Spontaneous abortion (SA) remains a clinical challenge in early pregnancy. It has been reported that endoplasmic reticulum stress (ERS) is implicated in pregnancy-related complications. However, the precise mechanistic role of ERS in SA pathogenesis remains elusive. This study aims to explore the therapeutic potential of targeting ERS-related decidual dysfunction in SA.

An ERS model was established in both decidualized stromal cells (DSCs) and pregnant mice through tunicamycin (Tu) administration. Chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays were performed to determine the interaction between XBP1s and the transcription factor binding site (TFBS) of tumor necrosis factor receptor-associated factor 6 (TRAF6). Mitochondrial membrane potential (MMP) and mitochondrial function were assessed using JC-1 and TMRM staining following ERS induction in DSCs. The effects of XBP1s inhibitors on mitochondrial metabolism and autophagy were evaluated through RT-qPCR, Western blotting, RNA-Seq, TUNEL assays, ROS and MitoSOX detection, and histological analyses in Tu-treated DSCs and SA patients. STF-083010 (STF) or shXBP1 was utilized to assess the inhibitory effects of X-box binding protein 1 (XBP1s) on DSC function both in vitro and in vivo.

We observed significant upregulation of XBP1s in decidual tissues from SA patients and Tu-exposed DSCs. Tu exposure significantly increased the proportion of TUNEL-positive cells and upregulated pro-inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-18) in DSCs. XBP1s inhibition via shXBP1 or pharmacological inhibitor STF attenuated Tu-induced apoptosis and inflammatory cytokine expression. Notably, STF or shXBP1 treatment enhanced MMP and upregulated LC3-II expression in Tu-treated DSCs, indicating autophagy activation.Intriguingly, chloroquine (CQ)-mediated autophagy suppression exacerbated apoptosis in STF/Tu-co-treated DSCs, suggesting that XBP1s inhibition confers cytoprotection through autophagy induction. Mechanistically, XBP1s directly bound to the TFBS of TRAF6, a ubiquitin E3 ligase. TRAF6 overexpression exacerbated mitochondrial dysfunction and apoptosis while suppressing autophagy via inhibition of mTORC2/Akt pathway in Tu-treated DSCs.

XBP1s inhibition restored mitochondrial homeostasis and promoted autophagy by modulating the TRAF6/mTORC2 axis under ERS conditions, providing novel mechanistic insights into SA pathogenesis and potential therapeutic targets.

Embryo implantation relies on complex mother-fetus interactions. Abnormal decidualization can cause various pregnancy complications such as placental abnormalities, preeclampsia, and fetal growth restriction. circRNAs play a key role in various cellular processes. This study focuses on the role of circ-Hdac4, a circRNA derived from the Hdac4 gene, in decidualization and placental function. Mouse models revealed a spatiotemporally regulated expression of circ-Hdac4 in the endometrium during early pregnancy, with enhanced expression surrounding implantation sites. In vitro and in vivo assays confirmed that circ-Hdac4 is crucial for stromal cell decidualization, as its knockdown resulted in reduced expression of decidualization markers and disrupted endometrial architecture. Furthermore, we found that circ-Hdac4 functions as a microRNA sponge for miR-30c, which negatively regulates RBPJ, a critical protein for decidual remodeling. Proteomic analysis revealed that RBPJ was downregulated upon circ-Hdac4 silencing, and we validated the direct interaction between miR-30c and RBPJ using luciferase reporter assays. A mouse preeclampsia model showed that downregulation of circ-Hdac4 during decidualization exacerbated preeclampsia-related phenotypes, including reduced fetal counts, weights, and placental weights. In addition, we observed decreased expression of circ-Hdac4 and RBPJ in the decidual surface of placental tissues from preeclampsia patients, further supporting our findings in the mouse model. Collectively, our study provides evidence that circ-Hdac4 regulates decidualization through the miR-30c-RBPJ axis and that its abnormal expression during decidualization contributes to placental dysfunction in preeclampsia. This research offers novel insights into the molecular mechanisms underlying pregnancy complications and potential therapeutic targets for their prevention and treatment.

While Zika virus (ZIKV) infection in pregnant women is known to increase the risk of miscarriage and stillbirth, the mechanism by which ZIKV infection leads to the inability to continue a pregnancy is not clear. In our common marmoset models of ZIKV infection in pregnant individuals, miscarriage was observed in dams infected in the first or second trimester, and preterm delivery was observed in a dam infected in the third trimester. Serum progesterone levels were significantly lower prior to miscarriage or preterm delivery in the infected marmosets. To elucidate the pathology of the placental region just before the onset of ZIKV-induced miscarriage, we newly prepared an infected marmoset in the first trimester of pregnancy and euthanized it when the serum progesterone concentration was markedly reduced. Pathological analysis revealed significant degeneration in cells at the maternal-fetal interface, presumably trophoblasts. Cleaved-caspase was widely observed in the endometrial to placental region, and TNFα at 200 pg/mL was detected in the amniotic fluid, suggesting that apoptosis may progress in the endometrium and placenta, leading to decreased trophoblast function and miscarriage. ZIKV NS1 protein was found sporadically in the cellular degeneration area and widely in the basal layer of the endometrium. Furthermore, the viral protein was frequently detected in the follicles and corpus luteum of the ovary. The developed ZIKV infection model in pregnant marmosets would be useful not only to better understand the mechanism of ZIKV-induced miscarriage but also to analyze the effects of the viral infection on female reproductive tissues.

Although several viruses, including Zika virus (ZIKV), are known to increase the risk of miscarriage upon viral infection, the mechanism by which miscarriage is induced by viral infection is largely unknown. This is partly due to the difficulty of pathological analysis of maternal tissues in the period following viral infection and prior to miscarriage. In this study, we predicted the occurrence of miscarriage by monitoring serum progesterone levels and performed pathological analysis of peri-placental tissues at a time point assumed to be just before miscarriage. This is the first report of trophoblast degeneration prior to miscarriage, suggesting that the experimental method used here is useful for analyzing the pathogenesis of virus infection-related miscarriage. Further immunostaining revealed that ZIKV NS1 was distributed not only in the uterus but also in the ovaries, with particularly pronounced staining of oocytes. Whether ZIKV infection affects female reproductive function should be clarified in the future.

Glyphosate-based herbicides (GBHs) are the most widely used herbicides in the United States, accounting for 19% of estimated global use. Although the Environmental Protection Agency (EPA) has reaffirmed that the active ingredient glyphosate (GLY) is safe for humans, recent studies on exposure have suggested association with cancer, metabolic disorders, endocrine disruption and infertility, Alzheimer's and Parkinson's disease, and psychological disorders. Current literature on the effects of GLY exposure on reproductive function suggests potential clinical implications on women's reproductive health, including polycystic ovarian syndrome (PCOS), endometriosis, infertility, and adverse pregnancy outcomes. The continued debate surrounding GLY exposure increasingly exemplifies the public health issue surrounding its consequences on female reproductive health, human fertility, and the potential epigenetic effects. In this review, we discuss the potential mechanisms of toxicity and endocrine disruption of GLY on the female reproductive tract and highlight possible implications of GLY exposure on reproductive health outcomes. GLY adversely affects the female reproductive system through increased oxidative stress, endocrine disruption of reproductive hormones, histological changes in ovarian and uterus tissue, and diminished ovarian function in human cell lines and animals. We conclude that increased research efforts are warranted regarding the safety and efficacy of GBH as it pertains to female reproduction, as well as investments in cost-effective alternatives with the potential to reduce GBH usage.

Decidual CD8+T (dCD8+T) cells are pivotal in the maintenance of the delicate balance between immune tolerance towards the fetus and immune resistance against pathogens. The endometrium and decidua represent the uterine environments before and during pregnancy, respectively, yet the composition and phenotypic alterations of uterine CD8+T cells in these tissues remain unclear. Using flow cytometry and analysis of transcriptome profiles, we demonstrated that human dCD8+T and endometrial CD8+T (eCD8+T) cells exhibited similar T cell differentiation statuses and phenotypes of tissue infiltrating or residency, compared to peripheral CD8+T (pCD8+T) cells. However, dCD8+T cells showed decreased expression of coinhibitory marker (PD-1), chemotaxis marker (CXCR3), and tissue-resident markers (CD69 and CD103), along with increased expression of granzyme B and granulysin, compared to eCD8+T cells. In vitro cytotoxicity assays further demonstrated that dCD8+T cells had greater effector functions than eCD8+T cells. Additionally, both in vitro and in vivo chemotaxis assays confirmed the recruitment of non-resident effector memory T cell subsets to the pregnant decidua, contributing to the dCD8+T cell-mediated anti-infection mechanism at the maternal-fetal interface. This work demonstrates dCD8+T cells replenished from the circulation retain their cytotoxic capacity, which may serve as an enhanced defense mechanism against infection during pregnancy.

Implantation is a complex and tightly regulated process essential for the establishment of pregnancy. It involves dynamic interactions between a receptive uterus and a competent embryo, orchestrated by ovarian hormones such as estrogen and progesterone. These hormones regulate proliferation, differentiation, and gene expression within the three primary uterine tissue types: myometrium, stroma, and epithelium. Advances in genetic manipulation, particularly the Cre/loxP system, have enabled the in vivo investigation of the role of genes in a uterine compartmental and cell type-specific manner, providing valuable insights into uterine biology during pregnancy and disease. The development of endometrial organoids has further revolutionized implantation research. They mimic the native endometrial structure and function, offering a powerful platform for studying hormonal responses, implantation, and maternal-fetal interactions. Combined with omics technologies, these models have uncovered the molecular mechanisms and signaling pathways that regulate implantation. This review provides a comprehensive overview of uterine-specific genetic tools, endometrial organoids, and omics. We explore how these advancements enhance our understanding of implantation biology, uterine receptivity, and decidualization in reproductive research.

We aim to increase knowledge on pregnancy and delivery risks in vascular Ehlers-Danlos Syndrome (vEDS). Our outcomes can contribute to establishing future guidelines for pregnancy and delivery management in women with vEDS.

Retrospective multicentre cohort study.

Women with vEDS due to pathogenic/likely pathogenic (P/LP) COL3A1 variants are at increased risk for arterial dissection and pregnancy-related complications during pregnancy and delivery.

Women with a P/LP COL3A1 variant were included from 2019 until 2021.

Genetic and clinical data was collected through retrospective analysis.

Description of the genotype and pregnancy-related outcomes.

We collected information about 121 pregnancies of 43 women with vEDS, including nine women with a haploinsufficient variant. Neither uterine rupture nor life-threatening or fatal vascular events occurred in the perinatal period. The miscarriage rate was 19% (23/121) and 19.1% of the live births were preterm (18/94). Miscarriages were significantly more frequent in women with a glycine substitution in COL3A1 compared to other COL3A1 variant types (19/23, 82.6%, p = 0.018). Thirty-four women had a vaginal birth (79.1%), including 1/7 with known vEDS. Eight deliveries were complicated by severe perineal tears, and six by postpartum haemorrhage.

No pregnancy-related deaths, arterial dissections or uterine ruptures occurred in our cohort. Since no life-threatening events occurred during pregnancy and delivery, discouragement of pregnancy in all women with vEDS in current guidelines might be too strict. Based on these data, we propose a shared decision-making process.

This study is the first attempt to examine the effects of NETA on immune cells and telocytes. The results of this study form an important knowledge base for the development of new information on the mechanism of contraceptive action of NETA in the uterus. Norethisterone acetate (NETA) is a synthetic progestogen medication commonly utilized in birth control pills, menopausal hormone therapy, and for curing abnormal uterine bleeding and endometriosis. Furthermore NETA has many beneficial uses in veterinary medicine as control and synchronization of estrous cycle. The impact of NETA on the endometrial stromal cells (ESCs), telocytes, and uterine immune cells is not well understood. Therefore, this study focuses on assessing changes in uterine immune cells, ESCs, and telocytes following exposure to NETA in albino rats. To achieve this objective, fourteen adult female albino rats were randomly divided into two groups: a control group and an NETA-treated group. Rats in the control group received daily pelleted food, water, and were oral administered of 2 ml distilled water. In contrast, rats in the NETA-treated group received daily pelleted food, water, and were orally administered 20 µg of NETA dissolved in 2 ml distilled water. The experiment spanned three weeks. The findings of this study revealed that NETA usage increases the infiltration and activity of immune cells (eosinophils, neutrophils, macrophages, lymphocytes, and mast cells). Furthermore, it enhances the vesicular activity of uterine telocytes and their communication with various immune cells. NETA also influences decidualization and the immunoexpression of progesterone receptors in uterine epithelial and immune cells. This study concludes that the primary mechanism by which NETA controls pregnancy is through decidual (pregnancy-like) effects or improper decidualization, which inhibits fertilization and implantation respectively. Our research provides evidence of the contraceptive mechanism of NETA from an immunological perspective in an animal model.

This study aims to investigate the function of miR-424 and miR-503, identified as putative regulatory miRNAs of FOXO1, a key factor for decidualization. The expression of both miR-424 and miR-503 in human endometrial stromal cells (HESCs) were measured before and after decidualization. Then, HESCs were transfected with both miR-424 and miR-503 before decidualization. Quantitative reverse transcription PCR, actin staining analysis, migration assay, fluorescence immunostaining, and luciferase assay were performed. MiR-424 and miR-503 expression was decreased after decidualization. Overexpression of both miR-424 and miR-503 inhibited major decidual maker genes, including FOXO1, PRL, IGFBP1, WNT4, and SCARA5, and altered F-actin's subcellular distribution from the periphery to all over the cytoplasm, concomitantly increasing cell mobility. Moreover, immunohistochemical analysis revealed overexpression of both miRNAs resulted in FOXO1 protein accumulation in the cytoplasm. Knocking down FOXO1 decreased SCARA5 expression, revealing SCARA5 is a downstream target of FOXO1. In addition, a luciferase reporter assay confirmed that the 3'-untranslated region of FOXO1 mRNA is targeted by miR-424. These results suggest that both miRNAs may play an important role in endometrial decidualization by regulating transcriptional activity of FOXO1, which alters decidualization-related gene expression such as SCARA5.Abstract: Journal standard instruction requires an unstructured abstract; hence structured abstract changed to unstructured.Thank you for the correction. I approve this change.

Human endometrial mesenchymal stem cells (H-EMSCs) can inhibit endometrial fibrosis and repair damaged endometrium. However, direct cell injection into dam-aged endometrium shows limited cell survival. Cell seeding onto biomaterial-based electrospun membranes could improve H-EMSCs' survival and prolong their stay at the damaged endometrium. Polycaprolactone (PCL), silk fibroin (SF) and hyaluronic acid (HA) are synthetic or natural biomaterials used by the biomedicine field, however, their effects on the biological activities of H-EMSCs remain unclear.

In this study, CD90+CD73+CD45- H-EMSCs were extracted from human endometrium and H-EMSCs showed enhanced adhesion, proliferation on PCL-HA vs. PCL, PCL-SF, establishing the potential of the composite to address cell survival issues.

H-EMSCs cultured on PCL-HA showed decreased IL-6 gene expression and increased IL-10, VEGFA, TGF-β gene expression vs. PCL-SF, establishing the potential to create a favorable micro-environment for generating vascularized endometrial tissues. PCL, PCL-SF, PCL-HA all supported CD90 and Meflin expression of the seeded H-EMSCs, establishing PCL as a platform to form enhanced biomaterial composites for endometrial repair in the future.

This study provided significant evidence sup-porting the potential of appropriately tailored composites of PCL and HA to moder-ate inflammation and wound-healing, which can be applied for endometrial tissue repair and regeneration.

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.

Prior to embryo implantation, the endometrial stromal cells (ESCs) during the menstrual cycle undergo a significant structural and functional transformation known as decidualization to support conception. During this process, glucose consumption and utilization by endometrial cells increase to meet energy demands. Abnormal glucose metabolism in the endometrium impairs decidualization, leading to pregnancy complications, including implantation failure and pregnancy loss. However, the mechanisms modulating glucose metabolism in endometrial stromal cells during decidualization are still unclear. In this review, we describe the functions and regulation of glucose transporters (GLUTs) involved in glucose uptake, as well as the modulation of key enzymes catalyzing glucose utilization. Moreover, we present recent findings on the role of glucose related metabolites in the decidualization of ESCs.

Endometriosis is an estrogen dependent disease, which is related to infertility. Decidualization is a prerequisite for successful implantation of human embryos, and endometriosis affects the occurrence of decidualization. However, the mechanism that affects decidualization in endometriosis is not fully understood. Here, we find that Aurora kinase A (AURKA) is upregulated in the eutopic endometrium of endometriosis. AURKA inhibits the decidualization of stromal cells in the eutopic endometrium of endometriosis. Furthermore, in animal experiments, AURKA promotes endometriosis and inhibits decidualization in mice with endometriosis, leading to decreased expression of decidualization markers, such as prolactin, insulin-like growth factor-binding protein-1, and desmin. Afterwards, we find that nuclear factor-κB (NF-κB) p65 is a new substrate of AURKA. AURKA interacts with p65 to promote its phosphorylation and nuclear translocation. Meanwhile, AURKA enhances the protein stability of p65 by prolonging its half-life. In summary, AURKA inhibits the decidualization of the eutopic endometrium in patients with endometriosis by regulating p65, which may provide new ideas for improving decidualization defect in patients with endometriosis.

During development, the remodelling of fibrillar components of the uterine extracellular matrix (ECM), mediated by the matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), plays an essential role in embryonic survival. Previously, we observed that in the plains viscacha (Lagostomus maximus), only caudal implantation sites (IS) contain viable embryos, whereas embryos at cranial and middle IS die and are reabsorbed. The objective of this study was to analyse the distribution and expression of key components of the endometrial ECM, including fibrillar collagens, MMPs 2 and 9, and TIMPs 1 and 2, in three uterine segments (US) of the non-pregnant adult viscachas. In sections from three US, we observed a significant craniocaudal increase in collagen fibres (Van Gieson and Picrosirius red staining) and elastic fibres (Verhoeff-Van Gieson trichrome staining), along with the immunolabelling levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 (immunohistochemistry). Zymography revealed similar gelatinolytic activity of MMP-2 in the three US but higher than the MMP-9 activity. However, MMP-9 activity in the caudal segment was significantly higher than that in the cranial and middle ones. These findings suggest that uterine ECM variations along the craniocaudal axis may contribute to uterine remodelling processes that regulate embryonic survival during gestation.

The uterus is a complex organ that requires precise signaling networks to mediate functions necessary for homeostasis and reproductive processes. The transforming growth factor β (TGFβ) superfamily regulates integral signaling pathways throughout many physiological processes, including cell proliferation, differentiation, and development. In this review, we summarize the current understanding of how the TGFβ signaling family controls key uterine functions, with a specific focus on the endometrium. These uterine functions include endometrial receptivity, implantation, decidualization, placentation, remodeling, and regeneration. Improving our understanding of the signaling networks that regulate these processes is integral to identifying, diagnosing, and treating uterine and reproductive diseases such as endometriosis, adenomyosis, recurrent pregnancy loss, and recurrent implantation failure.

Recurrent pregnancy loss (RPL) of unknown genesis is a complex condition with multifactorial origins, including genetic, hormonal, and immunological factors. However, the specific mechanisms underlying endocervical cell proliferation disorders in women with RPL remain inadequately understood, particularly concerning the role of microbiota and viral infections. The aim of this study was to investigate the mechanisms of endocervical cell proliferation disorders in women with RPL of unknown genesis by examining microbiota, human papillomavirus (HPV) typing, and the expression levels of key molecular biological markers, including p16/Ki-67, BCL-2, miR-145, and miR-34a. A prospective observational comparative study was executed on women with RPL and healthy pregnant controls with full ethical approval. Samples were collected for HPV typing and immunocytochemical analysis to evaluate the expression of p16, Ki-67, BCL-2, and the anti-oncogenic microRNAs (miR-145 and miR-34a). The expression of mRNA for the progesterone receptor (PGR-A) was also assessed, alongside local immune status markers, including proinflammatory T-lymphocytes (Th17/Th1) and regulatory CD4+ Tregs. Overexpression of p16, Ki-67, and BCL-2 was observed in 52.5% of women with RPL who had an ASC-US/LSIL cytogram, with the average double expression of p16/Ki-67 being three times higher than in the healthy pregnant group. A significant decrease in PGR-A mRNA expression in the endocervix of women with RPL was noted, accompanied by a dysregulated local immune status characterized by an increased prevalence of Th17/Th1 cells and a reduction in regulatory CD4+ Tregs. Additionally, the expression of miR-145 and miR-34a in the endocervix and endometrium of women with RPL significantly differed from the physiological pregnancy group, particularly in the context of high-risk HPV infection. The findings describe that disorders of endocervical cell proliferation in women with RPL of unknown genesis are associated with overexpression of specific molecular markers, impaired immune regulation, and altered microRNA profiles. These alterations may contribute to the pathophysiology of RPL, highlighting the need for further research into targeted interventions that could improve reproductive outcomes in affected individuals.

Cadmium (Cd) is a toxic heavy metal with a high propensity to accumulate within the body, and Cd accumulation has been shown to cause organ damage. However, it is unclear whether Cd accumulation is a cause of impaired decidualization, which induces to spontaneous abortion (SA). In this study, we found that the decidual Cd concentration was increased in patients with SA and positively correlated with the occurrence of SA. The levels of two decidualization markers (prolactin, PRL and insulin-like growth factor binding protein 1, IGFBP1) were reduced in the decidua of all-cause SA patients. Using 8-week ICR female mice, we further established a uterus-specific Cd accumulation mouse model and verified that Cd-accumulating mice had increased numbers of absorbed fetuses and defective decidualization. Finally, using in vitro-cultured human ENdometrial stromal cells (hEnSCs), we found that Cd accumulation significantly inhibited decidualization; and moreover, Cd treatment downregulated the regulatory genes upstream of PRL and IGFBP1 such as PGR, ESR1, ESR2 and FOXO1. This study suggests that Cd accumulation could produce impaired decidualization by downregulating the upstream regulators of PRL and IGFBP1, thereby increasing the risk of SA. Our study offered new possibilities for the prevention and treatment of spontaneous abortion.

Recurrent implantation failure (RIF) is characterized by the repeated failure of implantation, often linked to impaired endometrial receptivity. This study investigates how granulocyte colony-stimulating factor (G-CSF) promotes endometrial stromal cell decidualization.

THESCs (human telomerase reverse transcriptase-immortalized endometrial stromal cells) were used as an in vitro cell model to induce decidualization. The effects of G-CSF on the expression of decidualization genes and apoptosis during decidualization were examined. Additionally, a chemical inhibitor of signal transducer and activator of transcription 3 (STAT3) and the small interfering RNA (siRNA) targeting Homeobox A10 (Hoxa10) were employed to explore the involvement of the STAT3/HOXA10 axis in the action of G-CSF.

G-CSF promoted decidualization markers expression and suppressed apoptosis in THESCs Treatment with G-CSF enhanced STAT3 activation during decidualization induction. STAT3 inhibition diminished the effects of G-CSF on decidualization marker expression and apoptosis suppression. Furthermore, it was demonstrated that G-CSF increased Hoxa10 expression in a STAT3-dependent manner. Silencing Hoxa10 abrogated the effects of G-CSF on promoting decidualization.

G-CSF enhances decidualization of endometrial stromal cells via STAT3/HOXA10 axis activation. These findings suggest that optimal G-CSF delivery strategies could improve endometrial receptivity in RIF patients.

Recurrent miscarriage (RM) is a distressing and complicated adverse pregnancy outcome. It is commonly recognized that insufficient decidualization could result in RM, but the molecular mechanisms of decidual impairment are still not fully understood. Thus, this study aimed to identify novel key genes potentially involved in RM and explore their roles played in endometrial decidualization.

Initially, a combinative analysis of decidual and mid-secretory endometrial transcriptomes was performed to discover hub genes involved in the etiology of RM. And the expression levels of hub genes were evaluated in both primary decidual stromal cells (DSCs) and decidual tissues. Subsequently, the immortalized human endometrial cell line, T-HESCs, was used to investigate whether FXYD1 overexpression affects decidualization by regulating Na/K-ATPase activity.

FXYD domain containing ion transport regulator 1 (FXYD1) was identified as a hub gene in the pathogenesis of RM through various bioinformatic methods. Abnormally increased FXYD1 expression was observed in DSCs and decidual tissues from RM patients compared to that of the normal group. Furthermore, in vitro decidualization was obviously inhibited by the overexpression of FXYD1. Additionally, Na/K-ATPase activity was significantly elevated during decidualization, whereas overexpression of FXYD1 reduced Na/K-ATPase activity. Bufalin, a Na/K-ATPase inhibitor, showed an effectively inhibitory effect on decidualization.

Collectively, FXYD1 was discovered as a hub gene associated with RM, and its expression levels in RM patients were significantly upregulated. Increased FXYD1 expression might lead to decidualization defects by reducing Na/K-ATPase activity, of which presented a novel prospective treatment target for RM.

Endometrial decidualization resistance (DR) is implicated in various gynecological and obstetric conditions. Here, using a multi-omic strategy, we unraveled the cellular and molecular characteristics of DR in patients who have suffered severe preeclampsia (sPE). Morphological analysis unveiled significant glandular anatomical abnormalities, confirmed histologically and quantified by the digitization of hematoxylin and eosin-stained tissue sections. Single-cell RNA sequencing (scRNA-seq) of endometrial samples from patients with sPE (n = 11) and controls (n = 12) revealed sPE-associated shifts in cell composition, manifesting as a stromal mosaic state characterized by proliferative stromal cells (MMP11 and SFRP4) alongside IGFBP1+ decidualized cells, with concurrent epithelial mosaicism and a dearth of epithelial-stromal transition associated with decidualization. Cell-cell communication network mapping underscored aberrant crosstalk among specific cell types, implicating crucial pathways such as endoglin, WNT and SPP1. Spatial transcriptomics in a replication cohort validated DR-associated features. Laser capture microdissection/mass spectrometry in a second replication cohort corroborated several scRNA-seq findings, notably the absence of stromal to epithelial transition at a pathway level, indicating a disrupted response to steroid hormones, particularly estrogens. These insights shed light on potential molecular mechanisms underpinning DR pathogenesis in the context of sPE.

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.

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 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 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.

At the maternal-fetal interface, tightly regulated levels of retinoic acid (RA), the physiologically active metabolite of vitamin A, are required for embryo implantation and pregnancy success. Herein, we utilize mouse models, primary human cells, and pharmacological tools to demonstrate how depletion of RA signaling via RA receptor (RAR) disrupts implantation and progression of early pregnancy. To inhibit RAR signaling during early pregnancy, BMS493, an inverse pan-RAR agonist that prevents RA-induced differentiation, was administered to pregnant mice during the peri-implantation period. Attenuation of RA/RAR signaling prior to embryo implantation results in implantation failure, whereas attenuation of RA/RAR signaling after embryo implantation disrupts the post-implantation decidual vasculature and results in pregnancy failure by mid-gestation. To inhibit RAR signaling during human endometrial stromal cell (HESC) decidualization, primary HESCs and decidualized primary HESCs were transfected with silencing RNA specific for human RARA. Inhibition of RA/RARA signaling prevents initiation of HESC decidualization, but not maintenance of the decidualized HESC phenotype. These data show that RA/RAR signaling is required for maintenance of the decidual vasculature that supports early pregnancy in mice, and distinct RAR signaling is required for initiation, but not maintenance of primary HESC decidualization in vitro.

Recurrent pregnancy loss represents a common disorder that affects up to 2% of the women aiming at childbirth with long-term consequences on family and society. Factors contributing to it in more than half of the cases are still unknown. Comparative proteomic analysis can provide new insights into the biological pathways underlining the pathogenesis of recurrent pregnancy loss. Until now, chorionic villi, decidua, placenta, endometrium, and maternal blood from women with recurrent pregnancy loss have been analyzed by comparative proteomics studies. In this review, we aimed to provide a critical evaluation of the published comparative studies of recurrent pregnancy loss on human samples, gathered by systematic literature search using PubMed and Google Scholar databases. We provide a detailed overview of the analyzed materials, proteomics platforms, proposed candidate biomarkers and altered pathways and processes linked with recurrent pregnancy loss. The top, most identified and validated biomarker candidates from all studies are discussed, followed by bioinformatics analysis of the available high-throughput data and presentation of common altered processes and pathways in recurrent pregnancy loss. Finally, future directions aimed at developing new and efficient therapeutic strategies are discussed as well.

Understanding human endometrial dynamics in the establishment of endometrial receptivity remains a challenge, which limits early diagnosis and treatment of endometrial-factor infertility. Here, we decode the endometrial dynamics of fertile women across the window of implantation and characterize the endometrial deficiency in women with recurrent implantation failure. A computational model capable of both temporal prediction and pattern discovery is used to analyze single-cell transcriptomic data from over 220,000 endometrial cells. The time-series atlas highlights a two-stage stromal decidualization process and a gradual transitional process of the luminal epithelial cells across the window of implantation. In addition, a time-varying gene set regulating epithelium receptivity is identified, based on which the recurrent implantation failure endometria are stratified into two classes of deficiencies. Further investigation uncovers a hyper-inflammatory microenvironment for the dysfunctional endometrial epithelial cells of recurrent implantation failure. The holistic characterization of the physiological and pathophysiological window of implantation and a computational tool trained on this temporal atlas provide a platform for future therapeutic developments.

To examine whether a history of hysteroscopic adhesiolysis (HA)-treated intrauterine adhesions (IUAs) was associated with an increased risk of adverse obstetrical outcomes in subsequent pregnancies.

Retrospective cohort study.

A tertiary-care hospital in Shanghai, China.

A cohort of 114 142 pregnant women who were issued an antenatal card and received routine antenatal care in Shanghai First Maternity and Infant Hospital, between January 2016 and October 2021.

From the cohort of 114 142 pregnant women, each woman with a history of HA-treated IUA prior to the current pregnancy (n = 780) was matched with four women without a history of IUAs (n = 3010) using propensity score matching. The matching variables were maternal age and parity, mode of conception, pre-pregnancy body mass index and prior history of abortion.

Pregnancy complications, placental abnormalities, postpartum haemorrhage and adverse birth outcomes.

Compared with women with no history of IUAs, women with a history of HA-treated IUAs were at higher risk of pre-eclampsia (RR 1.69, 95% CI 1.23-2.33), placenta accreta spectrum (RR 4.72, 95% CI 3.9-5.73), placenta praevia (RR 4.23, 95% CI 2.85-6.30), postpartum haemorrhage (RR 2.86, 95% CI 1.94-4.23), preterm premature rupture of membranes (RR 3.02, 95% CI 1.97-4.64) and iatrogenic preterm birth (RR 2.86, 95% CI 2.14-3.81). Those women were also more likely to receive cervical cerclage (RR 5.63, 95% CI 3.95-8.02) during pregnancy and haemostatic therapies after delivery (RR 2.17, 95% CI 1.75-2.69). Moreover, we observed that the RRs of those adverse obstetrical outcomes increased with the increasing number of hysteroscopic surgeries.

This study found that a history of HA-treated IUAs, especially a history of repeated HAs, was associated with an increased risk of adverse obstetrical outcomes.

Advancements in single-cell analyzis technologies, particularly single-cell RNA sequencing (scRNA-seq) and Fluorescence-Activated Cell Sorting (FACS), have enabled the analyzis of cellular diversity by providing resolutions that were not available previously. These methods enable the simultaneous analyzis of thousands of individual transcriptomes, facilitating the classification of cells into distinct subpopulations, based on transcriptomic differences, adding a new level of complexity to biomolecular and medical research. Fibroblasts, despite being one of the most abundant cell types in the human body and forming the structural backbone of tissues and organs, remained poorly characterized for a long time. This is largely due to the high morphological similarity between different types of fibroblasts and the lack of specific markers to identify distinct subpopulations. Once thought to be cells responsible solely for the synthesis of extracellular matrix (ECM) components, fibroblasts are now recognized as active participants in diverse physiological processes, including inflammation and antimicrobial responses. However, defining the molecular profile of fibroblast subpopulations remains a significant challenge. In this comprehensive review, which is based on over two thousand research articles, we focus on the identification and characterization of fibroblast subpopulations and their specific surface markers, with an emphasis on their potential as molecular targets for selective cell isolation. By analyzing surface markers, alongside intra- and extracellular protein profiles, we identified multiple fibroblast subtypes within the female reproductive system. These subtypes exhibit distinct molecular signatures and functional attributes, shaped by their anatomical localization and the surrounding physiological or pathological conditions. Our findings underscore the heterogeneity of fibroblasts and their diverse roles in various biological contexts. This improved understanding of fibroblast subpopulations paves the way for innovative diagnostic and therapeutic strategies, offering the potential for precision targeting of specific fibroblast subsets in clinical applications.

As advantageous as sexual reproduction is during progeny generation, it is also an expensive and treacherous reproductive strategy. The viviparous eukaryote has evolved to survive stress before, during, and after pregnancy. An important and conserved intracellular pathway for the control of metabolic stress is autophagy. The autophagy process occurs in multiple stages through the coordinated action of autophagy-related genes. This review summarizes the evidence that autophagy is an integral component of reproduction. Additionally, we discuss emerging in vitro techniques that will enable cellular and molecular studies of autophagy and its associated pathways in reproduction. Finally, we discuss the role of autophagy in the pathogenesis and progression of several pregnancy-related disorders such as preterm birth, preeclampsia, and intra-uterine growth restriction, and its potential as a therapeutic target.

Decidualization of endometrial stromal cells is a prerequisite for successful embryo implantation and early pregnancy. Decidualization dysregulation results in implantation failure. In our previous study, we reported that PAI-1 is abnormally downregulated in the endometrial tissue samples of patients with recurrent implantation failure. This study will explore the dynamic expression changes of PAI-1 in the endometrium during the menstrual cycle and its molecular mechanism affecting endometrial decidualization. Our findings indicated that the abundance of PAI-1 increased in the mid-secretory phase and attached a peak in the decidual phase in the endometrium of women with regular menstrual cycles. In human endometrial stromal cells (HESCs), PAI-1 knockdown attenuated endometrial decidualization by upregulating VEGFR2/PI3K/AKT signaling pathway and impaired the F-actin reorganization. Furthermore, axitinib (a VEGFR2 inhibitor) was used to inhibit the VEGFR2 protein activity and the results suggested that it eliminated the effects of PAI-1 on PI3K/AKT signaling pathways and F-actin remodeling. In addition, the interaction between PAI-1 and KNG1 was confirmed by coimmunoprecipitation assay in HESCs. Altogether, PAI-1-KNG1 may enhance the decidualization of endometrium by inhibiting VEGFR2/PI3K/AKT signaling pathway-mediated F-actin reorganization in healthy females.

Preeclampsia (PE) is a prevalent and multifaceted pregnancy disorder, characterized by high blood pressure, edema, proteinuria, and systemic organ dysfunction. It remains one of the leading causes of pregnancy complications, yet its exact origins and pathophysiological mechanisms are not fully understood. Currently, the only definitive treatment is delivery, often requiring preterm termination of pregnancy, which increases neonatal and maternal morbidity and mortality rates, particularly in severe cases. This highlights the urgent need for further research to elucidate its underlying mechanisms and develop targeted interventions. PE is thought to result from a combination of factors, including inflammatory cytokines, trophoblast dysfunction, and environmental influences, which may trigger epigenetic changes, particularly DNA methylation. The placenta, a vital organ for fetal and maternal exchange, plays a central role in the onset of PE. Increasing evidence suggests a strong association between DNA methylation, placental function, and the development of PE. This review focuses on the impact of DNA methylation on placental development and its contribution to PE pathophysiology. It aims to clarify the epigenetic processes essential for normal placental development and explore potential epigenetic biomarkers and therapeutic targets for PE. Such insights could lead to the development of novel preventive and therapeutic strategies for this condition.

Hypertensive disorders of pregnancy (HDP) remain a significant global health burden despite medical advancements. HDP prevalence appears to be rising, leading to increased maternal and fetal complications, mortality, and substantial healthcare costs. The etiology of HDP are complex and multifaceted, influenced by factors like nutrition, obesity, stress, metabolic disorders, and genetics. Emerging evidence suggests environmental pollutants, particularly Per- and polyfluoroalkyl substances (PFAS), may contribute to HDP development.

This review integrates epidemiological and mechanistic data to explore the intricate relationship between PFAS exposure and HDP.

Studies show varying degrees of association between PFAS exposure and HDP, with some demonstrating positive correlations, particularly with preeclampsia. Meta-analyses suggest potential fetal sex-specific differences in these associations.

Mechanistically, PFAS exposure appears to disrupt vascular hemodynamics, placental development, and critical processes like angiogenesis and sex steroid regulation. Experimental studies reveal alterations in the renin-angiotensin system, trophoblast invasion, oxidative stress, inflammation, and hormonal dysregulation - all of which contribute to HDP pathogenesis. Elucidating these mechanisms is crucial for developing preventive strategies.

Targeted interventions such as AT2R agonists, caspase inhibitors, and modulation of specific microRNAs show promise in mitigating adverse outcomes associated with PFAS exposure during pregnancy.

Further research is needed to comprehensively understand the full spectrum of PFAS-induced placental alterations and their long-term implications for maternal and fetal health. This knowledge will be instrumental in developing effective preventive and therapeutic strategies for HDP in a changing environmental landscape.

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.

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.

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.

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.

The purpose of this study was to evaluate the relationship of thin endometrial thickness (EMT) on the maternal and child health outcome of frozen-thawed embryo transfer (FET) cycles with singletons.

The retrospective cohort study included 1,771 live singleton deliveries, with 273 in the thin endometrium group (EMT ≤ 7.5 mm) and 1,498 in the control group (EMT > 7.5 mm). Pregnancy, perinatal complications and neonatal outcomes were compared between the two groups.

Women in the thinner endometrium group had higher rates of preeclampsia (7.69% vs. 7.00%), placenta previa (4.39% vs. 2.43%), postpartum haemorrhage (15.38% vs. 11.42%) than the control groups, although they were not significantly different. Significant difference was observed in the rates of placental abruption (1.09% vs. 0.07%, P = 0.001), abnormal placental cord insertion (3.66% vs. 1.74%, P = 0.011), placental adherence (15.38% vs. 7.14%, P < 0.001) between the two groups. No significant difference could be found regarding preterm labour, macrosomia, Apgar ≤ 7, large for gestational age (LGA) and appropriate for gestational age (AGA), and singletons from the thinner endometrium group had a significantly lower birthweight than those from the controls. Then after adjusting for confounders, thinner endometrium was still statistically significantly associated with placental adherence, postpartum haemorrhage and low birthweight (LBW).

These findings highlight the important role of endometrial thickness in influencing perinatal and obstetric-neonatal outcomes in FET cycles. The study contributes to the growing body of evidence supporting the clinical relevance of endometrial thickness in FET cycles and underscores the need for close monitoring and management of pregnancies in women with a thin endometrium. Future research should focus on elucidating the underlying mechanisms and identifying effective interventions to improve endometrial thickness and pregnancy outcomes in this patient population.

Lactate was once considered as metabolic waste for a long time. In 2019, Professor Zhao Yingming's team from the University of Chicago found that lactate could also be used as a substrate to induce histone lactylation and regulate gene expression. Since then, researchers have discovered that lactate-mediated lactylation play important regulatory roles in various physiological and pathological processes.

In this review, we aim to discuss the roles and mechanisms of lactylation in human health and diseases, as well as the effects of lactylation on proteins and metabolic modulators targeting lactylation.

In this work, we emphasize the crucial regulatory roles of lactylation in the development of numerous physiological and pathological processes. Of relevance, we discuss the current issues and challenges pertaining to lactylation. This review provides directions and a theoretical basis for future research and clinical translation of lactylation.

Previous experimental studies have found that exposure to Microcystin-leucine arginine can impact pregnancy outcomes in female mice. The impact of MC-LR on early pregnancy in mammals is not yet well understood. Both mice and humans need to undergo decidualization to maintain pregnancy. In this study, we tried to evaluate whether MC-LR affects decidualization process in mice. Our research showed that MC-LR decreased maternal weight gain, uterine weight, and implantation site weight. These findings suggested that MC-LR exerted adverse effects on decidualization. In mice, we examined decreased number of polyploid decidual cells, but marked proliferation of mouse endometrial stromal cells the expression levels of prolactin (PRL)and insulin-like growth factor binding protein 1 (IGFBP1) were significantly downregulated in the decidual tissue and primary endometrial stromal cells following MC-LR treatment. Furthermore, further in vitro experiments identified that MC-LR promoted endometrial stromal cell division and cycle transition. Lastly, our study demonstrated that MC-LR impaired decidualization through the PI3K/AKT/FOXO1 pathway. Collectively, these data suggested that exposure to MC-LR impaired decidualization during early pregnancy.