Effects of hydrosalpinx on pinopodes, leukaemia inhibitory factor, integrin beta3 and MUC1 expression in the peri-implantation endometrium

Study of hydrosalpinx on endometrial growth and expression of HOXA10mRNA and related factors

Objective

The objective of the study is to extract the patient's endometrium at the time of proliferative stage using hydrosalpinx in order to culture the cells and decidualization induction in vitro. Further, the study is also intended at identifying the expression of HOXA10mRNA and related factors and understand the hydrosalpinx's impact upon the working mechanism of endometrial cells.

Methods

Once the extraction of the primary cells is over, the cells are cultured and other activities are performed such as the cell identification, CCK8 assay, cell decidua induction and HE staining. The researchers assessed the expression levels of HOXA10, IGFBP1 and avβ3 in either proliferation or secretion of the endometrium. This was accomplished using Western blot assay and real-time fluorescence quantitative PCR.

Results

The results confirmed that at the time of endometrial proliferation, there was a decline in the expression of HOXA10 as a result of tubal effusion influence. This affected its expression in the secretory stage i.e., corresponding function. Further, a significant decline was observed in the levels of HOXA10mRNA of endometrial cells that were subjected to continuous tubal effusion, post decidualization. It was found that during decidualization, if thetubal effusion is removed, it is possible to restore the expression of HOXA10mRNA to a certain extent, though it is not possible to reach the general endometrial level. So, in terms of clinical aspects, the expression of HOxa10 mRNA by the endometrial cells decreases significantly when blocking the hydrosalpinx.

Conclusions

Among hydrosalpinx patients, one of the major mechanisms that damage the endometrium was found to be the abnormal expression of HOXA10 followed by IGFBP1 and avβ3, its downstream genes. This further results in the implantation of the embryo as well. Though it is possible to gradually repair the damage after the removal of hydrosalpinx, the recovery is a time-consuming process.

Optimizing intrauterine insemination and spontaneous conception in women with unilateral hydrosalpinx or tubal pathology: A systematic review and narrative synthesis

BACKGROUND

Tubal surgery's role in infertile women with unilateral tubal pathology (e.g. hydrosalpinx, tubal occlusion) who desire spontaneous or intrauterine insemination (IUI) conception where in-vitro fertilisation is infeasible remains unclear.

OBJECTIVE

To conduct a systematic review on fertility outcomes in women with unilateral tubal pathology desiring to conceive spontaneously or via IUI and to find guidance to support therapeutic tubal procedures to help these women conceive.

SEARCH STRATEGY

Using a protocol registered on PROSPERO (ID CRD42021248720), we searched PubMed, EMBASE, CINAHL, and Cochrane Library from inception until June 2022. Bibliographies were reviewed to identify other relevant articles.

DATA COLLECTION AND ANALYSIS

Two authors independently selected and extracted data. Disagreements were resolved by a third author. Studies presenting fertility outcome data in infertile women with unilateral tubal pathologies desiring spontaneous or IUI conception were included. Methodologic quality was assessed using a modified Newcastle Ottawa Scale for observational studies and the Institute of Health Economics Quality Appraisal Checklist for case series. Primary outcomes collated included cumulative pregnancy rate (CPR) and pregnancy rate per cycle (PR/cycle). Secondary outcomes such as ectopic pregnancy, birth outcomes, and pelvic inflammatory disease were collated. These were stratified by the types of unilateral tubal occlusion (UTO) i.e. hydrosalpinx, proximal tubal occlusion (PTO), or distal tubal occlusion (DTO) MAIN RESULTS: Two studies reported spontaneous or IUI pregnancies after treatment of unilateral hydrosalpinx with one reporting a pregnancy rate of 88% within 5.6 months on average. Thirteen studies compared IUI outcomes between women with UTO vs unexplained infertility and bilateral tubal patency (controls). Almost all were retrospective cohort studies and identified UTO by hysterosalpingography. In general, PTOs had no difference in PR/cycle and CPR compared to controls and significantly higher PR/cycle to DTOs. Women with DTOs had minimal incremental CPR benefit with each additional IUI cycle.

CONCLUSIONS

Therapeutic salpingectomy or tubal occlusion improve IUI or spontaneous conception in women with hydrosalpinx, although more prospective studies are needed. While significant study heterogeneity hampered assessment of fertility outcomes, overall, infertile women with PTOs had similar IUI pregnancy outcomes to those with bilateral tubal patency while DTOs had inferior PR/cycle. This review highlights significant deficiencies in the evidence guiding management for this group of patients.

Effects of Hydrosalpinx on Endometrial Implantation Failures: Evaluating Salpingectomy in Women Undergoing in vitro fertilization

Hydrosalpinx is a disease characterized by the obstruction of the salpinx, with progressive accumulation in the shape of a fluid-filled sac at the distal part of the tuba uterina, and closed to the ovary. Women with hydrosalpinges have lower implantation and pregnancy rates due to a combination of mechanical and chemical factors thought to disrupt the endometrial environment. Evidence suggests that the presence of hydrosalpinx reduces the rate of pregnancy with assisted reproductive technology. The main aim of the present is review to make an overview of the possible effects of hydrosalpinx on in vitro fertilization (IVF). We conducted a literature search on the PubMed, Ovid MEDLINE, and Google Scholar data bases regarding hydrosalpinx and IVF outcomes. Hydrosalpinx probably has a direct toxic effect on sperm motility and on the embryos. In addition, the increasing liquid inside the salpinges could alter the mechanisms of endometrial receptivity. The window of endometrial receptivity is essential in the implantation of blastocysts, and it triggers multiple reactions arising from the endometrium as well as the blastocysts. Hydrosalpinx could influence the expression of homeobox A10 (HOXA10) gene, which plays an essential role in directing embryonic development and implantation. Salpingectomy restores the endometrial expression of HOXA10; therefore, it may be one mechanism by which tubal removal could result in improved implantation rates in IVF. In addition, salpingectomy does not affect the ovarian response, nor reduces the antral follicle count. Further studies are needed to establish the therapeutic value of fluid aspiration under ultrasonographic guidance, during or after oocyte retrieval, in terms of pregnancy rate and ongoing pregnancy.

Application of a Nomogram for Predicting the Risk of Subchorionic Hematoma in Early Pregnancy With In Vitro Fertilization-Embryo Transfer/Frozen Embryo Transfer

BACKGROUND

Subchorionic hematoma (SCH) is common in early pregnancy achieved by in vitro fertilization-embryo transfer/frozen embryo transfer (IVF-ET/FET), and is associated with adverse obstetric outcomes. However, there are no methods known to accurately predict the occurrence of SCH.

OBJECTIVE

To establish a nomogram prediction model for predicting the risk of SCH in early pregnancy with IVF-ET/FET and to analyze pregnancy outcomes of patients with SCH.

METHODS

Patients who underwent IVF-ET/FET treatment and were diagnosed with clinical pregnancy were enrolled in our study. A total of 256 patients with SCH were enrolled in the SCH group, and 526 patients without SCH in the control group. Logistic regression was used to screen risk factors for SCH, and the nomogram was developed according to the regression coefficient of relevant variables. Discrimination, effect, calibration, and the predictive model's clinical usefulness were assessed using the C-index, the area under the receiver operating characteristic standard curve, calibration plot, and decision curve analysis. Internal validation was assessed using bootstrapping validation. The effects of SCH on pregnancy outcomes were analyzed.

RESULTS

A multivariate logistic regression analysis showed that fresh embryo transfer, polycystic ovary syndrome, hydrosalpinx, and thin endometrium were risk factors affecting the occurrence of SCH. Based on the above factors, a predictive model for the risk of SCH was created. The model displayed good discrimination, with a C-index of 0.783 (95% confidence interval: 0.750-0.816), area under the receiver operating characteristic standard curve of 0.783, and good calibration. A high C-index value of 0.765 could still be reached in the interval validation. Decision curve analysis showed that the nomogram was clinically useful when the intervention was decided at the SCH possibility threshold of 4%-87%. For patients with successful deliveries, the occurrence of SCH did not influence the gestational weeks of delivery, mode of delivery, preterm birth, height, and weight of the newborn.

CONCLUSION

We screened the risk factors for SCH in patients who underwent IVF-ET/FET treatment. Successful establishment of a nomogram can effectively predict the occurrence of SCH. Furthermore, the incidence of miscarriage is higher in patients with SCH.

Pinopodes: Recent advancements, current perspectives, and future directions

Successful embryo implantation is a complex and highly regulated process involving precise synchronization between the fetal-derived trophoblast cells and maternal uterine luminal epithelium. Multiple endocrine-driven factors are important for controlling the timely receptivity of the uterus, and this complexity underscores implantation failure as a major cause of recurrent infertility associated with assisted reproductive technologies. One particular cellular structure often hypothesized to promote receptivity is the pinopode or uterodome - a hormonally regulated, large cellular protrusion on the uterine epithelial surface. Recent clinical studies associate pinopodes with favorable fertility outcomes in women, and because they are directly linked to an increase in progesterone levels, the potential utility of these hormone-regulated cell biological structures in predicting or improving implantation in a clinical setting holds promise. In this review, we aim to generate interest in pinopodes from the broader cell biology and endocrinology communities, re-examine methodologies in pinopode research, and identify priorities for future investigation of pinopode structure and function in women's reproductive health.

The ultrastructural effects of surgical treatment of hydrosalpinx on the human endometrium: a light and electron microscopic study

Hydrosalpinx is a disease commonly observed in women and characterized by the obstruction which is in the shape of a fluid-filled sac at the distal part of tuba uterina closed to the ovary. In this study, we aimed to obtain endometrial tissue samples from the hydrosalpinx patients, before and after the surgical treatment and compare these endometrial tissue samples by using light and electron microscope. Endometrial tissue samples were obtained from the 24 women with bilateral hydrosalpinx range 19-46 years before and after the surgical treatment, and normal endometrial tissues were collected from five women without hydrosalpinx and evaluated as a control group. In endometrial samples of hydrosalpinx patients; it was observed that large and unregulated interstitial spaces representing the organellar destruction, membranous whorl structures associated with organelle destruction, thinning in the surface epithelium, decreasing in numbers of microvillus and pinopodes in microvilli cells, increasing in heterochromatin and picnotic changes in the nucleus, expansion, and vacuolization in the endoplasmic reticulum cisternae in the apical cytoplasm and intraepithelial macrophages and lymphocytes were rised in number. Although mild structural changes were observed in endometrial tissues obtained after surgical treatment of hydrosalpinx, surface epithelium, glandular and stromal cell structures were more similar to control endometrial specimens. In conclusion; serious structural changes have occurred in endometrial tissues of hydrosalpinx patients. These structural abnormalities have removed after surgical treatment so it is considered that surgical treatment is effective in patients with hydrosalpinx.

Does the dysregulation of matrix metalloproteinases contribute to recurrent implantation failure?

INTRODUCTION

The progress in in vitro fertilization (IVF) techniques for infertility management has led to the investigation of embryo implantation site proteins such as Matrix metalloproteinases (MMPs), which may have a key role in embryo-endometrium crosstalk and in the molecular mechanisms of the embryo implantation. Areas covered: Numerous studies have generated much information concerning the relation between the different proteins at the site of implantation such as cytokines, growth factors, adhesion molecules and MMPs. However, the exact role of the MMPs in embryo implantation and the impact of their dysregulation in recurrent implantation failure have yet to be characterized. Expert commentary: The proteomic investigation of the MMPs and their molecular pathways may enable scientists and clinicians to correct this dysregulation (via appropriate means of prevention and treatment), better manage embryo transfer during IVF cycles, and thus increase the ongoing pregnancy rate.

Cytokines, growth factors and macromolecules as mediators of implantation in mammalian species

Implantation is one of the most critical steps in mammalian reproduction and implantation failure constitutes a major cause of infertility in both animals and humans. The mechanism of implantation is exclusively under the control of ovarian steroids progesterone and oestrogen whose actions are mediated in a complex phenomenon that involves a number of cytokines and growth factors. According to a plethora of literature on implantation in mammalian species, prominent of these cytokines and growth factor playing crucial roles in implantation include integrin, osteopontin, integrin, insulin-like growth factor and leukaemia inhibitory factor. Others are cluster domain 44, hyaluronan system and many non-adhesive molecules such as glycoprotein mucin 1. In this review, the specific roles played by these molecules are expatiated. Generally, they function as adhesive molecules that facilitate attachment of ligands/proteins on the trophectoderm to their respective receptors on endometrial luminal epithelia or vice versa. Sometimes, they also function as signalling molecules that enhance communication between implanting blastocyst and receptive endometrium. This is of particular importance in embryo culture and embryo transfer where in vitro derived blastocyst unlike the in vivo condition, is not exposed to these substances and hence, their absence may be partly responsible for the low implantation rate observed in the surrogate. Appreciation of the roles played by these cytokines, growth factors and molecules as revealed in this review will spur further research on these topics, facilitate their inclusion in embryo culture media (if positively required) and are considered as vital aspect while developing strategies to improve fertility.

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.

Label-free proteomics uncovers energy metabolism and focal adhesion regulations responsive for endometrium receptivity

The menstrual cycle of the female uterus leads to periodic changes of the endometrium. These changes are important for developing the endometrial receptivity and for achieving competency of embryo implantation. However, the molecular events underlying the endometrial receptivity process remain poorly understood. Here we applied an LC-MS-based label-free quantitative proteomic approach to compare the endometrial tissues in the midsecretory (receptive) phase with the endometrial tissues in the proliferative phase from age-matched woman (n = 6/group). The proteomes of endometrial tissues were extracted using an SDS-based detergent, digested by the filter-aided sample preparation procedures, and subsequently analyzed by nano-LC-MS/MS (Orbitrap XL) with a 4 h gradient. Reliable protein expression profiles were reproducibly obtained from the endometrial tissues in the receptive and proliferative phases. A total of 2138 protein groups were quantified under highly stringent criteria with a false discovery rate of <1% for peptide and protein groups. Among these proteins, 317 proteins had differences in expression that were statistically significant between the receptive and proliferative phases. Direct protein-protein interaction network analyses of these significantly changed proteins showed that the up-regulation of creatine kinase B-type (CKB) in the receptive phase may be related to endometrium receptivity. The interaction network also showed that proteins related to cell-cell adhesion were down-regulated. Moreover, the results from KEGG pathway analyses are consistent with the protein-protein interaction results. The proteins, including alpha-actinin (ACTN), extracellular matrix proteins, integrin alpha-V, and so on, that are involved in the focal adhesion pathway were down-regulated in the receptive phase compared with the proliferative phase, which may facilitate the implantation of the fertilized ovum. Selected proteins were validated by Western blot analysis and indirect immunofluorescence, including the up-regulation of CKB and down-regulation ACTN in the receptive phase. In summary, our proteomic analysis study shows potential for predicting the endometrial remodeling from the proliferative to the receptivity phase in women, and these results also reveal the key biological mechanisms (such as energy metabolism and focal adhesion) underlying human endometrial receptivity.

Role of Mucin 1 and Glycodelin A in recurrent implantation failure

OBJECTIVE

To evaluate and compare the levels of Mucin 1 (MUC-1) and Glycodelin A (GdA) in precisely timed endometrial biopsies and blood samples taken from women with recurrent implantation failure, and women with proven fertility, in a control group.

DESIGN

Molecular studies in human blood and tissue.

SETTING

University hospital.

PATIENT(S)

Women with recurrent implantation failure and women with proven fertility.

INTERVENTION(S)

Primary endometrial cells and blood samples during the implantation "window" (between day 7 and day 9 after the surge in luteinizing hormone).

MAIN OUTCOME MEASURE(S)

Expression of MUC-1 and GdA in the human endometrium and in blood during the implantation window were analyzed by enzyme-linked immunosorbent assay. Additionally, MUC-1 and GdA levels in tissue were analyzed by western blot during the same period.

RESULT(S)

Both blood and tissue measurements of MUC-1 and GdA were significantly lower in women with recurrent implantation failure than in fertile women during the implantation window. In addition, we found a highly significant correlation between blood vs. tissue measurements of both MUC-1 and GdA.

CONCLUSION(S)

The present study reveals that blood and tissue levels of MUC-1 and GdA are much lower in women with RIF, compared with those in fertile women. Receptivity can be evaluated with noninvasive blood sampling, rather than more-invasive endometrium sampling, as the blood and tissue measurements of MUC-1 and GdA are correlated.

Leukemia inhibitory factor: roles in embryo implantation and in nonhormonal contraception

Leukaemia inhibitory factor (LIF) plays an indispensible role in embryo implantation. Aberrant LIF production is linked to implantation failure. LIF regulates multiple processes prior to and during implantation such as uterine transformation into a receptive state, decidualization, blastocyst growth and development, embryo-endometrial interaction, trophoblast invasion, and immune modulation. Due to its critical role, LIF has been a target for a nonhormonal contraception. In this review, we summarize up-to-date information on the role of LIF in implantation and its role in contraception.

Prospective assessment of midsecretory endometrial leukemia inhibitor factor expression versus ανβ3 testing in women with unexplained infertility

OBJECTIVE

To evaluate endometrial leukemia inhibitor factor (LIF) expression as a marker of endometrial receptivity in women with unexplained infertility (UI).

DESIGN

Prospective case-control study.

SETTING

University-associated infertility clinics.

PATIENT(S)

Women with UI for more than 1 year and healthy control women.

INTERVENTION(S)

Endometrial biopsy.

MAIN OUTCOME MEASURE(S)

Time to pregnancy was compared between patients with UI who were evaluated for endometrial LIF protein as well as ανβ3 integrin expression. Endometrium was evaluated using immunohistochemistry (IHC) and messenger RNA by real time reverse transcriptase-polymerase chain reaction (PCR) (quantitative real-time reverse transcriptase-PCR) in samples from women with UI as well as healthy control women.

RESULT(S)

Leukemia inhibitor factor was expressed in epithelial cells in a cyclic fashion in controls, and overall expression in the secretory phase was similar between controls and women with UI, whereas ανβ3 integrin expression was reduced. However, using quantitative real-time PCR, LIF messenger RNA abundance was 4.4-fold lower in women with low levels of ανβ3 integrin expression compared with samples with normal integrins. By immunohistochemistry, ανβ3 integrin expression was always lacking when the histology was out of phase, whereas LIF expression was only negative in a subset of those samples. Reduced endometrial LIF expression was strongly associated with poor reproductive outcomes.

CONCLUSION(S)

Endometrial LIF expression peaks in the midsecretory phase and is reduced in some women with UI. The use of LIF in combination with ανβ3 integrin as biomarkers appears to be superior to integrin testing alone when evaluating endometrial receptivity, primarily because of its earlier pattern of expression during the secretory phase.

NF κB expression increases and CFTR and MUC1 expression decreases in the endometrium of infertile patients with hydrosalpinx: a comparative study

BACKGROUND

Hydrosalpinx are associated with infertility, due to reduced rates of implantation and increased abortion rates. The aims of this study were to investigate the expression of cystic fibrosis transmembrane conductance regulator (CFTR), nuclear factor kappa B (NF KappaB) and mucin-1 (MUC-1), and analyze the correlation between the expression of CFTR and NF KappaB or MUC1, in the endometrium of infertile women with and without hydrosalpinx.

METHODS

Thirty-one infertile women with laparoscopy-confirmed unilateral or bilateral hydrosalpinx and 20 infertile women without hydrosalpinx or pelvic inflammatory disease (control group) were recruited. Endometrial biopsy samples were collected and the expression of CFTR, NF KappaB and MUC1 were analyzed using immunohistochemistry and quantitative real-time PCR.

RESULTS

CFTR, NF KappaB and MUC1 mRNA and protein expression tended to increase in the secretory phase compared to the proliferative phase in both groups; however, these differences were not significantly different. The endometrium of infertile patients with hydrosalpinx had significantly higher NF KappaB mRNA and protein expression, and significantly lower CFTR and MUC1 mRNA and protein expression, compared to control infertile patients. A positive correlation was observed between CFTR and MUC1 mRNA expression (r = 0.65, P < 0.05); a negative correlation was observed between CFTR mRNA and NF KappaB mRNA expression (r = -0.59, P < 0.05).

CONCLUSIONS

Increased NF KappaB expression and decreased CFTR and MUC1 expression in the endometrium of infertile patients with hydrosalpinx reinforce the involvement of a molecular mechanism in the regulation of endometrial receptivity.

Administration of calcitonin promotes blastocyst implantation in mice by up-regulating integrin β3 expression in endometrial epithelial cells

STUDY QUESTION

Does exogenous calcitonin improve the efficiency of implantation in mice by increasing uterine receptivity?

SUMMARY ANSWER

The administration of calcitonin could improve the efficiency of implantation by increasing the expression of several receptivity-related genes in endometrial epithelial cells (EECs).

WHAT IS KNOWN ALREADY

Calcitonin is one of the biomarkers of uterine receptivity, which is transiently produced in the uterine epithelia during the period of implantation both in humans and mouse.

STUDY DESIGN, SIZE, DURATION

Hormone-replaced mice were used for in vivo experiments. To evaluate the effect of calcitonin on uterine receptivity, the expression of endometrial genes was analyzed 36 h after i.p. injection of 0.5 IU calcitonin in a treatment group versus saline in the control. To evaluate the effect of calcitonin on implantation efficiency in vivo, two groups received 0.5 IU or 2 IU calcitonin (i.p.) 24 h before embryo transfer, and a control group received saline (i.p.) (n = 18 mice per group). Implantation sites were counted 7 days after embryo transfer. The RL95-2 human endometrial carcinoma cell line was used to study the mechanisms underlying the effect of calcitonin on gene expression in the endometria. Using an in vitro model of endometrium-trophoblast interaction, established with RL95-2 cells and JAR (human choriocarcinoma cell line) trophoblast, endometrial receptivity was evaluated by comparing attachment and outgrowth of JAR spheroids in control and treatment groups.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Uterine receptivity in ovariectomized mice was induced by injection of estradiol and progesterone. Expression of eight genes in murine endometrium and RL95-2 cells was analyzed by real-time RT-PCR, western blot, immunohistochemical analysis, flow cytometry and enzyme-linked immunosorbent assay. We tested the effects of a protein kinase C inhibitor, matrigel and an antibody against integrin αvβ3 using RL95-2 cells and performed attachment and outgrowth assays using the in vitro model of endometrium-trophoblast interaction. Implantation efficiency was evaluated by counting the implantation sites after embryo transfer.

MAIN RESULTS AND THE ROLE OF CHANCE

Calcitonin up-regulated αvβ3 in RL95 cells, which in turn resulted in increased levels of the leukemia inhibitory factor (LIF) and heparin binding-epidermal growth factor (HB-EGF) mRNA (both P < 0.01 versus control) and protein (both P < 0.05 versus control). The attachment and expansion of JAR spheroids was promoted by pretreatment of EECs with calcitonin (P < 0.05 versus control) together with significantly increased expression of αvβ3, LIF and HB-EGF. Moreover, the injection of calcitonin in the preimplantation phase increased the total number of implantation sites in treatment groups (55 in control versus 78 and 85 in 0.5 and 2 IU groups, respectively). Compared with the control group (3.11 ± 2.14), the average number of implantation sites in the 2 IU calcitonin treatment group increased (4.72 ± 1.87, P = 0.022).

LIMITATIONS, REASONS FOR CAUTION

Experiments were performed in mice and human cell lines but not in primary cultures of human endometrial cells.

WIDER IMPLICATIONS OF THE FINDINGS

The findings presented here have important implications, in that calcitonin administration (currently used for treatment of hypercalcemia or osteoporosis) may have clinical benefits in assisted reproduction programs, by facilitating endometrial receptivity and embryo implantation. However, further studies are required to confirm these findings.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by National Science Foundation of China (No. 81170619). There are no financial or commercial conflicts in this study.

Pinopodes, leukemia inhibitory factor, integrin-β3, and mucin-1 expression in the peri-implantation endometrium of women with unexplained recurrent pregnancy loss

OBJECTIVE

To compare pinopode morphology and coverage, and expression of leukemia inhibitory factor (LIF), integrin-β3, and mucin-1 (MUC1) in the peri-implantation endometrium of women with unexplained recurrent pregnancy loss (RPL) versus normal fertile women.

DESIGN

Exploratory clinical study.

SETTING

University-affiliated assisted reproductive center.

PATIENT(S)

Women undergoing assisted reproduction at centers of reproductive medicine in two university teaching hospitals.

INTERVENTION(S)

Endometrial biopsy samples were obtained from women with RPL (test group, n = 30) and normal fertile women (control group, n = 26) 7 days after the day of luteinizing hormone peak. Pinopode morphology and coverage were assessed by use of scanning electron microscopy. Expression of LIF, integrin β3, and MUC1 were evaluated by immunohistochemical staining.

MAIN OUTCOME MEASURE(S)

Pinopode morphology and coverage, and the expression of LIF, integrin-β3, and MUC1 in both groups.

RESULT(S)

Pinopode morphology and coverage, and the expression of LIF and integrin-β3 showed no statistically significant differences between the two groups. The expression of MUC1 was statistically significantly reduced in the glandular epithelial cells and endometrial lumen of the RPL group compared with controls.

CONCLUSION(S)

The morphology and the coverage of pinopodes and expression of LIF and integrin-β3 did not change, but MUC1 expression was statistically significantly reduced in women with RPL compared with normal women.

Expression and activation of the membrane-cytoskeleton protein ezrin during the normal endometrial cycle

OBJECTIVE

To examine total ezrin expression (ezrin and phospho-ezrin) through the normal endometrial cycle and to correlate ezrin activation and localization with cytologic changes.

DESIGN

Experimental laboratory study.

SETTING

University medical centers.

PATIENT(S)

Reproductive-age women.

INTERVENTION(S)

A total of 36 samples of normal early, mid-, and late proliferative- and secretory-phase endometrium were studied for immunoreactive total ezrin (ir-T-ezrin) and phospho-ezrin (ir-p-ezrin) expression by histology, immunohistochemistry, and Western blotting.

MAIN OUTCOME MEASURE(S)

Total ezrin and phospho-ezrin expressions through the normal endometrial cycle.

RESULT(S)

Throughout the cycle ir-T-ezrin is present in the epithelium. The intensity and localization of both ir-ezrin and ir-p-ezrin vary greatly throughout the cycle. The main findings include the following: lateral localization of ir-ezrin/ir-p-ezrin in association with membrane specializations; dense staining around secretory vacuoles (secretory phase); dense staining of the apical surfaces, including microvilli and pinopodes of epithelial cells, especially during the mid- to late secretory phases; and the presence of ezrin in the glandular secretions. Immunoreactive total ezrin and ir-p-ezrin were not expressed by stromal fibroblasts.

CONCLUSION(S)

Ezrin is a prominent protein in the cycling endometrium. The most striking findings were the gravitation of ir-ezrin/ir-p-ezrin to the periphery of secretory vacuoles, localization on apical surfaces of the luminal epithelium, dense ezrin staining in secretory-phase epithelial cell plumes, and the presence of ir-ezrin/ir-p-ezrin in secretory-phase luminal secretions. These findings may have functional implications, especially for implantation biology.