Expression and significance of miR-30d-5p and SOCS1 in patients with recurrent implantation failure during implantation window

The identification of key genes and pathways in polycystic ovary syndrome by bioinformatics analysis of next-generation sequencing data

Background

Polycystic ovary syndrome (PCOS) is a reproductive endocrine disorder. The specific molecular mechanism of PCOS remains unclear. The aim of this study was to apply a bioinformatics approach to reveal related pathways or genes involved in the development of PCOS.

Methods

The next-generation sequencing (NGS) dataset GSE199225 was downloaded from the gene expression omnibus (GEO) database and NGS dataset analyzed is obtained from in vitro culture of PCOS patients’ muscle cells and muscle cells of healthy lean control women. Differentially expressed gene (DEG) analysis was performed using DESeq2. The g:Profiler was utilized to analyze the gene ontology (GO) and REACTOME pathways of the differentially expressed genes. A protein–protein interaction (PPI) network was constructed and module analysis was performed using HiPPIE and cytoscape. The miRNA-hub gene regulatory network and TF-hub gene regulatory network were constructed. The hub genes were validated by using receiver operating characteristic (ROC) curve analysis.

Results

We have identified 957 DEG in total, including 478 upregulated genes and 479 downregulated gene. GO terms and REACTOME pathways illustrated that DEG were significantly enriched in regulation of molecular function, developmental process, interferon signaling and platelet activation, signaling, and aggregation. The top 5 upregulated hub genes including HSPA5, PLK1, RIN3, DBN1, and CCDC85B and top 5 downregulated hub genes including DISC1, AR, MTUS2, LYN, and TCF4 might be associated with PCOS. The hub gens of HSPA5 and KMT2A, together with corresponding predicted miRNAs (e.g., hsa-mir-34b-5p and hsa-mir-378a-5p), and HSPA5 and TCF4 together with corresponding predicted TF (e.g., RCOR3 and TEAD4) were found to be significantly correlated with PCOS.

Conclusions

These study uses of bioinformatics analysis of NGS data to obtain hub genes and key signaling pathways related to PCOS and its associated complications. Also provides novel ideas for finding biomarkers and treatment methods for PCOS and its associated complications.

Investigating the Imperative Role of microRNAs Expression in Human Embryo Implantation: A Narrative Review Based on Recent Evidence

BACKGROUND/OBJECTIVES

Embryo implantation is a highly complex process that requires the precise regulation of numerous molecules to be orchestrated successfully. Micro RNAs (miRNAs) are small non-coding RNAs that regulate gene expression and play a crucial role in the regulation of embryo implantation. This article aims to summarize the key findings of the literature regarding the role of miRNAs in human embryo implantation, emphasizing their involvement in critical stages such as decidualization, endometrial receptivity and trophoblast adhesion.

METHODS

This review includes primary research articles from the past decade. The studies utilize a range of experimental methodologies, including gene expression analysis and in vitro studies.

RESULTS

MicroRNAs, like miR-320a, miR-149, and miR30d secreted by preimplantation embryos and blastocysts significantly influence endometrial receptivity by promoting essential cellular processes, such as cell migration and trophoblast cell attachment, while others-miR17-5p, miR-193-3p, miR-372, and miR-542-3p-secreted from the endometrium regulate the decidualization phase. During the apposition and adhesion phases, miRNAs play a complex role by promoting, for example, miR-23b-3p, and inhibiting-as do miR-29c and miR-519d-3p-important biological pathways of these stages. During invasion, miR-26a-5p and miR-125-5p modulate important genes.

CONCLUSIONS

This review underscores the critical impact of miRNAs in the regulation of embryo implantation and early pregnancy. The ability of miRNAs to modulate gene expression at various stages of reproduction presents promising therapeutic avenues for improving assisted reproductive technologies outcomes and addressing infertility. Further research into miRNA-based diagnostic tools and therapeutic strategies is essential to enhance our understanding of their role in reproductive health and to exploit their potential for clinical applications.

Acupuncture combined with gonadotropin-releasing hormone agonists improves endometrial receptivity and pregnancy outcome in patients with recurrent implantation failure of in vitro fertilization-embryo transfer

OBJECTIVE

Gonadotropin-releasing hormone agonists (GnRHa), combined with other auxiliary treatments, can improve pregnancy outcomes in in vitro fertilization-embryo transfer (IVF-ET). This research investigated the effect of acupuncture combined with GnRHa in patients with recurrent implantation failure (RIF) of IVF-ET.

METHODS

A total of 164 patients who intended to undergo frozen-thawed embryo transfer after RIF of IVF-ET were selected for experiments and then divided into the control (received conventional hormone replacement therapy (HRT) for endometrial preparation) and study groups (received a combination of acupuncture, GnRHa, and HRT for endometrial preparation) (n = 82). Endometrial thickness (EMT), endometrial morphological classification, submucosal uterine blood flow classification, clinical pregnancy rate, embryo implantation rate, and early abortion rate for each transfer cycle were compared between the two groups.

RESULTS

EMT of the study group was higher than that of the control group 1 day before transfer. There were more patients with linear endometrium (A + B type) in the study group on the day of endometrial transformation than in the control group. The number of patients with type I submucosal uterine blood flow in the study group was decreased and the number of patients with type III was increased compared with the control group on the day of endometrial transformation. The clinical pregnancy rate and embryo implantation rate of the study group were higher than those of the control group.

CONCLUSION

Acupuncture combined with GnRHa improves the endometrial receptivity of patients with RIF of IVF-ET, thereby increasing clinical pregnancy rates and improving pregnancy outcomes.

Impact of miRNAs in the pathoetiology of recurrent implantation failure

Recurrent implantation failure (RIF) is a condition with a multifactorial basis. Recent research has focused on the role of genetic factors in the pathophysiology of RIF. Of particular note, miRNAs have been found to contribute to the pathogenesis of RIF. Several miRNA polymorphisms have been investigated in this context. Moreover, dysregulation of expression of a number of miRNAs, including miR-374a-5p, miR-145-5p, miR-30b-5p, miR-196b-5p, miR-22, miR-181 and miR-145 has been found in RIF. This review concentrates on the role of miRNAs in RIF to help in identification of the molecular basis for this condition and design of more effective methods for management of RIF, especially in a personalized manner that relies on the expression profiles of miRNAs in the peripheral blood or endometrium.

Non-coding RNAs in Recurrent implantation failure

Recurrent implantation failure (RIF), defined as the inability to achieve conception following multiple consecutive in-vitro fertilization (IVF) attempts, represents a complex and multifaceted challenge in reproductive medicine. The emerging role of non-coding RNAs in RIF etiopathogenesis has only gained prominence over the last decade, illustrating a new dimension to our understanding of the intricate network underlying RIF. Successful embryo implantation demands a harmonious synchronization between an adequately decidualized endometrium, a competent blastocyst, and effective maternal-embryonic interactions. Emerging evidence has clarified the involvement of a sophisticated network of non-coding RNAs, including microRNAs, circular RNAs, and long non-coding RNAs, in orchestrating these pivotal processes. Disconcerted expression of these molecules can disrupt the delicate equilibrium required for implantation, amplifying the risk of RIF. This comprehensive review presents an in-depth investigation of the complex role played by non-coding RNAs in the pathogenesis of RIF. Furthermore, it underscores the vast potential of non-coding RNAs as diagnostic biomarkers and therapeutic targets, with the ultimate goal of enhancing implantation success rates in IVF cycles. As ongoing research continues to unravel the intercalated web of molecular interactions, exploiting the power of non-coding RNAs may offer promising avenues for mitigating the challenges posed by RIF and improving the outcomes of assisted reproduction.

Research progress on the STAT signaling pathway in pregnancy and pregnancy-associated disorders

Signal transducer and activator of transcription (STAT) proteins, pivotal regulators of signaling cascades, undergo activation in response to the stimulation of cytokines and growth factors, and participate in biological processes, including inflammation, immune responses, cell proliferation, and differentiation. During the process of pregnancy, STAT signaling is involved in regulating embryonic implantation, endometrial decidualization, and establishing and maintaining maternal-fetal immune tolerance. Increasing evidence suggests that aberrant STAT signaling contributes to the occurrence and development of pregnancy disorders, including repeated implantation failure (RIF), preeclampsia (PE), recurrent spontaneous abortion (RSA), preterm birth (PTB) and gestational diabetes mellitus (GDM). Elucidating the molecular mechanisms of the STAT signaling pathway holds promise for further understanding the establishment and maintenance of normal pregnancy, and thereby providing potent targets and strategic avenues for the prevention and management of ailments associated with pregnancy. In this review, we summarized the roles of the STAT signaling pathway and its related regulatory function in embryonic implantation, endometrial decidualization, and maternal-fetal immune tolerance. In conclusion, in-depth research on the mechanism of the STAT signaling pathway not only enhances our understanding of normal pregnancy processes but also offers STAT-based therapeutic approaches to protect women from the burden of pregnancy-related disorders.

Interleukin-6 as A Useful Predictor of Endometriosis-Associated Infertility: A Systematic Review

Endometriosis is a chronic inflammatory disease defined by the presence of endometrial-like tissue outside the uterine cavity. Several authors have reported on the association between changes in inflammatory marker levels and the maintenance or progression of endometriosis and associated infertility. Interleukin-6 (IL-6) is the most studied cytokine in endometriosis and has important functions in reproductive physiology. The aim of this study is to review systematically available evidence about altered IL-6 concentrations in endometriosis-related infertility. This is a systematic review including all studies until December 2022 in which IL-6 in serum, peritoneal fluid, follicular fluid, or endometrial biopsy specimens was measured and that correlated their findings with endometriosis- associated infertility. Fifteen studies were included in the systematic review. There seems to be a correlation between elevated serum and peritoneal fluid IL-6 concentrations and the occurrence of endometriosis-associated infertility. IL-6 may be a potential diagnostic or biomarker tool for the prediction of endometriosis-related infertility. However, the numerous biases affecting the available studies, and challenges in endometriosis research reproducibility must be considered. Future investigations should pay attention to factors that may affect the results, such as the choice of suitable control groups, and carefully consider other pathological conditions affecting the patients, endometriosis stage, and type of lesion.

Human blastocysts uptake extracellular vesicles secreted by endometrial cells containing miRNAs related to implantation

STUDY QUESTION

Are the extracellular vesicles (EVs) secreted by the maternal endometrium uptaken by human embryos and is their miRNA cargo involved in implantation and embryo development?

SUMMARY ANSWER

Data suggest that EVs secreted by human endometrial epithelial cells are internalized by human blastocysts, and transport miRNAs to modulate biological processes related to implantation events and early embryo development.

WHAT IS KNOWN ALREADY

Successful implantation is dependent on coordination between maternal endometrium and embryo, and EVs role in the required cell-to-cell crosstalk has recently been established. In this regard, our group previously showed that protein cargo of EVs secreted by primary human endometrial epithelial cells (pHEECs) is implicated in biological processes related to endometrial receptivity, embryo implantation, and early embryo development. However, little is known about the regulation of these biological processes through EVs secreted by the endometrium at a transcriptomic level.

STUDY DESIGN, SIZE, DURATION

A prospective descriptive study was performed. Endometrial biopsies were collected from healthy oocyte donors with confirmed fertility on the day of oocyte retrieval, 36 h after the LH surge. pHEECs were isolated from endometrial biopsies (n = 8 in each pool) and cultured in vitro. Subsequently, conditioned medium was collected and EVs were isolated and characterized. Uptake of EVs by human blastocysts and miRNA cargo of these EVs (n = 3 pools) was analyzed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

EVs were isolated from the conditioned culture media using ultracentrifugation, and characterization was performed using western blotting, nanoparticle tracking analysis, and transmission electron microscopy. EVs were fluorescently labeled with Bodipy-TR ceramide, and their uptake by human blastocysts was analyzed using confocal microscopy. Analysis of the miRNA cargo of EVs was performed using miRNA sequencing, target genes of the most expressed miRNA were annotated, and functional enrichment analysis was performed.

MAIN RESULTS AND THE ROLE OF CHANCE

EVs measured 100-300 nm in diameter, a concentration of 1.78 × 1011 ± 4.12 × 1010 (SD) particles/ml and expressed intraluminal protein markers Heat shock protein 70 (HSP70) and Tumor Susceptibility Gene 101 (TSG101), in addition to CD9 and CD81 transmembrane proteins. Human blastocysts efficiently internalized fluorescent EVs within 1-2 h, and more pronounced internalization was observed in the hatched pole of the embryos. miRNA-seq analysis featured 149 annotated miRNAs, of which 37 were deemed most relevant. The latter had 6592 reported gene targets, that in turn, have functional implications in several processes related to embryo development, oxygen metabolism, cell cycle, cell differentiation, apoptosis, metabolism, cellular organization, and gene expression. Among the relevant miRNAs contained in these EVs, we highlight hsa-miR-92a-3p, hsa-let-7b-5p, hsa-miR-30a-5p, hsa-miR-24-3p, hsa-miR-21-5p, and hsa-let-7a-5p as master regulators of the biological processes.

LIMITATIONS, REASONS FOR CAUTION

This is an in vitro study in which conditions of endometrial cell culture could not mimic the intrauterine environment.

WIDER IMPLICATIONS OF THE FINDINGS

This study defines potential biomarkers of endometrial receptivity and embryo competence that could be useful diagnostic and therapeutic targets for implantation success, as well as open insight further investigations to elucidate the molecular mechanisms implicated in a successful implantation.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Spanish Ministry of Education through FPU awarded to M.S.-B. (FPU18/03735), the Health Institute Carlos III awarded to E.J.-B. (FI19/00110) and awarded to H.F. by the Miguel Servet Program 'Fondo Social Europeo «El FSE invierte en tu futuro»' (CP20/00120), and Generalitat Valenciana through VALi+d Programme awarded to M.C.C.-G. (ACIF/2019/139). The authors have no conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER

N/A.

The transcriptional foundations of interferon-λ-mediated endometrial cell to uterine receptivity

PROBLEM

Interferon-λ (IFN-λ) is a novel non-redundant regulator that participates in the fetal-maternal immune interaction, including immune regulation, uterine receptivity, cell migration and adhesion, and endometrium apoptosis. However, the exact transcriptional foundation for endometrial signaling of IFN-λ is not completely understood, and studies regarding IFN-λ to implantation failure in vivo are limited.

METHOD OF STUDY

The gene expression profile of human endometrial Ishikawa cell line treated with IFN-λ or IFN-α (100 ng/mL) for 6 h was analyzed using RNA-sequencing. Real-time qPCR, western blotting, and enzyme-linked immunosorbent assay (ELISA) tests were used to validate these sequencing data. An in vivo IFN-λ knock-down mouse pregnancy model was performed, and the phenotype analysis and the intrauterine biomarkers detection were applied with the uterus samples.

RESULTS

High levels of messenger RNA (mRNA) were detected for genes previously associated with endometrial receptivity, including LIF, AXL, CRYAB, EPHB2, CCL5, and DDX58, following IFN-λ treatment. Moreover, the data indicated IFN-λ reduced pro-inflammatory gene activity compared with IFN-α, including members of the ISG, TNF, SP100 and interleukin genes. The in vivo mouse pregnancy model showed that inhibition of intrauterine IFN-λ results in aberrant epithelial phenotype and significantly decreases the embryo implantation rates and derails normal uterine receptivity.

CONCLUSIONS

These findings demonstrate the antagonistic and agonistic roles of IFNs in the endometrial cell, suggesting a selective role of IFN-λ in endometrial receptivity and immunological tolerance regulation. Moreover, the findings provide valuable insight into potential biomarkers related to endometrial receptivity and facilitate an understanding of the molecular changes observed during infertility treatment and contraception usage.

MicroRNAs, small regulatory elements with significant effects on human implantation: a review

Embryo implantation is a critical process for achieving a successful pregnancy and live birth. The proper implantation must have a synchronized interaction between blastocyst and a receptive endometrium. Many genes are involved in the modulation of precise molecular events during implantation. MicroRNAs (miRNAs) have been extensively reported as gene regulatory molecules on post-transcriptional levels involved in various biological processes such as gametogenesis, embryogenesis, and the quality of sperm, oocyte, and embryos. A plethora of evidence has demonstrated critical roles for miRNAs in regulating genes involved in the implantation process; hence, dysregulation of miRNAs could be associated with significant impairments in implantation, such as recurrent implantation failure. In addition to the indispensable role of miRNAs in the intracellular control of gene expression, they can also be secreted into extracellular fluid and circulation. Therefore, miRNAs in body fluids and blood may be exploited as non-invasive diagnostic biomarkers for different pathological and physiological conditions. Recently, several studies have focused on the discovery of miRNAs function in the implantation process by appraising miRNAs and their target genes in human embryos, endometrial tissue, and cell culture models. Moreover, it was revealed that there could be a significant association between endometrial receptivity or implantation status and the expression of miRNAs in human body fluids, reinforcing their role as non-invasive biomarkers. In the current work, we reviewed the studies concerning the role of intracellular and extracellular miRNAs in human implantation and the influence of their dysregulation on implantation disorders.

Hypoxia-sensitive miRNA regulation via CRISPR/dCas9 loaded in hybrid exosomes: A novel strategy to improve embryo implantation and prevent placental insufficiency during pregnancy

Assisted reproductive techniques as a new regenerative medicine approach have significantly contributed to solving infertility problems that affect approximately 15% of couples worldwide. However, the success rate of an in vitro fertilization (IVF) cycle remains only about 20%-30%, and 75% of these losses are due to implantation failure (the crucial rate-limiting step of gestation). Implantation failure and abnormal placenta formation are mainly caused by defective adhesion, invasion, and angiogenesis. Placental insufficiency endangers both the mother's and the fetus's health. Therefore, we suggested a novel treatment strategy to improve endometrial receptivity and implantation success rate. In this strategy, regulating mir-30d expression as an upstream transcriptomic modifier of the embryo implantation results in modified expression of the involved genes in embryonic adhesion, invasion, and angiogenesis and consequently impedes implantation failure. For this purpose, "scaffold/matrix attachment regions (S/MARs)" are employed as non-viral episomal vectors, transfecting into trophoblasts by exosome-liposome hybrid carriers. These vectors comprise CRISPR/dCas9 with a guide RNA to exclusively induce miR-30d gene expression in hypoxic stress conditions. In order to avoid concerns about the fetus's genetic manipulation, our vector would be transfected specifically into the trophoblast layer of the blastocyst via binding to trophoblast Erb-B4 receptors without entering the inner cell mass. Additionally, S/MAR episomal vectors do not integrate with the original cell DNA. As an on/off regulatory switch, a hypoxia-sensitive promoter (HRE) is localized upstream of dCas9. The miR-30d expression increases before and during the implantation and placental insufficiency conditions and is extinguished after hypoxia elimination. This hypothesis emphasizes that improving the adhesion, invasion, and angiogenesis in the uterine microenvironment during pregnancy will result in increased implantation success and reduced placental insufficiency, as a new insight in translational medicine.

Growth hormone inhibits the JAK/STAT3 pathway by regulating SOCS1 in endometrial cells in vitro: a clue to enhance endometrial receptivity in recurrent implantation failure

Recurrent implantation failure (RIF) is defined as failure to achieve clinical pregnancy after at least 3 transfers of good-quality embryos by natural or artificial means. RIF is often a complex problem with a wide variety of etiologies and mechanisms as well as treatment options. In this study, using immunohistochemistry and Western blot, we demonstrated that the expression of leukemia inhibitory factor (LIF), Janus kinase 1 (JAK1), and signal transducer and activator of transcription 3 (STAT3) was increased, while that of suppressor of cytokine signaling 1 (SOCS1) was decreased in RIF patients. Growth hormone (GH) administration proved to have positive effects on embryo implantation in RIF patients, but the action mechanism of GH has not been elucidated yet. To this aim, we studied the effects of GH on the proliferation in vitro of endometrial adenocarcinoma Ishikawa cells. GH stimulated the expression of LIF and SOCS1, and through SOCS1 inhibits the expression of phosphorylated STAT3, and finally inhibits the occurrence of RIF. Excessive phosphorylation of STAT can lead to decreased endometrial receptivity and abnormal embryo implantation. We also examined the effects of LIF overexpression and an LIF inhibitor (EC330) on the JAK/STAT pathway. LIF promoted cell proliferation, and the up-regulation of LIF increased the expression of SOCS1 and JAK1/STAT3 pathway-related genes in Ishikawa cells. As GH can inhibit the JAK1/STAT3 pathway through LIF, we hypothesize that upregulating SOCS1 may be a potential approach to treat RIF at the molecular level. GH can inhibit the JAK1/STAT3 pathway through LIF, up-regulating SOCS1 to treat RIF at the molecular level.

Commercially Available Molecular Approaches to Evaluate Endometrial Receptivity: A Systematic Review and Critical Analysis of the Literature

Despite the advances in the field of reproductive medicine, implantation failure represents a challenging condition affecting 10-30% of patients subjected to in vitro fertilization (IVF). Research has focused on the identification of molecules playing crucial roles in endometrial receptivity, with the aim of designing predictive tools for efficient detection of the implantation window. To that end, novel molecular genomic and transcriptomic approaches have been introduced as promising tools to enable personalized approaches with the aim of optimizing embryo transfer dating. However, the clinical value of these approaches remains unclear. The aim of this study is to provide a systematic review and critical analysis of the existing evidence regarding the employment of commercially available novel approaches to evaluate endometrial receptivity. An Embase and PubMed/Medline search was performed on 1 February 2022. From the 475 articles yielded, only 27 were included and analyzed. The considerable heterogeneity of the included articles indicates the uniqueness of the implantation window, showcasing that the optimal time for embryo transfer varies significantly between women. Moreover, this study provides information regarding the technical aspects of these advanced molecular tools, as well as an analysis of novel possible biomarkers for endometrial receptivity, providing a basis for future research in the field.

New insights into Chlamydia pathogenesis: Role of leukemia inhibitory factor

Chlamydia trachomatis (Ct) is the leading cause of bacterial sexually transmitted infections worldwide. Since the symptoms of Ct infection are often subtle or absent, most people are unaware of their infection until they are tested or develop severe complications such as infertility. It is believed that the primary culprit of Ct-associated tissue damage is unresolved chronic inflammation, resulting in aberrant production of cytokines, chemokines, and growth factors, as well as dysregulated tissue influx of innate and adaptive immune cells. A member of the IL-6 cytokine family, leukemia inhibitory factor (LIF), is one of the cytokines induced by Ct infection but its role in Ct pathogenesis is unclear. In this article, we review the biology of LIF and LIF receptor (LIFR)-mediated signaling pathways, summarize the physiological role of LIF in the reproductive system, and discuss the impact of LIF in chronic inflammatory conditions and its implication in Ct pathogenesis. Under normal circumstances, LIF is produced to maintain epithelial homeostasis and tissue repair, including the aftermath of Ct infection. However, LIF/LIFR-mediated signaling – particularly prolonged strong signaling – can gradually transform the microenvironment of the fallopian tube by altering the fate of epithelial cells and the cellular composition of epithelium. This harmful transformation of epithelium may be a key process that leads to an enhanced risk of infertility, ectopic pregnancy and cancer following Ct infection.

Fresh or Frozen Embryo Transfer in The Antagonist In Vitro Fertilization Cycles: A Retrospective Cohort Study

BACKGROUND

Gonadotropin-releasing hormone antagonist (GnRH-ant), widely adopted protocol, is more in line with the physiological processes, and induces a shorter and more cost-effective ovarian stimulation. In order to assess the success rate of embryo transferring (ET) in the antagonist in vitro fertilization (IVF) cycles, we compared the fresh ET with the frozen ET outcomes.

MATERIALS AND METHODS

In this retrospective cohort study, one hundred five cases of ET of the infertility clinic of the Besat hospital (Kurdistan, Iran) between March 2014 to March 2020 that were treated with antagonist cycle (both fresh and frozen) were analyzed. The difference between the two groups in baseline data and reproductive outcomes were evaluated using Independent sample t test, Mann-Whitney U test, Chi-squared test, and Fisher's exact test in SPSS software (version 22).

RESULTS

Out of 105 cases, 48 and 57 were in the fresh and frozen ET groups, respectively. The participants age was 35.75 ± 4.9 Y. In the fresh ET group, and 33.98 ± 5.1 Y in the frozen ET group. The percentage of chemical pregnancy was 12 (25%) in the fresh ET group and 15 (26.3%) in the frozen ET group (P=0.8); Clinical pregnancy rate was 11 (22.9%) in the fresh ET group and 11 (19.3%) in the frozen ET group (P=0.6); the rate of abortion in the fresh ET group was 3 (6.3%, P=0.2), and in the frozen ET group was 8 (14%, P=0.2); and the live birth rate was 9 (18.8%) in the fresh ET group, in comparison with 7 (12.3%) in the frozen ET group (P=0.3).

CONCLUSION

Not statistically significant, the percentage of chemical pregnancy and abortion were higher in the frozen ET group. The percentage of clinical pregnancy and live birth were higher in the fresh ET group.

TOP2A deficit-induced abnormal decidualization leads to recurrent implantation failure via the NF-κB signaling pathway

BACKGROUND

Successful implantation is a complex process that is influenced by embryo quality, endometrial receptivity, immune factors, and the specific type of in vitro fertilization protocol used. DNA topoisomerase IIα (TOP2A) is a well-known protein involved in cell proliferation; however, its expression and effect on the endometrium in recurrent implantation failure (RIF) have not been fully elucidated.

METHODS

The human endometrial tissues of healthy controls and patients with RIF were collected. A proteomic analysis was performed to evaluate the differentially expressed proteins between the RIF group and the fertile control group. The expression patterns of TOP2A in the human preimplantation endometrium of the patients with RIF were determined by immunohistochemical staining, Western blotting and qRT-PCR. TOP2A knockdown (sh-TOP2A) T-HESCs were generated using lentiviruses. The expression of TOP2A in T-HESCs was manipulated to investigate its role in decidualization. The TOP2A-related changes in decidualization were screened by mRNA sequencing in decidualized TOP2A knockdown and control T-HESCs and then confirmed by Western blotting and immunofluorescence staining. TOP2A-deficient mice were generated by injection of TOP2A-interfering adenovirus on GD2.5 and GD3.5.

RESULTS

We performed a proteomic analysis of endometrial tissues to investigate the potential pathogenesis of RIF by comparing the patients with RIF and the matched controls and found that TOP2A might be a key protein in RIF. TOP2A is ubiquitously expressed in both stromal and glandular epithelial cells of the endometrium. The data indicate that TOP2A expression is significantly lower in the mid-secretory endometrium of women with RIF. TOP2A expression was downregulated under stimulation by 8-bromo-cAMP and MPA. Ablation of TOP2A resulted in upregulated expression of decidual biomarkers and morphological changes in the cells. Mechanistic analysis revealed that TOP2A regulates the NF-κB signaling pathway in decidualized T-HESCs. The TOP2A-deficient mice exhibited lower fetal weights.

CONCLUSIONS

Our findings revealed that abnormal expression of TOP2A affects decidualization and changes the "window of implantation", leading to RIF. TOP2A participates in the processes of decidualization and embryo implantation, functioning at least in part through the NF-κB pathway. Regulating the expression of TOP2A in the endometrium may become a new strategy for the prevention and treatment of RIF.

MicroRNA signatures in plasma and plasma exosome during window of implantation for implantation failure following in-vitro fertilization and embryo transfer

BACKGROUND

MicroRNAs (miRNAs) are small, non-coding RNAs that are dysregulated in many diseases and can act as biomarkers. Although well-studied in cancer, the role of miRNAs in embryo implantation is poorly understood. Approximately 70% of embryos fail to implant following in-vitro fertilization and embryo transfer, 10% of patients experienced recurrent implantation failure. However, there are no well-established biomarkers that can predict implantation failure. Our purpose is to investigate distinct miRNA profiles in plasma and plasma exosomes during the window of implantation between patients with failed implantation and successful implantation.

METHODS

We select a nested case-control population of 12 patients with implantation failure or successfully clinical pregnancy using propensity score matching. RNA was extracted from plasma and plasma exosomes collected during the window of implantation (WOI). MicroRNA expression in all samples was quantified using microRNA sequencing. The intersection of differently expressed miRNAs in plasma and exosomes were further validated in the GEO dataset. Significantly altered microRNAs in both plasma and plasma exosomes were then subjected to target prediction and KEGG pathway enrichment analyses to search for key signaling pathways. WGCNA analysis was performed to identify hub miRNAs associated with implantation.

RESULTS

13 miRNAs were differentially expressed in both plasma and plasma exosomes in patients with implantation failure. Among them, miR-150-5p, miR-150-3p, miR-149-5p, and miR-146b-3p had consistent direction changes in endometrium of patients with recurrent implantation failure (RIF), miR-342-3p had consistent direction changes in blood samples of patients with RIF. Pathway enrichment analysis showed that the target genes of differentially expressed miRNAs are enriched in pathways related to embryo implantation. WGCNA analysis indicated that miR-150-5p, miR-150-3p, miR-146b-3p, and miR-342-3p are hub miRNAs.

CONCLUSIONS

Implantation failure is associated with distinct miRNA profiles in plasma and plasma exosomes during WOI.