AlphaVBeta3 Integrin expression within uterine endometrium in unexplained infertility: a prospective cohort study

Decoction of Yougui Wan combined with Wuzi Yanzong Wan ameliorates thin endometrium in a mouse model

BACKGROUND

This study aimed to determine the effect and mechanism of the Decoction of Yougui Wan combined with Wuzi Yanzong Wan (DYWWYW), a traditional Chinese herbal formula, in a mouse model with thin endometrium induced by 95% ethanol.

METHODS

Thin endometrium mice were treated with progynova (0.002 mg) as well as a low and high dose of DYWWYW (0.05 and 0.5 mL DYWWYW, respectively, diluted in 2 mL normal saline). Western blotting and qRT-PCR analyses were performed to determine the protein and mRNA expression levels, respectively, of integrin αγβ3 and leukaemia inhibitor factor (LIF) in uterus tissues. Serum oestradiol and progesterone concentrations were determined via ELISA. The remaining thin endometrium mice were mated with male mice, and the number of embryos implanted in the different groups was calculated.

RESULTS

A high dose of DYWWYW effectively ameliorated the injury of endometrium caused by 95% ethanol. The levels of oestradiol, progesterone, αγβ3 and LIF in thin endometrium mice treated with a high dose of DYWWYW were also significantly elevated. Additionally, a high dose of DYWWYW remarkably increased the number of embryo implantations in mice with thin endometrium.

CONCLUSION

DYWWYW has improvement effects on thin endometrium by elevating the levels of endogenous oestradiol, progesterone, αγβ3, and LIF in a mouse model.

Cyclosporine A improves the binding of mouse embryos to fibronectin

AIM

The binding of integrin αvβ3 with endometrial fibronectin (FN) promotes the migration of preimplantation embryos in mice. We have previously shown that cyclosporine A (CsA) improves the adhesion and invasion of mouse preimplantation embryos. In this study, we evaluated the roles of calcium ions and downstream signaling factors in the binding of integrin αvβ3 to FN.

METHODS

Female Institute of Cancer Research (ICR) mice were superovulated and mated, and two-cell embryos were harvested from the oviducts and cultured to the blastocyst stage The adhesion and stretching growth of hatched embryos in laminin-coated dishes were evaluated, and integrinβ3 expression was determined using qPCR. Blastocytes were cultured with 0 or 1 μM $$ \upmu \mathrm{M} $$ cyclosporine A (CsA) and the attachment of embryonic integrin αvβ3 to FN120 was observed using a fluorescent bead. To further determine the mechanism, the cells were also incubated with calcium ions and protein kinase C and calmodulin antagonists. The binding of integrin αvβ3 to FN120 was examined via confocal laser scanning microscopy.

RESULTS

The adhesion and stretching growth of peri-implantation embryos were greater and integrinβ3 expression was higher in the 1 μM CsA group than in the 0 μM CsA group (p < 0.05). When incubated with calcium ions and protein kinase C and calmodulin antagonists, the ability of peri-implantation embryos to bind to FN decreased; CsA treatment promoted this binding.

CONCLUSION

This study revealed that CsA up - regulates integrinβ3 expression in peri - implantation embryos and promotes binding to FN via calcium ions, and protein kinase C, and calmodulin. These findings provide evidence supporting the beneficial effect of CsA on the peri - implantation embryo adhesion.

Autologous PRP therapy for thin endometrium: A self-controlled case series study across menstrual cycles

OBJECTIVES

Thin endometrium (TE) compromises endometrial receptivity, often leading to implantation failure and lower clinical pregnancy rates. As autologous platelet-rich plasma (PRP) emerges as a potential remedy, the present study focused on its therapeutic effects on TE in infertile women who underwent frozen embryo transfer.

STUDY DESIGN

Patients with TE who underwent frozen embryo transfer treatment in our hospital were included. To diminish individual variability, a self-controlled series approach was used. Two menstrual study cycles were arranged for each participant before the actual embryo transfer cycle; PRP treatment was conducted in the second cycle. Key metrics analyzed included endometrial thickness and the expression of specific endometrial biomarkers including HOXA-10, Ki67, and αvβ3 integrin. Transvaginal ultrasound was employed to measure endometrial thickness on Days 11 and 14, and an endometrial biopsy was conducted on progesterone Day 5 of the first two cycles. Pregnancy outcomes were observed after the embryo transfer cycle.

RESULTS

PRP treatment significantly increased the median endometrial thickness, from 5.8 mm to 6.5 mm (P = 0.0066). Additionally, PRP treatment resulted in a statistically significant increase in the H-score for all endometrial markers. Importantly, during the subsequent embryo transfer cycle with PRP treatment, two patients successfully achieved pregnancies, both culminating in live births.

CONCLUSIONS

These findings emphasize the potential of PRP in improving endometrial conditions, especially for individuals grappling with thin endometrium issues, as underscored by this self-comparison methodology.

Differential expression of tsRNAs and miRNAs in embryo culture medium: potential impact on embryo implantation

PURPOSE

Can small RNA derived from embryos in conditioned embryo culture medium (ECM) influence embryo implantation?

METHODS

We employed small RNA sequencing to investigate the expression profiles of transfer RNA-derived small RNA (tsRNA) and microRNA (miRNA) in ECM from high-quality and low-quality embryos. Quantitative real-time PCR was employed to validate the findings of small RNA sequencing. Additionally, we conducted bioinformatics analysis to predict the potential functions of these small RNAs in embryo implantation. To establish the role of tiRNA-1:35-Leu-TAG-2 in embryonic trophoblast cell adhesion, we utilized co-culture systems involving JAR and Ishikawa cells.

RESULTS

Our analysis revealed upregulation of nine tsRNAs and four miRNAs in ECM derived from high-quality embryos, whereas 37 tsRNAs and 12 miRNAs exhibited upregulation in ECM from low-quality embryos. The bioinformatics analysis of tsRNA, miRNA, and mRNA pathways indicated that their respective target genes may play pivotal roles in both embryo development and endometrial receptivity. Utilizing tiRNA mimics, we demonstrated that the prominently expressed tiRNA-1:35-Leu-TAG-2 in the low-quality ECM group can be internalized by Ishikawa cells. Notably, transfection of tiRNA-1:35-Leu-TAG-2 into Ishikawa cells reduced the attachment rate of JAR spheroids.

CONCLUSION

Our investigation uncovers significant variation in the expression profiles of tsRNAs and miRNAs between ECM derived from high- and low-quality embryos. Intriguingly, the release of tiRNA-1:35-Leu-TAG-2 by low-quality embryos detrimentally affects embryo implantation and endometrial receptivity. These findings provide fresh insights into understanding the molecular foundations of embryo-endometrial communication.

When the Embryo Meets the Endometrium: Identifying the Features Required for Successful Embryo Implantation

Evaluation of the optimal number of embryos, their quality, and the precise timing for transfer are critical determinants in reproductive success, although still remaining one of the main challenges in assisted reproduction technologies (ART). Indeed, the success of in vitro fertilization (IVF) treatments relies on a multitude of events and factors involving both the endometrium and the embryo. Despite concerted efforts on both fronts, the overall success rates of IVF techniques continue to range between 25% and 30%. The role of the endometrium in implantation has been recently recognized, leading to the hypothesis that both the "soil" and the "seed" play a central role in a successful pregnancy. In this respect, identification of the molecular signature of endometrial receptivity together with the selection of the best embryo for transfer become crucial in ART. Currently, efforts have been made to develop accurate, predictive, and personalized tests to identify the window of implantation and the best quality embryo. However, the value of these tests is still debated, as conflicting results are reported in the literature. The purpose of this review is to summarize and critically report the available criteria to optimize the success of embryo transfer and to better understand current limitations and potential areas for improvement.

Effect of Chinese patent medicine Kunling Pill on endometrial receptivity: A clinical trial, network pharmacology, and animal-based study

Although pregnancy success rates are raised with assisted reproductive technology, it still cannot meet clinical demands. Kunling Pill (KLP), a traditional Chinese medicine, is widely used in various gynecological disorders, particularly in improving fertility and pregnancy rates. However, the underlying mechanism of how KLP affects pregnancy outcomes remains unclear. This study aimed to explore the effects and mechanisms of KLP on endometrial receptivity. Firstly, a retrospective trial was conducted to validate the efficacy of KLP on repeated implantation failure (RIF) patients. The result indicated a significant increase in the proportion of live birth in KLP group (30.56%) compared to the control group (16.89%). Secondly, network pharmacology methods predicted the active components and network targets of KLP. Endometrial receptivity is closely associated with the activation of inflammatory factors, predicting the function of KLP on the immune system. The estrogen and apoptotic signaling pathways were also highlighted in the gene ontology enrichment analysis. Thirdly, a decreased endometrial receptivity model was established by controlled ovarian hyperstimulation (COH) in female C57BL/6 mice, divided into the COH and KLP groups. Normal female mice are as control group. In vivo, KLP administration could increase endometrial thickness and the number of endometrial glands and pinopodes. In the endometrium, KLP supplementation upregulated the expressions of estrogen receptor α, progesterone receptor, endothelial nitric oxide synthase, and integrin αVβ3 in the murine uterus and reduced serum levels of estrogen and progesterone. KLP regulated the uterine immune cells and inhibited cell apoptosis in the ovary via Bcl-2/Bax/caspase-3 pathway. In conclusion, KLP administration raised the live birth rate in RIF patients to optimize medication regimens, mainly because KLP ameliorated impaired endometrial receptivity.

Assisted reproductive technology outcomes and gene expression in unexplained infertility patients

Background: Unexplained infertility (UI) can be a frustrating and challenging diagnosis for doctors and couples as it can be difficult to understand why they are unable to conceive despite increasing diagnostic tools. Assisted reproductive technology (ART) procedures have been successfully applied to many couples aiming to overcome UI. However, they can be not only expensive but also require multiple cycles to achieve a successful pregnancy. The endometrium and the follicular fluid have been investigated as target tissues not only to determine the cause of UI but also to increase conception rates. Results: In this study, we analyzed the outcomes of ART in 223 UI couples and gene expression associated with DNA modification, cell death, immune response and senescence (TET1, TET2, BCL2, BAK1, HMGA2, IL-6, IL-8) in infertile women's endometrium and follicular fluid. We found significant differences in women who successfully got pregnant compared to women unable to conceive depending on age, duration of infertility, number of retrieved oocytes, zygotes, transferred embryos. Further, the expression of genes BAK1 (pro-apoptotic), TET2 (associated with epigenetic DNA modification) and IL-6 (associated with immune responses) were significantly higher in the endometrium of women who successfully got pregnant. Conclusion: Younger parental age couples showed higher ART success rates, shorter duration of infertility, higher number of retrieved oocytes, zygotes and transferred embryos. The gene expression analysis revealed significant changes in the endometrium depending on genes associated with cell death and immune response which were upregulated in females with diagnosed unexplained infertility.

Could maternal serum MFG-E8 level predict adverse first trimester pregnancy outcome? A preliminary study

BACKGROUND

Milk fat globule-epidermal growth factor 8 (MFG-E8) is expressed in the endometrial epithelium and its expression increases during the implantation process. Due to this knowledge, we aimed to investigate the maternal serum MFG-E8 levels on both healthy pregnant women in the first trimester and pregnant women complicated with missed abortion and threatened abortion in the first trimester.

METHODS

This prospective, cross-sectional study was conducted in a tertiary referral hospital, department of obstetrics between July 2020 and February 2021 after ethical committee approval. The study population was consisted of 30 healthy pregnant women (HP) in the first trimester, 30 pregnant women suffering from threatened abortion (TA) in the first trimester and 30 pregnant women suffering from missed abortion (MA) in the first trimester. Maternal serum MFG-E8 levels were analyzed with enzyme linked immunosorbent assay. Delivery and neonatal outcomes of the study population was evaluated. The continuous variables were compared among three groups with variance analysis with post hoc tests. The categorical variables were compared with chi-square and Fisher's exact tests where applicable.

RESULTS

The mean age of the study population was 29.36 ± 5.31 years. There was no significant difference among three groups for parameters of age, body mass index, parity number, and gestational week. Despite being within normal ranges, the mean neutrophil and international normalized ratio values of the three groups showed statistically significant difference (p < 0.05). The mean maternal serum MFG-E8 levels of MA, TA, and HP groups were 270 ± 152.3, 414.7 ± 236.7, and 474 ± 222.5 ng/mL, respectively (p = 0.001). It was found that mean of MFG-E8 of the MA group was statistically significantly lower than those of the other two groups (p < 0.05).

DISCUSSION

Although maternal serum MFG-E8 level seems to be a parameter that differ between live and nonlive pregnancies, studies with large number of cases are needed to discuss our results and to determine a cut-off value for prediction.

Integrins and ligands, are correlated at pig placental interface during pregnancy?

In the present work, we emphasize the studies about integrins and their receptors in pig placental interface at different times of gestation. Uterine placental interface (n=24) of 17-, 30-, 60- and 70-days gestation (dg) and non-pregnant uterus (n=4) of crossbred sows were used. The presence of αvβ3 and α5β1 integrins, and their ligands fibronectin (FN), and osteopontin (OPN) were detected by immunohistochemistry, and the immunolabelled area percentage (IAP) and the optical density (OD) were determined. The integrins and its ligands analyzed have presented peaks of expression in early and mid-gestation, both in IAP and the OD area decreasing at 70 dg. These temporal changes showed us that the molecules studied in this work participate in embryo/feto-maternal attachment, variably. Besides, we found a significant correlation both in the intensity and in the extension of immunostaining for trophoblastic FN and endometrial αvβ3, and trophoblastic OPN and endometrial α5β1, throughout the entire pig pregnancy. At late gestation, take place a notable placental remodelation with subsequent removal or renewal of folds at the uterine-placental interface that results in the loss of focal adhesions. The decrease of the expression of some integrins and their ligands in late gestation, particularly at 70 dg, would demonstrate that there would be other adhesion molecules and other ligands that could be participating in the establishment of the maternal-fetal interface.

Evolutionary divergence of embryo implantation in primates

Implantation of the conceptus into the uterus is absolutely essential for successful embryo development. In humans, our understanding of this process has remained rudimentary owing to the inaccessibility of early implantation stages. Non-human primates recapitulate many aspects of human embryo development and provide crucial insights into trophoblast development, uterine receptivity and embryo invasion. Moreover, primate species exhibit a variety of implantation strategies and differ in embryo invasion depths. This review examines conservation and divergence of the key processes required for embryo implantation in different primates and in comparison with the canonical rodent model. We discuss trophectoderm compartmentalization, endometrial remodelling and embryo adhesion and invasion. Finally, we propose that studying the mechanism controlling invasion depth between different primate species may provide new insights and treatment strategies for placentation disorders in humans. This article is part of the theme issue 'Extraembryonic tissues: exploring concepts, definitions and functions across the animal kingdom'.

High-Throughput In Vitro Screening Identified Nemadipine as a Novel Suppressor of Embryo Implantation

Current contraceptive methods interfere with folliculogenesis, fertilization, and embryo implantation by physical or hormonal approaches. Although hormonal contraceptive pills are effective in regulating egg formation, they are less effective in preventing embryo implantation. To explore the use of non-hormonal compounds that suppress embryo implantation, we established a high-throughput spheroid-endometrial epithelial cell co-culture assay to screen the Library of Pharmacologically Active Compounds (LOPAC) for compounds that affect trophoblastic spheroid (blastocyst surrogate) attachment onto endometrial epithelial Ishikawa cells. We identified 174 out of 1280 LOPAC that significantly suppressed BeWo spheroid attachment onto endometrial Ishikawa cells. Among the top 20 compounds, we found the one with the lowest cytotoxicity in Ishikawa cells, P11B5, which was later identified as Nemadipine-A. Nemadipine-A at 10 µM also suppressed BeWo spheroid attachment onto endometrial epithelial RL95-2 cells and primary human endometrial epithelial cells (hEECs) isolated from LH +7/8-day endometrial biopsies. Mice at 1.5 days post coitum (dpc) treated with a transcervical injection of 100 µg/kg Nemadipine-A or 500 µg/kg PRI-724 (control, Wnt-inhibitor), but not 10 µg/kg Nemadipine-A, suppressed embryo implantation compared with controls. The transcript expressions of endometrial receptivity markers, integrin αV (ITGAV) and mucin 1 (MUC1), but not β-catenin (CTNNB1), were significantly decreased at 2.5 dpc in the uterus of treated mice compared with controls. The reduction of embryo implantation by Nemadipine-A was likely mediated through suppressing endometrial receptivity molecules ITGAV and MUC1. Nemadipine-A is a potential novel non-hormonal compound for contraception.

New Insights into the Activities of D-Chiro-Inositol: A Narrative Review

D-chiro-inositol (DCI) is a natural compound detectable in cell membranes, which is highly conserved as a biological signaling molecule. In mammals, its function is primarily characterized in the intracellular transduction cascade of insulin. In particular, insulin signal promotes the release of pivotal DCI-containing molecules. In fact, impaired release of DCI is a common feature of insulin-resistant tissues, and insulin-sensitizing pharmaceuticals induce higher concentrations of free DCI. Moreover, it also plays important roles in several other processes. DCI is involved in the regulation of steroidogenesis, due to its regulatory effects on steroidogenic enzymes, including 17α-hydroxylase, 3β-hydroxysteroid dehydrogenase, and aromatase. Such regulation of various enzymes indicates a mechanism by which the body regulates different processes via a single molecule, depending on its concentration. DCI also reduces the expression of integrin β3, which is an adhesion molecule involved in embryo implantation and cellular phenomena such as survival, stemness, and invasiveness. In addition, DCI seems to have important anti-inflammatory activities, like its 3-O-methyl-ether, called pinitol. In vitro evidence demonstrates that treatment with both compounds induces a reduction in pro-inflammatory factors—such as Nf-κB—and cytokines—such as TNF-α. DCI then plays important roles in several fundamental processes in physiology. Therefore, research on such molecule is of primary importance.

A 3D endometrial organotypic model simulating the acute inflammatory decidualisation initiation phase with epithelial induction of the key endometrial receptivity marker, integrin αVβ3

STUDY QUESTION

Is it possible to develop a simplified physiological in vitro system representing the key cell-types associated with a receptive endometrial phenotype?

SUMMARY ANSWER

We present a new concept to investigate endometrial receptivity, with a 3D organotypic co-culture model to simulate an early and transient acute autoinflammatory decidual status that resolves in the induction of a receptive endometrial phenotype.

WHAT IS KNOWN ALREADY

Embryo implantation is dependent on a receptive uterine environment. Ovarian steroids drive post-ovulation structural and functional changes in the endometrium, which becomes transiently receptive for an implanting conceptus, termed the ‘window of implantation’, and dysregulation of endometrial receptivity is implicated in a range of reproductive, obstetric, and gynaecological disorders and malignancies. The interactions that take place within the uterine microenvironment during this time are not fully understood, and human studies are constrained by a lack of access to uterine tissue from specific time-points during the menstrual cycle. Physiologically relevant in vitro model systems are therefore fundamental for conducting investigations to better understand the cellular and molecular mechanisms controlling endometrial receptivity.

STUDY DESIGN, SIZE, DURATION

We conducted an in vitro cell culture study using human cell lines and primary human cells isolated from endometrial biopsy tissue. The biopsy tissue samples were obtained from three women attending gynaecological outpatient departments in NHS Lothian. The work was carried out between December 2016 and April 2019, at the MRC Centre for Reproductive Health, Queen’s Medical Research Institute, University of Edinburgh.

PARTICIPANTS/MATERIALS, SETTING, METHODS

An endometrial stromal cell (ESC) line, and endometrial epithelial cells (EECs) isolated from endometrial biopsy tissue and expanded in vitro by conditional reprogramming, were used throughout the study. Immunocytochemical and flow cytometric analyses were used to confirm epithelial phenotype following conditional reprogramming of EECs. To construct an endometrial organotypic co-culture model, ESCs were embedded within a 3D growth factor-reduced Matrigel structure, with a single layer of conditionally reprogrammed EECs seeded on top. Cells were stimulated with increasing doses of medroxyprogesterone acetate, cAMP and oestradiol, in order to induce ESC decidual transformation and endometrial receptivity. Decidual response and the induction of a receptive epithelial phenotype were assessed by immunocytochemical detection and quantitative in-cell western analyses, respectively.

MAIN RESULTS AND THE ROLE OF CHANCE

A transient up-regulation of the interleukin-33 receptor protein, ST2L, was observed in ESCs, indicating a transient autoinflammatory decidual response to the hormonal stimulation, known to induce receptivity gene expression in the overlying epithelium. Hormonal stimulation increased the EEC protein levels of the key marker of endometrial receptivity, integrin αVβ3 (n = 8; *P < 0.05; ***P < 0.0001). To our knowledge, this is the first demonstration of a dedicated endometrial organotypic model, which has been developed to investigate endometrial receptivity, via the recapitulation of an early decidual transitory acute autoinflammatory phase and induction of an epithelial phenotypic change, to represent a receptive endometrial status.

LIMITATIONS, REASONS FOR CAUTION

This simplified in vitro ESC-EEC co-culture system may be only partly representative of more complex in vivo conditions.

WIDER IMPLICATIONS OF THE FINDINGS

The 3D endometrial organotypic model presented here may offer a valuable tool for investigating a range of reproductive, obstetric, and gynaecological disorders, to improve outcomes for assisted reproductive technologies, and for the development of advances in contraceptive methods.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported in part by a Medical Research Council Centre Grant (project reference MR/N022556/1). R.F. was the recipient of a Moray Endowment award and a Barbour Watson Trust award. C.-J.L. is a Royal Society of Edinburgh Personal Research Fellow, funded by the Scottish Government. The authors have no conflicts of interest to declare.

Role of prolidase activity and oxidative stress biomarkers in unexplained infertility

OBJECTIVE

Our aim was to explore the significance of serum prolidase enzyme activity and oxidative stress in women with unexplained infertility (UEI).

METHODS

In this case-control study (n = 160; 86 cases; 74 controls) prolidase enzyme activity and total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), and vitamin E were measured in plasma using enzyme-linked immunosorbent assays.

RESULTS

Prolidase enzyme activity and TAS levels were particularly higher in the patient group (P = 0.013, P = 0.001, respectively). Decreased OSI levels were detected in the patient group (P = 0.001). There was a positive relationship of prolidase with vitamin E in both patient and control groups (r = 0.892, P = 0.001, and r = 0.659, P = 0.001, respectively). A positive, but weak, relationship was identified between prolidase activity and TOS levels and also between vitamin E and TOS levels in the UEI group (r = 0.265, P = 0.049, and r = 0.288, P = 0.014, respectively). No association was found between prolidase and TOS levels or between vitamin E and TOS levels in the control group (r = 0.0097, P = 0.527, and r = 0.085, P = 0.610, respectively).

CONCLUSION

Our results showed an association between serum prolidase activity and oxidative stress in UEI patients. Further studies including greater groups are required to show the role of reactive oxygen species in UEI.

Extracellular superoxide produced by Enterococcus faecalis reduces endometrial receptivity via inflammatory injury

PROBLEM

Chronic endometritis (CE) can cause infertility. Enterococcus faecalis is an opportunistic pathogen that is often found in the endometrium of CE patients. However, the mechanisms by which E. faecalis affects endometrial health are still unclear. In this study, we investigated the mechanism how extracellular superoxide produced by E. faecalis affected the endometrial receptivity.

METHOD OF STUDY

Superoxide production was blocked by deleting menB gene in E. faecalis OG1RF. Endometrial epithelial cells were infected by superoxide-producing E. faecalis OG1RF and superoxide-deficient strain WY84. Inflammatory cytokines, apoptosis, and biomarkers for the endometrial receptivity were analyzed.

RESULTS

Infection of endometrial epithelial cells with superoxide-producing E. faecalis OG1RF induced expression of inflammatory cytokines, promoted apoptosis, and down-regulated expression of receptivity biomarkers compared to uninfected control. In contrast, superoxide-deficient E. faecalis WY84 had little effect on inflammatory cytokine production, apoptosis, and endometrial receptivity biomarkers.

CONCLUSIONS

Extracellular superoxide produced by E. faecalis is an important virulence factor for E. faecalis-induced endometritis leading to reduced receptivity of endometrial epithelial cells.

Electroacupuncture Improves Pregnancy Outcomes in Rats with Thin Endometrium by Promoting the Expression of Pinopode-Related Molecules

A thin endometrium affects the success of assisted reproduction due to low endometrial receptivity. Acupuncture improves endometrial receptivity and promotes the formation of pinopodes, the ultrastructure marker implantation window. However, the specific underlying mechanisms remain unclear. In this study, the efficacy of acupuncture treatment and its underlying mechanism were investigated by analyzing pregnancy rate, pinopode formation, and related molecular markers in thin endometrium model rats. Absolute ethanol (95%) was injected into the uteruses of female Sprague-Dawley rats to construct a thin endometrium model. In this model, acupuncture stimulation at EX-CA1, SP6, and CV4 ameliorated the pregnancy rate. Significantly increased embryo implantation, endometrial thickness, numbers of glands, and blood vessels were observed in the electroacupuncture (EA) group compared to the model group. The number of pinopodes in the EA group was abundant, with a shape similar to that of the control group. Additionally, significantly higher expression levels of pinopode-related markers, including integrin αvβ3, homeobox A10 (HOXA10), heparin-binding EGF-like growth factor (HBEGF), estrogen receptor alpha (ERα), and progesterone receptor (PR), were observed in the EA group than those in the model group. In conclusion, EA had a positive effect on the endometrial receptivity of thin endometrium model rats by improving pinopode formation through multiple molecular targets.

Binding of microRNA-135a (miR-135a) to homeobox protein A10 (HOXA10) mRNA in a high-progesterone environment modulates the embryonic implantation factors beta3-integrin (ITGβ3) and empty spiracles homeobox-2 (EMX2)

Background

Patients with elevated circulating progesterone concentrations on the day of the human chorionic gonadotropin (hCG) trigger had relatively low implantation rates during assisted reproductive treatments. In this study, we assess the hypothesis that different concentrations of progesterone regulate the expression of homeobox protein A10 (HOXA10) and its downstream genes through miRNA-135a.

Methods

MicroRNA-135a (miR-135a), HOXA10, beta3-integrin (ITGβ3), and empty spiracles homeobox-2 (EMX2) expression levels in endometrial tissues from patients with elevated progesterone were measured. To determine the threshold of progesterone level which can impair implantation, Ishikawa cells were used to determine the expression of the aforementioned 4 genes after exposure to 5 graded concentrations of progesterone. The dual-luciferase reporter assay was used to verify whether miR-135a regulated the expression of HOXA10. Furthermore, the effects of HOXA10 on the expression of key endometrial receptivity genes ITGβ3 and EMX2 were confirmed.

Results

High progesterone levels promoted miR-135a expression in vivo, and miR-135a bound to the 3'-untranslated region (3'-UTR) of HOXA10 mRNA to inhibit HOXA10 expression. Reduction of HOXA10 promoted EMX2 expression and inhibited ITG-3 production. Progesterone promoted the expression of HOXA10 in vitro at low concentrations. However, when the concentration was greater than 10⁻⁷ ng/mL, progesterone inhibited HOXA10 by promoting miR-135a expression, thereby altering the expression of related genes and affecting endometrial receptivity.

Conclusions

In vitro, the trend in miR-135a expression (which first decreased and then increased) was in direct contrast to that of HOXA10 expression (which first increased and then decreased) as progesterone levels increased. The key factors regulating endometrial receptivity included ITGβ3 and EMX2, which were confirmed to be regulated by HOXA10. High progesterone levels affected miR-135a expression, and miR-135a inhibited HOXA10 expression, thereby affecting endometrial receptivity.

Assessment of endometrial receptivity during implantation window in women with unexplained infertility

This study aimed to assess the endometrial receptivity during implantation window in women with unexplained infertility. A prospective study recruited 168 women with unexplained infertility and 169 fertile women. Ultrasonic parameters and biomarkers in the uterine fluid were detected. The endometrial vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were significantly higher in fertile women as compared with unexplained infertile women, and the integrin αvβ3, vascular endothelial growth factor (VEGF), tumor necrosis factor alpha (TNF-α), and leukemia inhibitory factor (LIF) levels in uterine fluid were significantly higher in fertile women. The biochemical pregnancy rate, clinical pregnancy rate, and ongoing pregnancy rate in fertile women were 20.12%, 18.34%, and 17.75%, respectively, which were significantly higher compared with unexplained infertile women (7.14%, 5.36%, and 4.17%, respectively). Endometrial thickness (ET), endometrial volume (EV), VI, FI, and VFI measured by ultrasound, and the integrin αvβ3, VEGF, TNF-α, and LIF levels in uterine fluid were all significantly higher in pregnant women as compared with nonpregnant women. The best parameters of ultrasonic indicators for predicting endometrial receptivity in women with unexplained infertility were FI(AUC = 0.894, sensitivity 93.8%, and specificity 83.1%). Integrin αvβ3 had the best predictive value for endometrial receptivity among biomarkers in the uterine fluid (AUC = 0.921, sensitivity 96.7%, and specificity 89.5%). Women with unexplained infertility present declined endometrial receptivity. Endometrial ultrasonic parameters detected by three-dimensional power Doppler and biomarkers in the uterine fluid may be effective indicators to predict endometrial receptivity.

Chlorpyrifos effects on integrin alpha v and beta 3 in implantation window phase

Chlorpyrifos (CPF), as a worldwide pesticide, can effect on the integrins αv and β3 which play a main role in the implantation window. Therefore, the aim of this study was to consider CPF effects on integrin alpha v and beta 3 in implantation window phase. Thirty female NMRI mice were separated into groups of CPF, sham, and control. After 6 weeks, each group was mated, and on the 5th day of gestation, all mice were euthanized. Estradiol and progesterone levels were detected by the enzyme-linked immunosorbent assay (ELISA) test; two subunits of integrins (αv and β3) genes and proteins of endometrium were analyzed by real-time polymerase chain reaction (RT-PCR) and immunohistochemistry method, respectively. Fibrosis of the liver which evaluated by Masson's trichrome stain was increased in the CPF group compared with the others. But estradiol and progesterone levels were significantly decreased in CPF groups. Based on the findings, the proportion of genes' expressions of integrin subunits declined by the effect of CPF, while there was not any notable consequence on mice in the sham group. Alpha v and beta 3 integrin proteins expressed in all groups, but the concentration of these proteins in CPF groups was lower than in other groups. This study has shown that the decline of estradiol and progesterone downregulates the expression of αv and β3 integrins which were influenced by CPF exposure. Changing these patterns of proteins could have numerous influences on unsuccessful implantation. Therefore, this experimental study recommends that inclusive consideration of the effects of insecticides may be crucial to women's unrecognized cause of infertility.

Fecundity disorders in older women: declines in follicular development and endometrial receptivity

Background

Little research is available on follicular development and endometrial receptivity in older women. This study aimed to assess follicular development and endometrial receptivity, and to evaluate ultrasonic parameters in predicting endometrial receptivity during the implantation window in older women.

Methods

For this prospective case-control study, 224 older women and 215 young women were recruited. The follicular development and endometrial thickness were monitored by transvaginal ultrasound. During the implantation window, the pulsatility index (PI) and resistance index (RI) of the uterine arteries and subendometrial region, endometrial volume, vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated between the two groups. The ultrasonic parameters were used to assess endometrial receptivity in older women.

Results

The serum anti-Mullerian hormone (AMH) concentration and antral follicle count (AFC) were significantly lower in older women than in young women. The average diameter of the dominant follicle on days 14, 16, and 18 of the menstrual cycle were significantly smaller, and the subendometrial region RI on days 12, 14, 16, and 18 of the menstrual cycle were significantly higher in older women than in young women. The normal ovulation rate was significantly lower in older women than in young women. The subendometrial region RI was significantly higher, and the endometrial VI, FI, and VFI were significantly lower in older women compared with young women. The biochemical pregnancy rate, clinical pregnancy rate and ongoing pregnancy rate of older women were significantly lower than in young women. The best ultrasonic parameter for predicting endometrial receptivity during the implantation window in older women was VI (AUC =0.889, sensitivity 92.6% and specificity 85.4%).

Conclusions

Older women present decreased serum AMH concentrations and AFC, defined as indicators of ovarian reserve function. Older women are characterized by decreased follicular development and endometrial receptivity, which may lead to fecundity disorders.

Influence of Follicular Fluid and Seminal Plasma on The Expression of Endometrial Receptivity Genes in Endometrial Cells

Objective

Endometrial receptivity plays a key role in pregnancy success in assisted reproduction cycles. Recent evidence suggests that seminal plasma (SP) and follicular fluid (FF) influence the uterine endometrium to improve implantation of the embryo and the establishment of pregnancy. In this study, we attempt to assess the influence of FF and SP on the expression levels of main endometrial receptivity genes (HOXA10, HOXA11, ITGAV, ITGB3 and LIF) in endometrial stromal cells.

Materials and Methods

In this experimental study, SP and FF were collected from 15 healthy fertile men and 15 healthy fertile women, respectively. Tissue specimens of the endometrium were obtained from 12 women undergoing hysterectomy for benign conditions. After endometrial stromal cell isolation and culture, dose- and time-dependent cytotoxic effects of pooled FF and SP on 3D-cultured endometrial cells were evaluated. A second independent set of 12 endometrium samples was treated under determined optimum conditions and evaluated for gene expression analysis using quantitative real-time polymerase chain reaction (qRT-PCR).

Results

The results of this study indicated that exposure of endometrial stromal cells to FF resulted in the elevated expression of HOXA10 (fold change=2.6, P=0.02), HOXA11 (fold change=3.3, P=0.002), LIF (fold change=4.6, P=0.0003), ITGB3 (fold change=3.5, P=0.012), and ITGAV (fold change=2.8, P=0.001) compared to untreated cells. In addition, we found that SP-treated endometrial cells showed increased mRNA levels of only the LIF gene (fold change=2.5, P=0.008) compared to untreated cells.

Conclusion

Human SP and FF may modulate the endometrial receptivity and improve the implantation rate in assisted reproduction cycles through the up-regulation of endometrial receptivity genes.

Promoting Roles of Embryonic Signals in Embryo Implantation and Placentation in Cooperation with Endocrine and Immune Systems

Embryo implantation in the uterus is an essential process for successful pregnancy in mammals. In general, the endocrine system induces sufficient embryo receptivity in the endometrium, where adhesion-promoting molecules increase and adhesion-inhibitory molecules decrease. Although the precise mechanisms remain unknown, it is widely accepted that maternal–embryo communications, including embryonic signals, improve the receptive ability of the sex steroid hormone-primed endometrium. The embryo may utilize repulsive forces produced by an Eph–ephrin system for its timely attachment to and subsequent invasion through the endometrial epithelial layer. Importantly, the embryonic signals are considered to act on maternal immune cells to induce immune tolerance. They also elicit local inflammation that promotes endometrial differentiation and maternal tissue remodeling during embryo implantation and placentation. Additional clarification of the immune control mechanisms by embryonic signals, such as human chorionic gonadotropin, pre-implantation factor, zona pellucida degradation products, and laeverin, will aid in the further development of immunotherapy to minimize implantation failure in the future.

A Study on the Presence of Osteopontin and α3β1 Integrin in the Endometrium of Diabetic Rats at the Time of Embryo Implantation

BACKGROUND

Embryo implantation is a critical and multifactorial phenomenon which can be affected by any alteration in molecular micro construction of endometrium. The aim of the current study was to evaluate the effects of diabetes on osteopontin (OPN) and α3β1 integrin proteins level at the time of endometrial receptivity.

METHODS

Twenty-eight female rats were divided into control, diabetic, pioglitazone-treated and metformin-treated groups. Western blot was performed to determine the OPN and α3β1 integrin proteins in rats' endometrium at the time of implantation. Data were analyzed by analysis of variance (ANOVA) and p<0.05 was considered statistically significant.

RESULTS

OPN increased significantly in the diabetic group in comparison with control (p<0.001), metformin-treated (p=0.008) and pioglitazone-treated groups (p< 0.001). Furthermore, α3β1 integrin protein level in diabetic group had a significant difference in comparison with that of the control (p<0.001), metformin-treated (p= 0.026) and pioglitazone-treated groups (p<0.001).

CONCLUSION

OPN and α3β1 integrin proteins are involved in embryo implantation and their changes in diabetic condition can affect fertility. Treatment with pioglitazone and metformin improved the level of OPN and α3β1 integrin proteins while pioglitazone was more effective.

Spatial organization of endometrial gene expression at the onset of embryo attachment in pigs

BACKGROUND

During the preimplantation phase in the pig, the conceptus trophoblast elongates into a filamentous form and secretes estrogens, interleukin 1 beta 2, interferons, and other signaling molecules before attaching to the uterine epithelium. The processes in the uterine endometrium in response to conceptus signaling are complex. Thus, the objective of this study was to characterize transcriptome changes in porcine endometrium during the time of conceptus attachment considering the specific localization in different endometrial cell types.

RESULTS

Low-input RNA-sequencing was conducted for the main endometrial compartments, luminal epithelium (LE), glandular epithelium (GE), blood vessels (BV), and stroma. Samples were isolated from endometria collected on Day 14 of pregnancy and the estrous cycle (each group n = 4) by laser capture microdissection. The expression of 12,000, 11,903, 11,094, and 11,933 genes was detectable in LE, GE, BV, and stroma, respectively. Differential expression analysis was performed between the pregnant and cyclic group for each cell type as well as for a corresponding dataset for complete endometrium tissue samples. The highest number of differentially expressed genes (DEGs) was found for LE (1410) compared to GE, BV, and stroma (800, 1216, and 384). For the complete tissue, 3262 DEGs were obtained. The DEGs were assigned to Gene Ontology (GO) terms to find overrepresented functional categories and pathways specific for the individual endometrial compartments. GO classification revealed that DEGs in LE were involved in 'biosynthetic processes', 'related to ion transport', and 'apoptotic processes', whereas 'cell migration', 'cell growth', 'signaling', and 'metabolic/biosynthetic processes' categories were enriched for GE. For blood vessels, categories such as 'focal adhesion', 'actin cytoskeleton', 'cell junction', 'cell differentiation and development' were found as overrepresented, while for stromal samples, most DEGs were assigned to 'extracellular matrix', 'gap junction', and 'ER to Golgi vesicles'.

CONCLUSIONS

The localization of differential gene expression to different endometrial cell types provided a significantly improved view on the regulation of biological processes involved in conceptus implantation, such as the control of uterine fluid secretion, trophoblast attachment, growth regulation by Wnt signaling and other signaling pathways, as well as the modulation of the maternal immune system.

Diabetes mellitus increased integrins gene expression in rat endometrium at the time of embryo implantation

Background

Diabetes mellitus deeply changes the genes expression of integrin (Itg) subunits in several cells and tissues such as monocytes, arterial endothelium, kidney glomerular cells, retina. Furthermore, hyperglycemia could impress and reduce the rate of successful assisted as well as non-assisted pregnancy. Endometrium undergoes thorough changes in normal menstrual cycle and the question is: What happens in the endometrium under diabetic condition?

Objective

The aim of the current study was to investigate the endometrial gene expression of α3, α4, αv, Itg β1 and β3 subunits in diabetic rat models at the time of embryo implantation.

Materials and Methods

Twenty-eight rats were randomly divided into 4 groups: control group, diabetic group, pioglitazone-treated group, and metformin-treated group. Real-time PCR was performed to determine changes in the expression of Itg α3, α4, αv, β1, and β3 genes in rat's endometrium.

Results

The expression of all Itg subunits increased significantly in diabetic rats' endometrium compared with control group. Treatment with pioglitazone significantly reduced the level of Itg subunits gene expression compared with diabetic rats. While metformin had a different effect on α3 and α4 and elevated these two subunits gene expression.

Conclusion

Diabetes mellitus significantly increased the expression of studied Itg subunits, therefore untreated diabetes could be potentially assumed as one of the preliminary elements in embryo implantation failure.

Expression of adhesion and extracellular matrix genes in human blastocysts upon attachment in a 2D co-culture system

STUDY QUESTION

What are the changes in human embryos, in terms of morphology and gene expression, upon attachment to endometrial epithelial cells?

SUMMARY ANSWER

Apposition and adhesion of human blastocysts to endometrial epithelial cells are predominantly initiated at the embryonic pole and these steps are associated with changes in expression of adhesion and extracellular matrix (ECM) genes in the embryo.

WHAT IS KNOWN ALREADY

Both human and murine embryos have been co-cultured with Ishikawa cells, although embryonic gene expression associated with attachment has not yet been investigated in an in vitro implantation model.

STUDY DESIGN, SIZE, DURATION

Vitrified human blastocysts were warmed and co-cultured for up to 48 h with Ishikawa cells, a model cell line for receptive endometrial epithelium.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Six days post-fertilization (6dpf) human embryos were co-cultured with Ishikawa cells for 12, 24 (7dpf) or 48 h (8dpf) and attachment rate and morphological development investigated. Expression of 84 adhesion and ECM genes was analysed by quantitative PCR. Immunofluorescence microscopy was used to assess the expression of three informative genes at the protein level. Data are reported on 145 human embryos. Mann-Whitney U was used for statistical analysis between two groups, with P < 0.05 considered significant.

MAIN RESULTS AND THE ROLE OF CHANCE

The majority of embryos attached to Ishikawa cells at the level of the polar trophectoderm; 41% of co-cultured embryos were loosely attached after 12 h and 86% firmly attached after 24 h. Outgrowth of hCG-positive embryonic cells at 8dpf indicated differentiation of trophectoderm into invasive syncytiotrophoblast. Gene expression analysis was performed on loosely attached and unattached embryos co-cultured with Ishikawa cells for 12 h. In contrast to unattached embryos, loosely attached embryos expressed THBS1, TNC, COL12A1, CTNND2, ITGA3, ITGAV and LAMA3 and had significantly higher CD44 and TIMP1 transcript levels (P = 0.014 and P = 0.029, respectively). LAMA3, THBS1 and TNC expressions were validated at the protein level in firmly attached 7dpf embryos. Thrombospondin 1 (THBS1) resided in the cytoplasm of embryonic cells whereas laminin subunit alpha 3 (LAMA3) and tenascin C (TNC) were expressed on the cell surface of trophectoderm cells. Incubation with a neutralizing TNC antibody did not affect the rate of embryo attachment or hCG secretion.

LARGE SCALE DATA

None.

LIMITATIONS, REASONS FOR CAUTION

This in vitro study made use of an endometrial adenocarcinoma cell line to mimic receptive luminal epithelium. Also, the number of embryos was limited. Contamination of recovered embryos with Ishikawa cells was unlikely based on their differential gene expression profiles.

WIDER IMPLICATIONS OF THE FINDINGS

Taken together, we provide a 'proof of concept' that initiation of the implantation process coincides with the induction of specific embryonic genes. Genome-wide expression profiling of a larger sample set may provide insights into the molecular embryonic pathways underlying successful or failed implantation.

STUDY FUNDING AND COMPETING INTEREST(S)

A.A. was supported by a grant from the 'Instituut voor Innovatie door Wetenschap en Technologie' (IWT, 121716, Flanders, Belgium). This work was supported by the 'Wetenschappelijk Fonds Willy Gepts' (WFWG G142 and G170, Universitair Ziekenhuis Brussel). The authors declare no conflict of interest.

Genetics and Epigenetics of Infertility and Treatments on Outcomes

CONTEXT

Infertility affects 10% of the reproductive-age population. Even the most successful treatments such as assisted reproductive technologies still result in failed implantation. In addition, adverse pregnancy outcomes associated with infertility have been attributed to these fertility treatments owing to the presumed epigenetic modifications of in vitro fertilization and in vitro embryo development. However, the diagnosis of infertility has been associated with adverse outcomes, and the etiologies leading to infertility have been associated with adverse pregnancy and long-term outcomes.

EVIDENCE ACQUISITION

We have comprehensively summarized the data available through observational, experimental, cohort, and randomized studies to better define the effect of the underlying infertility diagnosis vs the epigenetics of infertility treatments on treatment success and overall outcomes.

EVIDENCE SYNTHESIS

Most female infertility results from polycystic ovary syndrome, endometriosis, and unexplained infertility, with some cases resulting from a polycystic ovary syndrome phenotype or underlying endometriosis. In addition to failed implantation, defective implantation can lead to problems with placentation that leads to adverse pregnancy outcomes, affecting both mother and fetus.

CONCLUSION

Current research, although limited, has suggested that genetics and epigenetics of infertility diagnosis affects disease and overall outcomes. In addition, other fertility treatments, which also lead to adverse outcomes, are aiding in the identification of factors, including the supraphysiologic hormonal environment, that might affect the overall success and healthy outcomes for mother and child. Further studies, including genome-wide association studies, epigenomics studies, and experimental studies, are needed to better identify the factors leading to these outcomes.

Myosin 1F Regulates M1-Polarization by Stimulating Intercellular Adhesion in Macrophages

Intestinal macrophages are highly mobile cells with extraordinary plasticity and actively contribute to cytokine-mediated epithelial cell damage. The mechanisms triggering macrophage polarization into a proinflammatory phenotype are unknown. Here, we report that during inflammation macrophages enhance its intercellular adhesion properties in order to acquire a M1-phenotype. Using in vitro and in vivo models we demonstrate that intercellular adhesion is mediated by integrin-αVβ3 and relies in the presence of the unconventional class I myosin 1F (Myo1F). Intercellular adhesion mediated by αVβ3 stimulates M1-like phenotype in macrophages through hyperactivation of STAT1 and STAT3 downstream of ILK/Akt/mTOR signaling. Inhibition of integrin-αVβ3, Akt/mTOR, or lack of Myo1F attenuated the commitment of macrophages into a pro-inflammatory phenotype. In a model of colitis, Myo1F deficiency strongly reduces the secretion of proinflammatory cytokines, decreases epithelial damage, ameliorates disease activity, and enhances tissue repair. Together our findings uncover an unknown role for Myo1F as part of the machinery that regulates intercellular adhesion and polarization in macrophages.

Overexpression of Translocation Associated Membrane Protein 2 Leading to Cancer-Associated Matrix Metalloproteinase Activation as a Putative Metastatic Factor for Human Oral Cancer

Translocation associated membrane protein 2 (TRAM2) has been characterized as a component of the translocon that is a gated channel at the endoplasmic reticulum (ER) membrane. TRAM2 is expressed in a wide variety of human organs. To date, no information is available regarding TRAM2 function in the genesis of human cancer. The purpose of this study was to investigate the status of the TRAM2 gene in oral squamous cell carcinoma (OSCC) cells and clinical OSCC samples. Using real-time quantitative reverse transcriptase-polymerase chain reaction, Western blotting analysis, and immunohistochemistry, we detected accelerated TRAM2 mRNA and protein expression levels both in OSCC-derived cell lines and primary tumors. Moreover, TRAM2-positive OSCC tissues were correlated closely (P<0.05) with metastasis to regional lymph nodes and vascular invasiveness. Of note, knockdown of TRAM2 inhibited metastatic phenotypes, including siTRAM2 cellular migration, invasiveness, and transendothelial migration activities with a significant (P<0.05) decrease in protein kinase RNA(PKR) - like ER kinase (PERK) and matrix metalloproteinases (MMPs) (MT1-MMP, MMP2, and MMP9). Taken together, our results suggested that TRAM2 might play a pivotal role in OSCC cellular metastasis by controlling major MMPs. This molecule might be a putative therapeutic target for OSCC.

Oviductal glycoprotein 1 (OVGP1) is expressed by endometrial epithelium that regulates receptivity and trophoblast adhesion

PURPOSE

To study the regulation and functions of oviductal glycoprotein 1 (OVGP1) in endometrial epithelial cells.

METHODS

Expression of OVGP1 in mouse endometrium during pregnancy and in the endometrial epithelial cell line (Ishikawa) was studied by immunofluorescence, Western blotting, and RT-PCR. Regulation of OVGP1 in response to ovarian steroids and human chorionic gonadotropin (hCG) was studied by real-time RT-PCR. OVGP1 expression was knockdown in Ishikawa cells by shRNA, and expression of receptivity associated genes was studied by real-time RT-PCR. Adhesion of trophoblast cell line (JAr) was studied by in vitro adhesion assays.

RESULTS

OVGP1 was localized exclusively in the luminal epithelial cells of mouse endometrium at the time of embryo implantation. Along with estrogen and progesterone, hCG induced the expression of OVGP1 in Ishikawa cells. Knockdown of OVGP1 in Ishikawa cells reduced mRNA expression of ITGAV, ITGB3, ITGA5, HOXA10, LIF, and IL15; it increased the expression of HOXA11, MMP9, TIMP1, and TIMP3. Supernatants derived from OVGP1 knockdown Ishikawa cells reduced the adhesiveness of JAr cells in vitro. Expression of OVGP1 mRNA was found to be significantly lowered in the endometrium of women with recurrent implantation failure.

CONCLUSION

OVGP1 is specifically induced in the luminal epithelium at the time of embryo implantation where it regulates receptivity-related genes and aids in trophoblast adhesion.

Adhesion in Physiological, Benign and Malignant Proliferative States of the Endometrium: Microenvironment and the Clinical Big Picture

Although the developments in cellular and molecular biology over the last few decades have significantly advanced our understanding of the processes and players that regulate invasive disease, many areas of uncertainty remain. This review will discuss the contribution of dysregulated cell⁻cell and cell⁻matrix adhesion to the invasion in both benign and malignant contexts. Using the endometrium as an illustrative tissue that undergoes clinically significant invasion in both contexts, the adhesion considerations in the cells ("seed") and their microenvironment ("soil") will be discussed. We hope to orientate this discussion towards translational relevance for the diagnosis and treatment of endometrial conditions, which are currently associated with significant morbidity and mortality.