients with ≥ 1 previously failed Euploid-ET (n = 119) or ≥ 2 failed Donor-ET (n = 158) who underwent Euploid-ET/Donor-ET during the same period without performing an ERA test. Only blastocyst stage embryos were included. IR/PR was compared between the post-ERA ET and the last ET in the control group.

RESULTS

There was no statistically significant difference regarding IR [55.6% (34.6-76.5%) vs. 65.0% (56.9-73.1%)] nor PR (58.3% vs.70.6%, p = 0.238) in the Euploid-ET ERA vs. Euploid-ET control groups. In the Donor-ET arm, both IR [26.8% (12.3-41.4%) vs. 57.2% (50.1-64.3%)] and PR (34.4% vs. 65.2%, p = 0.001) were significantly lower in the ERA group. Multivariate analysis confirmed that performing an ERA test did not influence the PR in the Euploid-ET arm and was associated with a diminished PR in the Donor-ET arm. In the ERA group, 41.1% patients were non-receptive (NR). No significant difference was found regarding IR/PR in NR vs. receptive patients in both Euploid-ET/Donor-ET arms.

CONCLUSIONS

In our sample, the performance of an ERA test did not improve pregnancy outcomes. Future prospective studies in larger samples are needed to confirm the role of the ERA test in Euploid-ET/Donor-ET.

Medical or surgical treatment before embryo transfer improves outcomes in women with abnormal endometrial BCL6 expression

PURPOSE

To evaluate the effect of medical or surgical treatment prior to embryo transfer in women with elevated endometrial BCL6 expression and suspected endometriosis in a prospective, cohort study design at a university-associated infertility clinic.

METHODS

All subjects had at least 1 year of unexplained infertility (UI) and each prospectively underwent endometrial biopsy and immunostaining for the oncogene BCL6, prior to embryo transfer during an assisted reproductive technology (ART) cycle. To be included, subjects had to have an abnormal BCL6 result, defined by elevated HSCORE ≥ 1.4. Women that were pre-treated with laparoscopy or medical suppression with GnRH agonist (depot leuprolide acetate; Lupron®, Abbvie, Inc., Chicago, IL) for 2 months were compared to a group that went untreated (controls). Endpoints included implantation rate (IR), clinical pregnancy rate (CPR), and live birth rate (LBR), and as well as cycle characteristics. Miscarriage rate were also compared between treatment and control group.

RESULTS

Women in each group had similar characteristics. Those treated by medical suppression and those undergoing laparoscopy for endometriosis had a significantly higher LBR, (5/10; 50%; 95%CI 23.7 to 76.3%) and (11/21; 52.4%; 95%CI 32.4 to 71.7), respectively, compared to controls (4/54; 7.4%; 95%CI 2.9 to 17.6). An absolute benefit of 44.2% (16/31; 95%CI 24.6 to 61.2) and a number need to treat of 3 for those that received treatment (medical suppression and laparoscopy), compared to no treatment. Miscarriages were significantly more common in the control group.

CONCLUSIONS

Women with suspected endometriosis and aberrant endometrial BCL6 expression have worse reproductive outcomes following embryo transfer, including a high miscarriage rate, poor IR, and low LBR and CPR compared to cycles pre-treated with medical and surgical management.

Role of mTOR Signaling in Female Reproduction

Mammalian target of rapamycin (mTOR) is a conserved serine/threonine kinase of the phosphatidylinositol kinase-related kinase family that regulates cell growth, metabolism, and autophagy. Extensive research has linked mTOR to several human diseases including cancer, neurodegenerative disorders, and aging. In this review, recent publications regarding the mechanisms underlying the role of mTOR in female reproduction under physiological and pathological conditions are summarized. Moreover, we assess whether strategies to improve or suppress mTOR expression could have therapeutic potential for reproductive diseases like premature ovarian failure, polycystic ovarian syndrome, and endometriosis.

Insulin Regulates Glycogen Synthesis in Human Endometrial Glands Through Increased GYS2

CONTEXT

Glycogen synthesis is a critical metabolic function of the endometrium to prepare for successful implantation and sustain embryo development. Yet, regulation of endometrial carbohydrate metabolism is poorly characterized. Whereas glycogen synthesis is attributed to progesterone, we previously found that the metabolic B isoform of the insulin receptor is maximally expressed in secretory-phase endometrium, indicating a potential role of insulin in glucose metabolism.

OBJECTIVE

We sought to determine whether insulin or progesterone regulates glycogen synthesis in human endometrium.

DESIGN, PARTICIPANTS, OUTCOME MEASUREMENTS

Endometrial epithelial cells were isolated from 28 healthy women and treated with insulin, medroxyprogesterone (MPA), or vehicle. Intracellular glycogen and the activation of key enzymes were quantified.

RESULTS

In epithelia, insulin induced a 4.4-fold increase in glycogen, whereas MPA did not alter glycogen content. Insulin inactivated glycogen synthase (GS) kinase 3α/β (GSK3α/β), relieving inhibition of GS. In a regulatory mechanism, distinct from liver and muscle, insulin also increased GS by 3.7-fold through increased GS 2 (GYS2) gene expression.

CONCLUSIONS

We demonstrate that insulin, not progesterone, directly regulates glycogen synthesis through canonical acute inactivation of GSK3α/β and noncanonical stimulation of GYS2 transcription. Persistently elevated GS enables endometrium to synthesize glycogen constitutively, independent of short-term nutrient flux, during implantation and early pregnancy. This suggests that insulin plays a key, physiological role in endometrial glucose metabolism and underlines the need to delineate the effect of maternal obesity and hyperinsulinemia on fertility and fetal development.

Paternal age and assisted reproductive technology: problem solver or trouble maker?

In our society, the number of couples with advanced reproductive age seeking fertility treatment is increasing steadily. While the negative effect of female age on assisted reproductive technology (ART) outcomes is well established, the impact of paternal age needs to be clarified. We reviewed the current literature to determine whether advanced paternal age affects the results of ART and the health of resulting offspring. We found that the published literature is overall supportive of a positive association between advanced paternal age (>40 years) and semen quality deterioration. However, the existing evidence does not corroborate nor discard the influence of advanced paternal age on ART outcomes. Similarly, the effect of paternal age on the health of ART offspring remains equivocal, although data from naturally-conceived children clearly indicates that advanced paternal age increases the frequency of genetic, neurodevelopmental, and psychiatric diseases in the progeny. Noteworthy, the current literature is limited and subjected to bias due to the impact of maternal age as a critical confounder. Health care providers should discuss with concerned couples the available options to counteract the possible negative influence of advanced paternal age on ART outcomes and health of resulting offspring. These include identification and treatment of underlying conditions with potential negative long-term effects on fertility, sperm freezing at a young age, and use of antioxidant supplements for men at risk of excessive oxidative stress. Aged male partner from couples undergoing ART, in particular men of 50 years and older, should consider use of preimplantation genetic testing as a means to detect embryo abnormalities and select euploid embryos for transfer to the uterine cavity.

Decay-accelerating factor promotes endometrial cells proliferation and motility under ovarian hormone stimulation

The intent of the study was to explore the elevating expression of decay-accelerating factor(DAF) exerts influence on biological behaviors of endometrial stromal cells except in classical immunology on the basis of bioinformatic statistics and clinical miscarriages findings suggesting its potential role in the establishment of endometrial receptivity. We confirmed that DAF locates on the cellular surface of endometrial epithelium and stroma. By using plasmid transfection to down-regulate DAF expression in primary endometrial stromal cells(ESCs), we discovered that DAF expression in ESCs increases in response to estradiol and progesterone stimulation in dose- and time-dependent manners; moreover, tamoxifen and RU486 stimulations to block estrogen receptors(ERs) and progesterone receptors(PRs) respectively result in reduced DAF mRNA and protein, and it is more obvious to block PRs. Meanwhile, knocked-down DAF in ESCs weakens the proliferation, migration and invasion of endometrial cells. Cell cycle analysis showed knocked-down DAF accumulates cells in S phase and diminishes cells in G0/G1 phase, which substantiates DAF mediates endometrial cells proliferation. In conclusion, DAF is a potential molecule involving in endometrial cellular proliferation and motility to verify up-expressed DAF during the WOI may facilitate endometrial physiobiological behavior changes, which shed light on DAF function and potential role in the endometrial receptivity establishment.

Endometrial pinopode biomarkers: Molecules and microRNAs

Ultrastructural changes on the apical surface of the luminal epithelium of the uterus are known as pinopodes. Their morphology in species and in special species is associated with different results about size, duration, and percentage of surface area covered by pinopodes. The content of pinopodes is different in rodents and humans. In mice and rats pinopodes have many vacuoles and no organelle that extends to the actin stalk above the microvilli. Human pinopodes do not have a large vacuole and contain the golgi complex, a rough endoplasmic reticulum, secretory vesicles, and mitochondria that extend from the entire cell surface. It has been suggested that pinopodes are good markers of endometrial receptivity and implantation window. There are several molecular markers related to the presence of pinopodes, including integrins, leukemia inhibiting factor (LIF), l-selectin, HOXA10, glutaredoxin, glycodelinA, heparin-binding epidermal growth factor, mucins, and microRNAs (miRNAs). Multiple lines of evidence have indicated that miRNAs could affect the expression of LIF and pinopodes in the endometrium and these molecules play key roles in implantation window processes. Here, we have summarized the morphology and function of pinopodes. Moreover, we have highlighted several molecules in relation to pinopodes that could be used as biomarkers.

Analysis of endometrial microbiota by 16S ribosomal RNA gene sequencing among infertile patients: a single-center pilot study

PURPOSE

The present study aimed to analyze the endometrial and vaginal microbiome among a Japanese infertile population by sequencing and the impact of the endometrial and vaginal environment on implantation.

METHODS

In total, 102 infertile (79 in vitro fertilization [IVF] and 23 non-IVF) patients and seven healthy volunteers were recruited from August to December, 2017. Endometrial fluid and vaginal discharge samples for sequencing were collected by using an intrauterine insemination catheter. The bacterial status of the endometrium and vagina were analyzed.

RESULTS

The Lactobacillus-dominated microbiota (>90% Lactobacillus spp.) in the endometrium vs vagina was 38% (30/79) vs 44.3% (44/79) in the IVF patients, 73.9% (17/23) vs 73.9% (17/23) in the non-IVF patients, and 85.7% (6/7) vs 85.7% (6/7) in the healthy volunteers. The percentage of endometrial Lactobacillus in the healthy volunteers was highly stable within the same menstrual cycle and even in the following cycle. The major taxonomies were Gardnerella, Streptococcus, Atopobium, Bifidobacterium, Sneathia, Prevotella, and Staphylococcus. Fifteen patients achieved pregnancy by a single vitrified-warmed blastocyst transfer during this study; the median percentage of Lactobacillus in the pregnant women was 96.45 ± 33.61%.

CONCLUSION

A considerable percentage of non-Lactobacillus-dominated (NLD) microbiota was found in the endometrium of Japanese infertile women. Increasing the endometrial level of the Lactobacilli to >90% might favor the implantation outcome of NLD infertile patients.

Mitochondrial tumor suppressor 1 is a target of AT-rich interactive domain 1A and progesterone receptor in the murine uterus

Objective

Progesterone receptor (PGR) and AT-rich interactive domain 1A (ARID1A) have important roles in the establishment and maintenance of pregnancy in the uterus. In present studies, we examined the expression of mitochondrial tumor suppressor 1 (MTUS1) in the murine uterus during early pregnancy as well as in response to ovarian steroid hormone treatment.

Methods

We performed quantitative reverse transcription polymerase chain reaction and immunohistochemistry analysis to investigate the regulation of MTUS1 by ARID1A and determined expression patterns of MTUS1 in the uterus during early pregnancy.

Results

The expression of MTUS1 was detected on day 0.5 of gestation (GD 0.5) and then gradually increased until GD 3.5 in the luminal and glandular epithelium. However, the expression of MTUS1 was significantly reduced in the uterine epithelial cells of Pgr^cre/+Arid1a^f/f and Pgr knockout (PRKO) mice at GD 3.5. Furthermore, MTUS1 expression was remarkably induced after P4 treatment in the luminal and glandular epithelium of the wild-type mice. However, the induction of MTUS1 expression was not detected in uteri of Pgr^cre/+Arid1a^f/f or PRKO mice treated with P4.

Conclusion

These results suggest that MTUS1 is a novel target gene by ARID1A and PGR in the uterine epithelial cells.

Implications of immune dysfunction on endometriosis associated infertility

Endometriosis is a complex, inflammatory disease that affects 6-10% of reproductive-aged women. Almost half of the women with endometriosis experience infertility. Despite the excessive prevalence, the pathogenesis of endometriosis and its associated infertility is unknown and a cure is not available. While many theories have been suggested to link endometriosis and infertility, a consensus among investigators has not emerged. In this extensive review of the literature as well as research from our laboratory, we provide potential insights into the role of immune dysfunction in endometriosis associated infertility. We discuss the implication of the peritoneal inflammatory microenvironment on various factors that contribute to infertility such as hormonal imbalance, oxidative stress and how these could further lead to poor oocyte, sperm and embryo quality, impaired receptivity of the endometrium and implantation failure.

The role of levothyroxine in obstetric practice

Thyroid hormones play a pivotal role in somatic growth, metabolic regulation and neurodevelopment. There is growing evidence regarding adverse obstetric and perinatal consequences of maternal thyroid hypofunction during early stages of pregnancy. These include: early pregnancy loss, preterm delivery and lower intelligence quotient (IQ) in children. Different clinical guidelines have been published by scientific societies for the management of thyroid diseases during pregnancy and levothyroxine (LT₄) has become a therapeutic agent increasingly prescribed by obstetricians. The aim of this work was to search for both similarities and controversial clinical aspects from the currently available literature. Guidelines published from 2011 onwards have been analysed and compared, in order to clarify the evidence about the involvement of thyroid dysfunction in pregnancy complications and the impact of LT₄ use in their prevention and/or treatment. This review summarizes the most updated knowledge about the effectiveness of LT₄ for pregnancy complications, the current recommendations and its application into clinical practice. KEY MESSAGES The use of levothyroxine in obstetric practices requires a correct diagnosis and to consider the specific recommendations for each thyroid dysfunction entity. The effectiveness and safety of levothyroxine treatment in preventing adverse perinatal events in pregnant women with clinical hypothyroidism is supported by all the current guidelines. Levothyroxine therapy is strongly recommended in all cases of overt hypothyroidism and in cases of subclinical hypothyroidism associated to positive thyroid autoimmunity.

Uterine natural killer cell progenitor populations predict successful implantation in women with endometriosis-associated infertility

PROBLEM

Uterine natural killer (uNK) cells play a critical role early in gestation. As we previously identified altered uNK cell development in endometriosis-associated infertility, we herein sought to characterize natural killer (NK) cell profiles in endometriosis that may predict embryo implantation.

METHOD OF STUDY

Study participants had a surgical diagnosis of endometriosis-associated infertility. Endometrial tissue and peripheral blood were obtained from 58 women. Thirty-three patients underwent artificial reproductive technology (IVF, ICSI, or IUI) within a mean of 9.5 months of surgery. NK and hematopoietic progenitor cells from endometrium and blood were analyzed by flow cytometry. Successful implantation was defined as a positive pregnancy test.

RESULTS

In successful implantation, populations of endometrial CD34⁺ hematopoietic stem cells were higher (3.97% vs 0.69%; P < .0004), and coexpression of NK cell marker CD56 was increased (81.1% vs 60.9%; P < .034) compared with patients who had failed implantation. In contrast, levels of blood NK progenitors were similar in both groups.

CONCLUSION

Our study revealed that uterine NK progenitor cell populations are markedly different in patients with endometriosis who proceed to successful or failed embryo implantation and may define a novel predictor of implantation success. Our findings also highlight the fundamental differences inherent in NK cell repertoires between blood and uterine compartments.

Smoking Decreases Endometrial Thickness in IVF/ICSI Patients

Introduction

Smoking is a serious problem for the health care system. Many of the compounds identified in cigarette smoke have toxic effects on the fertility of both females and males. The purpose of this study was to determine whether smoking affects clinical factors during IVF/ICSI therapy in a single-center reproductive unit.

Material and Methods

In a retrospective study of 200 IVF/ICSI cycles, endometrial thickness and the outcome of IVF/ICSI therapy were analyzed.

Results

Endometrial thickness was significantly lower in smoking patients than in non-smoking patients (10.4 ± 1.5 mm vs. 11.6 ± 1.8 mm). Age was significantly higher in women who failed to conceive. The total dose of gonadotropins administered was significantly lower in pregnant patients and the highest pregnancy rate was achieved with an rFSH protocol. BMI and number of cigarettes smoked did not influence treatment outcomes in this study.

Conclusion

We showed that smoking has a negative effect on endometrial thickness on the day of embryo transfer. This may help to further explain the detrimental influence of tobacco smoke on implantation and pregnancy rates during assisted reproduction therapy.

The high concentration of progesterone is harmful for endometrial receptivity and decidualization

Progesterone is required for the establishment and maintenance of mammalian pregnancy and widely used for conservative treatment of luteal phase deficiency in clinics. However, there are limited solid evidences available for the optimal timing and dose of progesterone therapy, especially for the possible adverse effects on implantation and decidualization when progesterone is administrated empirically. In our study, mouse models were used to examine effects of excess progesterone on embryo implantation and decidualization. Our data indicate that excess progesterone is not only harmful for mouse implantation, but also impairs mouse decidualization. In excess progesterone-treated mice, the impaired LIF/STAT3 pathway and dysregulated endoplasmic reticulum stress may lead to the inhibition of embryo implantation and decidualization. It is possible that the decrease in birth weight of excess progesterone-treated mice is due to a compromised embryo implantation and decidualization. Furthermore, excess progesterone compromises in vitro decidualization of human endometrial stromal cells.

The role of the endometrial receptivity array (ERA) in patients who have failed euploid embryo transfers

PURPOSE

Endometrial receptivity issues represent a potential source of implantation failure. The aim of this study was to document our experience with the endometrial receptivity array (ERA) among patients with a history of euploid blastocyst implantation failure. We investigated whether the contribution of the endometrial factor could be identified with the ERA test and if actionable results can lead to improved outcomes.

METHODS

A retrospective review was performed for 88 patients who underwent ERA testing between 2014 and 2017. Reproductive outcomes were compared for patients undergoing frozen embryo transfer (FET) using a standard progesterone protocol versus those with non-receptive results by ERA and subsequent FET according to a personalized embryo transfer (pET) protocol.

RESULTS

Of patients with at least one previously failed euploid FET, 22.5% had a displaced WOI diagnosed by ERA and qualified for pET. After pET, we found that implantation and ongoing pregnancy rates were higher (73.7 vs. 54.2% and 63.2 vs. 41.7%, respectively) compared to patients without pET, although differences were not statistically significant.

CONCLUSIONS

Our experience demonstrates that a significant proportion of patients with a history of implantation failure of a euploid embryo have a displaced WOI as detected by the ERA. For these patients, pET using a modified progesterone protocol may improve the outcomes of subsequent euploid FET. Larger randomized studies are required to validate these results.

High-throughput metabolomics used to identify potential therapeutic targets of Guizhi Fuling Wan against endometriosis of cold coagulation and blood stasis

Metabolomics is an emerging and robust discipline and involves the comprehensive evaluation of small molecule endogenous metabolites and enables the exploration of the pathogenesis of diseases. For example, endometriosis – a common disease which mostly occurs in women of childbearing age. A cure for endometriosis of cold coagulation and blood stasis (ECB) is highly sought after. This study was conducted to discover the potential biomarkers of ECB and the effective mechanism undertaken by Guizhi Fuling Wan (GFW) in treating ECB in rats. Urinary metabolomics were performed by using UPLC-Q-TOF-MS with pattern recognition methods to evaluate the changes in metabolic profiles and to identify biomarkers for elucidating the mechanism of the treatment of ECB with GFW. The results showed that urinary metabolism in the two groups were distinctly separated on the 28^th day, and a total of 20 differential biomarkers (16 in the positive mode, 4 in the negative mode) were confirmed involving several key metabolic pathways which included phenylalanine, tyrosine and tryptophan biosynthesis, valine, leucine and isoleucine biosynthesis, glyoxylate and dicarboxylate metabolism, tyrosine metabolism and the citrate cycle. Following the oral administration of GFW, certain pathways were affected; these included the following: phenylalanine, tyrosine and tryptophan biosynthesis, valine, leucine and isoleucine biosynthesis, glyoxylate and dicarboxylate metabolism, tyrosine metabolism, citrate cycle, steroid hormone biosynthesis, tryptophan metabolism, phenylalanine metabolism, primary bile acid biosynthesis, and aminoacyl-tRNA biosynthesis. This study also demonstrated that the administration of GFW affected the levels of urine endogenous metabolites, thereby laying a foundation for further study of the pharmacodynamical mechanism of GFW.

Metabolomics is an emerging and robust discipline and involves the comprehensive evaluation of small molecule endogenous metabolites and enables the exploration of the pathogenesis of diseases.

Endometrial BCL6 testing for the prediction of in vitro fertilization outcomes: a cohort study

OBJECTIVE

To evaluate endometrial BCL6 expression as a prognostic biomarker for IVF outcome in women with unexplained infertility (UI) before ET.

DESIGN

Prospective cohort study.

SETTING

University-associated infertility clinic.

PATIENT(S)

Women with UI for >1 year.

INTERVENTION(S)

We studied women with UI who underwent testing for endometrial BCL6, in an LH-timed midluteal phase biopsy and completed an IVF cycle and ET.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate (PR) and live birth rate per transfer was compared for women positive or negative for BCL6 expression. An abnormal BCL6 result was defined by an histologic score (>1.4).

RESULT(S)

Women with normal and abnormal BCL6 and those who conceived or not had similar characteristics. Women with low levels of BCL6 expression had a significantly higher clinical PR (11/17; 64.7%; 95% confidence interval [CI] 41.3-82.6) compared with women with abnormal (high) BCL6 expression (9/52; 17.3%; 95% CI 9.3-30.8). These results yield a relative risk of 0.267 (95% CI 0.13-0.53; P=.0004) for those with normal BCL6 expression, an absolute benefit of 47.4% (95% CI 22.5-72.0). Live birth rate was also significantly higher in women with low BCL6 expression (10/17; 58.8%; 95% CI 36.0-78.4) compared with women with abnormal BCL6 expression (6/52; 11.5%; 95% CI 5.4-23.0). The relative risk was 0.19 (95% CI 0.08-0.45; P=.0002), yielding an absolute benefit of 47.3% (95% CI 21.8-67.8).

CONCLUSION(S)

Aberrant BCL6 expression (histologic score, >1.4) was strongly associated with poor reproductive outcomes in IVF cycles in women with UI.

KRAS Activation and over-expression of SIRT1/BCL6 Contributes to the Pathogenesis of Endometriosis and Progesterone Resistance

Endometriosis is an inflammatory condition that is associated with progesterone resistance and cell proliferation, resulting in pain, infertility and pregnancy loss. We previously demonstrated phosphorylation of STAT3 in eutopic endometrium of infertile women with this disorder leading to over-expression of the oncogene BCL6 and stabilization of hypoxia-induced factor 1 alpha (HIF-1α). Here we report coordinated activation of KRAS and over-expression of Sirtuin 1 (SIRT1), a histone deacetylase and gene silencer, in the eutopic endometrium from women with endometriosis throughout the menstrual cycle. The mice with conditional activation of KRAS in the PGR positive cells reveal an increase of SIRT1 expression in the endometrium compared to control mice. The expression of progesterone receptor target genes including the Indian Hedgehog pathway genes are significantly down-regulated in the mutant mice. SIRT1 co-localizes with BCL6 in the nuclei of affected individuals and both proteins bind to and suppress the promoter of GLI1, a critical mediator of progesterone action in the Indian Hedgehog pathway, by ChIP analysis. In eutopic endometrium, GLI1 expression is reduced in women with endometriosis. Together, these data suggest that KRAS, SIRT1 and BCL6 are coordinately over-expressed in eutopic endometrium of women with endometriosis and likely participate in the pathogenesis of endometriosis.

Endometrial receptivity in the eutopic endometrium of women with endometriosis: it is affected, and let me show you why

The endometrium maintains complex controls on proliferation and apoptosis as part of repetitive menstrual cycles that prepare the endometrium for the window of implantation and pregnancy. The reliance on inflammatory mechanisms for both implantation and menstruation creates the opportunity in the setting of endometriosis for establishment of chronic inflammation that is disruptive to endometrial receptivity, causing both infertility and abnormal bleeding. Clinically, there can be little doubt that the endometrium of women with endometriosis is less receptive to embryo implantation, and strong evidence exists to suggest that endometrial changes are associated with decreased cycle fecundity as a result of this disease. Here we provide unifying concepts regarding those changes and how they are coordinated to promote progesterone resistance and estrogen dominance through aberrant cell signaling pathways and reduced expression of key homeostatic proteins in eutopic endometrium of women with endometriosis.

Efficacy of the endometrial receptivity array for repeated implantation failure in Japan: A retrospective, two-centers study

Aim

This study aimed to assess the efficacy of the endometrial receptivity array (ERA) as a diagnostic tool and the impact of personalized embryo transfer (pET) for the treatment of patients with recurrent implantation failure (RIF) in Japan.

Methods

Fifty patients with a history of RIF with frozen‐thawed blastocyst transfers were recruited from July, 2015 to April, 2016. Endometrial sampling for the ERA and histological dating and a pET according to the ERA were performed. The receptive (R) or non‐receptive (NR) status of the endometrium as a result of the first ERA, endometrial dating, and pregnancy rates after the pET were analyzed.

Results

Of the patients with RIF, 12 (24%) were NR. Among them, eight (66.7%) were prereceptive. A clinical follow‐up was possible in 44 patients who underwent the pET. The pregnancy rates were 58.8% per patient and 35.3% per first pET in the R patients and 50.0% per patient and 50.0% per first pET in the NR patients. Discrepancies between the ERA results and histological dating were seen more in the NR patients than in the R patients.

Conclusions

For patients with unexplained RIF, there is a significance in searching for their personal window of implantation (WOI) using the ERA, considering the percentage of those who were NR and the pregnancy rates that resulted from the pET. By transferring euploid embryos in a personal WOI, much better pregnancy rates are expected.

Frozen-thawed blastocyst transfer in natural cycle: feasibility in everyday clinical practice

PURPOSE

Transfer of frozen-thawed embryos in natural cycle is gaining consensus but evidence on this approach is scanty. The aim of this study is reporting on the feasibility of this type of policy in everyday clinical practice.

METHODS

We retrospectively selected all women undergoing the procedure between July 2013 and December 2014. During the study period, women were systematically scheduled for natural cycle if they referred regular menstrual cycles. Hormone replacement therapy (HRT) was conversely prescribed if the woman had irregular menstrual cycles or if the monitoring of the natural cycle failed. The analysis exclusively focussed on the first cycle per woman.

RESULTS

Overall, 251 women were selected. HRT was initially chosen in 52 women, leaving 199 women suitable for the natural cycle. This procedure could be performed in 194 of these women (97%, 95% CI 95-99%). Two additional women initially allocated to HRT ultimately performed the blastocyst transfer with natural cycle. Overall, 196 were thus treated with natural cycle (78%, 95% CI 73-83%). The basal characteristics of the women who did and did not undergo natural cycles were similar with the exceptions of serum FSH (p < 0.001) and AMH (p = 0.03). The live birth rate did not also differ (34% versus 31%, p = 0.63). Characteristics of women treated with the natural cycle who did (n = 67) and did not (n = 129) achieve a live birth did not differ.

CONCLUSION

Frozen-thawed blastocyst transfer in natural cycle can be successfully performed in the vast majority of women.

RNA-Binding Proteins in Female Reproductive Pathologies

RNA-binding proteins are key regulatory molecules involved primarily in post-transcriptional gene regulation of RNAs. Post-transcriptional gene regulation is critical for adequate cellular growth and survival. Recent reports have shown key interactions between these RNA-binding proteins and other regulatory elements, such as miRNAs and long noncoding RNAs, either enhancing or diminishing their response to RNA stabilization. Many RNA-binding proteins have been reported to play a functional role in mediation of cytokines involved in inflammation and immune dysfunction, and some have been classified as global post-transcriptional regulators of inflammation. The ubiquitous expression of RNA-binding proteins in a wide variety of cell types and their unique mechanisms of degradative action provide evidence that they are involved in reproductive tract pathologies. Aberrant inflammation and immune dysfunction are major contributors to the pathogenesis and disease pathophysiology of many reproductive pathologies, including ovarian and endometrial cancers in the female reproductive tract. Herein, we discuss various RNA-binding proteins and their unique contributions to female reproductive pathologies with a focus on those mediated by aberrant inflammation and immune dysfunction.

Effects of a hyperandrogenaemic state on the proliferation and decidualization potential in human endometrial stromal cells

OBJECTIVE

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women, involving hyperandrogenaemia and insulin resistance. Treatment options include dexamethasone, as well as the off-label use of metformin. To evaluate the impact of those drugs on cyclic changes in endometrial development, we tested possible effects of metformin and dexamethasone on endometrial stromal cells decidualisation, proliferation, and gene regulation in a hyperandrogenaemic microenvironment in vitro.

METHODS/DESIGN

Ten endometrial biopsies (of which five were decidualized in vitro) were used from regularly cycling women. Cells were treated with testosterone, dexamethasone, and metformin in different concentrations. Thereafter, cells were assessed for proliferation and decidualization capacity, as well as mTor and MMP-2 gene regulation.

RESULTS

Metformin showed a dose-dependent negative effect on prolactin secretion, a known decidualization marker. This effect was stronger in a hyperandrogenaemic condition and could not be compensated by dexamethasone. Testosterone had a dose dependent negative effect on proliferation in decidualized endometrial stromal cells. Dexamethasone slightly compensated the negative proliferative effect only in low-dose testosterone. High-dose metformin also showed a dose-dependent reduction in endometrial stromal cell proliferation without a major impact by testosterone or dexamethasone in decidualized and non-decidualized cells. High-dose metformin significantly reduced the expression of matrix metalloproteinase-2 (MMP-2) and mechanistic Target of Rapamycin (mTor), regardless of the concentration of dexamethasone and testosterone. The strongest effect could be observed for the combination with high-dose dexamethasone.

CONCLUSION

When therapies, such as metformin and dexamethasone, are used to normalize peripheral androgen levels in patients with PCOS, their effect on the endometrial microenvironment should be taken into consideration as well, especially metformin has to be used with caution because of its dose dependent, possibly inhibiting effect at the endometrial proliferation.

An animal model of effects of nicotine exposure on endometrial receptivity and embryo implantation in pregnancy

OBJECTIVE

This study aims at evaluating the endometrial receptivity in uterus of pregnant rats exposed to nicotine via examination of integrin expression by immunohistochemical effect.

METHODS

In this study, 16 healthy pregnant rats were divided into two groups of control and study groups each comprising eight rats. The rats randomised to study group were given a certain amount of nicotine before and during the pregnancy. Integrin expression was detected in uterus of all rats by immunohistochemical staining. The effect of nicotine exposure on embryo implantation and the endometrial receptivity were immunohistochemically and pathologically evaluated.

RESULTS

Comparison of both groups revealed no difference in living, viable foetuses. Intensity and universality of immunohistochemical staining of Integrin β3 for endometrial epithelium and endometrial stroma were detected to be identical between the groups.

CONCLUSION

No immunochemical effect was observed on integrin expression, which is a very important part of receptivity in an animal model created with pregnant rats that were transdermally exposed to nicotine. Our study demonstrated that the harmful effect of nicotine use before and pregnancy on implantation is limited at the level of integrin expression, in a dose-dependent manner and also by considering the method of administration.

Successful Pregnancy Outcome in Women with Recurrent IVF Failure and Anti-hCG Autoimmunity: A Report of Three Cases

We report three cases of effective management of infertility in women with a history of repeated unsuccessful IVF attempts, who have developed antibodies to hCG. A novel approach to conservative treatment of immunologic reproductive failure, suggested for selected patients, included membrane plasmapheresis, combined prednisolone, and intravenous immunoglobulin therapy. No adverse side effects were observed; all cases resulted in pregnancy and subsequent life births. In order to be given an adequate efficient treatment, women with recurrent implantation failure should be suspected for autoimmune factor of infertility and its possible association with anti-hCG autoimmunity.

Integrative Analyses of Uterine Transcriptome and MicroRNAome Reveal Compromised LIF-STAT3 Signaling and Progesterone Response in the Endometrium of Patients with Recurrent/Repeated Implantation Failure (RIF)

Intimate two-way interactions between the implantation-competent blastocyst and receptive uterus are prerequisite for successful embryo implantation. In humans, recurrent/repeated implantation failure (RIF) may occur due to altered uterine receptivity with aberrant gene expression in the endometrium as well as genetic defects in embryos. Several studies have been performed to understand dynamic changes of uterine transcriptome during menstrual cycles in humans. However, uterine transcriptome of the patients with RIF has not been clearly investigated yet. Here we show that several signaling pathways as well as many genes and microRNAs are dysregulated in the endometrium of patients with RIF (RIFE). Whereas unsupervised hierarchical clustering showed that overall mRNA and microRNA profiles of RIFE were similar to those of endometria of healthy women, many genes were significantly dysregulated in RIFE (cut off at 1.5 fold change). The majority (~75%) of differentially expressed genes in RIFE including S100 calcium binding protein P (S100P), Chemokine (C-X-C motif) ligand 13 (CXCL13) and SIX homeobox 1 (SIX1) were down-regulated, suggesting that reduced uterine expression of these genes is associated with RIF. Gene Set Enrichment analyses (GSEA) for mRNA microarrays revealed that various signaling pathways including Leukemia inhibitory factor (LIF) signaling and a P4 response were dysregulated in RIFE although expression levels of Estrogen receptor α (ERα) and Progesterone receptor (PR) were not significantly altered in RIFE. Furthermore, expression and phosphorylation of Signal transducer and activator of transcription 3 (STAT3) are reduced and a gene set associated with Janus kinase (JAK)-STAT signaling pathway is systemically down-regulated in these patients. Pairwise analyses of microRNA arrays with prediction of dysregulated microRNAs based on mRNA expression datasets demonstrated that 6 microRNAs are aberrantly regulated in RIFE. Collectively, we here suggest that dysregulation of several major signaling pathways and genes critical for uterine biology and embryo implantation may lead to uterine abnormalities in patients with RIF.

Protein Inhibitor of Activated STAT3 (PIAS3) Is Down-Regulated in Eutopic Endometrium of Women with Endometriosis

Endometriosis is a major cause of chronic pelvic pain and infertility. Activation of STAT3 appears central to the inflammatory phenotype of eutopic endometrium in women with endometriosis. However, the molecular mechanism by which this occurs remains unknown. Our objective is to determine how STAT3 activity is regulated in endometriosis. Protein inhibitor of activated STAT3 (PIAS3) is a negative regulator of STAT3 activity. We examined the levels of PIAS3 in endometrium from women with and without endometriosis using Western blot analysis and immunohistochemistry. Levels of PIAS3 are significantly lower, in contrast with phosphorylation of STAT3, in women with endometriosis compared to women without endometriosis. Furthermore, induction of endometriosis in the baboon showed a significant reduction of PIAS3 expression during the progression of the disease. Interferon-γ (INFγ) reduces PIAS3 protein levels and increases phospho-STAT3 levels through CXCL10 in endometrial cells, Ishikawa, and 12Z cells. These results suggest that attenuation of PIAS3 causes aberrant activation of STAT3 in endometriosis, leading to inflammatory changes that may impair fertility or cause pain.