Implantation and Establishment of Pregnancy in Human and Nonhuman Primates

Decoding immune tolerance in infertility: Exploring immune pathways and non-coding RNAs as pioneering biomarkers and therapeutic targets

Infertility, impacting a significant number of couples, is characterized by the failure to conceive after one year of consistent, unprotected sexual intercourse. It is multifactorial, with etiological contributors including ovulatory dysfunction, male reproductive anomalies, and tubal patency issues. Approximately 15% of infertility cases are classified as "unexplained," highlighting the complexity of this condition. Lifestyle determinants such as obesity and smoking further complicate reproductive outcomes, while infertility can also indicate underlying chronic health conditions. A specialized category, immune infertility, arises from a breakdown of immunological tolerance, an essential aspect for conception and the maintenance of pregnancy. The role of various immunological components, including immune cells, cytokines, chemokines, factors like HLA-G, etc., is pivotal in this context. Moreover, non-coding RNAs (ncRNAs) have emerged as critical regulators of immune tolerance within the reproductive axis. This review synthesizes the complex immunological pathways vital for successful implantation and the early stages of pregnancy alongside the regulatory roles of ncRNAs in these processes. Offering an integrated view of molecular and immunological interactions associated with infertility seeks to enhance our understanding of potential strategies to facilitate successful conception and sustain early pregnancy.

Your period and your pregnancy, a cohort study of pregnant patients investigating the associations between menstruation and birth outcomes in Australia: study protocol

INTRODUCTION

Early pregnancy care involves the screening and identification of women with risk factors for adverse pregnancy outcomes, including stillbirth or preterm birth, to tailor pregnancy care and interventions accordingly. Most stillbirths and approximately two-thirds of preterm births, however, occur in the absence of evident risk factors. The majority of stillbirths occur in the preterm period, yet there are few interventions targeting this period, and progress to reduce stillbirth rates remains slow. Placental dysfunction is a major contributor to stillbirth, particularly, preterm stillbirth. Here, the endometrial environment may shed light on factors that influence placental development and the trajectory of a pregnancy. Menstrual symptoms or abnormal uterine bleeding (AUB) can indicate endometrial disorders, which are associated with infertility and adverse pregnancy outcomes. Whether AUB is associated with pregnancy outcomes in the absence of a diagnosed endometrial pathology, however, remains unknown. Limited information regarding a woman's menstrual cycle is captured in routine early pregnancy assessments, such as the last menstrual period and menstrual cycle length. Given the latent diagnosis of endometrial disorders and that up to a third of all women experience AUB during their lifetime, determining the association between menstrual characteristics and pregnancy outcomes has the potential to uncover new clinical strategies to reduce adverse pregnancy outcomes. Therefore, this study aims to understand the association between menstruation and pregnancy outcomes to identify which menstrual characteristics could provide value as a pregnancy risk assessment tool.

METHODS AND ANALYSIS

This is a prospective study of women aged 18-45 with a singleton pregnancy. Participants will be recruited in early pregnancy at their antenatal appointment and not have a known diagnosed endometrial pathology (endometriosis, adenomyosis, endometrial cancer or an endometrial submucosal fibroid) or have had an endometrial ablation. Participants will also be excluded if there is a planned termination of pregnancy or a termination of pregnancy for psychosocial reasons. Women will complete a menstrual history survey to capture menstrual cycle length, regularity, level of pain, heaviness of flow and other menstrual symptoms. Participants will consent to having the survey data linked with their pregnancy and birth outcome information. The primary outcome is a composite of stillbirth, spontaneous preterm birth, pre-eclampsia or fetal growth restriction. Participants will also be invited to complete an optional fetal movements survey at 28-32 and 36+ weeks' gestation, and consent for placental collection at the time of birth will be sought.

ETHICS AND DISSEMINATION

Ethics approval was obtained from Monash Health Human Research Ethics Committee (83559) on 24 April 2024. The study will be conducted in accordance with these conditions. Findings will be disseminated through peer-reviewed publications and conference presentations.

The BMP Signaling Pathway: Bridging Maternal-Fetal Crosstalk in Early Pregnancy

The maintenance of early pregnancy is a complex and distinctive process, primarily characterized by critical reproductive events such as embryo implantation, trophoblasts differentiation, decidualization, and extravillous trophoblasts (EVTs) invasion etc. However, dysregulation of these essential reproductive processes can result in various pregnancy complications, including recurrent miscarriage, preeclampsia, and fetal growth restriction etc. Notably, these complications exhibit an interconnected regulatory network that suggests shared underlying pathophysiological mechanisms. Meanwhile, the role of the BMP signaling pathway in sustaining early pregnancy is increasingly being investigated and elucidated. In this review, we have clarified the specific molecular mechanisms which are fundamental to essential reproductive processes and summarize an overview of animal models associated with BMP signaling molecules. In addition, we present a novel perspective on several contentious viewpoints regarding the functional roles of BMP ligands. Therefore, we anticipated a comprehensive understanding of the precise ways in which the BMP signaling pathway affects reproductive events during early pregnancy could provide new perspectives and approaches for preventing and addressing early pregnancy complications.

Immunohistochemical Analysis of GATA2 Expression in Endometrium and its Relationship with Hormone Receptor Expression in Benign and Premalignant Endometrial Disorders

The GATA gene family encodes highly conserved zinc-finger transcription factors that facilitate the development and function of multiple organ systems including the uterus. In the endometrium, GATA2 functions in a positive autoregulatory loop with the progesterone receptor (PGR) and colocalizes with PGR on chromatin to promote PGR transcriptional programs. GATA2 also has PGR-independent functions that maintain endometrial cell identity, and GATA2 transcripts reportedly are down-regulated in endometrial disorders including endometriosis. This event is accompanied by a reciprocal increase in GATA6. Here, we applied custom anti-GATA2 monoclonal antibodies and performed GATA2 immunohistochemistry (IHC) on patient endometrial tissues corresponding to proliferative, secretory, inactive, and hormone-treated endometrium, as well as endometriosis and endometrial atypical hyperplasia/endometrioid intraepithelial neoplasia (EAH/EIN). We also performed IHC for the estrogen receptor, PGR, and GATA6 in relevant groups. The results reveal a tight correlation between GATA2 and PGR expression in the glandular and stromal cells of benign endometrium. GATA2 expression is markedly reduced in stromal but not glandular cells in endometriosis and EAH/EIN. This reduction in GATA2 expression does not lead to a detectable increase in GATA6 expression in endometriosis. Although average glandular GATA2 expression was preserved in endometriosis and EAH/EIN cases, its expression was decoupled from PGR, implying that alternative pathways regulate GATA2 levels in these disorders. Our findings indicate that GATA2 dysregulation is a feature of endometriosis and EAH/EIN, and support a model whereby loss of stromal GATA2 in these disorders contributes to their progesterone insensitivity.

Unraveling the Dynamics of Estrogen and Progesterone Signaling in the Endometrium: An Overview

The endometrium is crucial for the perpetuation of human species. It is a complex and dynamic tissue lining the inner wall of the uterus, regulated throughout a woman's life based on estrogen and progesterone fluctuations. During each menstrual cycle, this multicellular tissue undergoes cyclical changes, including regeneration, differentiation in order to allow egg implantation and embryo development, or shedding of the functional layer in the absence of pregnancy. The biology of the endometrium relies on paracrine interactions between epithelial and stromal cells involving complex signaling pathways that are modulated by the variations of estrogen and progesterone levels across the menstrual cycle. Understanding the complexity of estrogen and progesterone receptor signaling will help elucidate the mechanisms underlying normal reproductive physiology and provide fundamental knowledge contributing to a better understanding of the consequences of hormonal imbalances on gynecological conditions and tumorigenesis. In this narrative review, we delve into the physiology of the endometrium, encompassing the complex signaling pathways of estrogen and progesterone.

Correlation Between Maternal-Fetus Interface and Placenta-Mediated Complications

Pregnancy is a highly regulated biological phenomenon that involves the development of a semi-allogeneic fetus inside the uterus of the mother. The maternal-fetal interface is a critical junction where communication takes place between the fetal and maternal immune systems, which determine the outcome of the pregnancy. The interface is composed of the decidua and placenta. The main cells present at the maternal-fetal interface include invading trophoblasts, maternal immune cells, and decidual stromal cells. Although maternal tolerance is crucial for maintaining a successful pregnancy, the role of the placenta in pregnancy is also important. Dysregulation of the placenta leads to various placenta-mediated complications, such as preeclampsia, intrauterine growth restriction, and placental abruption. Although the exact mechanism involving these complications is unclear, research has elucidated various factors involved in these pregnancy disorders. This review aimed to provide a summary of the maternal-fetal interface and immune mechanisms involved in placenta-mediated complications.

Autophagy genes and signaling pathways in endometrial decidualization and pregnancy complications

Autophagy is a process that occurs in almost all eukaryotic cells and this process is controlled by several molecular processes. Its biological roles include the provision of energy, the maintenance of cell homeostasis, and the promotion of aberrant cell death. The importance of autophagy in pregnancy is gradually becoming recognized. In literature, it has been indicated that autophagy has three different effects on the onset and maintenance of pregnancy: embryo (embryonic development), feto-maternal immune crosstalk, and maternal (decidualization). In humans, proper decidualization is a major predictor of pregnancy accomplishment and it can be influenced by different factors. This review highlights the genes, pathways, regulation, and function of autophagy in endometrial decidualization and other involved factors in this process.

Exploring the effectiveness of endometrial receptivity array and immune profiling in patients with multiple implantation failure：A retrospective cohort study based on propensity score matching

This study aimed to evaluate the effectiveness of the endometrial receptivity array (ERA), endometrial immune profiling, and a combination of both in improving the pregnancy outcomes for multiple implantation failure patients. According to patients' willingness, 1429 women who incurred at least two or more consecutive implantation failures in IVF/ICSI treatment opted for frozen embryo transfer and were divided into four groups: 'No test', 'Immune Profiling', 'ERA' and 'ERA+ Immune Profiling'. Women in three test groups underwent timed endometrial biopsy for ERA, immune profiling, a combination of both. We observed the overall incidence rates of the displaced window of implantation (WOI) and endometrial immune dysregulation were 75.14% and 79.29%, respectively. After 1:1 propensity score matching (PSM), our data revealed that the 'ERA' and 'ERA + Immune Profiling' groups demonstrated significantly higher rates of biochemical, clinical, ongoing pregnancy, and implantation compared to the 'No test' group (p < 0.01). The 'Immune Profiling' group showed a higher implantation rate compared to 'No test' group (p < 0.05). Furthermore, when comparing three test groups, the 'ERA + Immune Profiling' group exhibited notably higher rates of clinical and ongoing pregnancy compared to the 'Immune Profiling' group (p < 0.017). However, there was no association between endometrial immune profiling and ERA phases, and their results did not differ between embryo implantation and non-implantation in these patients. Our findings underline the increased implantation rates by use of ERA and endometrial immune profiling in patients with multiple implantation failure, either individually or corporately. Moreover, a combination of both could improve their pregnancy outcomes significantly.

The Known, the Unknown and the Future of the Pathophysiology of Endometriosis

Endometriosis is one of the most common causes of chronic pelvic pain and infertility, affecting 10% of women of reproductive age. A delay of up to 9 years is estimated between the onset of symptoms and the diagnosis of endometriosis. Endometriosis is currently defined as the presence of endometrial epithelial and stromal cells at ectopic sites; however, advances in research on endometriosis have some authors believing that endometriosis should be re-defined as "a fibrotic condition in which endometrial stroma and epithelium can be identified". There are several theories on the etiology of the disease, but the origin of endometriosis remains unclear. This review addresses the role of microRNAs (miRNAs), which are naturally occurring post-transcriptional regulatory molecules, in endometriotic lesion development, the inflammatory environment within the peritoneal cavity, including the role that cytokines play during the development of the disease, and how animal models have helped in our understanding of the pathology of this enigmatic disease.

Material properties of nonpregnant and pregnant human uterine layers

The uterus has critical biomechanical functions in pregnancy and undergoes dramatic material growth and remodeling from implantation to parturition. The intrinsic material properties of the human uterus and how they evolve in pregnancy are poorly understood. To address this knowledge gap and assess the heterogeneity of these tissues, the time-dependent material properties of all human uterine layers were measured with nanoindentation. The endometrium-decidua layer was found to be the least stiff, most viscous, and least permeable layer of the human uterus in nonpregnant and third-trimester pregnant tissues. In pregnancy, the endometrium-decidua becomes stiffer and less viscous with no material property changes observed in the myometrium or perimetrium. Additionally, uterine material properties did not significantly differ between third-trimester pregnant tissues with and without placenta accreta. The foundational data generated by this study will facilitate the development of physiologically accurate models of the human uterus to investigate gynecologic and obstetric disorders.

The uterine secretory cycle: recurring physiology of endometrial outputs that setup the uterine luminal microenvironment

Conserved in female reproduction across all mammalian species is the estrous cycle and its regulation by the hypothalamic-pituitary-gonadal (HPG) axis, a collective of intersected hormonal events that are crucial for ensuring uterine fertility. Nonetheless, knowledge of the direct mediators that synchronously shape the uterine microenvironment for successive yet distinct events, such as the transit of sperm and support for progressive stages of preimplantation embryo development, remain principally deficient. Toward understanding the timed endometrial outputs that permit luminal events as directed by the estrous cycle, we used Bovidae as a model system to uniquely surface sample and study temporal shifts to in vivo endometrial transcripts that encode for proteins destined to be secreted. The results revealed the full quantitative profile of endometrial components that shape the uterine luminal microenvironment at distinct phases of the estrous cycle (estrus, metestrus, diestrus, and proestrus). In interpreting this comprehensive log of stage-specific endometrial secretions, we define the "uterine secretory cycle" and extract a predictive understanding of recurring physiological actions regulated within the uterine lumen in anticipation of sperm and preimplantation embryonic stages. This repetitive microenvironmental preparedness to sequentially provide operative support was a stable intrinsic framework, with only limited responses to sperm or embryos if encountered in the lumen within the cyclic time period. In uncovering the secretory cycle and unraveling realistic biological processes, we present novel foundational knowledge of terminal effectors controlled by the HPG axis to direct a recurring sequence of vital functions within the uterine lumen.NEW & NOTEWORTHY This study unravels the recurring sequence of changes within the uterus that supports vital functions (sperm transit and development of preimplantation embryonic stages) during the reproductive cycle in female Ruminantia. These data present new systems knowledge in uterine reproductive physiology crucial for setting up in vitro biomimicry and artificial environments for assisted reproduction technologies for a range of mammalian species.

Material Properties of Nonpregnant and Pregnant Human Uterine Layers

The uterus has critical biomechanical functions in pregnancy and undergoes dramatic material growth and remodeling from implantation to parturition. The intrinsic material properties of the human uterus and how they evolve in pregnancy are poorly understood. To address this knowledge gap and assess the heterogeneity of these tissues, the time-dependent material properties of all human uterine layers were measured with nanoindentation. The endometrium-decidua layer was found to be the least stiff, most viscous, and least permeable layer of the human uterus in nonpregnant and third-trimester pregnant tissues. In pregnancy, endometrium-decidua becomes stiffer and less viscous with no material property changes observed in the myometrium or perimetrium. Additionally, uterine material properties did not significantly differ between third-trimester pregnant tissues with and without placenta accreta. The foundational data generated by this study will facilitate the development of physiologically accurate models of the human uterus to investigate gynecologic and obstetric disorders.

Association between endometrial senescent cells and immune cells in women with repeated implantation failure

PURPOSE

The aim of this study was to compare women with recurrent implantation failure (RIF) and control group in terms of the associations between p16-positive senescent cells and certain types of immune cells in human endometrium during the mid-luteal phase METHODS: Immunohistochemical staining was performed in 116 endometrial biopsies taken from 57 women presenting RIF, and control group of 59 women who became pregnant after the first intracytoplasmic sperm injection. Endometrial tissue sections were stained immunohistochemically for p16 (Senescent cells), CD4 (T-helpers), CD8 (T-killers), CD14 (Monocytes), CD68 (Macrophages), CD56 (Natural killers), and CD79α (B-cells). The percentage of positively stained cells for each marker was calculated by HALO image analysis software. The quantity and the relationship between senescent cells and immune cells were assessed and compared between the two groups.

RESULTS

The correlation coefficient was highest between senescent cells and CD4+ cells and was lowest between senescent cells and CD14+ cells in RIF women, similarly to the control group. However, most of the observed correlations among senescent and immune cells weaken notably or disappear in the RIF group. When comparing senescent cell-to-immune cell quantitative ratios, only p16+/CD4+ cell ratio was significantly higher in RIF women as compared with patients from the control group.

CONCLUSION

Our study indicates that the quantity of senescent cells in human endometrium during the mid-luteal phase has the strongest association with the amount of T helpers. Moreover, the specificity of this association might have an important impact on the occurrence of RIF.

Mechanistic insights into the development of severe fetal growth restriction

Fetal growth restriction (FGR), which most commonly results from suboptimal placental function, substantially increases risks for adverse perinatal and long-term outcomes. The only "treatment" that exists is delivery, which averts stillbirth but does not improve outcomes in survivors. Furthermore, the potential long-term consequences of FGR to the fetus, including cardiometabolic disorders, predispose these individuals to developing FGR in their future pregnancies. This creates a multi-generational cascade of adverse effects stemming from a single dysfunctional placenta, and understanding the mechanisms underlying placental-mediated FGR is critically important if we are to improve outcomes and overall health. The mechanisms behind FGR remain unknown. However, placental insufficiency derived from maldevelopment of the placental vascular systems is the most common etiology. To highlight important mechanistic interactions within the placenta, we focus on placental vascular development in the setting of FGR. We delve into fetoplacental angiogenesis, a robust and ongoing process in normal pregnancies that is impaired in severe FGR. We review cellular models of FGR, with special attention to fetoplacental angiogenesis, and we highlight novel integrin-extracellular matrix interactions that regulate placental angiogenesis in severe FGR. In total, this review focuses on key developmental processes, with specific focus on the human placenta, an underexplored area of research.

Tebufenpyrad induces cell cycle arrest and disruption of calcium homeostasis in porcine trophectoderm and luminal epithelial cells

Tebufenpyrad is classified as a pyrazole acaricide and insecticide. It is widely used for several crops, especially in greenhouses, in several countries. While its unfavorable effects on non-target organisms have already been established, relatively little is known about its reproductive toxicity. Therefore, we demonstrated the biochemical effects of tebufenpyrad using porcine trophectoderm and porcine luminal epithelial cells, which are involved in implantation. We found that tebufenpyrad had antiproliferative effects and reduced cell viability. Tebufenpyrad also triggered apoptosis and excessive reactive oxygen species production. Furthermore, it induced cell cycle arrest in the G1 phase and disrupted calcium homeostasis in the cytosol and mitochondria. MAPK signaling pathways and the crosstalk among them were altered following tebufenpyrad treatment. In addition, the migration ability of cells was reduced after treatment with tebufenpyrad. Lastly, tebufenpyrad influenced the expression of genes related to pregnancy. Collectively, these results reveal the mechanism of the biochemical and physiological effects of tebufenpyrad to both trophectoderm and uterine cells and suggest that tebufenpyrad reduces the potential of successful implantation.

Reliability of Rodent and Rabbit Models in Preeclampsia Research

In vivo studies on the pathology of gestation, including preeclampsia, often use small mammals such as rabbits or rodents, i.e., mice, rats, hamsters, and guinea pigs. The key advantage of these animals is their short reproductive cycle; in addition, similar to humans, they also develop a haemochorial placenta and present a similar transformation of maternal spiral arteries. Interestingly, pregnant dams also demonstrate a similar reaction to inflammatory factors and placentally derived antiangiogenic factors, i.e., soluble fms-like tyrosine kinase 1 (sFlt-1) or soluble endoglin-1 (sEng), as preeclamptic women: all animals present an increase in blood pressure and usually proteinuria. These constitute the classical duet that allows for the recognition of preeclampsia. However, the time of initiation of maternal vessel remodelling and the depth of trophoblast invasion differs between rabbits, rodents, and humans. Unfortunately, at present, no known animal replicates a human pregnancy exactly, and hence, the use of rabbit and rodent models is restricted to the investigation of individual aspects of human gestation only. This article compares the process of placentation in rodents, rabbits, and humans, which should be considered when planning experiments on preeclampsia; these aspects might determine the success, or failure, of the study. The report also reviews the rodent and rabbit models used to investigate certain aspects of the pathomechanism of human preeclampsia, especially those related to incorrect trophoblast invasion, placental hypoxia, inflammation, or maternal endothelial dysfunction.

Sequential (two-step) day 3/day 5 frozen-thawed embryo transfer: does it improve the pregnancy rate of patients suffering recurrent implantation failure?

The best time of endometrial receptivity is the missing part of the implantation puzzle in patients with recurrent in vitro fertilization (IVF) failure. There are various treatment plans and strategies to meet the best endometrial timing for implantation. However, the lack of synchronization of the good-quality embryo with the patient's individual "window of implantation" is the hypothesis for most IVF failures so far. Sequential embryo transfer (ET) theoretically extends the availability time of embryos on the window of implantation. The study aimed to evaluate the improvement of pregnancy rate in sequential (two-step) frozen-thawed embryo transfer (FET) on day 3/day 5 in individuals who suffer from repeated IVF failures. This randomized controlled trial study was done in a university-affiliated infertility center for women with repeated consecutive IVF failures. Two hundred women aged 20-39 years who met our inclusion criteria were included in the study between January 2020 and September 2021. Participants were allocated with a 1:1 ratio to either sequential (two-step) ET on day 3/day 5 (study group, n=100) and conventional day 5 FET (n=100, control group). The frozen-thawed embryos were transferred to hormone replacement therapy-prepared endometrium in both groups. The primary outcomes were clinical pregnancy and implantation rates. The secondary outcomes were early pregnancy loss and multiple pregnancies. The demographic and clinical characteristics of the two groups were comparable. Clinical pregnancy rates were significantly higher in the sequential (two-step) FET group (40%) compared to the day 5 group (19%) (P<0.001). The sequential transfer of frozen-thawed embryos on day 3/day 5 was more effective than regular day 5 for patients suffering from repeated IVF failure.

The single-cell atlas of cultured human endometrial stromal cells

OBJECTIVE

To systematically analyze the cell composition and transcriptome of primary human endometrial stromal cells (HESCs) and transformed human endometrial stromal cells (THESCs).

DESIGN

The primary HESCs from 3 different donors and 1 immortalized THESC were collected from the human endometrium at the midsecretory phase and cultured in vitro.

SETTING

Academic research laboratory.

PATIENT(S)

None.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Single-cell ribonucleic acid sequencing analysis.

RESULT(S)

We found the individual differences among the primary HESCs and bigger changes between the primary HESCs and THESCs. Cell clustering with or without integration identified cell clusters belonging to mature, proliferative, and active fibroblasts that were conserved across all samples at different stages of the cell cycles with intensive cell communication signals. All primary HESCs and THESCs can be correlated with some subpopulations of fibroblasts in the human endometrium.

CONCLUSION(S)

Our study indicated that the primary HESCs and THESCs displayed conserved cell characters and distinct cell clusters. Mature, proliferative, and active fibroblasts at different stages or cell cycles were detected across all samples and presented with a complex cell communication network. The cultured HESCs and THESCs retained the features of some subpopulations within the human endometrium.

Exosomes from bone mesenchymal stem cells alleviate mifepristone-induced human endometrial stromal cell injury by inhibiting TLR3 via delivering miR-941

Objective

We aim to investigate the protective effect and underlying mechanisms of BMSCs-exo on human endometrial stromal cells (HESCs) induced by mifepristone in this study.

Methods

BMSCs-exo were extracted and then identified by transmission electron microscopy and western-blot assay. RT-PCR assay was used to determine the level of miR-941. MiR-941 mimics or inhibitor were transfected into BMSCs and the exosomes were extracted. Then, Cell activity, apoptosis rate, cell migration and invasion, as well as the expression of angiogenic proteins were determined in HESCs stimulated by mifepristone and BMSCs-exo. Next, Dual-luciferase reporting assay was used to verify the targeted binding of miR-941 to TLR3, and the TLR3 expression in HESCs was detected by RT-PCR and western-blot. Finally, TLR3 was overexpressed to evaluate the effects of miR-941 from BMSCs-exo on cell apoptosis, cell invasion and angiogenesis in HESCs induced by mifepristone.

Results

miR-941 was highly expressed in BMSCs-exo. Exosome miR-941 in BMSCs-exo inhibited the cell apoptosis, and promoted cell activity, cell migration, invasion as well as angiogenesis were also improved in HESCs induced by mifepristone. TLR3 was a target of miR-941, which was up-regulated in mifepristonetreated HESCs. We further found that miR-941 derived from BMSCs-exo down-regulated the expression of TLR3 in HESCs treated by mifepristone. In addition, TLR3 overexpression blocked the inhibition of miR-941 on mifepristone-induced cell apoptosis, as well as cell migration and angiogenesis in HESCs.

Conclusions

Thus, we concluded that BMSCs-exo has protective effect on mifepristone-induced cell damage by delivering miR-941 which targeted TLR3 and regulated cell activity, migration, and angiogenesis in HESCs.

Genetic Polymorphisms in MicroRNA-196a2 and the Risk of Human Abortion Related to Mycoplasma hominis

Mutations in some miRNAs are associated with human recurrent pregnancy loss (RPL). In parallel, Mycoplasma spp. are one of the most common infections in pregnant women. The objective of this study was to identify the relationship between miRNA196a-2 gene polymorphism and Mycoplasma hominis (M. hominis) infection as a possible cause of human abortion. A total of 160 cervical swab specimens were collected from women (80 samples with at least one abortion as case, and 80 samples without abortion as control). A PCR-based method using 16S rRNA gene and tetra primer amplification refractory mutation system-polymerase chain (Tetra-ARMS-PCR) were used to identify the presence of M. hominis infections and miRNA196a-2 genotypes of studied women, respectively. Results showed that 22.5% of women with abortion and 7.5% of women without abortion were infected with M. hominis, thereby suggesting a significant difference between the two groups (P < 0.05). Tetra-ARMSPCR indicated that no significant difference in frequency of genotypes existed between women experimenting abortion and control group. Independently to the presence of M. hominis infection, a significant difference (P < 0.05) was observed in genotypic frequencies of miRNA196a-2 between RPL women and those with one abortion. Estimation of the Odds Ratios indicated that the chance of recurrent abortions in TT genotypes of miRNA196a-2 was about three times more likely than CC in non-infected individuals and about five times more likely than CC in M. hominis-infected patients. Our results proposed the role of miRNA196a-2 genotypes in RPL either in M. hominis-infected or non-infected individuals.

The Regulators of Human Endometrial Stromal Cell Decidualization

Several factors are important for implantation and subsequent placentation in the endometrium, including immunity, angiogenesis, extracellular matrix, glucose metabolism, reactive oxidative stress, and hormones. The involvement or abnormality of these factors can impair canonical decidualization. Unusual decidualization can lead to perinatal complications, such as disruption of trophoblast invasion. Drastic changes in the morphology and function of human endometrial stromal cells (hESCs) are important for decidualization of the human endometrium; hESCs are used to induce optimal morphological and functional decidualization in vitro because they contain estrogen and progesterone receptors. In this review, we will focus on the studies that have been conducted on hESC decidualization, including the results from our laboratory.

Molecular Clues to Understanding Causes of Human-Assisted Reproduction Treatment Failures and Possible Treatment Options

More than forty years after the first birth following in vitro fertilization (IVF), the success rates of IVF and of IVF-derived assisted reproduction techniques (ART) still remain relatively low. Interindividual differences between infertile couples and the nature of the problems underlying their infertility appear to be underestimated nowadays. Consequently, the molecular basis of each couple's reproductive function and of its disturbances is needed to offer an individualized diagnostic and therapeutic approaches to each couple, instead of applying a standard or minimally adapted protocols to everybody. Interindividual differences include sperm and oocyte function and health status, early (preimplantation) embryonic development, the optimal window of uterine receptivity for the implanting embryo, the function of the corpus luteum as the main source of progesterone production during the first days of pregnancy, the timing of the subsequent luteoplacental shift in progesterone production, and aberrant reactions of the uterine immune cells to the implanting and recently implanted embryos. In this article, the molecular basis that underlies each of these abnormalities is reviewed and discussed, with the aim to design specific treatment options to be used for each of them.

Three-dimensional culture models of human endometrium for studying trophoblast-endometrium interaction during implantation

During implantation, a symphony of interaction between the trophoblast originated from the trophectoderm of the implanting blastocyst and the endometrium leads to a successful pregnancy. Defective interaction between the trophoblast and endometrium often results in implantation failure, pregnancy loss, and a number of pregnancy complications. Owing to ethical concerns of using in vivo approaches to study human embryo implantation, various in vitro culture models of endometrium were established in the past decade ranging from two-dimensional cell-based to three-dimensional extracellular matrix (ECM)/tissue-based culture systems. Advanced organoid systems have also been established for recapitulation of different cellular components of the maternal-fetal interface, including the endometrial glandular organoids, trophoblast organoids and blastoids. However, there is no single ideal model to study the whole implantation process leaving more research to be done pursuing the establishment of a comprehensive in vitro model that can recapitulate the biology of trophoblast-endometrium interaction during early pregnancy. This would allow us to have better understanding of the physiological and pathological process of trophoblast-endometrium interaction during implantation.

Increased Colocalization and Interaction Between Decidual Protein Kinase A and Insulin-like Growth Factor-Binding Protein-1 in Intrauterine Growth Restriction

Increased phosphorylation of decidual insulin-like growth factor-binding protein-1 (IGFBP-1) can contribute to intrauterine growth restriction (IUGR) by decreasing the bioavailability of insulin-like growth factor-1 (IGF-1). However, the molecular mechanisms regulating IGFBP-1 phosphorylation at the maternal-fetal interface are poorly understood. Protein kinase A (PKA) is required for normal decidualization. Consensus sequences for PKA are present in IGFBP-1. We hypothesized that the expression/interaction of PKA with decidual IGFBP-1 is increased in IUGR. Parallel reaction monitoring-mass spectrometry (PRM-MS) identified multiple PKA peptides (n=>30) co-immunoprecipitating with IGFBP-1 in decidualized primary human endometrial stromal cells (HESC). PRM-MS also detected active PKA^pThr197 and greater site-specific IGFBP-1 phosphorylation^{(pSer119), (pSer98+pSer101) (pSer169+pSer174)} in response to hypoxia. Hypoxia promoted colocalization [dual immunofluorescence (IF)] of PKA with IGFBP-1 in decidualized HESC. Colocalization (IF) and interaction (proximity ligation assay) of PKA and IGFBP-1 were increased in decidua collected from placenta of human IUGR pregnancies (n=8) compared with decidua from pregnancies with normal fetal growth. Similar changes were detected in decidual PKA/IGFBP-1 using placenta from baboons subjected to maternal nutrient reduction (MNR) vs controls (n=3 each). In baboons, these effects were evident in MNR at gestational day 120 prior to IUGR onset. Increased PKA-mediated phosphorylation of decidual IGFBP-1 may contribute to decreased IGF-1 bioavailability in the maternal-fetal interface in IUGR.

Potential of Plasma Rich in Growth Factors (PRGF-Endoret) to Enhance the Efficacy of Assisted Reproductive Techniques in Refractory Cases

Aim: Nowadays, infertility problems affect a high percentage of couples. This study aimed to evaluate the effect of plasma rich in growth factors (PRGF-Endoret, hereafter PRGF) as a promising coadjuvant therapy in assisted reproductive techniques and its possible role in implantation and pregnancy rates. This retrospective study included 36 PRGF cycles in 27 women with one of the following reproductive disorders: recurrent implantation failure (n = 16), repeated abortion (n = 8), and thin endometrium (n = 3).

Methods: PRGF was obtained from each patient and administered as three consecutive intrauterine instillations. The endometrial thickness was measured after each PRGF infusion and a good-quality embryo transfer was performed for every patient. Endometrial thickness, biochemical pregnancy, and miscarriage rate were the primary measured outcomes.

Results: PRGF increased the endometrial growth respecting the initial thickness in all cases. The biochemical pregnancy rate determined as positive beta-human chorionic gonadotropin (β-hCG) was 59%, considering the total number of patients; the ongoing pregnancy percentage was 48%. PRGF application day was relevant with a significant probability of achieving pregnancy (p < 0.01) when the first PRGF infusion was carried out beyond 6.5 days after the first day of the woman's cycle and the second one beyond 9.5 days of the menstrual cycle.

Conclusions: Intrauterine autologous PRGF infusion is a safe, easily accessible, and inexpensive therapy that could collaborate in fertility treatments by optimizing the endometrium for implantation and thus favoring the crosstalk between the embryo and the uterus improving the embryo-maternal dialogue.

GnRH antagonist weakens endometrial stromal cells growth ability by decreasing c-kit receptor expression

BACKGROUND

Several surveys have reported that patients treated with gonadotropin-releasing hormone antagonist (GnRH-ant) protocol showed a significantly lower rate of implantation and clinical pregnancy compared to GnRH agonist (GnRH-a) protocol during in vitro fertilization-fresh embryo transfer. Subsequent studies imputed this poor outcome to the negative effects of GnRH-ant on endometrial receptive. However, the mechanisms were not fully understood.

METHODS

The clinical data of 2815 patients undergoing fresh embryo transfer in our center were analyzed. Human endometrial stromal cells (ESCs) from healthy women undergoing elective pregnancy termination of a normal pregnancy at 8-10 weeks gestation were treated with GnRH-analogs or imatinib (c-kit receptor inhibitor). CCK8 and Flow cytometry were used to investigated the growth ability of ESCs. Immunofluorescence staining and western blot was used to detected the target proteins.

RESULTS

The clinical data showed that the endometrial thickness on HCG Day were significantly lower in GnRH-ant group. Although no difference of embryo quality in these two groups, GnRH-ant group showed remarkably decreased rate of HCG positive, embryo implantation and pregnancy. Moreover, GnRH-ant significantly reduced the proliferation and induced the apoptosis of ESCs. Furthermore, the expression and activation of c-kit receptor, which played pivotal roles during embryo implantation, were observably decreased by GnRH-ant. Inhibiting the activation of c-kit by imatinib remarkably suppressed the proliferation and promoted the apoptosis of ESCs. Additionally, the phosphorylation of AKT and expression of Cyclin D1, which were closely related with cellular growth, were distinctly lessened after treating with imatinib.

CONCLUSIONS

In summary, our study showed that GnRH-ant weakened the activization of c-kit receptor by decreasing its expression, causing the impaired growth ability of ESCs. Our findings provided a new insight into the effects of GnRH-ant on endometrium.

Genome-wide analysis of cervical secretions obtained during embryo transfer reveals the association between deoxyribonucleic acid methylation and pregnancy outcomes

OBJECTIVE

To study whether the methylation status of cervical secretions can reflect the ability of the endometrium to allow embryo implantation.

DESIGN

Case-control study.

SETTING

In vitro fertilization centers.

PATIENT(S)

Women undergoing embryo transfer cycles, in which at least 1 good-quality embryo was transferred.

INTERVENTION(S)

Collection of cervical secretions during the procedure of embryo transfer.

MAIN OUTCOME MEASURE(S)

Methylation profiles of cervical secretions in relation to pregnancy outcomes.

RESULT(S)

Genome-wide methylation profiles differ between cervical secretions from pregnancy and nonpregnancy cycles. Clustering analysis on the basis of the top 2,000 differentially methylated probes of cervical secretions from 28 pregnancy and 29 nonpregnancy cycles correctly categorized 86.0% of the samples in terms of conceptional status, which was verified in selected genes by quantitative methylation-specific polymerase chain reaction and validated in another independent sample set. The combination of selected genes was estimated to predict pregnancy outcomes with a maximal area under the receiver operating characteristic curve of 0.83.

CONCLUSION(S)

The methylation profiles of cervical secretions were associated with pregnancy outcomes in embryo transfer cycles. Although not clinically useful at present, deoxyribonucleic acid methylation in cervical secretions may shed new light on the less invasive assessment of endometrial receptivity.

Effects of Pregnancy-Specific Glycoproteins on Trophoblast Motility in Three-Dimensional Gelatin Hydrogels

Introduction

Trophoblast invasion is a complex biological process necessary for establishment of pregnancy; however, much remains unknown regarding what signaling factors coordinate the extent of invasion. Pregnancy-specific glycoproteins (PSGs) are some of the most abundant circulating trophoblastic proteins in maternal blood during human pregnancy, with maternal serum concentrations rising to as high as 200-400 μg/mL at term.

Methods

Here, we employ three-dimensional (3D) trophoblast motility assays consisting of trophoblast spheroids encapsulated in 3D gelatin hydrogels to quantify trophoblast outgrowth area, viability, and cytotoxicity in the presence of PSG1 and PSG9 as well as epidermal growth factor and Nodal.

Results

We show PSG9 reduces trophoblast motility whereas PSG1 increases motility. Further, we assess bulk nascent protein production by encapsulated spheroids to highlight the potential of this approach to assess trophoblast response (motility, remodeling) to soluble factors and extracellular matrix cues.

Conclusions

Such models provide an important platform to develop a deeper understanding of early pregnancy.

The Effect of Endometrial Cell Culture on α3 and β1 integrin Genes and Protein Expression in Type 2 Diabetic Rats at The Time of Implantation

OBJECTIVE

Given the prevalence of fertility problems in couples and the defect in embryo implantation as well as the low success rate of assisted reproductive techniques, it is necessary to investigate the causes of this phenomenon. Type 2 diabetes mellitus (T2DM) is a metabolic disease with multiple effects on various organs as well as the endometrium. In this study, the effects of endometrial cell culture on the expression of α3 and β1 integrin genes and protein in type 2 diabetic rats were investigated.

MATERIALS AND METHODS

In this experimental study, 35 female rats were divided into five groups: control, sham, diabetic, Pioglitazone-treated and Metformin-treated groups. First, rats were maintained in diabetic condition for 4 weeks. Then, treatment was performed for the next four weeks. Four weeks after induction of diabetes, rats were sacrificed at the time of embryo implantation. The uterus was removed. Endometrial cells were isolated and cultured for 7 days. Immunocytochemistry staining was used to confirm endometrial cells. Expression of α3 and β1 integrin genes was determined by real-time polymerase chain reaction (PCR) technique and the α3β1 protein content measured using Western blot both before and after endometrial cell culture.

RESULTS

The expression level of α3 integrin gene in the Pioglitazone-treated group compared with metformin-treated group was significantly decreased (P<0.001). The same result was observed in β1 integrin gene expression (P=0.004). Also, the α3β1 protein level increased in all diabetic groups, but its reduction was significantly greater in pioglitazonetreated group (P=0.004).

CONCLUSION

T2DM altered the expression of α3 and β1 integrin genes and related proteins, which endometrial cell culture regulated this disorder. According to these results, may be the endometrial cell culture can reduce the adverse effects of diabetes on α3 and β1 integrin expression at the level of gene and protein, in endometrial cells.

Recent Insights into Human Endometrial Peptidases in Blastocyst Implantation via Shedding of Microvesicles

Blastocyst implantation involves multiple interactions with numerous molecules expressed in endometrial epithelial cells (EECs) during the implantation window; however, there is limited information regarding the molecular mechanism underlying the crosstalk. In blastocysts, fibronectin plays a major role in the adhesion of various types of cells by binding to extracellular matrix proteins via the Arg-Gly-Asp (RGD) motif. In EECs, RGD-recognizing integrins are important bridging receptors for fibronectin, whereas the non-RGD binding of fibronectin includes interactions with dipeptidyl peptidase IV (DPPIV)/cluster of differentiation (CD) 26. Fibronectin may also bind to aminopeptidase N (APN)/CD13, and in the endometrium, these peptidases are present in plasma membranes and lysosomal membranes. Blastocyst implantation is accompanied by lysosome exocytosis, which transports various peptidases and nutrients into the endometrial cavity to facilitate blastocyst implantation. Both DPPIV and APN are released into the uterine cavity via shedding of microvesicles (MVs) from EECs. Recently, extracellular vesicles derived from endometrial cells have been proposed to act on trophectoderm cells to promote implantation. MVs are also secreted from embryonal stem cells and may play an active role in implantation. Thus, crosstalk between the blastocyst and endometrium via extracellular vesicles is a new insight into the fundamental molecular basis of blastocyst implantation.

Human implantation: The complex interplay between endometrial receptivity, inflammation, and the microbiome

Human embryo implantation is an intricate spatiotemporal process that involves the intimate association between the embryo and the endometrium of the mother. During implantation, the endometrium undergoes a dynamic cascade of gene activation and repression, largely driven by autocrine, paracrine, and endocrine action. Steroid hormones, such as estrogen and progesterone, act on a variety of targets including cellular adhesion molecules (CAMs), cytokines, and growth factors to facilitate the implantation process. Given the synchrony required to achieve implantation, it is unsurprising that embryo implantation represents a substantial problem for infertility patients. This is due to a complex interplay taking place at the level of the endometrium. This review discusses the intricacies of embryo implantation including the window of implantation, the cyclical phases of the endometrium, the implantation process itself, and features of endometrial receptivity. Additionally, we will discuss new research regarding inflammatory reproductive biology, epigenetics and microRNA, and the role of the vaginal and endometrial microbiome in implantation. A better understanding of embryo implantation and the interactions occurring at the level of the blastocyst and the endometrium will improve patient care for infertile patients who experience this frustrating challenge.

Notch signaling in reproduction

The Notch signaling pathway is conserved among mammalian species and controls proliferation, differentiation, and cell death in many organs throughout the body including the reproductive tract. Notch signaling plays critical roles in the development and function of both the male and female reproductive systems. Specifically, within the female reproductive tract, Notch signaling is hormone regulated and mediates key reproductive events important for ovarian and uterine function. In this review, we highlight the tissues that express Notch receptors, ligands, and downstream effectors and distinguish how these molecules regulate reproductive function in male and female mice, non-human primates, and humans. Finally, we describe some of the aberrations in Notch signaling in female reproductive pathologies and identify opportunities for future investigation.

Insights into the Regulation of Implantation and Placentation in Humans, Rodents, Sheep, and Pigs

Precise cell-specific spatio-temporal molecular signaling cascades regulate the establishment and maintenance of pregnancy. Importantly, the mechanisms regulating uterine receptivity, conceptus apposition and adhesion to the uterine luminal epithelia/superficial glandular epithelia and, in some species, invasion into the endometrial stroma and decidualization of stromal cells, are critical prerequisite events for placentation which is essential for the appropriate regulation of feto-placental growth for the remainder of pregnancy. Dysregulation of these signaling cascades during this critical stage of pregnancy can lead to pregnancy loss, impaired growth and development of the conceptus, and alterations in the transplacental exchange of gasses and nutrients. While many of these processes are conserved across species, significant variations in the molecular mechanisms governing maternal recognition of pregnancy, conceptus implantation, and placentation exist. This review addresses the complexity of key mechanisms that are critical for the establishment and maintenance of a successful pregnancy in humans, rodents, sheep, and pigs. Improving understanding of the molecular mechanisms governing these processes is critical to enhancing the fertility and reproductive health of humans and livestock species.

Effectiveness comparison between Endometrial Receptivity Array, Immune Profiling and the combination in treating patients with multiple implantation failure

PROBLEM

The clinical value of endometrial receptivity array (ERA), endometrial immune profiling, or a combination of both for multiple implantation failure patients is unclear.

METHOD OF STUDY

One hundred and seventy-two women with a history of at least two or more consecutive implantation failures in IVF/ICSI treatment were included. According to patients' willingness, they were divided into four groups, 'no treatment', 'Immune Profiling', 'ERA' and 'ERA + Immune Profiling'. Endometrial biopsy was examined by ERA, immune profiling alone, or combination, and intention was adopted accordingly. Pregnancy outcomes were compared, and the association between ERA phases and endometrial immune profiling was also assessed.

RESULTS

The overall incidence rate of the displaced window of implantation (WOI) and endometrial immune dysregulations were 84.9% and 75.3%, respectively. Implantation rate was significantly higher in the 'ERA + Immune Profiling' group than the 'no treatment' group (P = 0.007). Clinical pregnancy rate was somewhat improved in the three treatment groups but with a borderline significance (P = 0.071). After controlling for other confounders, 'ERA + Immune Profiling' treatment was associated with a higher pregnancy rate [aOR (95%CI)  =  3.412 (1.387-8.395), P = 0.008]. There was no association between endometrial immune profiling and ERA phases.

CONCLUSIONS

Our findings highlight the high incidence of displaced WOI and endometrial immune dysregulation in multiple implantation failure patients. The combination of ERA and endometrial immune profiling is more likely to have clinical value than ERA or immune profiling alone. These data suggested the unsubstitutability of ERA and endometrial immune profiling on the treatment outcome for multiple implantation failure patients. This article is protected by copyright. All rights reserved.

TOB1 modulates the decidualization of human endometrial stromal cells via the Notch pathway

BACKGROUND

Decidualization is critical for embryo implantation and the success of pregnancy; however, the mechanisms underlying this process remain largely unknown.

MATERIALS AND METHODS

In the present study, RNA sequencing was used to detect the expression levels of transducer of ERBB2/1(TOB1) in endometrial samples derived from proliferative and secretory phases. A decidualization model was induced using the combination of estrogen (E2) and progestin (P4) in human endometrial stromal cells (HESCs). The cell counting kit-8 assay was used to detect the viability of HESCs. Related proteins were detected by qPCR and western blot.

RESULT

The results indicated that TOB1 expression was upregulated in the secretory endometrial samples compared with the corresponding expression observed in the proliferative samples. The expression levels of TOB1 and Notch1 were markedly increased in E2P4-treated HESCs compared with those in the control cells. Treatment with E2P4 strongly suppressed the proliferation of HESCs and induced a G₁-phase cell cycle arrest. These effects were abolished by knockdown of TOB1 or treatment with of the cells with the Notch inhibitor N-[N-(3,5-difluorophenacetyl)-1-alanyl]-S-phenylglycine t-butyl ester.

CONCLUSIONS

Therefore, these findings highlighted an important role for TOB1/Notch signaling in E2P4-induced decidualization in HESCs, which may provide novel targets for improving the endometrial receptivity.

Uterine kisspeptin receptor critically regulates epithelial estrogen receptor α transcriptional activity at the time of embryo implantation in a mouse model

Embryo implantation failure is a major cause of infertility in women of reproductive age and a better understanding of uterine factors that regulate implantation is required for developing effective treatments for female infertility. This study investigated the role of the uterine kisspeptin receptor (KISS1R) in the molecular regulation of implantation in a mouse model. To conduct this study, a conditional uterine knockout (KO) of Kiss1r was created using the Pgr-Cre (progesterone receptor-CRE recombinase) driver. Reproductive profiling revealed that while KO females exhibited normal ovarian function and mated successfully to stud males, they exhibited significantly fewer implantation sites, reduced litter size and increased neonatal mortality demonstrating that uterine KISS1R is required for embryo implantation and a healthy pregnancy. Strikingly, in the uterus of Kiss1r KO mice on day 4 (D4) of pregnancy, the day of embryo implantation, KO females exhibited aberrantly elevated epithelial ERα (estrogen receptor α) transcriptional activity. This led to the temporal misexpression of several epithelial genes [Cftr (Cystic fibrosis transmembrane conductance regulator), Aqp5 (aquaporin 5), Aqp8 (aquaporin 8) and Cldn7 (claudin 7)] that mediate luminal fluid secretion and luminal opening. As a result, on D4 of pregnancy, the lumen remained open disrupting the final acquisition of endometrial receptivity and likely accounting for the reduction in implantation events. Our data clearly show that uterine KISS1R negatively regulates ERα signaling at the time of implantation, in part by inhibiting ERα overexpression and preventing detrimentally high ERα activity. To date, there are no reports on the regulation of ERα by KISS1R; therefore, this study has uncovered an important and powerful regulator of uterine ERα during early pregnancy.

Role of Maternal Infections and Inflammatory Responses on Craniofacial Development

Pregnancy is a tightly regulated immunological state. Mild environmental perturbations can affect the developing fetus significantly. Infections can elicit severe immunological cascades in the mother's body as well as the developing fetus. Maternal infections and resulting inflammatory responses can mediate epigenetic changes in the fetal genome, depending on the developmental stage. The craniofacial development begins at the early stages of embryogenesis. In this review, we will discuss the immunology of pregnancy and its responsive mechanisms on maternal infections. Further, we will also discuss the epigenetic effects of pathogens, their metabolites and resulting inflammatory responses on the fetus with a special focus on craniofacial development. Understanding the pathophysiological mechanisms of infections and dysregulated inflammatory responses during prenatal development could provide better insights into the origins of craniofacial birth defects.

In situ Synthesized Monosodium Urate Crystal Enhances Endometrium Decidualization via Sterile Inflammation During Pregnancy

High level of uric acid (UA) is the major origin of gout, and is highly associated with various pregnant complications, such as preeclampsia and gestational diabetes. However, UA’s level and role in the very early stage of pregnancy has not been uncovered. This study aims to investigate the relevance of serum UA and decidualization, an essential process for the establishment and maintenance of pregnancy in women and mice during the early stage of pregnancy. In this study, we first proved that expression level of UA synthase xanthine dehydrogenase (XDH) is highly increased along with decidualization of endometrial stromal cells in both in vitro and in vivo models. Furthermore, serum and endometrial levels of UA are higher in mice with decidualized uterin horn and in vitro decidualized stromal cells. The existence of monosodium urate (MSU) crystal was also confirmed by immunostaining. Next, the roles of MSU on decidualization were explored by both in vitro and in vivo models. Our data shows MSU crystal but not UA enhances the decidualization response of endometrial stromal cells, via the upregulation of inflammatory genes such Ptgs2 and Il11. inhibiting of Cox-2 activity abolishes MSU crystal induced higher expression of decidualization marker Prl8a2. At last, in women, we observed enriched expression of XDH in decidua compare to non-decidualized endometrium, the serum level of UA is significantly increased in women in very early stage of pregnancy, and drop down after elective abortion. In summary, we observed an increased serum UA level in the early stage of women’s pregnancy, and proved that the increased level of UA results from the expressed XDH in decidualizing endometrium of both human and mouse, leading to the formation of MSU crystal. MSU crystal can enhance the decidualization response via inflammatory pathways. Our study has uncovered the association between UA, MSU, and decidualization during the early stage of pregnancy.

Trophoblast derived extracellular vesicles specifically alter the transcriptome of endometrial cells and may constitute a critical component of embryo-maternal communication

BACKGROUND

The period of time when the embryo and the endometrium undergo significant morphological alterations to facilitate a successful implantation-known as "window of implantation"-is a critical moment in human reproduction. Embryo and the endometrium communicate extensively during this period, and lipid bilayer bound nanoscale extracellular vesicles (EVs) are purported to be integral to this communication.

METHODS

To investigate the nature of the EV-mediated embryo-maternal communication, we have supplemented trophoblast analogue spheroid (JAr) derived EVs to an endometrial analogue (RL 95-2) cell layer and characterized the transcriptomic alterations using RNA sequencing. EVs derived from non-trophoblast cells (HEK293) were used as a negative control. The cargo of the EVs were also investigated through mRNA and miRNA sequencing.

RESULTS

Trophoblast spheroid derived EVs induced drastic transcriptomic alterations in the endometrial cells while the non-trophoblast cell derived EVs failed to induce such changes demonstrating functional specificity in terms of EV origin. Through gene set enrichment analysis (GSEA), we found that the response in endometrial cells was focused on extracellular matrix remodelling and G protein-coupled receptors' signalling, both of which are of known functional relevance to endometrial receptivity. Approximately 9% of genes downregulated in endometrial cells were high-confidence predicted targets of miRNAs detected exclusively in trophoblast analogue-derived EVs, suggesting that only a small proportion of reduced expression in endometrial cells can be attributed directly to gene silencing by miRNAs carried as cargo in the EVs.

CONCLUSION

Our study reveals that trophoblast derived EVs have the ability to modify the endometrial gene expression, potentially with functional importance for embryo-maternal communication during implantation, although the exact underlying signalling mechanisms remain to be elucidated.

Azadirachta indica A. Juss (neem) as a contraceptive: An evidence-based review on its pharmacological efficiency

BACKGROUND

Azadirachta indica A. Juss. is an Indian medicinal plant with innumerable pharmacological properties. Studies have proven that the phytochemicals from neem possess remarkable contraceptive abilities with limited knowledge on its mechanism of action.

PURPOSE

The present review aims to summarize the efficiency of A. indica treatment as a contraceptive.

METHODS

The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were used. Published scientific articles on antifertility, antispermatogenic, antiovulation, hormone altering, contraceptive, and abortifacient activities of A. indica were collected from reputed Journals from 1980 to 2020 using electronic databases. Specific keywords search was completed to collect numerous articles with unique experiment design and significant results. This was followed by the selection of the requisite articles based on the criteria designed by the authors. Data extraction was based on the common research elements included in the articles.

RESULTS

A total of 27 studies were considered for reviewing, which included key pharmacological investigations. In the beginning, authors evaluated a number of publications on the contraceptive properties of A. indica, in which it was revealed that most of the publications were made between 2005 and 2009. All the collected articles were categorised and reviewed as antifertility, antispermatogenic, antiovulation, hormone altering, contraceptive, and abortifacient. Authors also assessed studies based on the plant parts used for pharmacological evaluations including leaves, seeds, stem-bark, and flowers. The article was primarily divided into different sections based on the previous works of authors on phytochemistry and pharmacological review articles.

CONCLUSION

Although A. indica is not reported with the complete alleviation of reproductive system in both male and female animal models, studies have proven its efficacy as a contraceptive. Extracts and phytochemicals from neem neither reduced the libido nor retarded the growth of secondary sexual characters, thus indicating only a temporary and reversible contraceptive activity. However, there is a dearth for clinical studies to prove the efficacy of A. indica as a herbal contraceptive.

Forced Suppression of let-7a-5p in Mouse Blastocysts Improves Implantation Rate

Embryo implantation requires appropriate communication between the blastocyst and endometrium. Recurrent implantation failure is an essential component of assisted reproductive technology. Also, miRNA-mediated gene expression impacts the implantation process, and the downregulation of some miRs, such as mmu-let-7a, improves this process. In the present study, we evaluated the effect of let-7a forced suppression on the mouse implantation rate. In total, 100 adult female mice and 10 adult male mice were included (Strain CD-1). We analysed the expression of let-7a and its potential mRNAs targets (Igf1, Il1a, Itgb3 and Tgfb1) in control, sham and antagomir-treated blastocysts using quantitative reverse transcription PCR (qRT-PCR). The control and treated blastocysts were transferred to the 20 pseudopregnant mice so that the effect of let-7a suppression on the rate of implantation could be determined. The expression level of let-7a in the treatment group was significantly downregulated (P=0.001) In contrast, no significant expression changes were observed for let-7a or mRNAs targets when the sham and control groups were compared (P>0.05). In comparison to the controls, the antagomir-treated group exhibited significantly upregulated expression levels of Igf1 (0.0167), Itgb3 (0.045) and Tgfb1 (0.0115). Additionally, the implantation rate was significantly higher in the treatment group (78%) than the control group (61%) (P=0.0098). We found that forced suppression of mmu-let-7a-5p through successful transfection of Anti-miR leads to upregulation of downstream genes, Igf1, Itgb3 and Tgfb1, which directly involved in the trophoblast-endometrium attachment and improve the implantation rate.

Clinical consequences of defective decidualization

Decidualization is characterized by a series of genetic, metabolic, morphological, biochemical, vascular and immune changes occurring in the endometrial stroma in response to the implanting embryo or even before conception and involves the stromal cells of the endometrium. It is a fundamental reproductive event occurring in mammalian species with hemochorial placentation. A growing body of experimental and clinical evidence strongly suggests that defective or disrupted decidualization contributes to the establishment of an inappropriate maternal-fetal interface. This has relevant clinical consequences, ranging from recurrent implantation failure and recurrent pregnancy loss in early pregnancy to several significant complications of advanced gestation. Moreover, recent evidence indicates that selected diseases of the endometrium, such as chronic endometritis and endometriosis, can have a detrimental impact on the decidualization response in the endometrium and may help explain some aspects of the reduced reproductive outcome associated with these conditions. Further research efforts are needed to fully understand the biomolecular mechanisms ans events underlying an abnormal decidualization response. This will permit the development of new diagnostic and therapeutic strategies aimed to improve the likelihood of achieveing a successful pregnancy.

Laboratory predictors of pregnancy in vitro fertilization

Identification of factors determining both of favorable and unfavorable outcome of IVF will increase the effectiveness of this method and optimize infertility treatment. The aim of the research is to analyze the correlation between serum IL-1α concentration, its gene rs1800587 (C/T) genotype carrier and thyroid-stimulating hormone (TSH), thyroid hormones (triiodothyronine (T3) and tetraiodothyronine (T4)), and evaluate the prognostic significance of their combinations in women with tube-peritoneal infertility under the IVF program. 120 patients with tube-peritoneal infertility who applied for an IVF program were examined. Depending on the outcome of the procedure, 2 groups of patients were allocated: 1 group - 40 women who had a pregnancy after IVF, 2 group - 80 patients who did not have a pregnancy. The content of IL-1α, TSH, T3, T4 was determined in blood by ELISA. Genotyping was performed on the rs1800587 (C/T) polymorphic marker of the IL-1α gene. TSH, T3, T4 were within the norm for both groups. In our study, women with a TSH concentration of 0.23 to 1.7 nmol/L had a chance of a favorable IVF outcome 1.4 times higher than with other TSH levels (p = 0.042901); with a T3 level of 1.0 to 1.8 nmol/L had a chance of becoming pregnant 5.7 times higher than with other levels of T3 (p = 0.00002). For T4 concentration, the confidence test was not achieved (p = 0.068505). The individual indicators of IL-1α, TSH, T3 and carrier of the genotype of the gene IL-1α at the preconceptive stage have lower diagnostic value than their combined combination. Three combinations have maximum predictive value: a combination of the T/T genotype of the IL-1α gene and the TSH level of 0.23 to 1.7 nmol/l - OR = 8.1 (p = 0.000048); combination of IL-1α of 28.7 to 85.1 pg/ml, T/T gene genotype IL-1α and TSH level of 0.23 to 1.7 nmol/l - OR = 8.1 (p = 0.000048); combination of IL-1α of 28.7 to 85.1 pg/ml, T/T gene genotype IL-1α, TSH level of 0.23 to 1.7 nmol/l and T3 level of 1.0 to 1.8 nmol/l - OR = 8.1 (p = 0.000146). Thus, proposed new prognostic markers of IVF program effectiveness.

In Vitro Implantation Model Using Human Endometrial SUSD2+ Mesenchymal Stem Cells and Myometrial Smooth Muscle Cells

Objective

This study evaluated a novel in vitro implantation model using human endometrial mesenchymal stem cells (EMSCs), SUSD2⁺, and myometrial smooth muscle cells (SMCs) that were co-cultured with mouse blastocysts as the surrogate embryo.

Materials and Methods

In this experimental study, SUSD2⁺ MSCs were isolated from human endometrial cell suspensions (ECS) at the fourth passage by magnetic-activated cell sorting. The ECS and SUSD2⁺ cells were separately co-cultured with human myometrial muscle cells for five days. After collection of mouse blastocysts, the embryos were placed on top of the co-cultured cells for 48 hours. The interaction between the embryo and the cultured cells was assessed morphologically at the histological and ultrastructural levels, and by expression profiles of genes related to implantation.

Results

Photomicrographs showed that trophoblastic cells grew around the embryonic cells and attached to theECS and SUSD2⁺ cells. Ultrastructural observations revealed pinopode and microvilli-like structures on the surfaces of both the ECS and SUSD2⁺ cells. Morphologically, the embryos developed to the egg-cylinder stage in both groups. Gene expression analysis showed no significant differences between the two groups in the presence of an embryo, but an increased expression of αV was detected in SUSD2⁺ cells compared to ECS cells in the absence of an embryo.

Conclusion

This study showed that SUSD2⁺ cells co-cultured with SMCs could interact with mouse embryos. The co-cultured cells could potentially be used as an implantation model.

Autophagy in the physiological endometrium and cancer

Autophagy is a highly conserved catabolic process and a major cellular pathway for the degradation of long-lived proteins and cytoplasmic organelles. An increasing body of evidence has unveiled autophagy as an indispensable biological function that helps to maintain normal tissue homeostasis and metabolic fitness that can also lead to severe consequences for the normal cellular functioning when altered. Recent accumulating data point to autophagy as a key player in a wide variety of physiological and pathophysiological conditions in the human endometrium, one of the most proficient self-regenerating tissues in the human body and an instrumental player in placental species reproductive function. The current review highlights the most recent findings regarding the process of autophagy in the normal and cancerous endometrial tissue. Current research efforts aiming to therapeutically exploit autophagy and the methodological approaches used are discussed.Abbreviations: 3-MA: 3-methyladenine; ACACA (acetyl-CoA carboxylase alpha); AICAR: 5-aminoimidazole-4-carboximide riboside; AKT: AKT serine/threonine kinase; AMPK: AMP-activated protein kinase; ATG: autophagy related; ATG12: autophagy related 12; ATG16L1: autophagy related 16 like 1; ATG3: autophagy related 3; ATG4C: autophagy related 4C cysteine peptidase; ATG5: autophagy related 5; ATG7: autophagy related 7; ATG9: autophagy related 9; Baf A1: bafilomycin A1; BAX: BCL2 associated X, apoptosis regulator; BCL2: BCL2 apoptosis regulator; BECN1: beclin 1; CACNA1D: calcium voltage-gated channel subunit alpha1 D; CASP3: caspase 3; CASP7: caspase 7; CASP8: caspase 8; CASP9: caspase 9; CD44: CD44 molecule (Indian blood group); CDH1: cadherin 1; CDKN1A: cyclin dependent kinase inhibitor 1A; CDKN2A: cyclin dependent kinase inhibitor 2A; CMA: chaperone-mediated autophagy; CQ: chloroquine; CTNNB1: catenin beta 1; DDIT3: DNA damage inducible transcript 3; EC: endometrial cancer; EGFR: epidermal growth factor receptor; EH: endometrial hyperplasia; EIF4E: eukaryotic translation initiation factor 4E; EPHB2/ERK: EPH receptor B2; ER: endoplasmic reticulum; ERBB2: er-b2 receptor tyrosine kinase 2; ERVW-1: endogenous retrovirus group W member 1, envelope; ESR1: estrogen receptor 1; FSH: follicle-stimulating hormone; GCG/GLP1: glucagon; GFP: green fluorescent protein; GIP: gastric inhibitory polypeptide; GLP1R: glucagon-like peptide-1 receptor; GLS: glutaminase; H2AX: H2A.X variant histone; HIF1A: hypoxia inducible factor 1 alpha; HMGB1: high mobility group box 1; HOTAIR: HOX transcript antisense RNA; HSPA5: heat shock protein family A (HSP70) member 5; HSPA8: heat shock protein family A (HSP70) member 8; IGF1: insulin like growth factor 1; IL27: interleukin 27; INS: insulin; ISL: isoliquiritigenin; KRAS: KRAS proto-oncogene, GTPase; LAMP2: lysosomal-associated membrane protein 2; lncRNA: long-non-coding RNA; MAP1LC3A/LC3A: microtubule associated protein 1 light chain 3 alpha; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MAPK8: mitogen-activated protein kinase 8; MAPK9: mitogen-activated protein kinase 9; MPA: medroxyprogesterone acetate; MTOR: mechanistic target of rapamycin kinase; MTORC1: mechanistic target of rapamycin kinase complex 1; MTORC2: mechanistic target of rapamycin kinase complex 2; MYCBP: MYC-binding protein; NFE2L2: nuclear factor, erythroid 2 like 2; NFKB: nuclear factor kappa B; NFKBIA: NFKB inhibitor alpha; NK: natural killer; NR5A1: nuclear receptor subfamily 5 group A member 1; PARP1: poly(ADP-ribose) polymerase 1; PAX2: paired box 2; PDK1: pyruvate dehydrogenase kinase 1; PDX: patient-derived xenograft; PIK3C3/Vps34: phosphatidylinositol 3-kinase catalytic subunit type 3; PIK3CA: phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha; PIK3R1: phosphoinositide-3-kinase regulatory subunit 1; PIKFYVE: phosphoinositide kinase, FYVE-type zinc finger containing; PPD: protopanaxadiol; PRKCD: protein kinase C delta; PROM1/CD133: prominin 1; PtdIns3K: class III phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; PTEN: phosphatase and tensin homolog; RB1CC1/FIP200: RB1 inducible coiled-coil 1; RFP: red fluorescent protein; RPS6KB1/S6K1: ribosomal protein S6 kinase B1; RSV: resveratrol; SGK1: serum/glucocorticoid regulated kinase 1; SGK3: serum/glucocorticoid regulated kinase family member 3; SIRT: sirtuin; SLS: stone-like structures; SMAD2: SMAD family member 2; SMAD3: SMAD family member 3; SQSTM1: sequestosome 1; TALEN: transcription activator-like effector nuclease; TGFBR2: transforming growth factor beta receptor 2; TP53: tumor protein p53; TRIB3: tribbles pseudokinase 3; ULK1: unc-51 like autophagy activating kinase 1; ULK4: unc-51 like kinase 4; VEGFA: vascular endothelial growth factor A; WIPI2: WD repeat domain, phosphoinositide interacting 2; XBP1: X-box binding protein 1; ZFYVE1: zinc finger FYVE domain containing 1.

Unravelling the potential of angiogenic factors for the early prediction of preeclampsia

Preeclampsia is a multisystem, multiorgan hypertensive disorder of pregnancy responsible for maternal and perinatal morbidity and mortality in low- and middle-income countries. The classic diagnostic features hold less specificity for preeclampsia and its associated adverse outcomes, suggesting a need for specific and reliable biomarkers for the early prediction of preeclampsia. The imbalance of pro- and antiangiogenic circulatory factors contributes to the pathophysiology of preeclampsia. Several studies have examined the profile of angiogenic factors in preeclampsia to search for a biomarker that will improve the diagnostic ability of preeclampsia and associated adverse outcomes. This may help in more efficient patient management and the reduction of associated health care costs. This article reviews the findings from previous studies published to date on angiogenic factors and suggests a need to apply a multivariable model from the beginning of pregnancy and continuing throughout gestation for the early and specific prediction of preeclampsia.

Fractalkine enhances endometrial receptivity and activates iron transport towards trophoblast cells in an in vitro co-culture system of HEC-1A and JEG-3 cells

Endometrium receptivity and successful implantation require a complex network of regulatory factors whom production is strictly controlled especially at the implantation window. Many regulators like steroid hormones, prostaglandins, cytokines, extracellular matrix proteins and downstream cell signalling pathways are involved in the process of embryo-endometrium interaction. Our work reveals the effect of fractalkine (FKN), a unique chemokine on progesterone receptor, SOX-17 and NRF2 expressions in HEC-1A endometrial cell line. FKN activates fractalkine receptor signalling and the expression of SOX-17 through progesterone receptor in HEC-1A endometrial cells, and as a consequence it increases endometrial receptivity. Fractalkine also activates the NRF2-Keap-1 signal transduction pathway regulating the IL-6 and IL-1β cytokine productions, which increase endometrial receptivity, as well. The NRF2 transcription factor increases the expression of the iron exporter ferroportin in HEC-1A cells activating iron release towards JEG-3 trophoblast cells. The iron measurements show that iron content of endometrial cells decreases while heme concentration increases at FKN treatment. At the same time, the trophoblast cells show increased iron uptake and total iron content. Based on our results it seems that FKN enhances the establishment of endometrial receptivity and meanwhile it regulates the iron homeostasis of endometrium contributing to the iron availability of the trophoblast cells and the embryo.

Inflammatory Markers in Peripheral Blood Cells Cannot Predict Intrauterine Insemination Outcome: A Retrospective Cohort Study

Background:

Although infertility is known as a chronic inflammatory condition, the effect of the increased inflammatory response on IUI success is not clear. Systemic inflammation can be calculated by applying various hematological markers.

Aims:

We aimed to evaluate the ability of hematologic parameters of inflammation in predicting intrauterine insemination (IUI) outcome.

Study Setting and Design:

A total of 334 infertile couples included in this retrospective cohort study. The study population comprised of all couples who were candidates for ovulation induction and IUI due to polycystic ovary syndrome (PCOS) (n = 147) or unexplained infertility (UI) (n = 187).

Materials and Methods:

The inflammatory parameters in the complete blood count parameters, such as neutrophil-lymphocyte ratio, platelet lymphocyte ratio, platelet distribution width, plateletcrit were obtained on IUI day and compared between the two groups. The predictive values of these markers for IUI outcome were calculated.

Results:

There were 44 pregnancies (13.2%) in the whole study cohort. There were no significant differences between the pregnant and nonpregnant groups regarding the evaluated parameters (all P > 0.05). Also, no significant difference was observed between the patients with PCOS and UI in terms of those parameters. The area under receiver operating characteristic (ROC) curve analysis revealed that none of the inflammatory markers can predict pregnancy in intrauterine insemination cycles. Further prospective studies are needed to verify our findings.

Conclusion:

We found no relationship between the hematologic inflammatory markers and IUI outcome.Therefore these markers cannot be used for prediction of pregnancy.

Notch1 is crucial for decidualization and maintaining the first pregnancy in the mouse†

The endometrium undergoes a pregnancy-delivery-repair cycle multiple times during the reproductive lifespan in females. Decidualization is one of the critical events for the success of this essential process. We have previously reported that Notch1 is essential for artificial decidualization in mice. However, in a natural pregnancy, the deletion of Notch1 (PgrCre/+Notch1f/f, or Notch1d/d) only affects female fertility in the first 30 days of a 6-month fertility test, but not the later stages. In the present study, we undertook a closer evaluation at the first pregnancy of these mice to attempt to understand this puzzling phenomenon. We observed a large number of pregnancy losses in Notch1d/d mice in their first pregnancy, which led to the subfertility observed in the first 30 days of the fertility test. We then demonstrated that the initial pregnancy loss is a consequence of impaired decidualization. Furthermore, we identified a group of genes that contribute to Notch1 regulated decidualization in a natural pregnancy. Gene ontogeny analysis showed that these differentially expressed genes in the natural pregnancy are involved in cell-cell and cell-matrix interactions, different from genes that have been previously identified from the artificial decidualization model, which contribute to cell proliferation and apoptosis. In summary, we determined that Notch1 is essential for normal decidualization in the mouse uterus only in the first pregnancy but not in subsequent ones.

Differential regulation of osteopontin and CD44 correlates with infertility status in PCOS patients

Endometrial receptivity is mediated by adhesion molecules at the endometrium-trophoblast interface where osteopontin (OPN) and CD44 form a protein complex that plays an important role in embryo recognition. Here, we undertook a prospective study investigating the expression and regulation of OPN and CD44 in 50 fertile and 31 infertile ovulatory polycystic ovarian syndrome (PCOS) patients in the proliferative and secretory phases of the natural menstrual cycle and in 12 infertile anovulatory PCOS patients. Endometrial biopsies and blood samples were evaluated for expression of OPN and CD44 using RT-PCR, immunohistochemistry and ELISA analysis to determine circulating levels of OPN, CD44, TNF-α, IFN-γ and OPN and CD44 levels in biopsy media. Our findings highlighted an increased level of circulating OPN and CD44 in serum from infertile patients that inversely correlated with expression levels in endometrial tissue and positively correlated with levels secreted into biopsy media. OPN and CD44 levels positively correlated to each other in serum and media from fertile and PCOS patients, as well as to circulating TNF-α and IFN-γ. In vitro analysis revealed that hormone treatment induced recruitment of ERα to the OPN and CD44 promoters with a concomitant increase in the expression of these genes. In infertile patients, inflammatory cytokines led to recruitment of NF-κB and STAT1 proteins to the OPN and CD44 promoters, resulting in their overexpression. These observations suggest that the endometrial epithelial OPN-CD44 adhesion complex is deficient in ovulatory PCOS patients and displays an altered stoichiometry in anovulatory patients, which in both cases may perturb apposition. This, together with elevated circulating and local secreted levels of these proteins, may hinder endometrium-trophoblast interactions by saturating OPN and CD44 receptors on the surface of the blastocyst, thereby contributing to the infertility associated with ovulating PCOS patients. KEY MESSAGES: • Endometrial epithelial OPN-CD44 adhesion complex levels are deficient in ovulatory PCOS patients contributing to the endometrial infertility associated with ovulating PCOS patients. • Circulating levels of OPN, CD44 and inflammatory cytokines TNF-α and IFN-γ are altered in infertile PCOS patients. • Increased levels of both OPN and CD44 in biopsy media and serum inversely correlate with endometrial expression of these markers in endometrial tissue. • In infertile PCOS patients, high levels of oestrogens and inflammatory cytokines stimulate the recruitment of transcription factors to the OPN and CD44 promoters to enhance gene transcription. • Our study identifies a novel crosstalk between the CD44-OPN adhesion complex, ERα, STAT1 and NF-κB pathways modulating endometrial receptivity.